The document analyzes land use/cover changes over 35 years in Northern Afar rangelands, Ethiopia using remote sensing data and interviews. It finds a rapid reduction in woodland (97%) and grassland (88%) between 1972 and 2007, while bushland increased over 3-fold and cultivated land grew over 8-fold. Major drivers of change included severe droughts in the 1970s and 1980s, an increase in dry years recently, and immigration/sedentarization of pastoralists. Continued land use/cover changes coupled with a drier climate could highly impact peoples' livelihoods and threaten the pastoral production system.
This document describes research on developing habitat suitability models for black-tailed prairie dogs in the southern Great Plains. The researchers used long-term datasets on prairie dog colony locations across 7 study sites to create models based on soil properties, topography, and climate. The models show that suitable habitat is positively associated with soil organic matter, pH, clay and depth, and negatively associated with slope and sand. Certain soil-climate interactions were also important. The resulting maps can help prioritize conservation areas for prairie dogs and associated species under climate change.
This research paper examines how plant species richness varies along a subtropical elevation gradient in eastern Nepal. The study analyzes species richness data from 1500 to 100 meters above sea level, divided into 15 100-meter elevation bands. Species were counted in standardized plots and assigned to different life forms, including trees, shrubs, climbers, herbs and ferns. Climate variables like potential evapotranspiration and mean annual rainfall were analyzed to explain variations in species richness of different life forms along the elevation gradient. The results found relationships between climate variables and species richness for woody life forms but not for herbaceous life forms. A water-energy dynamics model was found to explain 63-70% of the variation in species richness for
This document summarizes a study on biodiversity change along a gradient of human impact within the Ferlo Biosphere Reserve in northern Senegal. The study analyzed woody vegetation across 110 plots in the core area, buffer zone, and transition area. A total of 49 species across 16 families were identified. Species abundance and diversity indices revealed that the buffer zone and transition area, which experience greater human activity, had higher diversity and stand organization than the core area. The four most abundant species comprised 68% of total individuals. The study found biodiversity varied along the human impact gradient within the reserve.
Rotem et al 2011 The Effect of anthropogenic resources on the space-use patt...Guy Rotem
This study examined how the space-use patterns of golden jackals are affected by proximity to human villages in Israel. The researchers radio-tracked 16 jackals, 8 near villages and 8 further away. They found that jackals near villages had smaller home ranges and core areas than those further away. Jackals near villages also moved less during the day than those in more natural areas. However, nighttime movement did not differ between the two groups, though jackals near villages moved in a less directional manner. The presence of abundant, predictable food sources from human villages compressed jackal space use and altered their movement patterns.
Myanmar is one of the most forested countries in mainland South-east Asia. These forests support a large number of important species and endemics and have great value for global efforts in biodiversity conservation.
Carbon stock of woody species along Altitude gradient in Alemsaga Forest, Sou...Agriculture Journal IJOEAR
Purpose: Forest ecosystems play a significant role in the climate change mitigation and biodiversity conservation. Therefore carbon determination provide clear indications of the possibilities of promoting forest development and management for mitigating of climate change through soil and vegetation carbon sequestration. The study was carried out to quantify carbon stock potential in Alemsaga Forest, South Gondar zone. Research method: Vegetation data Collection was made using a systematic sampling method; laying six transect lines with 500 m apart and 54 quadrants of 20 m X 20 m established 200 m distant to each other along the transect lines. In these plots, abundance, DBH and heights of all woody species were recorded, and soil sample was collected 1m X1m from the four corners and center of each quadrant. General allometric model was used for estimating above and belowground biomass. The organic carbon content of the soil samples was determined in the laboratory. Finding: A total of 66 woody plant species belong to 42 families were identified, Fabaceae was the most dominant families. The total mean above and belowground carbon stock was 216.86 ton/ha and 114.71 ton/ha respectively and soil organic carbon (SOC) 103.15 ton/ha. Above and belowground carbon increased as altitude decreased, but SOC increases with increase of altitude. Originality/value: Carbon stock estimation in the forest helps to manage the forests sustainably from the ecological, economic and environmental points of view and opportunities for economic benefit through carbon trading to farmers.
This document describes research on developing habitat suitability models for black-tailed prairie dogs in the southern Great Plains. The researchers used long-term datasets on prairie dog colony locations across 7 study sites to create models based on soil properties, topography, and climate. The models show that suitable habitat is positively associated with soil organic matter, pH, clay and depth, and negatively associated with slope and sand. Certain soil-climate interactions were also important. The resulting maps can help prioritize conservation areas for prairie dogs and associated species under climate change.
This research paper examines how plant species richness varies along a subtropical elevation gradient in eastern Nepal. The study analyzes species richness data from 1500 to 100 meters above sea level, divided into 15 100-meter elevation bands. Species were counted in standardized plots and assigned to different life forms, including trees, shrubs, climbers, herbs and ferns. Climate variables like potential evapotranspiration and mean annual rainfall were analyzed to explain variations in species richness of different life forms along the elevation gradient. The results found relationships between climate variables and species richness for woody life forms but not for herbaceous life forms. A water-energy dynamics model was found to explain 63-70% of the variation in species richness for
This document summarizes a study on biodiversity change along a gradient of human impact within the Ferlo Biosphere Reserve in northern Senegal. The study analyzed woody vegetation across 110 plots in the core area, buffer zone, and transition area. A total of 49 species across 16 families were identified. Species abundance and diversity indices revealed that the buffer zone and transition area, which experience greater human activity, had higher diversity and stand organization than the core area. The four most abundant species comprised 68% of total individuals. The study found biodiversity varied along the human impact gradient within the reserve.
Rotem et al 2011 The Effect of anthropogenic resources on the space-use patt...Guy Rotem
This study examined how the space-use patterns of golden jackals are affected by proximity to human villages in Israel. The researchers radio-tracked 16 jackals, 8 near villages and 8 further away. They found that jackals near villages had smaller home ranges and core areas than those further away. Jackals near villages also moved less during the day than those in more natural areas. However, nighttime movement did not differ between the two groups, though jackals near villages moved in a less directional manner. The presence of abundant, predictable food sources from human villages compressed jackal space use and altered their movement patterns.
Myanmar is one of the most forested countries in mainland South-east Asia. These forests support a large number of important species and endemics and have great value for global efforts in biodiversity conservation.
Carbon stock of woody species along Altitude gradient in Alemsaga Forest, Sou...Agriculture Journal IJOEAR
Purpose: Forest ecosystems play a significant role in the climate change mitigation and biodiversity conservation. Therefore carbon determination provide clear indications of the possibilities of promoting forest development and management for mitigating of climate change through soil and vegetation carbon sequestration. The study was carried out to quantify carbon stock potential in Alemsaga Forest, South Gondar zone. Research method: Vegetation data Collection was made using a systematic sampling method; laying six transect lines with 500 m apart and 54 quadrants of 20 m X 20 m established 200 m distant to each other along the transect lines. In these plots, abundance, DBH and heights of all woody species were recorded, and soil sample was collected 1m X1m from the four corners and center of each quadrant. General allometric model was used for estimating above and belowground biomass. The organic carbon content of the soil samples was determined in the laboratory. Finding: A total of 66 woody plant species belong to 42 families were identified, Fabaceae was the most dominant families. The total mean above and belowground carbon stock was 216.86 ton/ha and 114.71 ton/ha respectively and soil organic carbon (SOC) 103.15 ton/ha. Above and belowground carbon increased as altitude decreased, but SOC increases with increase of altitude. Originality/value: Carbon stock estimation in the forest helps to manage the forests sustainably from the ecological, economic and environmental points of view and opportunities for economic benefit through carbon trading to farmers.
A study was conducted at a sawah site in Ghana to examine the relationship between landscape
position and some selected soil properties with the aim of generating adequate data for modeling
landscape relationships and to aid both researchers and farmers in taking critical management
decisions. Soil properties namely total porosity, moisture content, infiltration rates, hydraulic
conductivity, sand content, silt content, clay content, gravel concentration, bulk density, soil pH, total
nitrogen, soil organic matter and cation exchange capacity were collected and analysed. Data were
collected at the foot slopes, middle slopes and at the upper slopes from four major landuses (maize, oil
palm, natural vegetation and plantain) in the study area. Simple statistical parameters such as mean
and standard deviation were used to analyse the data. Moisture content, total porosity, soil pH, organic
matter and carbon and total nitrogen increased downslope whilst sand content, clay content, bulk
density occurred at upper slopes decreased downslope. Management practices appeared to have
influenced infiltration rate, hydraulic conductivity and silt content.
Mapping of Wood Carbon Stocks in the Classified Forest of Wari-Maro in Benin ...AI Publications
The Emissions Reducing program related to Deforestation and Forest Degradation (Redd +) calls for the development of approaches to quantify and spatialize forest carbon in order to design more appropriate forest management policies. The mapping of carbon stocks was done in the Wari-Maro Forest Reserve. To achieve this, forest inventory data (in situ) and remotely sensed data (Landsat 8 image) were used to construct a wood carbon stock forecasting model. Simple linear regression was used to test the correlation between these two variables. In situ surveys indicate that 64% of carbon stocks are contributed by forest formations, 32.72% are provided by savannah formations and 3.27% are from anthropogenic formations. The quantitative relationship between NDVI and carbon in situ shows a very good correlation with a high coefficient of determination R² = 91%. The carbon map generated from the model identified fronts of deforestation through their low carbon content. This remote sensing approach indicates that forest formations sequester 60% of forest carbon. The savannah formations reserve 33%, the anthropic formations bring only 6% of the stocks. Mapping has further captured the spatial variability among land use types, thus providing arguments to fully meet the objectives of Redd +.
Characterizing Forest Degradation using Multiple SAR ApproachesCIFOR-ICRAF
This study uses multiple synthetic aperture radar (SAR) approaches to characterize forest degradation in tropical peatland forests in Sumatra, Indonesia. Quad-polarimetric ALOS PALSAR and Landsat 5 TM data were analyzed. Polarimetric features and supervised classifications using multilayer perceptron neural network and maximum likelihood were performed. The multilayer perceptron neural network classification using radar backscatter and Landsat bands achieved the highest accuracy of 79.9% for differentiating between peat swamp forest and other land uses. SAR data shows potential for characterizing forest degradation but further study on feature selection is needed to increase classification accuracy.
Diversity and abundance of terrestrial mammals in the northern periphery of ...Innspub Net
The Tanoé-Ehy Marsh Forest (TEMF), an unprotected forest that is about to be turn into a voluntary nature reserve is a forest block in south-eastern Côte d’Ivoire known as being of great importance for the conservation of biodiversity. But in the rainy season, that forest is largely over flooded and terrestrial mammals are likely to move to the periphery and make them vulnerable to anthropogenic threats. Our objectives are to determine the diversity, the relative abundance of terrestrial mammals and their spatial distribution in the northern periphery of the TEMF during the rainy season. We collected data by conducting recce surveys after interviews with local people. In total, we obtained 33 species among which ten primates’ species were identified. According to the recce survey, the African Civet (Civettictis civetta) and the Bushbuck (Tragelaphus scriptus) are the most common and abundant species in the study area with 12.7% and 12.0% of relative abundance respectively. In addition, six of the listed species are on the IUCN Red List, including Piliocolobus waldronae, a critically endangered species, Cercocebus lunulatus and Cercopithecus roloway endangered species, Colobus vellerosus, Phataginus tetradactyla and Phataginus tricuspis, three vulnerable species. Thus, the consideration of the periphery for the sustainable management of the TEMF is proving to be an imperative.
Deforestation drivers, carbon emission estimate and setting forest reference ...CIFOR-ICRAF
This document discusses methods for estimating deforestation drivers, carbon emissions, and setting forest reference levels in Indonesia. It analyzes land cover maps and remote sensing data to identify deforestation areas and activities between 2000-2009. Carbon stocks are estimated using field data, biomass maps, and assigning average carbon densities to land cover types. Estimates of cumulative carbon emissions from land use change over this period range from 1.8 to 7.4 gigatons depending on the method. The document advocates for Indonesia to develop national forest reference levels using a stepwise approach combining socioeconomic data with estimates of deforestation rates and carbon stocks.
Land use/ land cover classification and change detection mapping: A case stud...AI Publications
The study attempts to determine the land use/land cover expansion that occurred in the area over a period of thirty years. Multi temporal Landsat satellite images TM 1986, ETM+ 2001, 2006 and 2018 from the United States Geological Survey (USGS) website as primary dataset. Area of interest was clipped in ArcGIS environment and then enhanced and classified in ENVI. Using supervised classification algorithm, the images were classified into bare land, built-up area, vegetation and water body used to carry out change detection analysis or time series analysis. In-addition, figures from National Population Commission (NPC) were used. Change detection analyses was carried out on the imageries to obtain the physical expansion of the area. The Land Consumption Rate (LCR) and Land Absorption Coefficient (LAC) were determined as well. Accuracy assessment was carried out on the images classified using the confusion matrix with Ground truth image tool on ENVI. An overall kappa coefficient was generated from this assessment which proved to be a very good result. Results obtained from the analysis of built-up area dynamics for the past four decades revealed that the town has been undergoing urban expansion processes. There was an increase in the built-up area between 1986 and 2018 which is largely due to the increase in population of Lagos state based on its high Urbanization rate. Vegetation cover reduced between 1986 and 2001, which is reasonable considering the rate at which the built-up area was increasing. But between 2001 and 2006, vegetation increased a little, this due to farming in 2006. Bare land had an inconsistent change. The increase in bare land could be as result of bush burning while the reduction could be as a result of more farming in the state or development of more built-up areas. It is recommended that Global change research efforts should be encouraged through international research partnerships to establish international land use /land cover science program to bridge the gap between climate researchers, decision makers and land managers; There was more reduction in vegetation than increase which poised a great danger that could cause greenhouse effect on the environment. Government at all levels should ensure that all these land use/land cover types are maintained to save our ecological biodiversity.
This document discusses methods for inventorying and monitoring tree resources outside of forests using high-resolution aerial imagery. It summarizes research mapping trees in agricultural landscapes to quantify their ecosystem functions. The research uses object-based image analysis of National Agriculture Imagery Program imagery to map trees at county-scales. Functions like windbreaks and riparian areas are identified. Historical windbreak plantings are also digitized from archives to assess changes over time. The research aims to fill gaps in quantifying trees outside forests to better account for their benefits.
Mapping and Monitoring Spatial-Temporal Cover Change of Prosopis Species Colo...inventionjournals
ABSTRACT: This study integrates Gis and remote sensing to detect, quantify and monitor the rate at which Prosopis species colonization has been taking place since its introduction. Multi-date Landsat 30m resolution imageries covering a period of 25 years were classified into four classes i.e. Prosopis species dominated canopy, mixed woodland, grass land and bush land and finally bare land and agricultural fields. Change detection analysis was performed using 10% threshold to identify and quantify areas where change or No change has occurred. The results indicate that the area under bare land and agricultural fields decreased at a rate of 18.22% per year from 29% in 1985 to 3% in 1990. Between 2005 and 2010 it decreased from 9% in 2005 to 5% in 2010 at a rate of 8.94% per year. Prosopis species colonization has been increasing since 1985 where it was at 0% increasing to 51% in 1990 at a rate of 58.18% per year. Between 2005 and 2010 it decreased from 56% in 2005 to stand at 44% in 2010 at a rate of 4.34% per year. The study found out that there is no threat of desertification in the study area as a result of Prosopis species colonizing the landscape. More studies to be done to identify sustainable method of controlling Prosopis species colonization to avoid more loss of agricultural land and grazing fields.
This study assessed whether introducing a legume pasture in a subtropical cereal cropping system can reduce synthetic nitrogen (N) inputs and nitrous oxide (N2O) emissions. The study compared N2O emissions and yields in a sorghum crop following either a legume pasture (alfalfa and sulla) or grass pasture (rhodes grass and wheat) rotation under two N fertilization rates. N2O emissions were monitored from crop planting to final seedbed preparation using an automated system. Preliminary results showed that the legume pasture supplied enough N to support crop growth while low carbon residues limited denitrification and N2O emissions compared to the grass pasture. Introducing a leg
1. The document analyzes land cover change in the Trifinio region, a protected area spanning Guatemala, Honduras, and El Salvador using satellite imagery from 2000-2015.
2. Preliminary results found land cover changes from forest to bare soil from 2005-2010 which coincided with a severe drought, and forests recovered by 2015.
3. Future research could create new land cover classifications to better detect forest variation over time and assess the effectiveness of each country's conservation policies in the transnational region.
Geoinformation support of forest management for sustainable development of th...Liashenko Dmytro
The global trend of forest overcutting is an important
the object of research in connection with climate change
and the need to ensure the sustainable development of
territories. An important issue is an adaptation of
sustainable development goals for a particular forest
areas. The territory of the Tyachiv district of the
Zakarpattia region in Ukraine was chosen as a key
region. A list of stakeholders interested in conflict-free
and inexhaustible forest use has been identified. The
the paper analyzes the existing approaches to sustainable
forest use proposes a conceptual model of forest
management (major stakeholders and their interests),
identifies features of the methodology of
geoinformation support for management and control
of forest use and forest protection.
This document summarizes a study that analyzed fern species richness along an elevational gradient in central Nepal from 100-4800 meters above sea level. The study found a unimodal relationship between species richness and elevation, with the maximum number of fern species occurring at 2000 meters. Fern species richness was found to have a unimodal response to energy gradients and a linear response to moisture gradients. The peak in fern species coincided with elevations that have higher moisture levels due to more rainy days and presence in the cloud zone.
This document summarizes a study that reconstructed global patterns of land use change from 1700-2000 at a 1 degree resolution. The study estimated land conversions, wood harvesting, and resulting secondary lands annually. Key results found that 42-68% of the global land surface was impacted by human land use activities during this period. Total secondary lands increased by 10-44 million km^2, around half of which was forested. The study provides the first global gridded estimates of its kind, and results were generally consistent with other data sources. Remaining challenges include better understanding agriculture land dynamics and developing integrated models to estimate future land use change impacts.
Male Antarctic fur seal pups foraged significantly farther from their birth site at South Georgia than female pups. Over the course of winter, both male and female pups' locations shifted eastward and moved farther from the continental shelf, possibly to exploit different prey in upper water columns. The study tracked 10 pups (5 males in 2001, 5 females in 2002) using satellite tags to analyze their at-sea distribution in relation to sex and environmental conditions between years.
1) The document discusses livestock-water interactions in the Gumara watershed of Ethiopia. It assesses livestock water productivity (LWP) under different farming systems and management practices.
2) LWP varies between farming systems and is highest for wealthy farmers who practice early livestock off-take. Collective management of communal grazing lands, with regulated grazing and resting periods, helps sustain pasture quality and reduces runoff and soil loss.
3) Determinants of good pasture condition on communal lands include larger areas of restricted grazing land and lower oxen numbers per village. Proper management of communal grazing resources is important for mixed smallholder systems in water-scarce areas.
This document discusses the history of local government in Ethiopia and whether it has shifted from being an apparatus of control. It describes how Ethiopia transitioned from a decentralized system before 1855 to a highly centralized unitary state by the 20th century. Local authorities were used as political and administrative extensions of the central government to exert control over opposition and extract resources. While decentralization began in 1991, the document argues local authorities still primarily serve as a means of control rather than promoting grassroots democracy and development as intended. It provides historical context on how local control evolved under different emperors up until the 1974 revolution.
This document summarizes research into using laser excitation of cesium ions to enhance the performance of thermionic energy converters (TECs). The researchers have developed a particle-in-cell model of a planar diode discharge to simulate TEC operation and are using it to model the effects of laser excitation on current-voltage characteristics. They have also designed a laboratory test cell to experimentally validate the effects of laser excitation on TEC performance. Initial results suggest laser excitation could substantially improve TEC current density and efficiency over conventional ignited or triode configurations.
This document summarizes the research methodology used in a study to develop a microcontroller-based device to monitor air pollution levels. The study used a developmental research design to construct the device out of locally available, low-cost materials. The device was designed to monitor harmful gases like carbon monoxide in parking garages and provide information to people in those areas. The conceptual framework outlines the resources, steps, and feedback involved in planning, building, programming, testing, and evaluating the pollution monitoring device.
This study evaluated the effects of three sowing methods (drilling, broadcasting, and broadcasting in standing water) and three seed rates (125 kg/ha, 150 kg/ha, 175 kg/ha) on the growth and yield of wheat. The experiment was conducted during the 2004-2005 winter season in Quetta, Pakistan using a randomized complete block design with four replications. Results showed that drilling wheat at a seed rate of 150 kg/ha significantly increased various growth and yield parameters compared to other treatments. This treatment led to taller plants, more tillers per plant, more spikes per plant, more grains per spike, higher 1000-grain weight, and greater grain and straw yield per plot. Uniform seed distribution and proper
A study was conducted at a sawah site in Ghana to examine the relationship between landscape
position and some selected soil properties with the aim of generating adequate data for modeling
landscape relationships and to aid both researchers and farmers in taking critical management
decisions. Soil properties namely total porosity, moisture content, infiltration rates, hydraulic
conductivity, sand content, silt content, clay content, gravel concentration, bulk density, soil pH, total
nitrogen, soil organic matter and cation exchange capacity were collected and analysed. Data were
collected at the foot slopes, middle slopes and at the upper slopes from four major landuses (maize, oil
palm, natural vegetation and plantain) in the study area. Simple statistical parameters such as mean
and standard deviation were used to analyse the data. Moisture content, total porosity, soil pH, organic
matter and carbon and total nitrogen increased downslope whilst sand content, clay content, bulk
density occurred at upper slopes decreased downslope. Management practices appeared to have
influenced infiltration rate, hydraulic conductivity and silt content.
Mapping of Wood Carbon Stocks in the Classified Forest of Wari-Maro in Benin ...AI Publications
The Emissions Reducing program related to Deforestation and Forest Degradation (Redd +) calls for the development of approaches to quantify and spatialize forest carbon in order to design more appropriate forest management policies. The mapping of carbon stocks was done in the Wari-Maro Forest Reserve. To achieve this, forest inventory data (in situ) and remotely sensed data (Landsat 8 image) were used to construct a wood carbon stock forecasting model. Simple linear regression was used to test the correlation between these two variables. In situ surveys indicate that 64% of carbon stocks are contributed by forest formations, 32.72% are provided by savannah formations and 3.27% are from anthropogenic formations. The quantitative relationship between NDVI and carbon in situ shows a very good correlation with a high coefficient of determination R² = 91%. The carbon map generated from the model identified fronts of deforestation through their low carbon content. This remote sensing approach indicates that forest formations sequester 60% of forest carbon. The savannah formations reserve 33%, the anthropic formations bring only 6% of the stocks. Mapping has further captured the spatial variability among land use types, thus providing arguments to fully meet the objectives of Redd +.
Characterizing Forest Degradation using Multiple SAR ApproachesCIFOR-ICRAF
This study uses multiple synthetic aperture radar (SAR) approaches to characterize forest degradation in tropical peatland forests in Sumatra, Indonesia. Quad-polarimetric ALOS PALSAR and Landsat 5 TM data were analyzed. Polarimetric features and supervised classifications using multilayer perceptron neural network and maximum likelihood were performed. The multilayer perceptron neural network classification using radar backscatter and Landsat bands achieved the highest accuracy of 79.9% for differentiating between peat swamp forest and other land uses. SAR data shows potential for characterizing forest degradation but further study on feature selection is needed to increase classification accuracy.
Diversity and abundance of terrestrial mammals in the northern periphery of ...Innspub Net
The Tanoé-Ehy Marsh Forest (TEMF), an unprotected forest that is about to be turn into a voluntary nature reserve is a forest block in south-eastern Côte d’Ivoire known as being of great importance for the conservation of biodiversity. But in the rainy season, that forest is largely over flooded and terrestrial mammals are likely to move to the periphery and make them vulnerable to anthropogenic threats. Our objectives are to determine the diversity, the relative abundance of terrestrial mammals and their spatial distribution in the northern periphery of the TEMF during the rainy season. We collected data by conducting recce surveys after interviews with local people. In total, we obtained 33 species among which ten primates’ species were identified. According to the recce survey, the African Civet (Civettictis civetta) and the Bushbuck (Tragelaphus scriptus) are the most common and abundant species in the study area with 12.7% and 12.0% of relative abundance respectively. In addition, six of the listed species are on the IUCN Red List, including Piliocolobus waldronae, a critically endangered species, Cercocebus lunulatus and Cercopithecus roloway endangered species, Colobus vellerosus, Phataginus tetradactyla and Phataginus tricuspis, three vulnerable species. Thus, the consideration of the periphery for the sustainable management of the TEMF is proving to be an imperative.
Deforestation drivers, carbon emission estimate and setting forest reference ...CIFOR-ICRAF
This document discusses methods for estimating deforestation drivers, carbon emissions, and setting forest reference levels in Indonesia. It analyzes land cover maps and remote sensing data to identify deforestation areas and activities between 2000-2009. Carbon stocks are estimated using field data, biomass maps, and assigning average carbon densities to land cover types. Estimates of cumulative carbon emissions from land use change over this period range from 1.8 to 7.4 gigatons depending on the method. The document advocates for Indonesia to develop national forest reference levels using a stepwise approach combining socioeconomic data with estimates of deforestation rates and carbon stocks.
Land use/ land cover classification and change detection mapping: A case stud...AI Publications
The study attempts to determine the land use/land cover expansion that occurred in the area over a period of thirty years. Multi temporal Landsat satellite images TM 1986, ETM+ 2001, 2006 and 2018 from the United States Geological Survey (USGS) website as primary dataset. Area of interest was clipped in ArcGIS environment and then enhanced and classified in ENVI. Using supervised classification algorithm, the images were classified into bare land, built-up area, vegetation and water body used to carry out change detection analysis or time series analysis. In-addition, figures from National Population Commission (NPC) were used. Change detection analyses was carried out on the imageries to obtain the physical expansion of the area. The Land Consumption Rate (LCR) and Land Absorption Coefficient (LAC) were determined as well. Accuracy assessment was carried out on the images classified using the confusion matrix with Ground truth image tool on ENVI. An overall kappa coefficient was generated from this assessment which proved to be a very good result. Results obtained from the analysis of built-up area dynamics for the past four decades revealed that the town has been undergoing urban expansion processes. There was an increase in the built-up area between 1986 and 2018 which is largely due to the increase in population of Lagos state based on its high Urbanization rate. Vegetation cover reduced between 1986 and 2001, which is reasonable considering the rate at which the built-up area was increasing. But between 2001 and 2006, vegetation increased a little, this due to farming in 2006. Bare land had an inconsistent change. The increase in bare land could be as result of bush burning while the reduction could be as a result of more farming in the state or development of more built-up areas. It is recommended that Global change research efforts should be encouraged through international research partnerships to establish international land use /land cover science program to bridge the gap between climate researchers, decision makers and land managers; There was more reduction in vegetation than increase which poised a great danger that could cause greenhouse effect on the environment. Government at all levels should ensure that all these land use/land cover types are maintained to save our ecological biodiversity.
This document discusses methods for inventorying and monitoring tree resources outside of forests using high-resolution aerial imagery. It summarizes research mapping trees in agricultural landscapes to quantify their ecosystem functions. The research uses object-based image analysis of National Agriculture Imagery Program imagery to map trees at county-scales. Functions like windbreaks and riparian areas are identified. Historical windbreak plantings are also digitized from archives to assess changes over time. The research aims to fill gaps in quantifying trees outside forests to better account for their benefits.
Mapping and Monitoring Spatial-Temporal Cover Change of Prosopis Species Colo...inventionjournals
ABSTRACT: This study integrates Gis and remote sensing to detect, quantify and monitor the rate at which Prosopis species colonization has been taking place since its introduction. Multi-date Landsat 30m resolution imageries covering a period of 25 years were classified into four classes i.e. Prosopis species dominated canopy, mixed woodland, grass land and bush land and finally bare land and agricultural fields. Change detection analysis was performed using 10% threshold to identify and quantify areas where change or No change has occurred. The results indicate that the area under bare land and agricultural fields decreased at a rate of 18.22% per year from 29% in 1985 to 3% in 1990. Between 2005 and 2010 it decreased from 9% in 2005 to 5% in 2010 at a rate of 8.94% per year. Prosopis species colonization has been increasing since 1985 where it was at 0% increasing to 51% in 1990 at a rate of 58.18% per year. Between 2005 and 2010 it decreased from 56% in 2005 to stand at 44% in 2010 at a rate of 4.34% per year. The study found out that there is no threat of desertification in the study area as a result of Prosopis species colonizing the landscape. More studies to be done to identify sustainable method of controlling Prosopis species colonization to avoid more loss of agricultural land and grazing fields.
This study assessed whether introducing a legume pasture in a subtropical cereal cropping system can reduce synthetic nitrogen (N) inputs and nitrous oxide (N2O) emissions. The study compared N2O emissions and yields in a sorghum crop following either a legume pasture (alfalfa and sulla) or grass pasture (rhodes grass and wheat) rotation under two N fertilization rates. N2O emissions were monitored from crop planting to final seedbed preparation using an automated system. Preliminary results showed that the legume pasture supplied enough N to support crop growth while low carbon residues limited denitrification and N2O emissions compared to the grass pasture. Introducing a leg
1. The document analyzes land cover change in the Trifinio region, a protected area spanning Guatemala, Honduras, and El Salvador using satellite imagery from 2000-2015.
2. Preliminary results found land cover changes from forest to bare soil from 2005-2010 which coincided with a severe drought, and forests recovered by 2015.
3. Future research could create new land cover classifications to better detect forest variation over time and assess the effectiveness of each country's conservation policies in the transnational region.
Geoinformation support of forest management for sustainable development of th...Liashenko Dmytro
The global trend of forest overcutting is an important
the object of research in connection with climate change
and the need to ensure the sustainable development of
territories. An important issue is an adaptation of
sustainable development goals for a particular forest
areas. The territory of the Tyachiv district of the
Zakarpattia region in Ukraine was chosen as a key
region. A list of stakeholders interested in conflict-free
and inexhaustible forest use has been identified. The
the paper analyzes the existing approaches to sustainable
forest use proposes a conceptual model of forest
management (major stakeholders and their interests),
identifies features of the methodology of
geoinformation support for management and control
of forest use and forest protection.
This document summarizes a study that analyzed fern species richness along an elevational gradient in central Nepal from 100-4800 meters above sea level. The study found a unimodal relationship between species richness and elevation, with the maximum number of fern species occurring at 2000 meters. Fern species richness was found to have a unimodal response to energy gradients and a linear response to moisture gradients. The peak in fern species coincided with elevations that have higher moisture levels due to more rainy days and presence in the cloud zone.
This document summarizes a study that reconstructed global patterns of land use change from 1700-2000 at a 1 degree resolution. The study estimated land conversions, wood harvesting, and resulting secondary lands annually. Key results found that 42-68% of the global land surface was impacted by human land use activities during this period. Total secondary lands increased by 10-44 million km^2, around half of which was forested. The study provides the first global gridded estimates of its kind, and results were generally consistent with other data sources. Remaining challenges include better understanding agriculture land dynamics and developing integrated models to estimate future land use change impacts.
Male Antarctic fur seal pups foraged significantly farther from their birth site at South Georgia than female pups. Over the course of winter, both male and female pups' locations shifted eastward and moved farther from the continental shelf, possibly to exploit different prey in upper water columns. The study tracked 10 pups (5 males in 2001, 5 females in 2002) using satellite tags to analyze their at-sea distribution in relation to sex and environmental conditions between years.
1) The document discusses livestock-water interactions in the Gumara watershed of Ethiopia. It assesses livestock water productivity (LWP) under different farming systems and management practices.
2) LWP varies between farming systems and is highest for wealthy farmers who practice early livestock off-take. Collective management of communal grazing lands, with regulated grazing and resting periods, helps sustain pasture quality and reduces runoff and soil loss.
3) Determinants of good pasture condition on communal lands include larger areas of restricted grazing land and lower oxen numbers per village. Proper management of communal grazing resources is important for mixed smallholder systems in water-scarce areas.
This document discusses the history of local government in Ethiopia and whether it has shifted from being an apparatus of control. It describes how Ethiopia transitioned from a decentralized system before 1855 to a highly centralized unitary state by the 20th century. Local authorities were used as political and administrative extensions of the central government to exert control over opposition and extract resources. While decentralization began in 1991, the document argues local authorities still primarily serve as a means of control rather than promoting grassroots democracy and development as intended. It provides historical context on how local control evolved under different emperors up until the 1974 revolution.
This document summarizes research into using laser excitation of cesium ions to enhance the performance of thermionic energy converters (TECs). The researchers have developed a particle-in-cell model of a planar diode discharge to simulate TEC operation and are using it to model the effects of laser excitation on current-voltage characteristics. They have also designed a laboratory test cell to experimentally validate the effects of laser excitation on TEC performance. Initial results suggest laser excitation could substantially improve TEC current density and efficiency over conventional ignited or triode configurations.
This document summarizes the research methodology used in a study to develop a microcontroller-based device to monitor air pollution levels. The study used a developmental research design to construct the device out of locally available, low-cost materials. The device was designed to monitor harmful gases like carbon monoxide in parking garages and provide information to people in those areas. The conceptual framework outlines the resources, steps, and feedback involved in planning, building, programming, testing, and evaluating the pollution monitoring device.
This study evaluated the effects of three sowing methods (drilling, broadcasting, and broadcasting in standing water) and three seed rates (125 kg/ha, 150 kg/ha, 175 kg/ha) on the growth and yield of wheat. The experiment was conducted during the 2004-2005 winter season in Quetta, Pakistan using a randomized complete block design with four replications. Results showed that drilling wheat at a seed rate of 150 kg/ha significantly increased various growth and yield parameters compared to other treatments. This treatment led to taller plants, more tillers per plant, more spikes per plant, more grains per spike, higher 1000-grain weight, and greater grain and straw yield per plot. Uniform seed distribution and proper
1) The document discusses wordiness in writing and provides examples of wordy sentences.
2) It gives an example of a wordy 31-word sentence that is reduced to a clearer 13-word version by removing unnecessary words.
3) The document provides five examples of types of wordiness to avoid, such as redundant words, empty phrases, vague expressions that can be more clearly stated, unnecessary phrases, and passive voice. It encourages editing sentences by removing extra words to make writing more concise and impactful.
This document summarizes research into using laser excitation to enhance the production of cesium ions in thermionic energy converters (TECs). The researchers have developed a particle-in-cell model of a planar diode discharge to simulate TEC performance with and without laser ionization. They have also designed a laboratory test cell to experimentally validate the effect of laser excitation on TEC current-voltage characteristics. Future work will include refining the models, procuring parts for the test cell, and conducting experimental studies to analyze how laser excitation can increase TEC efficiency and be used in energy systems to reduce carbon emissions.
The document analyzes land use/cover changes over 35 years in Northern Afar rangelands, Ethiopia using remote sensing data and interviews. It finds a rapid reduction in woodland (97%) and grassland (88%) between 1972 and 2007, while bushland increased over 3-fold and cultivated land grew over 8-fold. Major drivers of change included severe droughts in the 1970s and 1980s, an increase in dry years recently, and immigration/sedentarization of pastoralists. Continued land use/cover changes coupled with a drier climate could highly impact peoples' livelihoods and threaten the pastoral production system.
This document summarizes research into using laser excitation to enhance the production of cesium ions in thermionic energy converters (TECs). The researchers have developed a particle-in-cell model of a planar diode discharge to simulate TEC performance with and without laser ionization. They have also designed a laboratory test cell to experimentally validate the effect of laser excitation on TEC current-voltage characteristics. Future work will include refining the models, procuring parts for the test cell, and conducting experimental studies to characterize optimized TEC performance with optical modulation. The goal is to increase TEC efficiency for applications in solar and combustion energy systems to reduce greenhouse gas emissions.
Texas Woman's University offers several fashion camps for students ages 10-18 to explore careers in fashion design and merchandising. The camps include hands-on activities like sketching, sewing, and screen printing. Camps are held in June and July on the TWU Denton campus and last 4-5 days, running from 8:30am to 5:30pm. The $395 registration fee covers supplies, activities, and meals, with an additional $295 option to stay in campus housing.
This document provides an overview of conceptual modeling using the Entity-Relationship (ER) model. It describes the basic concepts of the ER model including entities, attributes, relationships, and keys. It also covers ER schema notation, constraints on relationships, design choices, and enhanced ER features such as subclasses and specialization. Additionally, it outlines the steps for designing an ER schema and translating an ER schema into relational tables.
The document defines air pollution and classifies pollutants. It discusses how air pollution has changed the natural atmosphere since the Industrial Revolution. Primary pollutants such as particulate matter, sulfur and nitrogen compounds are directly emitted while secondary pollutants like ozone and acid droplets form from atmospheric chemical reactions. Regulations have developed to limit criteria pollutants and hazardous air pollutants that harm human health and the environment under laws like the Clean Air Act.
This document contains 11 problems related to strength of materials and beams from Prof. M. S. Sivakumar of IIT Madras. The problems cover topics such as computation of reactions, shear force, bending moment, and stresses in beams. Problem 11 asks the reader to calculate the maximum stress experienced in the steel and wood portions of a composite beam under a bending moment of 40 kNm, given the dimensions and moduli of the materials.
This document defines key database terms used in relational database management systems (RDBMS). It discusses different types of keys such as candidate keys, primary keys, foreign keys, and secondary/alternative keys. It also defines key terms like super key, simple key, compound key, and composite key. The primary purpose of keys is to uniquely identify each record in a database table and help establish relationships between tables.
The document contains 11 problems related to strength of materials and computation of reactions, shear forces, and bending moments for beams. Problem 1 provides the steps to calculate reactions for a simply supported beam with point loads applied. Problem 2 calculates reactions for a beam with a uniformly varying load. Problem 3 calculates reactions for a beam with an inclined point load applied. The remaining problems involve computation of shear forces and bending moments using various methods like section cut method, integration method, and considering beams with point loads, uniformly distributed loads, variable loads, and composite cross sections.
This document discusses the role of modelling in water resource systems planning and management. It begins by explaining how modelling provides a way to predict how proposed infrastructure designs or policies will impact water resource systems. It then discusses some of the challenges in modelling complex, real-world water systems which involve understanding many interconnected physical, ecological, social and political factors. The document concludes by arguing that while modelling is an important tool, it has limitations and model results alone do not replace the judgement of planners and managers.
1) The document discusses wordiness in writing and provides examples of wordy sentences.
2) It gives an example of a wordy 31-word sentence that is reduced to a clearer 13-word sentence by removing unnecessary words.
3) The document provides five examples of types of wordiness to avoid, such as redundant words, empty phrases, vague expressions, unnecessary phrases, and passive voice. It suggests being concise by using the simplest words that convey meaning.
Performance appraisal is a method used to evaluate an employee's job performance and quality of work. It provides feedback to employees, identifies training needs, and informs personnel decisions. There are various methods of appraisal, including rating scales, checklists, and management by objectives. Performance appraisal can be either past-oriented or focused on development. When done effectively, it benefits both employees and organizations.
This document summarizes key concepts in commutative ring theory, beginning with divisibility and ideals. It defines what it means for an element to divide another in a ring, as well as irreducible, prime, and unit elements. Ideals are introduced as additive subgroups that are closed under multiplication. Polynomial rings over a field are then discussed, proving they have unique factorizations. Irreducible polynomials are shown to be prime. The document provides numerous examples and proofs of fundamental results about divisibility, ideals, and factorization in commutative rings.
1. The document explains how to use the inverse matrix method to solve simultaneous linear equations. It shows how to write two equations as a matrix equation Ax = B.
2. It then states that to solve for x, we multiply both sides by the inverse of A. This gives x = A^-1B.
3. The document provides an example of using this method to solve the equations x + 2y = 4 and 3x - 5y = 1. It calculates the inverse of the matrix A and multiplies it by B to obtain the solution x=2, y=1.
The document describes the methodology used in a study to develop an interactive listening material application using Longtion Autorun. It involves:
1) Conducting a needs analysis through student questionnaires and teacher interviews to understand target and learning needs.
2) Designing instruction based on the needs analysis, syllabus, and curriculum to create interactive listening material using Longtion Autorun.
3) Developing the material, validating it with experts, testing it with students, revising it based on feedback, and creating the final product.
Major human and natural disruptions that facilitated vegetation cover removal...Alexander Decker
This document discusses major human and natural disruptions that facilitated vegetation cover removal in the Ethiopian highlands. It analyzes how prolonged civil unrest and conflicts, as well as catastrophic droughts, posed turning points that increased deforestation. During times of severe instability, only forests near religious institutions or with local protection laws survived. Much of Ethiopia's history involved internal and external wars that likely damaged the environment through troop movements and resource exploitation. The study examines deforestation patterns through community interviews in northern and southern Ethiopia to understand the nonlinear impacts of conflicts and droughts on natural resource degradation over decades.
Analysis of deforestation pattern in the Niger Delta region of NigeriaGlory Enaruvbe
This article analyzes the pattern of deforestation in the Niger Delta region of Nigeria between 1987 and 2013 using remote sensing data and geographic information systems. The results show an increasing rate of deforestation and loss of water bodies, and a decreasing rate of increase in exposed surfaces and settlements. The rate of increase in cropland/secondary vegetation is above average, while the rate of increase in sandbars is below average. These changes can lead to environmental degradation from loss of biodiversity and forest goods/services, and affect local social and economic conditions. The study recommends policies and strategies to slow the rate of forest loss and degradation.
A LITERATURE REVIEW ON LAND USE LAND COVER CHANGES.Sara Alvarez
This document provides a literature review on land use and land cover changes. It discusses how land use and land cover have undergone constant changes in recent decades due to both anthropogenic and natural factors. Remote sensing and GIS techniques have become important tools for monitoring and analyzing these changes over time. The document reviews several studies that have analyzed land use and land cover changes in various locations around the world using remote sensing data and detected changes such as decreases in forest area and increases in agricultural and urban land.
Guerreiro (2014). Biodiversity distribution in the western Sahara-Sahel the r...Ricardo Guerreiro
This document provides background information on a fieldwork internship conducted in North-West Africa to study biodiversity distribution patterns. The internship involved sampling amphibians and reptiles across five ecoregions in Morocco, Mauritania and Mali over 48 days. A total of 47 taxa were found with diversity increasing from north to south. Analyses of niche breadth for 11 taxa showed environmental variation impacts distribution. Distribution of four gecko species was evaluated against environmental factors using GIS, finding preferences for different temperature ranges between closely related species. Overall biodiversity follows a north-south precipitation gradient, and there are apparent ecological niche differences between Tarentola gecko taxa.
The role of indigenous knowledge in land management for carbon sequestration ...Alexander Decker
This document summarizes a study on the role of indigenous knowledge in land management practices among the Wolayta people in southern Ethiopia. The study found that the Wolayta have developed diverse indigenous land management practices over generations, as exhibited through their terminology and land classification systems. Some key practices identified include agroforestry and various soil and water conservation techniques. The study concludes that indigenous agroforestry has strong potential for carbon sequestration and sustaining ecosystem services. It recommends further research to quantify these benefits and better integrate appropriate indigenous practices into development efforts.
Water-related bird assemblages in an urban pond ‘archipelago’: Winter pattern...Maria Paola Di Santo
This study reports on the patterns of species occurrence, abundance and richness of a wintering water-related bird assemblage in an ‘archipelago’ of 70 small artificial urban ponds (AUPs) embedded in a metropolitan landscape (Rome, central Italy). A total of 20 species in 26 AUPs were sampled. Only the largest AUPs (>0.1 ha) contained all these species, except for Gallinula chloropus. The highest total mean species abundance was observed in the largest ponds, with statistically significant differences evident among size classes. Two significant spatial thresholds in species abundance and richness were observed (between 0.01 and 0.1 ha; between 0.1 and 1 ha in size). The abundance of single species was correlated with their frequency of occurrence. Ponds in urban areas must be larger than 0.1 ha to host a rich winter assemblage of birds, with a further increase in richness noted with a surface area larger than 1 ha. The highest number of species was observed in the larger ponds (>1 ha). The species richness of each AUP is directly correlated to their size (log-transformed species–area relationship: log S = 3.515 + 0.497 log A; R2 = 0.76). Further research should be conducted to confirm these patterns and to implement information useful for planning and management of artificial ponds in urban areas for this purpose.
Water hyacinth (Eichhornia crassipes (Mart.): Land use/land cover changes and...Agriculture Journal IJOEAR
Water hyacinth was officially reported in Ethiopia in 1956 at Koka Dam and Awash River and it is considered as a constraint to the development of the country. Thus, this study was undertaken to determine Water hyacinth and associated land cover/use changes, and capture perceptions regarding community-based management to enhance its proper control/eradication in Lume and Boa districts, east Shoa zone, Ethiopia using integrated approach. The method of study included Water hyacinth and associated land use/cover change analyses, focus group discussions, discussions with experts at the district, zone and region levels and undertaking consultative workshop. The land use/land cover change analyses revealed increased area coverage by Water hyacinth from about 145.53 ha in 1986 to 2319.48 ha in 2015 with decline in the area of water bodies and wetlands. The annual rate of increase in the area of the weed was about 51.51% while water bodies and wetlands declined by about 0.49% and 1.16%, respectively. Of the 10 group discussions undertaken in the study districts with the communities, 9 of them reported water hyacinth to increase in terms of area coverage since its appearance in their areas which concurs the results obtained from satellite image analyses and they reported the weed to be very harmful to their livelihood. Furthermore, the nine group discussants disclosed water hyacinth to be of no use to them. Recommendations included developing comprehensive management strategies and action plans, analysis and defining roles of each stakeholder, awareness creation, training, institutional linkages, co-management and reduction of nutrient load in water bodies.
Vegetation dynamics in the western himalayas, diversity indices and climate c...Shujaul Mulk Khan
Vegetation provides the first tropic trophic level in mountain ecosystems and hence requires proper documentation and quantification in relation to abiotic environmental variables both at individual and aggregate levels. The complex and dynamic Himalayas with their varying climate and topography exhibit diverse vegetation that provides a range of ecosystem services. The biodiversity of these mountains is also under the influence of diverse human cultures and land uses. The present paper is not only first of its kind but also quite unique because of the use of modern statistical techniques for the quantification of Diversity Indices of plant species and communities. The vegetation was sampled in three categories, i.e., trees, shrubs and herbs, as follows: a height of ≥ 5m were classified in the tree layer, shrubs were all woody species of height 1m and 5m and, finally, the herb layer comprised all herbaceous species less than 1m in height. The presence/absence of all vascular plants was recorded on pre-prepared data sheets (1, 0 data). For the tree layer, the diameter of trees at breast height was measured using diameter tape. Coverage of herbaceous vegetation was visually estimated according to Daubenmire and Braun Blanquet methods. It gives overall abundance of vascular plants on one hand and composition of these species on the other. Data was analysed in Canonical Community Coordination Package (CANOCO) to measure diversity indices of plant communities and habitat types. Results for five plant communities/habitat types indicated that plant biodiversity decreased along the altitude. Shannon Diversity Index values range between 3.3 and 4. N2 index and Index of Sample Variance were also designed. All of these Diversity Indices showed the highest values for the communities/habitats of north facing slopes at middle altitudes. Higher plant diversity at these slopes and altitudes can be associated to the period of snow cover which is longer and a relatively denser tree cover as compared to the southern slopes and hence the soil has high moisture which supports high biodiversity in return. Global warming causes desertification in number of fragile mountain ecosystem around the globe. These findings suggest that species diversity decreases along the measured ecological gradient under the influence of deforestation coupled with global climatic change.
This document summarizes a study of recent treeline dynamics in response to climatic variability in the Spanish Pyrenees. The researchers analyzed tree recruitment and treeline position changes over the past 100-300 years at three sites dominated by Pinus uncinata. They found that treelines ascended until the 1950s when temperature variability increased. During this later period, tree density within the ecotone was more sensitive to climate than treeline position. Tree recruitment responded positively to warm Marches while treeline position advanced during warm springs. Increased variability in March temperatures was found to decrease the likelihood of successful treeline ascent.
Climate Increases Regional Tree Growth Variability In Iberian Pine ForestsHibrids
This study analyzed tree ring width data from 38 pine forest sites across the Iberian Peninsula to examine changes in tree growth patterns and climate response over time. Principal component analysis identified a common macroclimatic signal shared among the tree chronologies. Tree growth variability, the frequency of narrow rings, and interannual growth sensitivity increased markedly in the second half of the 20th century, indicating that climate had a stronger limiting effect on growth. A shift was also detected around the mid-20th century, with growth becoming more strongly correlated with late summer/autumn temperatures of the previous year. This suggests increased water stress may be linked to higher growth synchronization among sites driven by climate changes.
Spatiotemporal analyses of land use and land cover changes in suleja local go...Alexander Decker
This document analyzes land use and land cover changes in Suleja Local Government Area of Niger State, Nigeria between 1987 and 2012 using satellite images. The study found increases in built up land, farmland, and bare soil, and declines in vegetation over this period. Specifically, built up land increased from 7.0 km2 in 1987 to 17.9 km2 in 2012, farmland increased from 50.1 km2 to 63.0 km2, and vegetation declined from 68.7 km2 to 43.1 km2. The increases are attributed to urbanization from population growth and migration near the capital city of Abuja. The changes can lead to environmental degradation if not managed sustainably.
patterns and determinants of floristic variation across lowland forests of bo...Valderes Sarnaglia
This document analyzes patterns of floristic variation across 220 forest plots in lowland Bolivia and relates this to environmental factors. It finds that floristic variation is strongly associated with differences in water availability and temperature, with climate having a stronger influence than soil properties. Analysis identifies five distinct floristic regions in lowland Bolivia. A total of 82 tree and palm species are identified as strong indicators of environmental preferences for one of the five regions. The study concludes that species composition may shift substantially with predicted changes in climate.
Article - Vegetation ecology of the Nooitgedacht section of Loskop Dam Nature...Sellina Nkosi
This study classified and mapped the vegetation of the Nooitgedacht section of Loskop Dam Nature Reserve in South Africa. Eleven plant communities were identified through classification of 170 vegetation plots. These communities include wetlands, riverine woodlands, grasslands, and represent both open and closed woodland areas. Species diversity was highest in plant communities 5 and 6. A vegetation map was produced showing the distribution of the plant communities across the study area.
Shrinkage and carbon stock in wetlands of fogera plain, north west ethiopiaAlexander Decker
This document summarizes a study on wetland shrinkage and carbon sequestration in wetlands in Fogera Plain, North West Ethiopia. Satellite images from 1973, 1994, and 2011 showed that the area of wetlands decreased from 25.73% to 19.59% of the total area over this period. Soil samples from different wetland types showed lower carbon content in sedimented wetlands compared to undisturbed wetlands, indicating sediment deposition reduces carbon sequestration. Interviews found local farmers draining wetlands for agriculture is a key cause of shrinkage. Overall, the study found wetland shrinkage and sediment deposition have weakened these ecosystems' ability to store carbon compared to less disturbed wet
Characterization of soils at angacha district in southern ethiopiaAlexander Decker
The document summarizes a study characterizing soils at Angacha Research Station in Ethiopia. Soil samples were collected from horizons in a soil pit and analyzed in the lab. The soil was found to be an Alfisol with a clay loam texture. It has good fertility with medium organic carbon content that decreases with depth. The soil has properties making it well suited for agriculture, including a subsurface clay accumulation and base saturation over 35%. Soil management should focus on maintaining organic carbon and nitrogen levels.
11.[6 16]characterization of soils at angacha district in southern ethiopiaAlexander Decker
The document summarizes a study characterizing soils at Angacha Research Station in Ethiopia. Soil samples were collected from horizons in a soil pit and analyzed in the lab. The soil was found to be an Alfisol with a clay loam texture. It has good fertility with medium organic carbon content that decreases with depth. The soil has properties making it well suited for agriculture, including a subsurface clay accumulation and relatively high base status. Soil characterization provides information needed to determine best management practices to maintain fertility.
1. The document provides instructions for using Dropbox to store and share files across devices. It explains how to install Dropbox on computers and mobile devices, upload and access files from any device, and share files and folders with others by generating links or setting up shared folders.
2. Dropbox allows users to automatically backup files to the cloud so they are safe if a device is lost or broken. Installed on multiple devices, it syncs files across all devices.
3. The instructions cover uploading and accessing files from any device with the Dropbox app, as well as sharing large files by generating links and collaborating on documents through shared folders.
This document introduces matrices through the theory of simultaneous linear equations. It discusses how matrices can represent systems of linear equations and how elementary row operations can be used to solve such systems. Specifically, it shows that elementary row operations preserve equivalence between systems of linear equations. It then provides examples of using row operations to determine that a system has no solution and to solve a system with an infinite number of solutions.
The document discusses finding the inverse of square matrices. It provides:
1. An overview of matrix inverses and conditions for their existence, such as a matrix being square and non-singular.
2. A formula for calculating the inverse of a 2x2 matrix using determinants.
3. Two methods for calculating the inverse of a 3x3 matrix - using Gauss elimination or determinants. Worked examples are provided.
This document discusses the laws of dry friction and coefficients of friction. It explains that when a horizontal force is applied to a block on a surface, a static friction force develops to counter the force and keep the block in equilibrium until the force reaches the maximum static friction limit. It also describes how angles of friction can be used and provides examples of problems involving dry friction, such as determining if a block will remain at rest or slide down an inclined plane.
The document summarizes research applying genetic algorithms to optimize the design of large water distribution networks. It describes using a genetic algorithm to minimize the total cost of a real network in Suez City, Egypt with 341 nodes and 389 pipes. The genetic algorithm optimizes pipe diameters to meet hydraulic constraints like minimum pressure levels at nodes. It presents the formulation of the optimization problem and genetic algorithm approach. The case study applies the method to the Suez City network, demonstrating the approach's ability to solve large-scale, real-world optimization problems.
Corruption is a major problem in the Philippines that undermines good governance and economic development. The Philippines ranks poorly in international corruption indexes and surveys show that the public perceives widespread corruption, especially in revenue collection agencies and infrastructure projects. While the government expresses commitment to anti-corruption efforts, systemic and institutionalized corruption are entrenched issues according to analyses of the Philippine experience with monopolies of power, lack of transparency and accountability, and a culture where corrupt practices are socially accepted.
05 chap 4 research methodology and design(1)ELIMENG
This chapter discusses the research methodology and design used in the study. It begins by explaining the importance of understanding the philosophical assumptions that underpin research. The research design is described as a descriptive and interpretive case study analyzed through qualitative methods. Data collection methods included questionnaires, participant observation, interviews, and member checking. The chapter then explores the interpretive research paradigm in more detail and discusses how this paradigm frames the study. It provides an overview of the key characteristics of interpretivism, including the nature of reality, knowledge, and the relationship between the researcher and participants.
This chapter discusses the research methodology and design used in the study. It begins by explaining the importance of understanding the philosophical assumptions that underpin research. The research design is described as a descriptive and interpretive case study analyzed through qualitative methods. Data collection methods included questionnaires, participant observation, interviews, and member checking. The chapter then explores the interpretive research paradigm in more detail and discusses how this paradigm frames the study. It provides an overview of the key characteristics of interpretivism, including the nature of reality, knowledge, and the relationship between the researcher and participants.
This document provides instructions for building a folding machine for sheet metal work. It describes the main components of the machine, which include a base frame assembly, two clamp assemblies, a clamping beam, and a folding beam. Detailed drawings and dimensions are provided for each component. The instructions then describe the step-by-step process for constructing each part and assembling them to complete the folding machine. Optional designs are also discussed that could adapt the machine for different sheet metal folding jobs.
This document summarizes research into using laser excitation of cesium ions to enhance the performance of thermionic energy converters (TECs). The researchers have developed a particle-in-cell model of a planar diode discharge to simulate TEC operation and are using it to model the effects of laser excitation on current-voltage characteristics. They have also designed a laboratory test cell to experimentally validate the effects of laser excitation on TEC performance. Initial results suggest laser excitation could substantially improve TEC current density and efficiency over conventional ignited or triode configurations.
The document describes the organization and architecture of the Intel 8086 microprocessor. It discusses the register organization including general purpose registers, segment registers, and flag register. It also describes the segmented memory addressing scheme, physical address calculation, and instruction queue. The key components of the 8086 architecture including the bus interface unit and execution unit are summarized.
The document describes research on optimizing the design of compound pressure vessels. It investigates the effects of interference radius, shrinkage tolerance, working pressure, and the ratio of outer to inner radius (k value) on the equivalent von Mises stress through finite element modeling. The key findings are:
1) Von Mises stress decreases slightly with increasing interference radius up to an optimum point, then increases with further increases in radius.
2) Von Mises stress decreases with increasing shrinkage tolerance up to an optimum point, then increases with further increases in tolerance.
3) Increasing the working pressure leads to a higher percentage reduction in von Mises stress from compounding.
4) Increasing the
This document discusses analysis of statically determinate structures. It covers idealized structure representation, principles of superposition and equilibrium equations. Examples are provided to classify structures as determinate or indeterminate, determine stability, and calculate reactions on beams, frames and compound structures by applying equilibrium equations. Unknown reactions are solved for as force components at supports.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
This document discusses the role of modelling in water resource systems planning and management. It begins by explaining how modelling provides a way to predict how proposed infrastructure designs or policies will impact water resource systems. It then discusses some of the challenges in modelling complex, real-world water systems which involve understanding many interconnected physical, ecological, social and political factors. The document concludes by arguing that while modelling is an important tool, it has limitations and model results alone do not replace the judgement of planners and managers.
This document discusses steam systems used in industrial processes. It provides information on:
- The properties of steam including enthalpy, saturation temperature, and phase diagrams.
- Components of steam distribution systems including piping, drainage, expansion, and insulation.
- Methods for sizing steam pipes to minimize pressure drop and optimize energy efficiency.
- The importance of proper steam trapping to remove condensate and maintain dry steam.
This document discusses various metal casting processes and defects that can occur. It describes permanent and expandable pattern casting processes like sand casting, shell molding, investment casting, and permanent mold casting. Common casting defects are outlined such as misruns, cold shuts, shrinkage cavities, and sand blows. Inspection methods like visual inspection, dimensional measurements, and non-destructive testing are used to detect defects in castings.
2. D. Tsegaye et al. / Agriculture, Ecosystems and Environment 139 (2010) 174–180 175
and the few attempts have been mainly outside the rangelands
in Ethiopia (e.g., Garedew et al., 2009; Reid et al., 2000). The Afar
rangeland in North-eastern Ethiopia is one notable example where
no information exists regarding land-use/cover changes.
The goal of this study is to map and to offer an increased under-
standing of the patterns of land-use/cover changes over time by
linking this to the main drivers of change in the arid and semi-
arid Northern Afar rangelands, Ethiopia. The objectives were first
to explore the dynamics of the land-use/cover in Northern Afar
rangeland – that is, what are the main land-use/cover types; to
what degree do land-use and cover change; and what have been
the most important transitions (i.e., conversions) among the land-
use/cover classes between 1972 and 2007? Secondly, what are the
major driving forces of the land-use/cover changes, and what are
the consequences associated with these changes?
2. Study area and methods
The study area covers 2506 km2 in the Northern Afar range-
lands of Ethiopia (including a small area in Eastern Tigray) and is
located between 13◦00 to 13◦45 N and 39◦40 to 40◦12 E. The study
site (Aba’ala district) encompasses a transitional area between the
Danakil depression of the Rift Valley and the North Western Rift
Valley escarpments. Aba’ala is characterized by an arid and semi-
arid climate and lies between 100 and 2500 m a.s.l., with elevation
increasing from East to West. Mean annual rainfall varies from 150
to 500 mm, the amount and reliability declining from West to East
(HTS, 1976; Tsegaye et al., 1999). Recurring droughts are common
in localized areas and sometimes affect the whole region (Meze-
Hausken, 2004). Although the long-term annual mean (379 mm)
has not changed greatly since the 1970s (Tsegaye et al., unpub-
lished), variability is high, with a 33% coefficient of variation
between years (Meze-Hausken, 2004). The most common veg-
etation cover types include scrubland and bushland dominated
by Acacia spp. with poor or no herbaceous cover (Tsegaye et al.,
1999).
Historically, Aba’ala was inhabited by Afar pastoralists engaged
in subsistence livestock production. For most of the pastoralists,
camels and goats are the main livestock species, while a few pas-
toralists and agro-pastoralists also keep cattle and sheep (Tsegaye
et al., 1999). Before the 1960s, the Northern Afar rangelands had no
permanent agricultural areas or settlements due to the pastoralist
way of life and the low human population. The total human pop-
ulation in the study area increased from 27,259 in 1996 to 37,943
in 2007 (CSA, 2008). Although not specified for the study area, the
annual growth rate for the Afar region between 1996 and 2007 was
2.2% (CSA, 2008).
Landsat MSS (Multispectral Scanner) acquired on November 2,
1972 (path 181, row 51), Landsat TM (Thematic Mapper) acquired
on January 5, 1986 (path 168, row 51), and ETM+ (Enhanced The-
matic Mapper Plus) acquired on March 12, 2007 (path 168, row
51) were used for this study. These dates were selected on the
basis of historical events such as droughts and policy changes, and
availability of satellite images. The ETM+ image was geo-referenced
using ground control points with a root mean square error (RMSE)
of 0.6 pixel. The MSS and TM images were geo-referenced using
the ETM+ as a master image. The Universal Transverse Mercator
(UTM) geographic projection, Clarke 1880 spheroid, and Adindan
(Ethiopia) zone 37 North datum were used in geo-referencing the
images. To make the three images compatible (Lillesand and Kiefer,
2000), all the MSS (57 m), TM (28.5 m), and ETM+ (30 m) images
were re-sampled to a 60 m × 60 m pixel size using the nearest-
neighbor re-sampling technique after Serra et al. (2003).
Seven land-use/cover classes were identified for image classi-
fication based on classification criteria for East African rangelands
(Pratt and Gwynne, 1977) and the new land cover map of Africa
(Mayaux et al., 2004), with minor modifications (Table 1). A pixel-
based supervised image classification with maximum likelihood
classification algorithm was used to map the land-use/cover classes
(Lillesand and Kiefer, 2000). A total of 570 ground truth points col-
lected from the field were used for 2007 image classification (285)
and validation (285). Aerial photographs from 1964 and 1994 were
used to acquire 400 and 452 points for the 1972 and 1986 image
classification and validation, respectively (i.e., half were used for
training and the other half for validation). The overall classification
accuracies and accuracies of the single land-use/cover classes are
shown in Table 1.
Then, the land-use/cover changes between the three periods
(i.e., 1972, 1986 and 2007) were quantified and a change detection
matrix of ‘from-to’ change was derived (Braimoh, 2006; Pontius et
al., 2004) to show land cover class conversion transitions during the
35-year period by overlaying the 1972 and 2007 images. In relation
to the transition matrix, net change and net change-to-persistence
ratio (Braimoh, 2006; Pontius et al., 2004) were computed to show
the resistance and vulnerability of a given land-use/cover type.
Image processing and mapping were undertaken using ILWIS Open
3.7 Remote Sensing and GIS software (ITC, 2009).
To further understand the dynamics of land-use/cover change,
possible major drivers and consequences of the changes were
explored using 35 key informants and group discussions (i.e., elders
and clan leaders of Afar pastoralists, immigrants, administrators
and development workers). In this study, more emphasis was given
to the most common drivers of change, including: (1) economic
factors related to agricultural expansion combined with infras-
tructural development and firewood extraction; (2) institutional
factors such as land tenure changes; (3) demographic factors such
as population growth and migration interlinked with previous fac-
tors; and (4) rainfall variability and shocks such as drought and
Table 1
Description of land-use/cover classes and accuracy assessment of classified images.
Land-use/cover class Description Accuracy (%)
1972 1986 2007
Producer’s User’s Producer’s User’s Producer’s User’s
Woodland Land with woody species cover >20% (height ranges 5–20 m) 92.31 85.71 100.00 76.67 80.77 87.50
Bushland Land with >20% bush or shrub cover (<5 m in height) 81.48 73.33 77.50 91.18 88.24 90.00
Bushy grassland Grassland with <20% bush or shrub cover 79.17 63.33 81.82 77.14 78.26 87.80
Grassland Grass and herb cover with scattered trees and shrubs 71.79 93.33 93.33 84.85 100.00 90.00
Scrubland Land with <5% total vegetation cover 64.86 80.00 66.67 87.50 81.13 86.00
Cultivated land Cropping fields. It also includes settlements 95.24 80.00 100.00 86.67 97.22 87.50
Bare land Non-vegetated areas such as rock outcrops, sand, and lava
(volcanic ash)
96.15 92.59 96.88 96.88 100.00 92.50
Overall accuracy 81.00 85.84 88.77
Kappa coefficienta
0.79 0.84 0.87
a
Kappa coefficient is dimensionless.
3. 176 D. Tsegaye et al. / Agriculture, Ecosystems and Environment 139 (2010) 174–180
Table 2
Land-use/cover in 1972, 1986 and 2007 in Northern Afar rangelands, Ethiopia.
Land-use/cover Absolute area cover (km2
) Cover change between periods (%)a
Proportionofdry-seasongrazingland(%)b
1972 1986 2007 1972–1986 1986–2007 1972–2007 1972 1986 2007
Woodland 209.13 70.07 7.02 −66.50 −89.98 −96.64 3.17 0.03 0.07
Bushland 98.55 236.49 375.68 139.98 58.86 281.22 0.51 2.71 1.50
Bushy grassland 444.01 322.97 409.23 −27.26 26.71 −7.83 41.56 21.62 16.50
Grassland 194.30 44.79 22.85 −76.95 −48.99 −88.24 25.58 10.47 2.89
Scrubland 1490.61 1660.69 1530.09 11.41 −7.86 2.65 26.83 59.05 54.47
Cultivated land 7.68 18.22 67.24 137.22 269.11 775.62 2.35 5.90 24.53
Bare land 61.82 152.86 93.99 147.29 −38.51 52.05 0.00 0.23 0.04
Total 2506.09 2506.09 2506.09
a
Cover change between periods was calculated as 100 × (A final year − A initial year)/A initial year, where A = area of the land-use/cover type.
b
Proportion of each land-use category in the dry-season grazing alluvial plain (total area = 125.44 km2
).
conflicts. Scores were given for the identified drivers using pair-
wise ranking. Although focused on identifying the specific changes
and causes, discussion questions were open-ended and designed
mainly to construct a time-line of historical events and identify
linkages to the land cover change trends. Published works and pub-
lic statistics were also used to document the scale and scope of the
major drivers.
The ‘ecological time-lines’ method developed by Reid et al.
(2000), who used this approach to elicit reasons for changes in
landscape-level as seen by local residents, was used to develop a
time-line of historical events.
3. Results
3.1. Land-use/cover change
Table 2 provides the magnitude of land-use/cover change in the Northern Afar
rangelands, and the supplementary electronic material (Fig. S1) depicts the spatial
land-use/cover changes. A rapid reduction in woodland from 8.35% to 0.28% and
grassland from 7.75% to 0.91% cover in the landscape took place between 1972 and
2007 (Table 2). During the 35-year period, the proportion of bushland trebled, while
the area of cultivated land increased eightfold (Table 2). Although cultivated area
still covered a small proportion of the landscape in 2007, its proportion in the alluvial
dry-season grazing land is large (Table 2). The increase in bushland and cultivated
land cover was large during the time period 1986–2007 compared to the earlier time
period 1972–1986, whereas both time periods saw similar declines in woodland and
grassland (Table 2). Bare land increased moderately, whereas bushy grassland and
scrubland cover showed little change during the 35-year period (Table 2). Although
it recovered between 1986 and 2007, bushy grassland cover was reduced in the
earlier period, 1972–1986 (Table 2). Bare land increased between 1972 and 1986,
but then declined between 1986 and 2007 (Table 2).
Between 1972 and 2007, the woodland in the landscape was mainly converted to
bushland, scrubland and bushy grassland (Table 3). Grassland was mainly converted
to scrubland and bushy grassland (Table 3). Cultivated land mainly converted from
scrubland, bushy grassland, and grassland. Although scrubland gained from bushy
grassland and others, at the same time an equivalent area of scrubland reverted to
bushy grassland and other land covers. The greatest net increase was for bushland,
primarily converted from scrubland and woodland cover types (Table 3).
Of the natural vegetation cover types, woodland and grassland experienced
the lowest persistence, whereas scrubland was the most persistent cover type
(Table 3). ‘Persistence’ is indicated in Table 3 as the bolded diagonal elements
for each land-use/cover class. The net change-to persistence ratio was large for
woodland (negative), cultivated land (positive), grassland (negative) and bushland
(positive) indicating the most dominant trends in the changing landscape (Table 3).
The net change-to persistence ratio is closer to zero for the remaining land-use/cover
classes, indicating that they had a higher tendency to persist rather than decline
or increase (Table 3). Overall, 53.06% (i.e., sum of diagonal elements) of the total
landscape remains unchanged (Table 3).
3.2. Drivers of land-use/cover change
From a range of biophysical, demographic, economic, infrastructural and tech-
nological factors, more than 15 drivers were perceived by the informants as being
important to land-use/cover changes in the study area (Fig. 1). Major historical
events (i.e., underlying causes of change) and consequent changes drawn from
responses of informants are shown in Fig. 2. Table 4 also shows the linkage between
the perceived drivers and the most important land-use/cover transitions between
1972 and 2007.
According to the Afar informants and local administrators, increased sedenta-
rization of Afar pastoralists and a high influx of migrants from the Tigray highlands
to the area took place, particularly after the severe 1984/85 drought, resulting in
an expansion of cultivation in the alluvial plains (Fig. 2, Table 4). The migrants
mentioned two critical push factors for migrating to the study area from Tigray
highlands. They were: (1) less favorable economic opportunities at their origin of
Table 3
Land-use/cover transition matrix showing major changes in the landscape (%), Afar, Ethiopia, 1972–2007.
To final state (2007)
Woodland Bushland Bushy grassland Grassland Scrubland Cultivated land Bare land Total 1972 Loss
From initial state (1972)
Woodland 0.13 4.69 1.22 0.00 2.16 0.05 0.09 8.35 8.22
Bushland 0.06 2.57 0.27 0.00 0.91 0.02 0.11 3.93 1.37
Bushy grassland 0.02 1.57 4.19 0.03 10.56 1.32 0.03 17.72 13.53
Grassland 0.00 0.05 3.33 0.68 3.26 0.42 0.00 7.75 7.07
Scrubland 0.07 5.83 7.23 0.20 43.62 0.78 1.74 59.48 15.86
Cultivated land 0.00 0.03 0.07 0.00 0.11 0.09 0.00 0.31 0.21
Bare land 0.00 0.25 0.02 0.00 0.42 0.00 1.78 2.47 0.69
53.06a
Summary
Total 2007 0.28 14.99 16.33 0.91 61.05 2.68 3.75
Gain 0.15 12.43 12.14 0.23 17.43 2.59 1.98
Net changeb
−8.07 11.06 −1.39 −6.84 1.58 2.38 1.28
Net persistence (Np)c
−62.08 4.31 −0.33 −10.06 0.04 26.44 0.72
Bolded diagonal elements represent proportions of each land-use/cover class that were static (persisted) between 1972 and 2007. The loss column and gain row indicate the
proportion of the landscape that experienced gross loss and gain in each class, respectively.
All the figures in the table are in percent except Np, which is a ratio.
a
The shaded figure is the sum of diagonals and represents the overall persistence (i.e., the landscape that did not change).
b
Net change = gain − loss.
c
Np refers to net change to persistence ratio (i.e., net change/diagonals of each class).
4. D. Tsegaye et al. / Agriculture, Ecosystems and Environment 139 (2010) 174–180 177
Fig. 1. Key driving forces of land-use/cover change perceived and ranked by Afar
pastoralists, Northern Afar rangelands, Ethiopia, 2007. The score is based on pair-
wise ranking of the driving forces.
migration caused by high human population densities and increased land degrada-
tion following the extreme droughts of 1973 and 1984/85; and (2) access to arable
land as a share croppers at their point of destination. The indigenous Afar pastoral-
ists listed access to relief distribution centers following the 1984/85 drought, free
access to arable land, and the availability of farm labor, as inducements for them to
sedentarize and become involved in agriculture.
The informants stated that migrants are the main cause of woodland cover
reduction as they are highly involved in charcoal and firewood sale (Table 4) in
addition to crop production. The migrants also added that woodland was highly
exploited for the purpose of permanent house construction (Table 4). It also func-
tions as an important safety net in time of hardship, and the sale of firewood serves
as a major source of income when coping with the effects of drought (Table 4).
According to the informants, the use of fire as a management tool was abandoned
because of bans imposed by extension agents (not legally enforced) and this was per-
ceived as contributing to bush encroachment in the escarpments (Table 4). Although
some areas have good vegetation cover, species less palatable to livestock, such
as Tarchonanthus camphoratus, Cadia purpurea and Aloe spp. commonly dominate.
The most threatened multipurpose tree species listed by the local people include
Fig. 2. Major events, causes and consequences of land-use/cover changes from 1972 to 2007 as seen by local people, Northern Afar rangelands, Ethiopia.
Table 4
Linkage between major land-use/cover change transitions and drivers as perceived by the local people.
Transition (from 1972 to 2007) Immediate causes Drivers
Woodland to bushland, bushy grassland,
scrubland, cultivated land
Exploitation of trees for firewood and construction
Alternative source of income to cope with the drought effects
When woodland loses, bushland replaces in the hilly areas
Drought in1973/4 and 1984/85
Immigration of people from other areas
Infrastructural development such as roads and
town establishment
Settlement policy
Bushland to bushy grassland, scrubland
and bare land
Exploitation of shrubs for firewood near settlements Increased settlement and population growth
Bushy grassland to bushland, scrubland
and cultivated land
Overgrazing reduces grass cover and gives way to bush cover
Overgrazing and firewood exploitation leads to less vegetation cover
(i.e. scrubland)
Conversion to agriculture in the alluvial plains reduces bushy grassland
Land tenure change from communal to private
use right
Sedentarization policy that promotes
agriculture
Increased livestock with the growing human
population
Increased demand for firewood
Absence of burning as a management tool
Scrubland to bushland, bushy grassland,
cultivated land and bare land
In some areas secondary succession leads to more vegetation cover
and in other areas disturbance leads to bare land or cultivated fields
Expansion of agriculture into marginal areas
Protection of some areas around homesteads
Scrubland to bushland, bushy grassland,
cultivated land and bare land
In some areas secondary succession leads to more vegetation cover
and in other areas disturbance leads to bare land or cultivated fields
Expansion of agriculture into marginal areas
Protection of some areas around homesteads
Cultivated land to scrubland Scrubland replaces when crop production is abandoned Increasing dry years in recent years
Bare land to bushland and scrubland Some bare areas were turned to bushland and scrubland when left
untouched (this occurred in areas where there was volcanic ash)
Natural succession: succession to more
vegetation cover in good years
5. 178 D. Tsegaye et al. / Agriculture, Ecosystems and Environment 139 (2010) 174–180
Dobera glabra, Cordia gharaf and Olea europaea. The informants particularly stated
that recruitment failure of D. glabra, an important food plant for both humans and
livestock in the wet-season grazing alluvial plains, could be an important indicator of
either grazing/browsing pressure or rainfall variability, or combinations of the two.
The pastoralists explained a shift in livestock species composition from domina-
tion by camel-cattle to small stock-camel has occurred as a response to changes in
vegetation types in recent years. They also remember that many of the wild animals
have disappeared including cheetah (Acinonyx jubatus soemmerringii), oryx (Oryx
gazella beisa), eland (Taurotragus oryx) and others are threatened – ostrich (Struthio
camelus) and soemmerring’s gazelle (Nanger soemmerringii) – in the study area. This
was attributed mainly to the long civil war that took place in the study area and to
the loss of woodland (Fig. 2, Table 2).
Overall, people stated that the changes in land-use/cover, mainly caused by
frequent droughts and increasing numbers of dry years among other drivers, highly
affected their lifestyles and have made them more dependent on relief aid.
4. Discussion
The arid and semi-arid rangelands in Northern Afar experienced
substantial and increasing rates of land-use/cover changes during
35 years from 1972 to 2007. There have been persistent changes,
both spatially and temporally, resulting in 47% of the total area
experiencing transitional changes among the land cover types. The
poor vegetation cover observed in 1986 compared to 1972 and 2007
indicates that most of the vegetation types suffered from short-
term direct and indirect drought effects. Bushland cover increase,
particularly in the hills and escarpments, indicates partial recovery
after the drought.
In the first period (1972–1986), the overall net transition to less
vegetation (i.e., bare land, scrubland and cultivated land) covered
about 272 km2, showing the direct and indirect impact of drought
and related causes. During this period, a rapid loss of woodlands
was mainly caused by the severe droughts in 1973 and 1984/85
(Meze-Hausken, 2004). There was also a change in the land tenure
system in 1975 encouraging subdivision of communal dry-season
grazing areas for crop production on either an individual basis
or through the establishment of farmers’ cooperatives (Omiti et
al., 1999). These events were important underlying causes of the
influx of people into Northern Afar from the highly populated and
degraded areas in the neighboring Tigray region (Meze-Hausken,
2004; Tsegaye et al., 1999). Campbell et al. (2005) note that this
form of migration is an adaptation strategy of people affected by
drought in arid and semi-arid areas.
As a result of continued migration of people from neighboring
areas together with the increased sedentarization of pastoralists,
more alluvial dry-season grazing areas were converted to crop-
land in the second period (1986–2007). However, immigration to
the study area very much reduced after 1991 following the estab-
lishment of ethnic-based administration and availability of labor
employment opportunities in the rapidly growing urban areas in
Tigray. In the second period, the net transition to more vegetation
cover was 143 km2, indicating some recovery after the 1984/85
drought, the process perhaps being related to natural and sec-
ondary re-growth.
As in other areas of East Africa (Reid et al., 2004), agricultural
expansion related to shifts in government policy has been one of
the key driving forces behind the land-use/cover changes in North-
ern Afar. Cultivation is seen by some as a better livelihood strategy
(e.g., Campbell et al., 2005) stemming from increasing population
and changes in relative prices between input and output (Vedeld,
1995), while others (e.g., Little et al., 2008) view it as an unsus-
tainable option that increases the risk to pastoralists. Although
pastoralists have persistently resisted sedentarization and farming
in the past (Chatty, 2007), we observed more voluntary farming
activities and sedentarization in Afar in recent years. Such changes
may be either intentionally driven by external factors or a spon-
taneous response to new opportunities or challenges (Reid et al.,
2004).
Before the introduction of other land-uses such as agriculture,
traditional institutions of the Afar communities were strongly orga-
nized to serve the needs of the members living within specified
physical boundaries. Although land is legally owned by the state,
grazing lands are communal properties accessible to all mem-
bers of a clan or groups of clans within the boundary (Hundie
and Padmanabhan, 2008). However, land under cultivation by
agro-pastoral communities is considered to be private property.
Although not fully implemented (Hundie and Padmanabhan, 2008),
the 1994 constitution declares (in Article 40) “Ethiopian pastoralists
have a right to free land for grazing and cultivation as well as the right
not to be displaced from their own lands”.
Although sedentarization of pastoralists is still continuing, more
involvement in agriculture may not continue in the study area due
to both increasing drought occurrence and a lack of technologi-
cal progress in favor of the existing spate irrigation practice. It is
observed in the field that many cropping fields left uncultivated
gradually revert to bushy grasslands mainly dominated by annual
forbs and Aloe spp. less palatable to livestock. Although there has
been a decline in agricultural activities due to reduced rainfall since
2000, a tendency to shift to irrigated agriculture is linked to the
increased sedentarization of pastoralists. There is a strong demand
for the use of improved gabions and dikes that allow better use of
the available floodwaters. Development actors (e.g., the Afar Inte-
grated Pastoral Development Programme) operating in the area
have introduced such improved systems and assisted the agro-
pastoralists in improving their flood diversion activities and have
in fact contributed to halting the practice of shifting cultivation that
converts more vegetated areas to cropping fields. While it is true
that such activities improve food security, it can also be argued that
more people may be attracted to sedentarize and become involved
in agriculture in the long-run.
Many studies conducted in African drylands have documented a
decline in woody vegetation cover (Lykke, 1998; Wezel and Haigis,
2000). Woodland loss is usually attributed to land clearing for
crop production (e.g., Vedeld, 1995), while bush encroachment is
attributed to overgrazing and absence of fire (e.g., Angassa and Oba,
2008; Oba et al., 2000). This is not the case in the study area, as
both woodland and bushland covers dominate hillsides and escarp-
ments unsuitable to either crop production or grazing. Rather,
observations revealed modification of woodland cover caused by
increased tree exploitation (i.e., tree felling for firewood and con-
struction).
The increased bushland cover at the expense of woodland also
indicates the impact of altered disturbance regimes such as avoid-
ing fire as a management tool besides continued wood harvesting
(Wiegand and Jeltsch, 2000). Like many rangelands in Africa, the
increase in bushland cover in the study area was not unexpected,
but the presence of more bushy cover mainly on the hilly areas and
escarpments where there is little or no grazing is striking. Other
studies have also noted the occurrence of bush encroachment in
areas where there is shallow soil depth and grazing is infrequent
(Brown and Archer, 1999).
The changes in land-use/cover in the study area thus indicate
resource degradation and vulnerability of people. The drivers and
related changes discussed above may therefore influence ecosys-
tem functioning in the rangelands through their impact on the
traditional mobility pattern between the wet- and dry-season graz-
ing areas. This may also lead to a decrease in the size of dry-season
grazing areas, isolation of crucial habitats such as permanent water
sources, particularly for large wild animals, indirectly resulting
in changing livestock species composition and directly disturb-
ing some plant species that may be threatened with extinction.
For instance, the failure of D. glabra recruitment in Northern Afar
rangelands was mainly a contribution of intense livestock browsing
(Tsegaye et al., 2009), indicating the severity of degradation. Most
6. D. Tsegaye et al. / Agriculture, Ecosystems and Environment 139 (2010) 174–180 179
pastoralists no longer keep cattle and have shifted to small stock
that can utilize bush-encroached areas. The increasing demand
for meat from the growing population in nearby towns in recent
years is also an opportunity to increase the goat population that
can browse on the increasing bush cover. It should therefore be
underscored that the shift from cattle-camel to small stock-camel
dominated livestock is not only a response to bush encroachment
but also a strategy to meet market demands.
The findings of this study support Illius and O’Connor’s (1999)
explanations regarding the rangeland management debate. In
conditions where key resource dry-season grazing areas are
encroached by agriculture, grazing-induced degradation often
occurs in other areas as they are heavily utilized during the dry-
season (Illius and O’Connor, 1999). In the study area, mobility is
constrained with a consequent overgrazing in the remaining areas.
This is evident in Northern Afar where the dry-season grazing areas
are encroached by other land-uses including agriculture. Such cir-
cumstances can occur in climatically highly variable environments
where mobility of pastoralists has been severely restricted (Vetter,
2005). The non-equilibrium approach, in which arid and semi-arid
rangelandsconditionsareseenasbeingdrivenbyrainfall andnotby
grazing (Behnke and Scoones, 1993; Ellis and Swift, 1988) may not
be fully applicable in a situation where pastoral groups have been
removed from part of their traditional grazing land, as witnessed
in this study.
The general trend observed in the study area implies a loss of
grassland and woodland cover and an increase in cultivated areas
and bushland cover. The present tendency may lead to more land
degradation if no assisted restoration is made. Continued land-
use/cover change, coupled with a drier climate, greatly affects
people’s livelihoods and puts the pastoral production system under
increasing threat.
Acknowledgments
We are grateful to the Development Fund of Norway for fund-
ing the research. The first author is also grateful to the Norwegian
State Educational Loan Fund (Lånekassen) for providing financial
assistance and Mekelle University in Ethiopia for granting a study
leave. We also wish to thank the two anonymous reviewers and the
editor for their constructive and professional comments.
Appendix A. Supplementary data
Supplementary data associated with this article can be found, in
the online version, at doi:10.1016/j.agee.2010.07.017.
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