Abstract. This study examines the effects of forest opening (clearcut) size on the surrounding forest-bird community with the objective of offering management suggestions for foresters who employ the clearcut method. I hypothesized that large and small clearcuts would have different effects on the forest-bird assemblage associated with each. I used the point-count method to assess bird abundance in clearcuts, on the edges, and 100 m into the forest from the edges of large and small clearcuts. I found that Neotropical migrant birds and forest-interior birds were the most affected by large clearcuts showing significantly lower abundance in forest areas 100 m from large clearcut edges than in forest areas 100 m from small clearcuts. Edge-open birds were more abundant in large clearcut openings and edges than in small clearcut openings and edges. Blue jays (an avian nest predator) were more abundant on the edges of large clearcuts than on the edges of small clearcuts. A recent study found that forest-interior bird abundance levels off after 100 m distance from small (0.4 ha) forest openings. This result combined with my findings suggest that small openings in the Second College Grant represent less of a disturbance to Neotropical migrants and forest-interior birds. Additionally, given higher abundances of an avian nest predator in large clearcuts, reproductive success could be much lower in areas associated with large clearcuts. Some species such as the White-throated Sparrow (Zonotrichia albicollis), however preferred large clearcuts suggesting that there are some benefits to overall bird abundance by including large clearcuts in a managed landscape.
West Fork Timber Company (WFTC) is a private timber company that manages approximately 54,000 acres on the western slopes of the Cascade Mountains. West Fork's goal was to develop a long-term harvest plan that would improve asset value over time, while simultaneously ensuring that habitat requirements set forth in their Habitat Conservation Plan (HCP) would be realized. The primary constraint set forth in the HCP is the maintenance of a unique Dispersal Landscape Index (DLI) within a narrow (+/- 5%) range of pre-determined levels for the life of the HCP. The DLI is derived by assigning different values to areas within specific distances of existing dispersal habitat (DH) in a complex formula; the dispersal habitat (DH) values are then summed and divided by the total number of acres in the forest to arrive at a DLI value for the ownership. This paper discusses DLI calculation and the challenges involved in modeling this problem, including the types of constraints needed in the strategic model, the spatial allocation of activities associated with existing and future stands in a Model II framework, and the development of a rapid DLI calculator to facilitate the evaluation of alternatives. Overall, West Fork was able to meet objective of higher returns from the forest while simultaneously demonstrating improvement in dispersal habitat over the next four decades.
4 ijfaf feb-2018-3-effect of different growth mediaAI Publications
Cordiaafricana(Lam.)is an economically and ecologically important component tree species of the Bamenda Highlands Forest which is under threat from over-exploitation. There is a need to develop high quality planting stock for increased availability and sustainability of the species. A study was carried out at the National Forestry Development Agency (ANAFOR) in Bamenda, North West of Cameroon, to evaluate the effect ofgrowth medium on sprouting and growth of vegetatively propagated C.africana(Lam.). Hardwood cuttings from lower branches of trees were grown in sand, sawdust, and a 1:1 sand: sawdust mixture in a non-mist propagator for three months. Data on percentage sprouting, days to sprouting, number of shoots, shoot height, stem diameter, stem volume, number of leaves, leaf length, leaf width, and leaf area were subjected to analysis of variance(ANOVA) and Scheffé’s multiple means comparison test at 5% level of probability. While sawdust significantly reduced values of all the plant traits, no significant differences were detected between sand and the sand: sawdust mixture. The results show that sand and 1:1 sawdust: sand are suitable alternatives for propagation of C. africana(Lam.)from branch cuttings.
West Fork Timber Company (WFTC) is a private timber company that manages approximately 54,000 acres on the western slopes of the Cascade Mountains. West Fork's goal was to develop a long-term harvest plan that would improve asset value over time, while simultaneously ensuring that habitat requirements set forth in their Habitat Conservation Plan (HCP) would be realized. The primary constraint set forth in the HCP is the maintenance of a unique Dispersal Landscape Index (DLI) within a narrow (+/- 5%) range of pre-determined levels for the life of the HCP. The DLI is derived by assigning different values to areas within specific distances of existing dispersal habitat (DH) in a complex formula; the dispersal habitat (DH) values are then summed and divided by the total number of acres in the forest to arrive at a DLI value for the ownership. This paper discusses DLI calculation and the challenges involved in modeling this problem, including the types of constraints needed in the strategic model, the spatial allocation of activities associated with existing and future stands in a Model II framework, and the development of a rapid DLI calculator to facilitate the evaluation of alternatives. Overall, West Fork was able to meet objective of higher returns from the forest while simultaneously demonstrating improvement in dispersal habitat over the next four decades.
4 ijfaf feb-2018-3-effect of different growth mediaAI Publications
Cordiaafricana(Lam.)is an economically and ecologically important component tree species of the Bamenda Highlands Forest which is under threat from over-exploitation. There is a need to develop high quality planting stock for increased availability and sustainability of the species. A study was carried out at the National Forestry Development Agency (ANAFOR) in Bamenda, North West of Cameroon, to evaluate the effect ofgrowth medium on sprouting and growth of vegetatively propagated C.africana(Lam.). Hardwood cuttings from lower branches of trees were grown in sand, sawdust, and a 1:1 sand: sawdust mixture in a non-mist propagator for three months. Data on percentage sprouting, days to sprouting, number of shoots, shoot height, stem diameter, stem volume, number of leaves, leaf length, leaf width, and leaf area were subjected to analysis of variance(ANOVA) and Scheffé’s multiple means comparison test at 5% level of probability. While sawdust significantly reduced values of all the plant traits, no significant differences were detected between sand and the sand: sawdust mixture. The results show that sand and 1:1 sawdust: sand are suitable alternatives for propagation of C. africana(Lam.)from branch cuttings.
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.
Ecological Forestry in Douglas-Fir (Pseudotsuga menziesii) Forests of the Pac...Lily Tidwell
Ecological forestry is an emerging concept in the field of forest management based on silvicultural techniques that emulate natural disturbance regimes, thus preserving a relatively natural functioning forest ecosystem. This paper discusses the application of these concepts in Douglas-Fir forests of the Pacific Northwestern United States.
The slides contain a summary on my research on the ''abundances and distribution of the five most preferred food species for the mountain gorilla of the Virungas''. The presentation was delivered at the University of Twente, the Faculty of Geo-Information Science and Earth Observation (ITC). It is part of a continuous follow up on the student's research - required for the successful completion of a Master of Science at ITC, NL
A framework for assessing and projecting climate change effects on forest com...Jennifer Costanza
Presented at US-IALE annual meeting in Baltimore, MD. We are using hierarchical classification to produce an empirical set of forest tree assemblages for use in projection, assessment, and monitoring of global change effects on forest communities.
Rangelands are more than just grass but rather complex and biodiverse ecosystems. Covering nearly half the world’s land area, they are in need of restoration and sustainable management.
The conservation value of regenerating tropical forest for amphibians crees foundation
The crees foundation conducts conservation research in the Manu Biosphere Reserve, Peru, to understand the biodiversity and conservation value of regenerating tropical forest.
Diversity and distribution of butterflies in the open and close canopy forest...Innspub Net
Butterflies were sampled in Cadaclan, San Fernando La Union Botanical Garden (LUBG) of North Luzon to provide information on species-level diversity trend and distribution of butterflies on the open and close canopy portion of the dipterocarp forest from 2012-2014 using field transect method Species accumulation curve shows that additional sampling is needed for the possible turnover of species. Butterfly abundance was higher in open canopy forest with a mean individual of 8.14 per 10 meters out of the 814 total individuals. The close canopy forest had only 4.57 mean individuals for the total of 457. Species level diversity was higher in open canopy forest (H’ = 1.957) compared with the closed canopy forest (H’ = 1.933). These results suggest that butterflies prefer open canopy forest or clearing for their plights. Butterfly spatial distribution was uneven in the dipterocarp forest of LUBG with only 6 species of aggregate assemblages and 98 species with random distribution. Get more articles at: http://www.innspub.net/volume-6-number-1-january-2015-jbes/
INDICATOR SPECIES ANALYSES OF WEED COMMUNITIES OF MAIZE CROP IN DISTRICT MARD...Shujaul Mulk Khan
Weeds are unwanted plant species growing in natural environment. Composition and abundance of weeds are influenced by number of environmental variables as well as farming practices in an ecosystem. Present study was formulated to measure the effect of environmental variables on weed species composition, abundance, distribution pattern and formation of various weeds communities in Union Council Shahbaz Ghari (total area 3956 ha, Agriculture land 1701 ha), District Mardan. Quantitative ecological techniques by adapting quadrat method were used to assess environmental variability and weed species distribution in the targeted region. Nine quadrats of 1×1 m2 size were placed randomly in 65 different fields of the UC. Phytosociological attributes such as density, frequency, relative density, relative frequency and Importance Values were measured for each field. Preliminary results showed that UC Shahbaz Ghari has 29 different weed species belong to 15 different families. Presence absence (1,0) data of 29 species and 65 fields were analyzed using Cluster and Two Way Cluster Analysesvia PC-ORD version 5 resulting four major weed communities. Dominant weed species of the area are Cyperus rotundus, Urochloa panicoides, Brachiaria ramosa, Dactyloctenium aegyptium, Commelina benghalensis and Canvolvulus arvensis while Cannabis sativa, Ipomea purpurea, Amaranthus blitoides, Xanthium strumarium, Lactuca dissecta and Cucurbita maxima are rare weed species. Indicator Species Analyses (ISA) of data identified indicators of each sort of micro environmental condition. Based on our findings, it is recommended that awareness can be created among farmers especially about their farming practices to minimize noxious weeds of maize crop
Key words: Cluster analyses, indicator species analyses, maize, PC-ORD, weeds and Weed communities.
Vegetation mapping and multivariate approach to indicator species of a forest...Shujaul Mulk Khan
Abstract
Questions
Does the plant species composition of Thandiani sub Forests Division (TsFD) correlate with edaphic, topographic and climatic variables? Is it possible to identify different plant communities in relation to environmental gradients with special emphasis on indicator species? Can this approach to vegetation classification support conservation planning?
Location
Thandiani sub Forests Division, Western Himalayas.
Methods
Quantitative and qualitative characteristics of species along with environmental variables were measured using a randomly stratified design to identify the major plant communities and indicator species of the Thandiani sub Forests Division. Species composition was recorded in 10 × 2.5 × 2 and 0.5 × 0.5 m square plots for trees, shrubs and herbs, respectively. GPS, edaphic and topographic data were also recorded for each sample plot. A total of 1500 quadrats were established in 50 sampling stations along eight altitudinal transects encompassing eastern, western, northern and southern aspects (slopes). The altitudinal range of the study area was 1290 m to 2626 m above sea level using. The relationships between species composition and environmental variables were analyzed using Two Way Cluster Analysis (TWCA) and Indicator Species Analysis (ISA) via PCORD version 5.
Results
A total of 252 plant species belonging to 97 families were identified. TWCA and ISA recognized five plant communities. ISA additionally revealed that mountain slope aspect, soil pH and soil electrical conductivity were the strongest environmental factors (p ≤ 0.05) determining plant community composition and indicator species in each habitat. The results also show the strength of the environment-species relationship using Monte Carlo procedures.
Conclusions
An analysis of vegetation along an environmental gradient in the Thandiani sub Forests Division using the Braun-Blanquet approach confirmed by robust tools of multivariate statistics identified indicators of each sort of microclimatic zones/vegetation communities which could further be used in conservation planning and management not only in the area studied but in the adjacent regions exhibit similar sort of environmental conditions.
Distribution and structure of conifers with special emphasis on taxus baccataShujaul Mulk Khan
Coniferous forests play important role in sustaining biodiversity and providing ecological services. Present study was conducted in Pir Panjal range, Western Himalayas to assess the present status of the conifers, in particular Taxus baccata population. Field data was obtained systematically using quadrate method. Environmental data including coordinates, altitude, slope gradient, aspect and intensity of anthropogenic disturbance was recorded by field survey method. The quantity of fuel wood consumption was measured using weight survey method. Three conifer species viz., Abies pindrow, Pinus wallichiana and Taxus baccata were found in 5 communities at different aspects in 1800 to 3000 m altitudinal range. Conifer stands showed an average tree density of 306 trees/ha with a regeneration value of 76 seedlings and saplings/ha and deforestation intensity of 82 stumps/ha respectively. T. baccata showed zero regeneration having no seedling or sapling in the whole study area. The stem to stump value was calculated as 4.08. A. pindrow was dominant in all the 5 communities with an Importance value percentage of 72.8% followed by P. wallichiana (19.5%). T. baccata was recorded sporadically throughout the altitudinal range having an IVI value of 7.9%. The T. baccata tree density was 26/ha whereas dead tree and stumps density was 27/ha with a stem/stump value of 0.98.The average fuel wood consumption recorded for the area was 4.08kg/capita/day. Pressure is increasing on conifers due to high level of fuel wood consumption as well as overgrazing due to limited available grazing area. The conifer species, especially T. baccata, demand immediate attention of forest management and policy makers for the conservation of these under pressure species.
A numerical analysis of understory plant associations in a Pinus wallichiana ...Innspub Net
The present investigation describes the structure and vegetation composition of the forest located in Murree Hills, Punjab, Pakistan. The study area is a part of Himalayans moist temperate forest. The vegetation zone entirely consists of shrubs or medium size trees. The plants give the appearance of a vast flower bed, composed principally of herbaceous species. These species are adapted to withstand the extremes of cold and desiccation. Study area range in altitude from 2100m-2300 m (A.S.L.). A total of 65 species, belonging to 62 genera and 39 families were recorded from 40 stands. Angiosperms contributed a major share while Pteridophytes contributed little to the floristic richness of the area. Data were analyzed by multivariate statistics including Cluster Analysis, Detrended Correspondence Analysis (DCA) and correlation co-efficient to detect the relations between altitudinal and some environmental factors with composition and structure of the plant communities. DCA axis 1 and axis 2 were used to interpret the data. Four vegetation types were delineated by Cluster Analysis which was then plotted on the first two axes a scattered diagram. The outcome of the cluster was confirmed by using DCA. There were significant differences in the flora composition as well as the edaphic factors along the altitudinal gradient. The results of the present investigation suggest a direct altitudinal and soil chemical factors pH, EC, cations and anions on the vegetation variation. Topography predicts species composition of the study area.
Pastoralists’ Perceptions towards Rangeland Degradation and Management in Don...AI Publications
Local land users often have different perceptions on the problems of rangeland degradation, compared to researchers and Government officials. This study was aimed at breaching this gap, by empirically exploring pastoralists’ perceptions regarding rangeland degradation in Donga-mantung. The pastoralists’ perceptions were studied through a descriptive statistics method. Focus group discussions, field observations and structured/semi-structured survey questionnaires, were used for data collection, where 200 pastoralists were targeted. The study covered seven Ardorates based on intensity of rangeland degradation (high, medium and less). The major findings indicate that, the main livestock production constraints were Insufficient and poor pasture (50.5%), cattle diseases (24.5%), Farmer/grazer conflicts (14.5%) and insufficient cattle drinking points (10.5%). Majority of respondents (59.5 %) confirmed that cattle population is declining in the study area. According to 59.5% of the respondents, the study area present range condition has deteriorated and become poor. The major causes for degradation were overgrazing, bush encroachment, soil erosion and limited care and attention paid to rangelands. The major socio-economic impacts of rangeland degradation were poverty (51.0%), food insecurity (35.5%) and conflicts (11.0%). The pastoralists of the study area traditionally practice rangeland management in different ways such as bush burning, bush clearing and herd mobility. A proportion of them (41.5%) have adopted the planting of improved pasture(s). Government and NGOs’ supports proved to be limiting in the study area. Nevertheless, the measures perceived by pastoralists to reduce degradation of their rangeland include; planting of improved pastures (40.5%), clearance of bushes that have encroach on rangelands (28.5%), establishing community awareness and community empowerment on rangeland degradation (17.0%), reducing the number of farmlands (9.5%) and reducing soil erosion (4.5%). This study showed the need for rangeland professionals, researchers, planners and other stakeholders to integrate the communities’ perceptions and existing indigenous ecological knowledge to ensure a sustainable rangeland management.
The present study aims to investigate the biodiversity of woody vegetation along a gradient of human impacting region in the three constituent parts of Ferlo Biosphere Reserve (FBR): the core area, the buffer zone and the transition area. We conducted an inventory of 110 plots of 900 m² each. Total species richness was 49 species distributed in 32 genera within 16 botanical families. The analysis of contesimal frequency showed that Guiera senegalensis is the most common species with a presence of 75% of such records. Examination of species abundance spectrum showed that four most abundant species such as Guiera senegalensis (29.5%), Combretum glutinosum (15.9%), Pterocarpus lucens (11.6%) and Boscia senegalensis (10 , 5%). These four species represent 68% of the total individuals of the RBF and are also the four most common species. The spectrum of abundance of families showed that Combretaceae is the best represented family with almost half of the number of species (49.7%). The representativeness of biological types and geographical affinity of the species has been established for the woody vegetation in the study area. The study of diversity indices revealed that the buffer zone and the transition area are subjected to multiple uses and experiencing human action. It has a greater diversity and a level of organization with higher timber stand than the central area which is an integral conservation zone.
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.
Ecological Forestry in Douglas-Fir (Pseudotsuga menziesii) Forests of the Pac...Lily Tidwell
Ecological forestry is an emerging concept in the field of forest management based on silvicultural techniques that emulate natural disturbance regimes, thus preserving a relatively natural functioning forest ecosystem. This paper discusses the application of these concepts in Douglas-Fir forests of the Pacific Northwestern United States.
The slides contain a summary on my research on the ''abundances and distribution of the five most preferred food species for the mountain gorilla of the Virungas''. The presentation was delivered at the University of Twente, the Faculty of Geo-Information Science and Earth Observation (ITC). It is part of a continuous follow up on the student's research - required for the successful completion of a Master of Science at ITC, NL
A framework for assessing and projecting climate change effects on forest com...Jennifer Costanza
Presented at US-IALE annual meeting in Baltimore, MD. We are using hierarchical classification to produce an empirical set of forest tree assemblages for use in projection, assessment, and monitoring of global change effects on forest communities.
Rangelands are more than just grass but rather complex and biodiverse ecosystems. Covering nearly half the world’s land area, they are in need of restoration and sustainable management.
The conservation value of regenerating tropical forest for amphibians crees foundation
The crees foundation conducts conservation research in the Manu Biosphere Reserve, Peru, to understand the biodiversity and conservation value of regenerating tropical forest.
Diversity and distribution of butterflies in the open and close canopy forest...Innspub Net
Butterflies were sampled in Cadaclan, San Fernando La Union Botanical Garden (LUBG) of North Luzon to provide information on species-level diversity trend and distribution of butterflies on the open and close canopy portion of the dipterocarp forest from 2012-2014 using field transect method Species accumulation curve shows that additional sampling is needed for the possible turnover of species. Butterfly abundance was higher in open canopy forest with a mean individual of 8.14 per 10 meters out of the 814 total individuals. The close canopy forest had only 4.57 mean individuals for the total of 457. Species level diversity was higher in open canopy forest (H’ = 1.957) compared with the closed canopy forest (H’ = 1.933). These results suggest that butterflies prefer open canopy forest or clearing for their plights. Butterfly spatial distribution was uneven in the dipterocarp forest of LUBG with only 6 species of aggregate assemblages and 98 species with random distribution. Get more articles at: http://www.innspub.net/volume-6-number-1-january-2015-jbes/
INDICATOR SPECIES ANALYSES OF WEED COMMUNITIES OF MAIZE CROP IN DISTRICT MARD...Shujaul Mulk Khan
Weeds are unwanted plant species growing in natural environment. Composition and abundance of weeds are influenced by number of environmental variables as well as farming practices in an ecosystem. Present study was formulated to measure the effect of environmental variables on weed species composition, abundance, distribution pattern and formation of various weeds communities in Union Council Shahbaz Ghari (total area 3956 ha, Agriculture land 1701 ha), District Mardan. Quantitative ecological techniques by adapting quadrat method were used to assess environmental variability and weed species distribution in the targeted region. Nine quadrats of 1×1 m2 size were placed randomly in 65 different fields of the UC. Phytosociological attributes such as density, frequency, relative density, relative frequency and Importance Values were measured for each field. Preliminary results showed that UC Shahbaz Ghari has 29 different weed species belong to 15 different families. Presence absence (1,0) data of 29 species and 65 fields were analyzed using Cluster and Two Way Cluster Analysesvia PC-ORD version 5 resulting four major weed communities. Dominant weed species of the area are Cyperus rotundus, Urochloa panicoides, Brachiaria ramosa, Dactyloctenium aegyptium, Commelina benghalensis and Canvolvulus arvensis while Cannabis sativa, Ipomea purpurea, Amaranthus blitoides, Xanthium strumarium, Lactuca dissecta and Cucurbita maxima are rare weed species. Indicator Species Analyses (ISA) of data identified indicators of each sort of micro environmental condition. Based on our findings, it is recommended that awareness can be created among farmers especially about their farming practices to minimize noxious weeds of maize crop
Key words: Cluster analyses, indicator species analyses, maize, PC-ORD, weeds and Weed communities.
Vegetation mapping and multivariate approach to indicator species of a forest...Shujaul Mulk Khan
Abstract
Questions
Does the plant species composition of Thandiani sub Forests Division (TsFD) correlate with edaphic, topographic and climatic variables? Is it possible to identify different plant communities in relation to environmental gradients with special emphasis on indicator species? Can this approach to vegetation classification support conservation planning?
Location
Thandiani sub Forests Division, Western Himalayas.
Methods
Quantitative and qualitative characteristics of species along with environmental variables were measured using a randomly stratified design to identify the major plant communities and indicator species of the Thandiani sub Forests Division. Species composition was recorded in 10 × 2.5 × 2 and 0.5 × 0.5 m square plots for trees, shrubs and herbs, respectively. GPS, edaphic and topographic data were also recorded for each sample plot. A total of 1500 quadrats were established in 50 sampling stations along eight altitudinal transects encompassing eastern, western, northern and southern aspects (slopes). The altitudinal range of the study area was 1290 m to 2626 m above sea level using. The relationships between species composition and environmental variables were analyzed using Two Way Cluster Analysis (TWCA) and Indicator Species Analysis (ISA) via PCORD version 5.
Results
A total of 252 plant species belonging to 97 families were identified. TWCA and ISA recognized five plant communities. ISA additionally revealed that mountain slope aspect, soil pH and soil electrical conductivity were the strongest environmental factors (p ≤ 0.05) determining plant community composition and indicator species in each habitat. The results also show the strength of the environment-species relationship using Monte Carlo procedures.
Conclusions
An analysis of vegetation along an environmental gradient in the Thandiani sub Forests Division using the Braun-Blanquet approach confirmed by robust tools of multivariate statistics identified indicators of each sort of microclimatic zones/vegetation communities which could further be used in conservation planning and management not only in the area studied but in the adjacent regions exhibit similar sort of environmental conditions.
Distribution and structure of conifers with special emphasis on taxus baccataShujaul Mulk Khan
Coniferous forests play important role in sustaining biodiversity and providing ecological services. Present study was conducted in Pir Panjal range, Western Himalayas to assess the present status of the conifers, in particular Taxus baccata population. Field data was obtained systematically using quadrate method. Environmental data including coordinates, altitude, slope gradient, aspect and intensity of anthropogenic disturbance was recorded by field survey method. The quantity of fuel wood consumption was measured using weight survey method. Three conifer species viz., Abies pindrow, Pinus wallichiana and Taxus baccata were found in 5 communities at different aspects in 1800 to 3000 m altitudinal range. Conifer stands showed an average tree density of 306 trees/ha with a regeneration value of 76 seedlings and saplings/ha and deforestation intensity of 82 stumps/ha respectively. T. baccata showed zero regeneration having no seedling or sapling in the whole study area. The stem to stump value was calculated as 4.08. A. pindrow was dominant in all the 5 communities with an Importance value percentage of 72.8% followed by P. wallichiana (19.5%). T. baccata was recorded sporadically throughout the altitudinal range having an IVI value of 7.9%. The T. baccata tree density was 26/ha whereas dead tree and stumps density was 27/ha with a stem/stump value of 0.98.The average fuel wood consumption recorded for the area was 4.08kg/capita/day. Pressure is increasing on conifers due to high level of fuel wood consumption as well as overgrazing due to limited available grazing area. The conifer species, especially T. baccata, demand immediate attention of forest management and policy makers for the conservation of these under pressure species.
A numerical analysis of understory plant associations in a Pinus wallichiana ...Innspub Net
The present investigation describes the structure and vegetation composition of the forest located in Murree Hills, Punjab, Pakistan. The study area is a part of Himalayans moist temperate forest. The vegetation zone entirely consists of shrubs or medium size trees. The plants give the appearance of a vast flower bed, composed principally of herbaceous species. These species are adapted to withstand the extremes of cold and desiccation. Study area range in altitude from 2100m-2300 m (A.S.L.). A total of 65 species, belonging to 62 genera and 39 families were recorded from 40 stands. Angiosperms contributed a major share while Pteridophytes contributed little to the floristic richness of the area. Data were analyzed by multivariate statistics including Cluster Analysis, Detrended Correspondence Analysis (DCA) and correlation co-efficient to detect the relations between altitudinal and some environmental factors with composition and structure of the plant communities. DCA axis 1 and axis 2 were used to interpret the data. Four vegetation types were delineated by Cluster Analysis which was then plotted on the first two axes a scattered diagram. The outcome of the cluster was confirmed by using DCA. There were significant differences in the flora composition as well as the edaphic factors along the altitudinal gradient. The results of the present investigation suggest a direct altitudinal and soil chemical factors pH, EC, cations and anions on the vegetation variation. Topography predicts species composition of the study area.
Pastoralists’ Perceptions towards Rangeland Degradation and Management in Don...AI Publications
Local land users often have different perceptions on the problems of rangeland degradation, compared to researchers and Government officials. This study was aimed at breaching this gap, by empirically exploring pastoralists’ perceptions regarding rangeland degradation in Donga-mantung. The pastoralists’ perceptions were studied through a descriptive statistics method. Focus group discussions, field observations and structured/semi-structured survey questionnaires, were used for data collection, where 200 pastoralists were targeted. The study covered seven Ardorates based on intensity of rangeland degradation (high, medium and less). The major findings indicate that, the main livestock production constraints were Insufficient and poor pasture (50.5%), cattle diseases (24.5%), Farmer/grazer conflicts (14.5%) and insufficient cattle drinking points (10.5%). Majority of respondents (59.5 %) confirmed that cattle population is declining in the study area. According to 59.5% of the respondents, the study area present range condition has deteriorated and become poor. The major causes for degradation were overgrazing, bush encroachment, soil erosion and limited care and attention paid to rangelands. The major socio-economic impacts of rangeland degradation were poverty (51.0%), food insecurity (35.5%) and conflicts (11.0%). The pastoralists of the study area traditionally practice rangeland management in different ways such as bush burning, bush clearing and herd mobility. A proportion of them (41.5%) have adopted the planting of improved pasture(s). Government and NGOs’ supports proved to be limiting in the study area. Nevertheless, the measures perceived by pastoralists to reduce degradation of their rangeland include; planting of improved pastures (40.5%), clearance of bushes that have encroach on rangelands (28.5%), establishing community awareness and community empowerment on rangeland degradation (17.0%), reducing the number of farmlands (9.5%) and reducing soil erosion (4.5%). This study showed the need for rangeland professionals, researchers, planners and other stakeholders to integrate the communities’ perceptions and existing indigenous ecological knowledge to ensure a sustainable rangeland management.
The present study aims to investigate the biodiversity of woody vegetation along a gradient of human impacting region in the three constituent parts of Ferlo Biosphere Reserve (FBR): the core area, the buffer zone and the transition area. We conducted an inventory of 110 plots of 900 m² each. Total species richness was 49 species distributed in 32 genera within 16 botanical families. The analysis of contesimal frequency showed that Guiera senegalensis is the most common species with a presence of 75% of such records. Examination of species abundance spectrum showed that four most abundant species such as Guiera senegalensis (29.5%), Combretum glutinosum (15.9%), Pterocarpus lucens (11.6%) and Boscia senegalensis (10 , 5%). These four species represent 68% of the total individuals of the RBF and are also the four most common species. The spectrum of abundance of families showed that Combretaceae is the best represented family with almost half of the number of species (49.7%). The representativeness of biological types and geographical affinity of the species has been established for the woody vegetation in the study area. The study of diversity indices revealed that the buffer zone and the transition area are subjected to multiple uses and experiencing human action. It has a greater diversity and a level of organization with higher timber stand than the central area which is an integral conservation zone.
From their hearts: How Our Female Ancestors Expressed Themselves in Letters a...Kathy Petlewski
Our female ancestors used letters and diaries to stay in touch with family and friends as well as express their most personal thoughts and memories. Find out how to find these records.
Study: The Future of VR, AR and Self-Driving CarsLinkedIn
We asked LinkedIn members worldwide about their levels of interest in the latest wave of technology: whether they’re using wearables, and whether they intend to buy self-driving cars and VR headsets as they become available. We asked them too about their attitudes to technology and to the growing role of Artificial Intelligence (AI) in the devices that they use. The answers were fascinating – and in many cases, surprising.
This SlideShare explores the full results of this study, including detailed market-by-market breakdowns of intention levels for each technology – and how attitudes change with age, location and seniority level. If you’re marketing a tech brand – or planning to use VR and wearables to reach a professional audience – then these are insights you won’t want to miss.
ECOLOGY, BEHAVIOR AND BIONOMICSEucalyptus Edge Effect on QEvonCanales257
ECOLOGY, BEHAVIOR AND BIONOMICS
Eucalyptus Edge Effect on Quercus-Herbivore Interactions
in a Neotropical Temperate Forest
C HERNÁNDEZ-SANTIN1, M CUAUTLE1 , M DE LAS N BARRANCO-LEÓN2, J GARCÍA-GUZMÁN1, El BADANO2,
F LUNA-CASTELLANOS1
1Depto de Ciencias Químico Biológicas, Univ de las Américas Puebla, Cholula, Puebla, Mexico
2División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica, San Luis Potosí, Mexico
AbstractKeywords
Quercus , herbivory, edge effect,
Lepidoptera caterpillars
Correspondence
M Cuautle, Depto de Ciencias Químico
Biológicas, Univ de las Américas Puebla,
Cholula, Puebla, Mexico; [email protected]
hotmail.com
Edited by Martin F Pareja – UNICAMP
Received 18 June 2018 and accepted 26
April 2019
* Sociedade Entomológica do Brasil 2019
Fragmentation leads to the formation of edges between habitats, which in
turn changes biotic and abiotic factors that might influence herbivory or
plant-herbivory interactions. The aims of this study were to describe the
herbivory community associated with oak (Quercus) and to determine the
effects of proximity to a Eucalyptus edge and season on insect herbivory.
We selected three forest sites that were subsequently divided into three
quadrants located at different distances from the Eucalyptus edge: edge
(0 m), intermediate (30 m), and oak forest interior (60 m). We randomly
selected 10 oak trees per quadrant and conducted monthly surveys, during
the dry and rainy season (from February to October 2010), where we
quantified leaf area and the percentage of herbivory. These were analyzed
using linear mixed models, with distance and season as fixed factors and
individual and site as random factors. The primary oak herbivores were
Lepidoptera caterpillars. We found that herbivory increased away from
the edge but just during the rainy season, although higher herbivory levels
were found during the dry season. These results seem to be related to a
specialist community of herbivorous associated to the Quercus. This study
emphasizes the importance of considering border effect, especially within
Natural Protected Areas to establish strategies to improve and maintain
native oak forest and the biodiversity of its Lepidoptera herbivorous
community.
Introduction
Landscape modification due to anthropogenic activities (e.g.,
land conversion to agricultural or livestock) has resulted in
habitat fragmentation, one of the major threats for forest
conservation (Buckley 2000, Franklin et al 2002).
Fragmentation is defined as the disruption or breakdown of
large vegetation patches into smaller ones resulting in a dis-
continuity of resource distribution that affects species occu-
pancy, reproduction, and/or survival (Franklin et al 2002).
One of the important features of this phenomenon is an
increase in edge length relative to the forest area, particular-
ly in small habitat fragments (Laurance 1991, Laurance &
Yensen 1991, Murcia 1995, Laurance et al 2007, De
Carvalho ...
Population Dynamics Of Small Mammals In Virginia Foreststsandrew
Population Dynamics of Small Mammals in Virginia Forests: Testing the Impacts of Weather, Deer, Acorns, and Shrub Cover.
Researchers:
T. Bernheim, M. Fu, S. Rowland, and A. Tsai
Population Structure and Threats to Sustainable Management of Woody Plant Spe...Innspub Net
This study was conducted to assess population structure and threat to the sustainable management of woody species in the various ago-ecosystems in Dutsin-Ma Local Government Area (LGA) Katsina State, Nigeria. Purposive and stratified random sampling techniques were used to collect data from 21 randomly demarcated 100m × 100m sample plots. All woody plant species found in the sample plots with stem diameter >2 cm at 20cm above ground, were recorded. Population structure was summarized by diameter classes. For the identification of threats, field and questionnaire surveys were used. A total of 50 questionnaires were distributed at ten questionnaires per ward in five out of the 11 wards in the LGA. The highest numbers (350) of small diameter trees (0.1-1.0cm) were recorded in the agrosilvopastoral system. This was followed by silvopastoral and agrisilviculture systems with 89 and 85, respectively. However, the highest number of large diameter woody tree species was recorded in the silvopastoral system followed by agrosilvopastoral and agrisilviculture systems. The regular reverse J-shaped and fairly regular reverse J-shaped size class distribution observed for agrosilvopastoral and silvopastoral respectively, suggest a recuperating population. Over exploitation, debarking, de-branching, root- digging, leaf harvesting, seed harvesting, poor regeneration, slow rate of growth, wind effect and bush burning were the major threats to sustainable management of woody plant species in the study area. The implications of our findings for sustainable management of woody plant species in the study area are discussed and recommendations made.
Mangrove ecology and species distribution along the Gorai Creek of Mumbai coa...AI Publications
The extensive mangrove forest of Gorai Creek, Mumbai coast, has recently seen substantial deterioration. The results of a study on mangrove diversity conducted in Gorai Creek on the Mumbai coast from June 2017 to May 2018 are presented here. During the course of the study, twelve species of mangroves from five families and eight genera were identified in each of the three study locations along the creek. Avicennia marina accounted for 13.44% of the Gorai creek marshes, confirming its predominance. Sonneratia alba, Avicennia officinalis, Rhizophora apiculata, Bruguiera cylindrica, Kandelia candel, and Acanthus ilicifolius are among the mangrove species found in the estuarine embayment, with other species strewn around. A diverse range of species, including endangered migratory birds and herpetofauna, can be found in these mangrove environments. Mangroves have been observed to have narrowed in density with time, and it is critical to begin conservation efforts as speedily as humanly possible.
Status of Bushbuck (Tragelaphus scriptus) and Buffalo (Syncerus caffer) in th...AI Publications
The study titled “Status of Bushbuck (Tragelaphus scriptus) and Buffalo (Syncerus caffer) in the North and South Eastern parts of the Kimbi-Fungom National Park (K-FNP) of the North West Region of Cameroon” was carried out in the rainy season from 1st May to 31st July 2015. The general objective was to contribute to the conservation of bushbuck and Buffalo in the K-FNP through the establishment of status of mammals which will serve as a guide for management decisions. The methodology employed was the “recce-walk”. Twenty seven (27) lines transects of 2 km long each were walked making a total effort of 53km. One hundred and fifty six (156) questionnaires were administered to the local population, twenty one (21) semi-structured interviews to households and seven (7) focus group discussions with local chiefs and notables were used to get local people’s perceptions about wildlife conservation in the NP. Results revealed a total of 13 species of mammals within the NP belonging to 6 families. The Bovidae family had the highest number of species represented by the buffalo (Syncerus caffer), bushbuck (Tragelaphus scriptus), the blue duiker (Cephalophus monticola) and the red duiker (Cephalophus dorsalis). The buffalo and the bushbuck recorded encounter rates of 0.85 and 0.34sign/km respectively. The Buffalo had a higher density in the North East of the South East compartment of the park while the bushbuck had a higher density in the south west of the north east compartment. There was a strong relationship (R2=0.792) between the encounter rate of mammals and anthropogenic activities. Ninety two (92.31%) of respondents recognized the importance of the NP because they depended on it for collection of NTFP’s (34.60%), hunting of Bushmeat (12.80%), fuel wood gathering (7.70%), religious activities (6.40%), agricultural land (5.10%), harvesting of medicinal plants(5.10%), source of clean water (5.10%), traditional rituals (3.80%) and traditional medicine harvesting (2.6%). Ninety seven percent (97.2%) supported wildlife conservation because of its touristic, aesthetic and for sustainability. Thirty four percent (34.60%) of the respondents were aware of community implication in managing the NP. K-FNP is poor in species abundance, species richness and flagship species. Associated benefits from ecotourism are far-fetched coupled with encroachment by grazers. We therefore recommend that the government, councils, NGOs and the local communities should step up conservation efforts.
Status of Bushbuck (Tragelaphus scriptus) and Buffalo (Syncerus caffer) in th...AI Publications
The study titled “Status of Bushbuck (Tragelaphus scriptus) and Buffalo (Syncerus caffer) in the North and South Eastern parts of the Kimbi-Fungom National Park (K-FNP) of the North West Region of Cameroon” was carried out in the rainy season from 1st May to 31st July 2015. The general objective was to contribute to the conservation of bushbuck and Buffalo in the K-FNP through the establishment of status of mammals which will serve as a guide for management decisions. The methodology employed was the “recce-walk”. Twenty seven (27) lines transects of 2 km long each were walked making a total effort of 53km. One hundred and fifty six (156) questionnaires were administered to the local population, twenty one (21) semi-structured interviews to households and seven (7) focus group discussions with local chiefs and notables were used to get local people’s perceptions about wildlife conservation in the NP. Results revealed a total of 13 species of mammals within the NP belonging to 6 families. The Bovidae family had the highest number of species represented by the buffalo (Syncerus caffer), bushbuck (Tragelaphus scriptus), the blue duiker (Cephalophus monticola) and the red duiker (Cephalophus dorsalis). The buffalo and the bushbuck recorded encounter rates of 0.85 and 0.34sign/km respectively. The Buffalo had a higher density in the North East of the South East compartment of the park while the bushbuck had a higher density in the south west of the north east compartment. There was a strong relationship (R2=0.792) between the encounter rate of mammals and anthropogenic activities. Ninety two (92.31%) of respondents recognized the importance of the NP because they depended on it for collection of NTFP’s (34.60%), hunting of Bushmeat (12.80%), fuel wood gathering (7.70%), religious activities (6.40%), agricultural land (5.10%), harvesting of medicinal plants(5.10%), source of clean water (5.10%), traditional rituals (3.80%) and traditional medicine harvesting (2.6%). Ninety seven percent (97.2%) supported wildlife conservation because of its touristic, aesthetic and for sustainability. Thirty four percent (34.60%) of the respondents were aware of community implication in managing the NP. K-FNP is poor in species abundance, species richness and flagship species. Associated benefits from ecotourism are far-fetched coupled with encroachment by grazers. We therefore recommend that the government, councils, NGOs and the local communities should step up conservation efforts.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
THE EFFECTS OF CLEARCUT SIZE ON THE BIRD COMMUNITY IN THE SECOND COLLEGE GRANT
1. THE EFFECTS OF CLEARCUT SIZE ON THE BIRD COMMUNITY IN
THE SECOND COLLEGE GRANT
JOSHUA R. MOONEY
Abstract. This study examines the effects of forest opening (clearcut) size on the
surrounding forest-bird community with the objective of offering management
suggestions for foresters who employ the clearcut method. I hypothesized that large and
small clearcuts would have different effects on the forest-bird assemblage associated with
each. I used the point-count method to assess bird abundance in clearcuts, on the edges,
and 100 m into the forest from the edges of large and small clearcuts. I found that
Neotropical migrant birds and forest-interior birds were the most affected by large
clearcuts showing significantly lower abundance in forest areas 100 m from large clearcut
edges than in forest areas 100 m from small clearcuts. Edge-open birds were more
abundant in large clearcut openings and edges than in small clearcut openings and edges.
Blue jays (an avian nest predator) were more abundant on the edges of large clearcuts
than on the edges of small clearcuts. A recent study found that forest-interior bird
abundance levels off after 100 m distance from small (0.4 ha) forest openings. This
result combined with my findings suggest that small openings in the Second College
Grant represent less of a disturbance to Neotropical migrants and forest-interior birds.
Additionally, given higher abundances of an avian nest predator in large clearcuts,
reproductive success could be much lower in areas associated with large clearcuts. Some
species such as the White-throated Sparrow (Zonotrichia albicollis), however preferred
large clearcuts suggesting that there are some benefits to overall bird abundance by
including large clearcuts in a managed landscape.
INTRODUCTION
Balancing timber management with bird conservation is a difficult endeavor. However,
given recent evidence of declines in many Neotropical migrant bird species (Robbins et
al. 1989a, Askins et al. 1990) it has become increasingly important to manage forested
lands to maintain avifauna diversity and abundance. Threats to migratory land birds in
their North American breeding ground include habitat destruction, degradation,
fragmentation, and loss of habitat diversity (Germaine et al. 1997). Forest fragmentation
increases the ratio of edge habitat to forest interior. Historically, edge habitat has been
seen as beneficial to a wide array of forest dwelling wildlife (e.g., Leopold 1933);
however, edge zones may contribute to reduced populations of bird species that require
2. large areas of forest interior habitat (Gates and Gysel 1978, Ambuel and Temple 1983,
Robinson 1992).
It is important to study Neotropical migratory birds because these birds provide a
useful model for developing general programs of land management and improving
current management schemes (Martin 1995). Neotropical migratory birds are model
organisms because: (1) they are ubiquitous; (2) they include a wide diversity of
coexisting species with varying ecologies; (3) they are sensitive to environmental
perturbations because they are mobile, short-lived, and differ in their environmental
requirements; and (4) their behaviors, demographic characters (fecundity, survival),
physiology, species interactions, and habitat use can be readily studied for many species
(Martin 1995). In addition, knowledge of their habitat requirements is critical to
conserving forest land to allow for successful breeding.
Given that a dominant proportion of birds that breed in the Northeast are Neotropical
migrants (MacArthur 1959), it is possible that factors affecting survival in their wintering
habitat may be more important than events in the breeding habitat. Some research has
found that migrants are limited chiefly by events and conditions in tropical wintering
grounds (Lack 1968, Fretwell 1972, 1986, Morse 1980b, Alerstam and Hogstedt 1982,
Baillie and Peach 1992, Morton 1992, Rappole et al. 1992). On the other hand,
fragmentation of forest habitats in eastern North America has been strongly implicated as
one cause of reduced breeding success, and consequently lowered breeding densities of
some songbird populations (Robbins 1979, Whitcomb et al. 1981, Ambuel and Temple
1983, Wilcove and Whitcomb 1983, Lynch and Whigham 1984, Wilcove and Robinson
1990). Long-distance migrants seem to be limited by both breeding and wintering
habitat; however, there is no clear study suggesting one is more important than the other.
Sherry and Holmes (1995) develop the idea of summer and winter limitation for migrant
birds, stating that “migrant bird populations appear to be limited contemporaneously by
their need for quality habitats in which to maintain high fecundity in summer and in
3. which to maintain high survival in winter.” Changes in breeding habitat are therefore at
least one of the important factors that could have profound effects on overall populations
of Neotropical migrant birds. Thus, it is important to study how forest management in
northeastern North America affects bird communities.
Factors associated with timber harvesting that affect bird communities can be
generally categorized in one of two ways: factors associated with increased edge resulting
from habitat fragmentation (“edge effects”), and those associated with reduced area of
suitable forest habitats (“area effects”) (Welsh and Healy 1993). Many studies have been
conducted in highly fragmented forests and have found that fragment area is a major
factor in determining the number and diversity of bird species present (Blake and Karr
1987, Askins et al. 1990). In addition, Donovan et al. (1995) found that small forest
fragments may be sink habitats for some species of Neotropical migrants requiring
immigration from nearby source areas to maintain populations.
Many areas of the Northeast include large tracts of contiguous forest. This is quite
different from many of the highly fragmented regions in which the aforementioned
studies were conducted. In areas of continuous forest, some studies have found increased
bird species richness and density near forest edge created by clearcuts, rivers, fields, or
power lines (McElveen 1979, Strelke and Dickson 1980, Hansson 1983, Germaine et al.
1997). However, other studies have not found such relationships (Kroodsma 1982, Small
and Hunter 1989).
Bird species diversity is often higher in managed forest areas (where timber
harvesting occurs – clearcutting, selective harvesting...) than in reserved forest areas due
to the increase in habitat diversity (Welsh and Healy 1993). However, it is important to
take this question to the next level and ask how bird species diversity (and abundance) is
affected by clearcut size in a managed area. Simply because some studies have shown
that bird species diversity is higher in areas where timber management occurs (Germaine
et al. 1997), should we assume that creating forest openings will increase diversity? The
4. answer to this question will have implications for timber management in the Northeast
and throughout the country. In some cases managing for diversity is not always the
answer. When a sensitive or endangered species is present, it may be more prudent to
ensure its survival. Clearcutting is a relatively common practice in the Second College
Grant and elsewhere in the Northeast. The size of clearcuts varies to a great degree.
Thus, it is important to look at the effects of clearcut size on bird communities, and to
come to some conclusion as to which size affords the greatest benefits.
Communication between researchers and forest managers is essential to designing
appropriate wildlife management schemes. The Second College Grant, where this study
was conducted, is a perfect forum for this type of discourse. Currently, the forester is
implementing a Wildlife Project, the goal of which is to manage the Grant for wildlife
while still harvesting timber. In order to implement a sound program the forester needs
input from researchers. This study will assist the Wildlife Project by providing
suggestions for bird management.
This study reports results of point count censuses of birds conducted in the Second
College Grant, a 10,930 ha parcel of land in northern New Hampshire owned by
Dartmouth College. The objectives were: (1) to examine the differences in bird diversity,
abundance, and species assemblage between large and small clearcuts, (2) to look at these
differences in detail by examining the effects of clearcut size on bird guilds across a
habitat gradient from inside the clearcuts to the edge to 100 m into the surrounding forest,
and (3) to focus specifically on how Neotropical migratory birds were affected. I tested
for these effects by comparing species diversity, similarity of species composition, and
the abundance of birds in several guilds in large (6.0 – 7.0 ha) and small (0.3 – 1.0 ha)
clearcuts. These variables were compared within the clearcuts, on the edges of the
clearcuts, and 100 m into the forest from the clearcut.
METHODS
5. STUDY AREAS
This study was conducted from 20 June - 30 July 1997 in the Second College Grant in
northern Coos County, NH. I selected four small and four large structurally similar study
sites by field reconnaissance. These sites were dominated by hardwood trees, but also
included coniferous tree species. Hardwood species included sugar maple (Acer
saccharum), white and yellow birch (Betula papyrifera, B. alleghaniensis), and beech
(Fagus grandifolia). Coniferous species were red spruce (Picea rubens), balsam fir
(Abies balsamea), and some Eastern hemlock (Tsuga canadensis). Aerial photos were
examined to ensure that substantial areas of forest surrounded each cut. The clearcuts
studied were of similar age; all had been harvested within 5 years. Small sites ranged in
size from approximately 0.3 - 1.0 ha. Large sites ranged in size from 6.0 - 7.0 ha (sizes
determined using a Global Positioning System and Trimble’s Pfinder GIS software).
VEGETATION MEASUREMENTS
To test whether my sites were structurally similar, I measured basal area of all trees larger
than 7.5 cm in an 11 m radius around my point count sites which were inside the
clearcuts, on the edges of the clearcuts, and 100 m into the forest from the clearcut edges
(see Figure 1). These measurements were taken in the four large sites and in the four
small sites. One of the large sites was excluded from the study because it differed
strongly in forest composition being composed chiefly of spruce.
BIRD CENSUSING
6. I recorded all birds heard or seen within a 50 m radius of my point count site during a 6
minute period. Point counts were conducted between 05:00 and 08:00 from 29 June
through 19 July. Three census points were established at each site (Fig. 1) and marked by
flagging. One point was located inside the clearcut, 100 m from the edge. The second
was located on the edge. The third was located 100 m into the interior forest. The points
were situated in a straight line to avoid overlap. Each census point was visited four times
throughout the course of the study period.
Figure 1. Clearcut, Edge, and Forest point count layout for a typical
clearcut site in the Second College Grant, New Hampshire.
BIRD GUILDS
To look at finer-scale differences in how birds were affected by clearcut size, I first
categorized the common bird species observed in the Grant on the basis of migratory
group. There were three categories: Neotropical migrants, Nearctic migrants, and
resident species. I then separated these species into groups based on habitat preference.
Forest-interior birds are those species with breeding territories concentrated away from
the forest edge. Interior-edge birds are species with territories both near the forest edge
7. and in the interior. Edge-open species are those with territories both in edge areas and in
openings (Whitcomb et al. 1981). Thirdly, I classified the species into foraging guilds
based on information in the literature (Ehrlich et al. 1988). Foliage-gleaners are those
species that forage insects from the leaves of trees. Ground-foragers are those species
that manipulate the forest floor in search of insects, and bark-probers probe into the bark
of trees with their bills for insects.
DATA ANALYSIS
Basal area, and diversity (Simpson’s Index) were analyzed with an ANOVA model that
included clearcut size, location (clearcut, edge, or forest), clearcut nested within clearcut
size, and clearcut size x location. Abundance within guilds (migratory group, habitat
association, and foraging strategy) was analyzed with an ANOVA model that included all
the above terms and additionally: guild, size x guild, and location x guild. All terms were
treated as fixed effects.
Similarity between large and small habitat groups was determined using the Bray-
Curtis (1957) measurement of species composition and relative abundance measures as
comparison criteria (Germaine et al. 1997), where:
"
similarity = $
(∑ 2Wi ) %
( A + B )' × 100%
# &
and: Wi = lower abundance of each species i present in both plots, A = number of
individuals present in assemblage 1 and B = number of individuals present in assemblage
2.
8. RESULTS
Basal area of coniferous trees was similar in large and small sites (Table 1; Fig 2). Basal
area of hardwood trees was also similar in large and small sites (Table 1; Fig 3).
Table 1. Summary of mean squares and F statistics for ANOVA models run with basal area of coniferous
trees and hardwood trees, and bird diversity as variables.
Basal Area (H) Basal Area (C) Bird Diversity
df MS F MS F MS F
Size 1 4.52 1.89 1.66 0.73 1.24 0.18
Site (Site) 5 1.39 0.58 1.06 0.46 3.88 0.58
Location 2 6.94 2.90 2.48 1.08 53.01 7.92**
Size x Location 2 0.77 0.32 0.07 1.03 0.91 0.14
Error 10 2.40 -- 2.28 -- 6.69 --
P < 0.05; ** P < 0.01; *** P < 0.001
(H) = Hardwood Trees; (C) = Coniferous Trees
.)tseroF dna ,egdE ,tucraelC( .)tseroF dna ,egdE ,tucraelC(
etis hcae ta snoitacol eerht ta nekat serusaem etis hcae ta snoitacol eerht ta nekat serusaem
aera lasaB .)4=n( setis llams dna )3=n( setis egral aera lasaB .)4=n( setis llams dna )3=n( setis egral
ni seert suorefinoc fo aera lasab naeM .2 erugiF ni seert doowdrah fo aera lasab naeM .3 erugiF
tucraelC egdE tseroF tucraelC egdE tseroF
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5.0 5.0
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I registered a total of 39 bird species (Appendix I) within 50 m of 21 point count
stations. Only species for which I recorded more than five individuals throughout the
data collection period (18 species) were included in the analyses. In addition, point
counts were inappropriate for censusing some species (Ruffed Grouse, Cedar Waxwing,
9. Chimney Swifts, hawks), consequently these birds were not included (see Appendix I for
list of all birds encountered).
Bird species diversity did not differ in large and small sites in the three locations
(clearcut, edge, forest) (Table 1; Fig 4). However, there was a highly significant effect of
location when diversity values of large and small sites were pooled (Table 1; Fig 4).
Diversity inside the clearcut (in both large and small sites) was significantly lower than
edge and forest values (F1,10 = 9.52, P = 0.01). There was no difference between diversity
in edge and forest areas (F1,10 = 0.41, P = 0.54).
tucraelC egdE tseroF
.)ES ± naem( 7991 ,erihspmaH weN ,tnarG
0
egelloC dnoceS eht ni setis )4 = n( llams dna )3 = n(
1
egral rof seirogetac tatibah eerht ni )xednI ytisreviD
s'nospmiS( seiceps drib fo ytisrevid naeM .4 erug2 iF
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egraL
Though diversity did not differ with clearcut size, the percent similarity between large
and small sites was low (Table 2). The differences in bird species present can be seen by
looking at the species common in each type of habitat (Table 3). Inside large and small
10. clearcuts, few of the species overlap suggesting very different bird assemblages. In edge
areas of large and small clearcuts more species overlap, and in forest areas a majority of
the species overlap indicating the relative similarity between the assemblages.
Table 2. Percent similarity within the bird community in clearcuts, edge zones, and interior forest zones of
large and small clearcut plots, Second College Grant, New Hampshire, 1997.
Small Clearcut Small Edge Small Forest
Large Clearcut 0.195 -- --
Large Edge -- 0.275 --
Large Forest -- -- 0.325
Table 3. Representation of where each species was relatively common (birds/site > 0.10) in the Second
College Grant, New Hampshire. Point counts were conducted inside clearcuts, on the edges of clearcuts
and in the forest 100 m from clearcut edges. Bird species are separated by migratory group.
Small site: Large Site: Small Site: Large site: Small Site: Large Site:
Migrant Group/Species Clearcut Clearcut Edge Edge Forest Forest
*
Neotropical Migrants
Blackburnian warbler X X X
Black-throated blue warbler X X X X
Black-throated green warbler X X X
Common yellowthroat X X X
Hermit thrush X X X X
Magnolia warbler X X X
Mourning warbler X X X
Northern parula X X X X
Ovenbird X X X
Red-eyed vireo X X X X X
Nearctic Migrants
White-throated sparrow X X X X
Winter wren X X X X
Yellow-bellied sapsucker X
Yellow-rumped warbler X
Residents
Black-capped chickadee X
Blue jay X X
Dark-eyed junco X X X X X X
Golden-crowned kinglet X X X X
The finer details of these differences in similarity are revealed by separating the
species observed into several groupings and analyzing the differences. The most
interesting result from analysis of the effects of size and location on the migratory
groupings (Neotropical migrant, Nearctic migrant, or Resident) was that there were
11. significantly more Neotropical migrant birds in the interior forest surrounding small
clearcuts than in the interior forest surrounding large clearcuts (F1,40 = 10.64, P = 0.002;
Figure 5). The other migratory status groups did not show any significant relationships
with size and location.
.50.0 < P * .)ES ± naem( 7991
,erihspmaH weN ,tnarG egelloC dnoceS eht ni setis
)4 = n( llams dna )3 = n( egral rof seirogetac tatibah
eerht ni sdrib tnargim fo ecnadnuba naeM .5 erugiF
tucraelC egdE tseroF
0
)etis/sdrib#( ecnadnuba naeM
1.0
2.0
3.0
4.0
llamS
5.0 *
egraL
The second grouping was based on habitat associations similar to those of Whitcomb
et al. (1981) and Germaine et al. (1997). There were significantly more forest-interior
birds in the forest 100 m from small clearcuts than in the forest 100 m from large
clearcuts (F1,40 = 5.64, P = 0.02; Figure 6). In contrast, there were significantly more
edge-open birds associated with large clearcuts (F1,40 = 5.05, P = 0.03; Figure 7) and
clearcut edges (F1,40 = 8.07, P = 0.007; Figure 7) than with small clearcuts and clearcut
edges. Interior-edge birds showed a preference for interior and edge zones as expected,
while exhibiting low abundance in clearcut areas (Appendix II). There was no effect of
clearcut size for interior-edge species (Table 4).
12. .50.0 < P * .)ES ± naem( 7991 ,erihspmaH .50.0 < P * .)ES ± naem( 7991 ,erihspmaH
weN ,tnarG egelloC dnoceS eht ni setis )4 = n( weN ,tnarG egelloC dnoceS eht ni setis )4 =
llams dna )3 = n( egral rof seirogetac tatibah eerht n( llams dna )3 = n( egral rof seirogetac tatibah eerht
ni sdrib roiretni-tserof fo ecnadnuba naeM .6 erugiF ni sdrib nepo-egde fo ecnadnuba naeM .7 erugiF
tucraelC egdE tseroF tucraelC egdE tseroF
0 0
)etis/sdrib#( ecnadnuba naeM
1.0
)etis/sdrib#( ecnadnuba naeM
1.0
2.0
2.0
3.0
3.0
4.0
llamS 4.0 llamS
5.0 *
egraL egraL
6.0 5.0 *
*
Table 4. Summary of mean squares and F statistics for ANOVA models run with migratory group, habitat
association, and foraging strategy as variables.
Migratory Group Habitat Association Foraging Strategy
df MS F MS F MS F
Size 1 0.89 0.16 0.48 1.20 0.89 0.14
Site (Site) 5 2.17 0.40 0.43 1.08 2.17 0.34
Location 2 121.52 22.34*** 10.42 26.30*** 121.52 19.27***
Guild 2 234.51 43.11*** 0.57 1.44 359.85 57.07***
Size x Location 2 31.20 5.73** 1.69 4.26* 31.20 4.95*
Size x Guild 2 10.96 2.01 2.13 5.37** 7.35 1.16
Location x Guild 4 76.62 14.08*** 4.70 11.85*** 55.57 8.81***
Error 44 5.44 -- 0.40 - 6.31 -
*P < 0.05; ** P < 0.01; *** P < 0.001
The third grouping was based on foraging strategies (Ehrlich et al. 1988). The
abundance of foliage-gleaning birds increased from clearcut to forest (F4,40 = 8.80 P <
0.001; Figure 8). Ground-foraging birds were most abundant in clearcut areas and edge
areas of large sites and in interior areas of small sites (Figure 9). There were no Yellow-
bellied Sapsuckers (the only commonly encountered bark-probing species) associated
with large clearcuts and they were most abundant in interior areas associated with small
clearcuts (see Appendix II).
13. large clearcuts than in small sites (Figure 10).
predators. They were more abundant in edge areas and interior areas associated with
Finally, I looked at the abundance of blue jays, which are potentially important nest
egraL
5.0 5.0
llamS
* egraL
* 4.0 llamS 4.0
3.0 3.0
*
2.0 2.0
1.0 1.0
)etis/sdrib#( ecnadnuba naeM
)etis/sdrib#( ecnadnuba naeM
0 0
tseroF egdE tucraelC tseroF egdE tucraelC
sdrib gnigarof-dnuorg fo ecnadnuba naeM .9 erugiF sdrib gninaelg-egailof fo ecnadnuba naeM .8 erugiF
llams dna )3 = n( egral rof seirogetac tatibah eerht ni llams dna )3 = n( egral rof seirogetac tatibah eerht ni
weN ,tnarG egelloC dnoceS eht ni setis )4 = n( weN ,tnarG egelloC dnoceS eht ni setis )4 = n(
erew snaem - * .)ES ± naem( 7991 ,erihspmaH .)ES ± naem( 7991 ,erihspmaH
.)50.0 < P( tnereffid yllacitsitats
14. .50.0 < P * .)ES ± naem( 7991 ,erihspmaH weN
,tnarG egelloC dnoceS eht ni setis )4 = n( llams dna
)3 = n( egral rof seirogetac tatibah eerht ni )srotaderp
tsen( syaj eulb fo ecnadnuba naeM .01 erugiF
tucraelC egdE tseroF
0
)etis/sdrib#( ecnadnuba naeM
1.0
2.0
3.0
4.0
5.0
6.0
* llamS
7.0
egraL
DISCUSSION
Clearcuts of different sizes affect the forest-bird community in different ways.
Neotropical migrant bird species and forest-interior species appear to be the most
sensitive bird groups to large (6.0 - 7.0 ha) clearcut disturbances in the Grant. Nearly all
bird species in eastern North America that showed declining trends from the late 1940s
until the late 1980s were Neotropical migrants or forest-interior birds and interior-edge
birds (Whitcomb et al. 1981). In light of this finding and others showing declining trends
in migratory songbirds and birds associated with forest-interior (Askins et al. 1990,
Robbins et al. 1989a) management strategies in the Second College Grant should reflect a
concern for these groups of birds.
Forest-interior and bark-probing birds are able to maintain relatively high abundances
around small clearcuts while they are at low abundance or are absent from areas
associated with large clearcuts. In addition, though ground-foraging birds showed high
abundances in large clearcuts and edge associated with large clearcuts, they also
15. maintained high abundances in forest 100 m from small clearcuts. This suggests that
large open areas are not necessary for maintaining high abundances of these species.
Edge-open birds did prefer large clearcuts and edge areas of large clearcuts over
small clearcuts and edge areas. These species were also present in small clearcuts (Table
3) suggesting that overall bird diversity in the Second College Grant does not benefit
from the presence of large openings. The overall abundance of birds, however, is
enhanced by the presence of large clearcut openings given that species such as the White-
throated Sparrow (Zonotrichia albicollis), Red-eyed Vireo (Vireo olivaceus), and Winter
Wren (Troglodytes troglodytes) were much more abundant in large clearcuts than in
small clearcuts (Appendix II). Of course, just how large openings should be to support a
higher abundance of edge-open birds must be determined for the Grant. This study
suggests that 6.0 – 7.0 ha clearcuts are more beneficial to edge-open species although
clearcuts smaller than 6.0 ha may support equally high abundances of edge-open species.
This question is important given that there may be some intermediate size clearcut that
Neotropical migrants, and forest-interior birds and edge-open species can all utilize.
Large clearcuts represent a major disturbance to the local landscape in which they are
carried out. Relative to small clearcuts, they destroy a larger amount of habitat for forest-
interior birds. Most importantly, it appears from my data that the effects of these large
disturbances extend further into the surrounding forest than the effects of a small clearcut.
Germaine et al. (1997) found that forest-interior bird abundance leveled off after 100 m
distance from small (0.4 ha) forest openings. My abundance measures 100 m from small
clearcuts in the Grant may therefore be representative of areas even further from clearcuts
(interior forest). If this is so, birds must be further away from large clearcuts than from
small clearcuts in order to maintain high abundance. Of course, we must note the
cumulative effect of many small clearcuts totaling to equal the size of one large clearcut.
It could be possible that many small clearcuts disturb more habitat for Neotropical
migrants and forest-interior birds. To assess this we must know the distance from a large
16. clearcut at which the abundance of migrants and forest-interior birds equals the
abundance 100 m away from a small clearcut. This information would be very useful for
developing a strategy to manage for Neotropical migrants and forest-interior birds which
are showing declines recently.
Blue jays, potentially important nest predators, are also more of a concern in large
clearcuts than in small clearcuts in the Grant. Their greater abundance in large sites may
explain why forest-interior birds and Neotropical migrants were more abundant in forest
100 m from small clearcuts than in forest 100 m from large clearcuts. In addition, forest
associated with large clearcuts may be more detectable or exploitable than forest adjacent
to small clearcuts by nest predators such as chipmunks, squirrels and avian nest predators
than the more discontinuous edges of small clearcuts (Germaine et al. 1997). An
increased presence of nest predators could have serious implications for reproductive
success. I did not measure nest success, but the differences I saw in abundance may be
even more pronounced in terms of reproductive success. Measuring reproductive success
in and around large and small clearcuts would provide land managers with an important
insight into the nature of the effects of clearcut size on the bird community.
This study shows the importance of looking beyond diversity measures as an
indication of management success. If management in the Grant based assessment of
different strategies strictly on the diversity of the bird assemblage present, much would
be overlooked. For instance, sensitive groups such as Neotropical migrants and forest-
interior species showing population declines would not show up in such an analysis.
To manage for Neotropical migrant and forest-interior species in the Second College
Grant, managers should limit clearcut size. Additional timber could be harvested using
selective cutting although the effects of this practice should be examined in future studies
as well. Such a strategy may be prudent given the nature of surrounding timber
management schemes. The land immediately east of the Grant is owned by a large paper
mill that harvests large tracts of forest (much larger than 6.0 – 7.0 ha) using the clearcut
17. method. Thus, in terms of larger landscape dynamics, edge-open birds may have an
abundance of habitat outside the Grant’s borders while Neotropical migrants and forest-
interior birds are more limited.
To manage for overall bird abundance within the Grant, management strategies
should include large and small clearcuts. This would benefit the most number of species
in terms of abundance. Again it is important to remember, however, that reproductive
success may be lower in forest associated with large clearcuts and one must be hesitant in
adopting a strategy that includes large clearcuts if the goal is to manage for edge-open
bird abundance.
Of course, it is important to consider the habitat requirements of wildlife other than
birds such as moose, bear, deer, and aquatic organisms. In addition, timber production
and the economics driving it are important factors to consider.
Future studies should attempt to synthesize concerns for other organisms with my
results for forest birds to provide the forester at the Grant with the necessary information
to implement a sound and effective Wildlife Program. In addition future work could
attempt to determine whether many small clearcuts which add up to the same amount of
area as one large clearcut would be more beneficial to the bird assemblage.
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