• Arsi University
Department of Geography and Environmental
Studies Specialization inEnviromntal disaster
Risk Management
Course Title : Environmental ecology and ecosystem management.
(GeDM 503)
• 1st year EDRM 1st semster Paper assignment work on Environmental
ecology and ecosystem management.
• Submitted by: Group 8
• Abera Bulto. ID No.GS/EX 0311/15
• Jemal Beshir ID NO GS/EX0323/15
.
Assela March 2023

Cont…
• Introduction
• Ecological model:-recognizemultiple levels of
influence on health behavior, including
intrapersonal/individual factors,which
influencebe havior such as knowledge
altitude belief and personality.
• An early critical element in the definition of
the ecological model is experience.

Cont…
• Invasive Species:-is an organism that is not
indigenous or native to particular area and can
cause great economic and environmental harm
to new area
• Desert locust isshort-horned grasshopper and
found primary in desert and dry areas of nothern
and easternafrica,arabia and south Asia.
Water hyacinth is afree-floating flowering
invasive aquatic plant originated from Amazone
Bsin south America

Cont…
1. Ecological models
• are important for environmental decision support because
they allow the consequences of alternative policies and
management scenarios to be explored.
• An early critical element in the definition of the ecological
model is experience. It highlights peoples interaction with
their physical and sociocultural environment.
• Ecological model also recognize multiple levels on influence
on health behaviors including intrapersonal/individual factor.
• The term is used to indicate that the scientifically relevant
features of any environment for human development include
not only its objective properties but also the way in which
these properties are subjectively experienced by the persons

Cont---
• Abasic grouping shows that ecological models in general
belong to three areas:biodemographic ,bioenergetics and
biogeovisual models include:
• flowcharts,graphs ,diagram and 3D model.
• An ecological models of health behavior emphasize the
environmental and policy contexts of behavior, while
incorporating social and psychological influences
(Gruenewald et al., 2014).
• It focuses on the linkages and relationships among multiple
factors (or determinants) affecting health.
• The core concept of ecological model is that behavior has
influences from multiple scales
including:individual,interpersonal, institutional, and
community used to design and evaluate environmental
interventions. White aComiskey2007.

Cont---
• 1.1 Levels of ecological Modeles
• the Ecological Model provides a framework for identifying
reasons for public health problems as well as for planning
interventions.
• The basis of the model is the recognition, that public health
problems are rarely caused only by wrong individual
behaviour but rather by a combination of factors from five
different levels:
• (1) Intrapersonal factors-Characteritcs of the individual such
as knowledge,attitudes, behavier ,self concept ,skills and
developmental history.
Include gender, values,goals,expectation,age,genetics,coping
skill,management skill,health literacy and counseling servece.

Cont---
• (2) Interpersonal factors – social network level: Who makes family
or household decisions? How much money is availably in
households and families and how are spending decisions reached?
• (3) Institutional factors – organizational level: Who has real
influence in the community? Are there organizations that prevent
positive changes or that could help bring about those changes?
How do the local marketing and distribution systems work?
• (4) Community factors – community level: Is there any institutional
support for solutions to public health problems? Have public health
problems even been identified as problems for the community by
the formal and informal leadership? What roles are played by local
businesses, schools, clinics, NGOs and other associations?
• (5) Policy factors – national level: What influence do national
policies (e.g. laws,

Cont---
• tariffs, grants, taxes) have on the public
health? Which parties and interests are
involved in the policy-making process?
• The Ecological Model is not just used to
identify problems but also to identify key
people, groups and resources that can help
bring about positive chain.

Socio-ecological-model-framework-
for-prevention-centers-for-disease-
control-Available

Cont---
1.2The importance of ecological model
• Allow integration between behavioral and
environmental change.
• It allows for attention to be given the
interaction between personal and
environmental factors.
• The model also can assist those in need with
education of how different factors can play a
role in their over all health.

Cont---
• 2 . Invasive Species
• an "invasive species" is a species that is:
• non-native (or alien) to the ecosystem under
consideration and,whose introduction causes or is
likely to cause economic or environmental harm or
harm to human health.
• .It can out compete native species for resources and
cause native species to go extinict or become
endanger.
• they typically do not have natural killer to keep their
population in check and they usually can reproduce
quickly.

Cont…

Cont---
2 .1. How do Invasive Species Spread?
• by human activities: People, and goods transported, travel
quickly around the world, and often carry uninvited species
with them.
• can be introduced to an area by ship ,water, firewood,
accidental release, and by people.
• Insects can be transported easily in wood, shipping palettes,
and crates shipped across the globe.
• Human activities, such as those involved in global commerce
and the pet trade, , such as those involved in global
commerce and the pet trade, are considered to be the most
common ways invasive plants, animals, microbes, and other
organisms are transported to new habitats.

Cont…
• 2.2 Impacts of Invasive Species.
• Invasive species can lead to the extinction of native
plants and animals.
• destroy biodiversity, and permanently alter habitats.
• the various impacts of invasive species -- economic
and social, environmental and ecological, and human
health.
• invasive species,modifies or disrupts the ecosystems it
colonizes.
• reduce water quality.
• Damage recrational opportunties.

Sutro-forest-in-ivy6021

Cont---
invasive species: Burmese python

Cont……
• 2.2.1Controlling mechanisms are:
• Mechanical: physical removing plant from
environment through cutting or pulling.
• Chemical: uses herbicides to kill plant.
• Biological: use plant diseases or insect
predictor. natural enemies
• Cultural:selection of pest-resistant
crops,winter cover crops,changing planting
dates.

Con….
• 3. The desert locust (Schistocerca gregaria ) is a
species of locust, a periodically swarming, short-
horned grasshopper in the family Acrididae.
• They are found primarily in the deserts and dry areas
of northern and eastern Africa, Arabia, and
southwest Asia.
• During population surge years, they may extend
north into parts of western Spain and southern Italy,
south into Eastern Africa, and east
• It is the most destructive migratory pest in the world.

desert-locust-800-l

Cont----
• In response to environmental stimuli dense and highly
mobile..
• They are ravenous eaters who consume their own weight
per day, targeting food crops and forage.
• a single square kilometer of swarm can contain up to 80
million adults, with the capacity to consume the same
amount of food in one day as 35,000 people..
3.1 Desert locust crisis 2020-2021
• Starting in early 2020, a massive desert locust upsurge
broke out across greater Eastern Africa, Southwest Asia,
and the area around the Red Sea, as favourable climatic
conditions allowed widespread breeding of the pest.

Cont---
3.1.2 Causes of desert locust
• Arises from an increase population density which
cause the locust to aggregate.
• Locust need to multiply, concentrated and
aggregate for swarms to form
• The gregarious form undergo color change
• A behavior change which make them band
together.

• 3.1.3 Consequence of desert locust
• Deterioration to vegetation and crops in the infested areas
• Major agricultural damage.
• Lead to famine and starvation.
• Eat every thing green and destroy crops
• Eating large quantity of food
• 3.1.4 Management of desert locust
• Techniques for managing locust swarms include:
• Cultural control: digging ,burning and bating[scattering locust food with
insecticides].
• Chemical or biological: dusting with insecticides and spraying liquid insecticides.
• Chemical pesticides have been the only effective method to control extreme
locust infestations.

Cont----
• 3.1.5 Where are Desert Locust found?
• Desert Locusts are usually restricted to the semi-arid and arid
deserts of Africa
• , the Near East and South-West Asia that receive less than 200
mm of rain annually.
• African Migratory Locust (Locusta migratoria migratorioides) -
Africa;
• Oriental Migratory Locust (Locusta migratoria manilensis) -
South-East Asia;
• Red Locust (Nomadacris septemfasciata) - Eastern Africa;
• Brown Locust (Locustana pardalina) - Southern Africa;

Cont..
4 . Water hyacinth (Eichhornia crassipes)
• is an aquatic weed native to South America.
it often referred to as the noxious beauty.
It can live and reproduce floating
• freely on the surface of fresh waters.
It is arguably ranked as one of the most
• noxious aquatic weed and continues to spread
aggressively throughout temperate, tropical
and sub-tropical

Cont….
• climates (Dagno, Lahlali, Friel, Bajji, & Jijakli,
2007).
• It has become a problem in all continents
apart
• from Europe. Water hyacinth grows over a
wide variety of wetland types such as lakes,
streams, ponds,
• waterways, ditches and backwater areas in
temperate and tropical zones (Ndimele, 2012).

Cont..
• Ever since its introduction outside the Amazon
Basin, water hyacinth has created
innumerable problems for communities.
• It interferes with water use by directly
obstructing navigation, blocking water-intake
• points, causing turbidity in shallow waters
used for domestic purposes, and interfering
with water flow in irrigation channels.

Cont…
4.1. Causes of water hyacinth
• The reason for the wide spread and growth
of the weed in these areas might be due to
eutrophication caused by ahigh level of
nutrients.
• Factors that can create favorable conditions
for this growth can be
salinity,PH,temperature,sun light and
reproduction systems of the invasive weed.

Cont….
4.2. Effective of water hyacinth
• Blockage of Canals and Rivers Causing Flooding
• Reduction of Biodiversity
• Oxygen Depletion and Reduced Water Quality
• Breeding Ground for Pests and Vectors
• Physical Obstruction
• Increased Evapotranspiration Rate
• Problems Related to Fishing
• Water hyacinth affects fish reproduction, feeding and
productivity.
• Effect on Human Health
• Water hyacinth offers a micro-habitat for a variety of disease
vectors such snails.

Water hyacinth in tana lake

Cont..
4.2.1 CONTROL OPTIONS OF WATER HYACINTH
• Reduction of Nutrient Inputs to the Water
• Mechanical Removal
• Manual Removal
• Manual extraction methods involve drainage of the water
body, manual removal of the weeds or pulling
• through nets using hands and/or rakes, as is done in Lake
Mutirikwi (90 km2) in Zimbabwe.
• Chemical Control
• This involves the application of herbicides for
controlling water hyacinth

Cont..
• REFERENCES
• Bicudo, D., Fonseca, B., Bini, L., Crossetti, L., Bicudo, C., & Araujo-Jesus, T. (2007).
Undesirable side-
• effects of water hyacinth control in a shallow tropical reservoir. Freshwater Biology,
52(6), 1120–1133.
• doi:10.1111/j.1365-2427.2007.01738.x
• Borokoni, T., & Babalola, F. (2012). Management of invasive plant species in
Nigeria through eco-
• nomic exploitation: Lessons from other countries. Management of Biological
Invasions, 3(1), 45–55.
• doi:10.3391/mbi.2012.3.1.05
• Center, T. D., Hill, M. P., Cordo, H., & Julien, M. H. (2002). Water hyacinth. Biological
control of in-
• vasive plants in the Eastern United States. USDA Forest Service Publication FHTET.

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