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
• Abasic grouping shows that ecological models in general
belong to three areas:biodemographic ,bioenergetics and
biogeovisual models include:
• flowcharts,graphs ,diagram and 3D model.
• Aecological 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.
• 1.1 Levels of ecological Modeles
• the Ecological Model provides a framework for identifying
reasons for public health problems as well as for planning
• 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
• (1) Intrapersonal factors-Characteritcs of the individual such
as knowledge,attitudes, behavier ,self concept ,skills and
Include gender, values,goals,expectation,age,genetics,coping
skill,management skill,health literacy and counseling servece.
• (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,
• 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.
1.2The importance of ecological model
• Allow integration between behavioral and
• It allows for attention to be given the
interaction between personal and
• The model also can assist those in need with
education of how different factors can play a
role in their over all health.
• 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
• they typically do not have natural killer to keep their
population in check and they usually can reproduce
2 .1. How do Invasive Species Spread?
• by human activities: People, and goods transported, travel
quickly around the world, and often carry uninvited species
• 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.
• 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
• invasive species,modifies or disrupts the ecosystems it
• reduce water quality.
• Damage recrational opportunties.
• 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
• 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
• 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.
• In response to environmental stimuli dense and highly
• 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.
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 toget
• 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
• Chemical or biological: dusting with insecticides and spraying liquid insecticides.
• Chemical pesticides have been the only effective method to control extreme
• 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) -
• Oriental Migratory Locust (Locusta migratoria manilensis) -
• Red Locust (Nomadacris septemfasciata) - Eastern Africa;
• Brown Locust (Locustana pardalina) - Southern Africa;