Describes about the concept, scope, definition of Biodiversity, threats of biodiversity, centre of Origin/diversity, Biodiversity hotspots, strartegies of BD conservation
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Lecture note on Biodiversity conservation
1. Dilla University
School of Graduate Studies
Department of Biology
Botanical Science Stream
Course Title: Biodiversity Conservation
Course Code: 513
Cr. Hr: 2
Instructor: Talemos S.
Semester II
Ac. Year 2017, Semester II
1
2. 1. What is Biodiversity
Conservation?
maintaining the diversity of living organisms,
their habitats and the interrelationships b/n
organisms and their environment.
What is biodiversity/ Biological Diversity?
variation of life at all levels of biological
organization
is a measure of the relative diversity among
organisms present in different ecosystems.
totality of genes, species, and ecosystems of a
region, used by ecologists.
2
3. Biological diversity: the variability
among living organisms from all sources
including, inter alia, terrestrial, marine
and other aquatic ecosystems and the
ecological complexes of which they are
part; this includes diversity within species,
between species and of ecosystems
(CBD, 1992).
Biological diversity deals with the
degree of nature’s variety in the
biosphere.
This variety can be observed at three
levels;
the genetic variability within a species,
the variety of species within a community,
and organization of species in an area into
distinctive plant and animal communities
constitutes ecosystem diversity.
Biodiverity is the result of billions of years
3
4. Three Main Components of BD
A. Genetic Diversity
the variety of genes contained within species of
plants, animals and micro-organisms.
Each species, varying from bacteria to higher plants
and animals, stores an immense amount of genetic
information.
For example, the number of genes is about 450-700
in mycoplasma, 4000 in bacteria (eg. Escherichia coli)
, 13,000 in Fruit-fly (Drosophila melanogaster);
32,000 – 50,000 in rice (Oryza sativa); and 35,000 to
45,000 in human beings (Homo sapiens).
This variation of genes, not only of numbers but of
structure also, is of great value as it enables a
population to adapt to its environment and to respond
to the process of natural selection.4
5. A. Genetic diversity…
Each member of any animal or plant species differs
widely from other individuals in its genetic makeup
because of the large number of combinations
possible in the genes that give every individual
specific characteristics.
Thus, for example, each human being is very
different from all others.
This genetic variability is essential for a healthy
breeding population of a species.
If the number of breeding individuals is reduced, the
dissimilarity of genetic makeup is reduced and in-
breeding occurs.
Eventually this can lead to the extinction of the
species.5
6. A. Genetic diversity…
The diversity in wild species forms the ‘gene pool’
from which our crops and domestic animals have
been developed over thousands of years.
Today the variety of nature’s bounty is being further
harnessed by using wild relatives of crop plants to
create new varieties of more productive crops and to
breed better domestic animals.
Modern biotechnology manipulates genes for
developing better types of medicines and a variety of
industrial products.
6
7. B. Species diversity
refers to the variety of species within a
geographical area.
Species diversity can be measured in terms of:
(a) Species richness – refers to the number of
various species in a defined area.
(b) Species abundance – refers to the relative
numbers among species. For example, the
number of species of plants, animals and
microorganisms may be more in an area than that
recorded in another area.
(c) Taxonomic or phylogenetic diversity – refers to
the genetic relationships between different groups
of species.
Species = a particular type of organism; a population
or group of populations whose members share certain
7
8. Evenness increases diversity
Increasing evenness greater diversity
True for all indices
Site 1 Site 2
S = 4
N = 8
S = 4
N = 8
Higher
Evenness,
Diversity
8
9. At the global level, an estimated 1.7 million species of
living organisms have been described to date and
many more are yet to be discovered.
It has been currently estimated that the total number
of species may vary from 5 - 50 millions.
Species diversity is not evenly distributed across the
globe.
The overall richness of species is concentrated in
equatorial regions and tends to decrease as one
moves from equatorial to polar regions.
In addition, biodiversity in land ecosystems generally
decreases with increasing altitude.
The other factors that influence biodiversity are
amount of rainfall and nutrient level in soil.
9
10. Measure of Biodiversity Assessment
Shannon-Wiener Index
Simpson index
Margalef Indexes
10
11. Shannon’s Diversity Index
Assume that there are n possible categories in a data
set and that their proportions are pi,.....,pn. Then
Shannon’s diversity index for this system is defined to
be :
H’ = -Σpi ln (pi)
accounts for both abundance and evenness of the
species present
The proportion of species i relative to the total number
of species (pi) is calculated, and then multiplied by the
natural logarithm of this proportion (lnpi).
11
12. Simpson’s Diversity Index, D
Simpson's diversity index (D) characterizes species
diversity in a community.
Simpson's diversity index (D) characterizes species
diversity in a community.
D = 1/(Σpi
2)
The proportion of species i relative to the total number of
species (pi) is calculated and squared.
The squared proportions for all the species are summed,
and the reciprocal is taken.
12
13. Margalefs index
Margalef's richness index: (S-1)/ ln (n), where S =
number of taxa, n = number of individuals
13
14. Spatial patterns of species richness
Point Richness: number of species that can be found
in a single point in space
Alpha (α-) richness: number of species found in a
small homogenous area
Beta (β-) richness: rate of change in species in
species composition across habitats
Gamma (γ-) richness: change across large
landscape gradients
Richness is directly related to physical environment,
productivity and structural complexity of communities
14
15. Limits of species richness
Productivity hypothesis: High productivity
results in higher number of species
Stability hypothesis- environments that are
stable tend to support higher number species
15
16. Ethiopian Biodiversity
There are between 6500 and 7000 higher plant species of
which about 12 per cent are endemic.
With regard to animals, there are known to be 284 wild
mammal, 861 bird, 201 reptile, 63 amphibian, 188 fish and
1225 arthropod species with about 10, 2, 5, 54, 0.6 and 21%
of endemism respectively.
There is an immense variation in the farmer’s varieties of
different
crops and breeds of livestock.
More than 100 crop plant species are cultivated with a
sizeable proportion of them having their center of origin or
diversity in Ethiopia.
There are also 30 cattle, 14 sheep, 14 goat, 4 camel, 4
donkey, 2 horse, 2 mule, 5 chicken and 5 honey bee
breeds/ecotypes/populations recorded which are indigenous
to the country.
16
18. An overview of sampling issues in species diversity&
abundance surveys
To ensure the most useful information, a biologist
must be familiar with basic sampling issues.
All biologists should know important issues when
sampling diversity, abundance and other parameters.
Consideration of these issues allows the biologists to
sample in a manner that, while not a perfect reflection
of the population will provide the best representation
of the true population as possible.
18
19. Every sampler should understand the following before
survey
i/ Setting objectives (suitable research questions)
ii/An important partner (the statistician)(which methods
to use?)
iii/What species to sample
Iv/ Where to sample
V/ Bias, sampling error, precision
Vi/ How to sample
Vii/When to sample
Viii/ How many samples to collect
ix/ comparing information from different surveys
x/preparing for the field
19
20. C. Ecosystem Diversity
is a functioning unit of interacting organisms (plant,
animal and microbe = biocoenosis) and their
interactions with their physical and chemical
environment (biotope) often linked to an area.
as the variety of ecosystems within a bigger
landscape and their variability over time
20
21. Ecosystem Diversity…
Ecosystem diversity relates to the variety of habitats,
biotic communities and ecological processes in the
biosphere as well as the diversity within ecosystems.
Diversity can be described at a number of different
levels and scales:
• Functional diversity is the relative abundance of
functionally different kinds of organisms.
• Community diversity is the number sizes and
spatial distribution of communities, and is sometimes
referred to as patchiness.
• Landscape diversity is the diversity of scales of
patchiness
21
22. Ecosystem Diversity…
No simple relationship exists between the diversity of an
ecosystem and ecological processes such as
productivity, hydrology, and soil generation.
Neither does diversity correlate neatly with ecosystem
stability, its resistance to disturbance and its speed of
recovery.
There is no simple relationship within any ecosystem
between a change in its diversity and the resulting
change in the system's processes.
For example, the loss of a species from a particular area
or region (local extinction or extirpation) may have little
or no effect on net primary productivity if competitors
take its place in the community.
The converse may be true in other cases. For example,
if herbivores such as zebra and wildebeest are removed
from the African savanna, net primary productivity of the
ecosystem decreases.
22
23. Ecosystem Diversity…
Despite these anomalies, Reid and Miller (1989)
suggest six general rules of ecosystem dynamics
which link environmental changes, biodiversity and
ecosystem processes.
1. The mix of species making up communities and
ecosystems changes continually.
2. Species diversity increases as environmental
heterogeneity or the patchiness of a habitat does,
but increasing patchiness does not necessarily
result in increased species richness.
3. Habitat patchiness influences not only the
composition of species in an ecosystem, but also
the interactions among species.
4. Periodic disturbances play an important role in creating
the patchy environments that foster high species richness.
They help to keep an array of habitat patches in various
23
24. 5. Both size and isolation of habitat patches can influence
species richness, as can the extent of the transition zones
between habitats.
These transitional zones, or `ecotones', support species which
would not occur in continuous habitats.
In temperate zones, ecotones are often more species rich than
continuous habitats, although the reverse may be true in
tropical forests .
6. Certain species have disproportionate influences on the
characteristics of an ecosystem.
These include keystone species, whose loss would transform
or undermine the ecological processes or fundamentally
change the species composition of the community.
24
25. Important Types of Species in conservation
Biology
1. What is a flagship species?
A flagship species is a species selected to act as an
ambassador, icon or symbol for a defined habitat,
issue, campaign or environmental cause.
By focusing on, and achieving conservation of that
species, the status of many other species which share
its habitat – or are vulnerable to the same threats -
may also be improved.
Flagship species are usually relatively large, and
considered to be 'charismatic' in western cultures.
Flagship species may or may not be keystone species
and may or may not be good indicators of biological
process.
Examples of flagship species include the Bengal tiger
(Panthera tigris), the Golden lion tamarin
(Leontopithecus rosalia), the African elephant
25
26. 2. What is a priority species?
The terms “flagship” and “keystone” have generally
consistent definitions across the conservation community,
however “priority species” is a WWF term, and is solely
for the purposes of planning and simple communication.
For WWF, a “priority species” may be either a flagship or
a keystone species and is chosen to represent an
ecoregion or region.
A “priority species” is reflective of a key threat across that
ecoregion such that conservation of the species will
contribute significantly to a broader threat mitigation
outcome.
It is often crucial to the economic and/or spiritual
wellbeing of peoples within that ecoregion.26
27. 3. What is a keystone species?
A species whose removal causes an
ecosystem to collapse
is a species that plays an essential role
in the structure, functioning or
productivity of a habitat or ecosystem at
a defined level (habitat, soil, seed
dispersal, etc).
Disappearance of such species may lead
to significant ecosystem change or
dysfunction which may have knock on
effects on a broader scale.
In many forests the fig tree is considered
a keystone species since during parts of
the year it is virtually the only tree
producing fruit.
During these lean times, many primates
and birds feed almost exclusively on fig
fruit.
Examples include the elephant's role in
maintaining habitat structure, and bats
and insects in pollination.
As keystone species, African
Elephants stop the progression of
27
28. Elephants browse on these
woody plants, yanking young
trees out by their roots or
stunting their growth by eating
the growth points on their
branches.
Even if a tree or two escapes
the weeding, they won't last
long. Sooner or later an
elephant will push the plant
over, yank it out of the ground,
or kill it slowly by prying away
its bark.
By focusing on keystone species,
conservation actions for that
species may help to preserve the
structure and function of a wide
range of habitats which are linked
with that species during its life
cycle.
28
29. 4. What is an indicator species?
An organism whose presence, absence
or abundance reflects a specific
environmental condition.
is a species or group of species chosen
as an indicator of, or proxy for, the state
of an ecosystem or of a certain process
within that ecosystem.
Examples include crayfish as indicators
of freshwater quality;
corals as indicators of marine processes
such as siltation, seawater rise and sea
temperature fluctuation;
peregrine falcons as an indicator of
pesticide loads; or native plants as
indicators for the presence and impact of
alien species.
The presence of river otters
indicates a healthy, clean river
system.
29 peregrine falcons
30. 5. Umbrella
Species
What is it?
Examples:
An organism whose protection
provides protection for a variety of
other organisms.
As top predators, grizzly bears
are especially vulnerable to
disturbances in their habitat
and food supply and thus
serve as an excellent indicator
species for the "wildness" and
the overall health of the
coastal ecosystem.
Grizzly bears are also an
excellent umbrella species
because they require large
home ranges.
30
31. Other Umbrella
species
examples
The Black Rhino - These iconic
animals serve as umbrella species
for wilderness conservation, in that
protecting them also safeguards
numerous other species of plants31
32. Other Umbrella
species
examples
Both the mountain lion and gray wolf
are great umbrella species because
by protecting these endangered
predators, their prey and habitat
must also be protected.32
33. 2. Benefits of Biological Diversity
The various benefits of biological diversity can be
grouped under three categories:
A) ecosystem services,
B) biological resources, and
C) social benefits.
33
34. A. Ecosystem services
Living organisms provide many ecological services free of
cost that are responsible for maintaining ecosystem
health.
Thus biodiversity is essential for the maintenance and
sustainable utilization of goods and services from
ecological system as well as from individual species.
i) Protection of water resources: Natural vegetation cover
helps in maintaining hydrological cycles, regulating and
stabilizing water run-off and acting as a buffer against
extreme events such as floods and droughts.
Vegetation removal results in siltation of dams and
waterways.
Wetlands and forests act as water purifying systems, while
mangroves trap silt thereby reducing impacts on marine
ecosystems.
34
35. ii/Soil protection:
Biological diversity helps in the conservation of
soil and retention of moisture and nutrients.
Clearing large areas of vegetation cover has
been often seen to accelerate soil erosion,
reduce its productivity and often result in flash
floods.
Root systems allows penetration of water to the
sub soil layer.
Root system also brings mineral nutrients to the
surface by nutrient uptake.
35
36. iii/ Nutrient storage and cycling:
Ecosystem perform the vital function of recycling
nutrients found in the atmosphere as well as in the
soil.
Plants are able to take up nutrients, and these
nutrients then can form the basis of food chains, to be
used by a wide range of life forms.
Nutrients in the soil, in turn, is replenished by dead or
waste matter which is transformed by micro-
organisms; this may then feed others such as
earthworms which also mix and aerate the soil and
make nutrients more readily available.
36
37. iv) Pollution reduction:
Ecosystems and ecological processes play an important role in
maintenance of gaseous composition of the atmosphere, breakdown of
wastes and removal of pollutants.
Some ecosystems, especially wetlands have the ability to breaking
down and absorb pollutants.
Natural and artificial wetlands are being used to filter effluents to
remove nutrients, heavy metals, suspended solids; reduce the BOD
(Biological Oxygen Demand) and destroy harmful micro-organisms.
v/Climate stability:
Vegetation influences climate at macro as well as micro levels.
Growing evidence suggests that undisturbed forests help to maintain
the rainfall in the
vicinity by recycling water vapor at a steady rate back into the
atmosphere.
Vegetation also exerts moderating influence on micro climate.
Cooling effect of vegetation is a common experience which makes
living comfortable.
Some organisms are dependent on such microclimates for their
existence.
37
38. Vi/Maintenance of ecological processes:
Different species of birds and predators help to control
insect pests, thus reduce the need and cost of artificial
control measures.
Birds and nectar–loving insects which roost and breed
in natural habitats are important pollinating agents of
crop and wild plants.
Some habitats protect crucial life stages of wildlife
populations such as spawning areas in mangroves
and wetlands.
Without ecological services provided by biodiversity it
would not be possible to get food, pure air to breathe
and would be submerged in the waste produced.38
39. B. Biological resources of economic
importance
i) Food, fibre, medicines, fuel wood and ornamental plants:
Five thousand plant species are known to have been used as
food by humans.
Only about 20 species feed the majority of the world’s population
and 3 or 4 only are the major staple crops to majority of
population in the world.
The cultivation and use of spices, herbs, medicinal and other
essential oil bearing plants is not new to Ethiopia.
It is as old as the crop themselves, and its history can be traced
back to the reign of Queen Sheba (992 BC).
Ethiopia is the origin and/or center of diversity for many of these
plant species.
About 70% of human and 90% of livestock population depend on
traditional medicine in Ethiopia similar to many developing
countries particularly that of Sub-Saharan African countries.
39
40. ii) Breeding material for crop improvement:
Wild relatives of cultivated crop plants contain
valuable genes that are of immense genetic value in
crop improvement programs.
Genetic material or genes of wild crop plants are used
to develop new varieties of cultivated crop plants for
restructuring of the existing ones for improving yield
or resistance of crops plants.
For example: rice grown in Asia is protected from four
main diseases by genes contributed by a single wild
rice variety.
40
41. iii/ Future resources: There is a clear relationship
between the conservation of biological diversity
and the discovery of new biological resources.
The relatively few developed plant species
currently cultivated have had a large amount of
research and selective
breeding applied to them.
Many presently under-utilised food crops have the
potential
to become important crops in the future.
Knowledge of the uses of wild plants by the local
people is often a source for ideas on developing
new plant products.41
42. C. Social benefits
i) Recreation:
Forests, wildlife, national parks and sanctuaries, garden
and aquaria have high entertainment and recreation value.
Ecotourism, photography, painting, film making and
literary activities are closely related.
ii) Cultural values:
Plants and animals are important part of the cultural life of
humans.
Human cultures have co-evolved with their environment
and biological diversity can be impart a distinct cultural
identity to different communities.
The natural environment serves the inspirational,
aesthetic, spiritual and educational needs of the
people, of all cultures. Eg. Ficus sp. conservation
42
43. *Research, Education and
Monitoring
There is still much to learn on how to get better
use from biological resources, how to maintain
the genetic base of harvested biological
resources, and how to rehabilitate degraded
ecosystems.
Natural areas provide excellent living laboratories
for such studies, for comparison with other areas
under systems of use and for valuable research
in ecology and evolution
43
44. In general, Biodiversity provides:
Food, fuel and fiber.
Shelter and building materials.
Purifies air and water.
Detoxifies and decomposes wastes.
Stabilizes and moderates Earth’s climate.
Moderates floods, droughts, wind, and temperature
extremes.
Generates and renews soil fertility and cycles nutrients.
Pollinates plants, including many crops.
Controls pests and disease.
Maintain genetic resources as key inputs to crop
varieties, livestock breeds, and medicines.
Provides cultural and aesthetic benefits.
Provides us the means to adapt to change.
44
45. Benefits of biodiversity: Medicine
Many species can provide
novel medicines;
we don’t want to drive
these extinct without ever
discovering their uses.
10 of our top 25 drugs
come directly from wild
plants;
the rest developed
because of studying the
chemistry of wild species.
45
46. Threats of Biodiversity
The major threats of Biodiversity include:
1/Habitat destruction/fragmentation
2/Invasive species
3/Population growth
4/Pollution
5/Overconsumption
46
47. Habitat destruction
Changing a habitat to suit human needs such as for
housing, farming, fuelwood …etc.
This displaces animals/plants. As the human population
grows, so does habitat destruction!
involves both loss and isolation of ecosystems
influenced 89%, 83% and 91 % of all threatened birds, mammals
and plants respectively
47
49. Habitat fragmentation
49
The process by which a natural landscape is broken up into
small parcels of natural ecosystems, isolated from one
another in a matrix of lands dominated by human activities, is
called fragmentation.
Breaking up large habitats into smaller habitats.
Creates an “edge” habitat where “inner” habitat used to be.
Some plants and animals cannot adapt to these changes.
Fragmented habitats have fragmented populations of the
constituent species.
Then, subject to the problems which face small populations.Fragmentation can be caused by natural
processes such as fires, floods, and
volcanic activity, but is more commonly
caused by human impacts.
50. Fragmentation…
50
Low genetic diversity and inbreeding represent
loss of biological diversity at the genetic level.
The small populations themselves are subject to
stochastic threats of various sorts, giving them
low likelihood of persistence
Fragmentation may occur through natural as
well as anthropogenic disturbances,
Natural forests, woodlands, savanna of the world
fragmented by conversion in to agriculture, timber,
and fuelwood
Farmers have sought to eliminate wild species
from their lands in order to reduce the effects of
pests, predators, and weeds, which harm
pollinator abundance
51. Fragmentation..
51
Even, more than 30% of protected areas (PAs) had
their land area under crops
Devastate large trees, diminishes forest structure
complexity
Short lived spp, w/c alters hydrological, C- cycles,
and GHG emissions
Habitat loss and fragmentation is the single greatest
threat to biodiversity worldwide, and mainly for
mammals today.
52. Invasive Species
52
Non-native species whose introduction and/or spread
outside their natural, past or present, ranges pose a
threat to biodiversity
Invasive species mainly out-compete native
species resulting in disruption of the ecosystem and
food chain.
Many native organisms are becoming endangered
by the effect of Invasive species.
Invasive species are the second largest threat to
biodiversity after habitat loss.
In Ethiopia, close to 35 invasive alien plant species
are posing negative impacts on native biodiversity,
agricultural lands, range lands, national parks, water
ways, lakes, rivers, power dams, road sides, urban
green spaces with great economy and social
consequences.
55. Impacts of Parthenium hysterophorus
55
reduction of 41 % to 97% in agricultural crops
Allelochemicals affect harmfully the activity of free
living & symbiotic nitrogen fixers in the soil
cause a total change in native vegetation,
decreases pasture productivity, carrying capacity
and land values .
blocks common pathways and orchards and
reduces the aesthetic value of parks, gardens and
residential areas
human health problems – skin problems
56. Characteristics of invasive species
pioneer species
high dispersal rates
found in disturbed habitats
Why are invasives successful? b/s no
diseases,
herbivores,
parasites, predators
better competitors than native species
28 April 2017
61. Population growth
61
Increasing population means greater demand for food,
shelter, fuel and water.
This often leads to habitat loss, pollution, resource
scarcity and overconsumption (in areas with enough
money)
Humans are coming into greater (more frequent)
contact with previously wild areas with high biodiversity
Population expected to reach 8 billion by 2020.
Human population growth exacerbates every other
environmental problem.
62. population…
62
>1.1 billion people live within 34 global BD
hotspots
1.3 % of popn live with in 3 major wilderness area:
upper Amazon, Congo river basin, and the New
Guinea Melanesia complex Islands(6% of
the earth’s surface)
Population growth in Ethiopia
>2.2 % per year, and
with 85 % of the popns relying on farming or herding for
their livelihoods,
popn growth places greater pressure on the land &
resources to provide for immediate human needs.
63. Popn growth resulted food production constraints
63
i. Areas wz great prodn constraints like steep hillsides & forest
areas, remain for conversion
ii. > 12 % of irrigated land shrank
iii. 10% of irrigated land becomes saline
iv. World fish harvest declined by 10%
v. Range land decline by 20%
vi. global climate change - exacerbating erratic RF & disease
vii. In Canada, subsidized agriculture abandoned, moving to high
prodn.
Falling prodn shows ecosystem & resource limits
Problem of feeding ever growing popn in dev’ping countries.
by 2025, sufficient food can be produced?????
Real constraint the price of food
many poor countries can’t purchase food,
gov’ts seek a policy of cheap food.
64. Population growth
To address this threat in Ethiopia,
family planning.
More people means
more habitat change,
more invasive species,
more pollution,
more overexploitation.
Along with increased resource consumption, it is the
ultimate reason behind proximate threats to BD.
28 April 2017
65. Pollution
65
o All forms of pollution pose a serious threat to
biodiversity, but in particular nutrient loading, primarily
of nitrogen and phosphorus, which is a major and
increasing cause of biodiversity loss and ecosystem
dysfunction.
o Pollution can alter the habitat to the point where some
plants and animals will not be able to adapt.
o Global Climate Change--many species are intolerant to
changes in temperature--affects feeding relationships
and breeding patterns.
o Acid rain/Air pollution-these types of issues do not
respect borders.
o US acid rain fell in Canada destroying sugar maple
forests which upset the amount/quality of maple syrup
produced.
66. Pollution…
66
The petrochemical industry generate such
strong air pollution that caused the death of
forest trees, leading to landslides.
The use of DDT and related chlorinated
hydrocarbons in the USA led to the
elimination of the peregrine falcon east of
the Mississippi, as well as major declines in
popns of birds at the end of long food
chains, such as bald eagles and brown
pelicans disrupt normal developmental and
reproductive processes.
In Ethiopia- the pesticide poisoning of honeybees.
unknown effect of floriculture chemicals
67. Case 2. Reducing the need for chemical pesticides in S.
China (Yunnan Province)
The rice fields the highest levels of pesticide use. This
wiped out many species in and around irrigated rice
affected the entire food chain, from microorganisms to insects to frogs and other species,
disappearance of vultures, some hawks, parts of Asia.
farmers have reduced the need for pesticides
using more diverse rice varieties to control rice blast
thousands of farmers found that planting more than one variety of rice helped
prevent the spread of D
increased rice yields by 89 %
rice blast declined by 94 %,
Then, the fields of rice became :
less costly chemicals
friendlier to wild biodiversity
In 2000, 4,500 has of rice fields planted with this method,
10 other provinces in China –beginning the method
28 April 2017
69. Overconsumption/Overexploitation/overharvesting
69
The over-exploitation (over-hunting, over-fishing, or
over-collecting) of a species or population can lead to its
demise.
Two meanings:
Overharvesting of species from the wild (too much
hunting, fishing…)
Overconsumption of resources (too much timber cutting,
fossil fuel use…)
In Sub-Saharan Africa over-exploitation involving
mammals hunted either (a) for ivory, horn, skin products
or trophies, or (b) to protect livestock or crop.
examples of these are elephant and rhinoceros
Industrialized nations make up 25% of the world’s
population, but use 75% of its resources.
US makes up only 5% of world’s pop--causes 33% of
71. 2.Centers/origin of biological diversity
The idea of CBD has been developed, reflecting the evolutionary
heartland for a taxon.
The identification of ‘hotspots’ or other centres of diversity is
one of the approaches to establishing priorities for BDC.
Since the time of Buffon and de Candolle, biogeographers have
realized that distribution of organisms has shifted overtime.
This realization led naturally to efforts to determine the birth
place, or center of origin, of each taxon
Two general questions motivated the search for centres of origin;
i/ first researchers wanted to know whether certain
geographic regions have served as cradles for the evolution
of new kinds of organisms;
ii/How biota have been assembled, where started, which
route they followed around the world and what factors have
created the pattern (endemism), disjunction, and diversity
etc.
71
72. 2.Centers/origin…
Mattew (1915) believed that the center of origin is where the
primitive forms live today.
This is in direct opposition to the Henning (1966) progression
rule, which holds that an ancestral population remains at or
near the point of origin and progressively more derived forms
are found at farther distances away from the centre in a
“stepping stone” pattern of sequential dispersal and speciation
events .
According to him ancestral popn remains at or near the point
of origin and the derived forms disperse outwards.
The concept of centres of origin of our domesticated species
was suggested by de Candolle in 1883.
Vavilov (Russia Genetist) found that:
There were certain areas in the world where crop plant
diversity was extremely intense, i.e. regions containing a high
level of diversity of a number of crops.
The areas of greatest diversity represent the centres where
the crops were originally domesticated.72
73. Centers/origin…
On the Vaviov’s ‘the Origin of Cultivated Plants’ (1926),
this concept became eventually & generally accepted for
the conservation of PGR as it established a clear link b/n
genetic diversity, its geographic distribution pattern and the
origin of the crop in question.
Vavilov defined the centre of diversity as a centre of
domestication of a particular crop.
Two types of centres of diversity exist:
i. Primary centre: the region from where a particular crop
originated and where the maximum diversity of that crop is
present , e.g. Teff, Coffee, enset, etc in Ethiopia.
ii. Secondary centre: those regions to which the particular
crop is introduced and domesticated, are many crops e.g.,
banana (SE asia), barley, in Ethiopia.
Caused by: the movement and exchange of crops
throughout history
73
74. Centers/origin…
•the high degree of diversity in these secondary centres is
due to:
a long history of cultivation of a crop,
combined with environmental, and
social factors supporting diversification.
The high degree of diversity in Vavilov’s ‘centres of origin’
does not refer primarily to the diversity of individual crop
varieties nor to distinctive properties, but rather to diversity
in general.
74
75. Plant domestication
Agriculture started in some limited number of
regions of the world, principally the near east or southwest
Asia, East Asia, Africa, Mesoamerica (Mexico & Central
America), and South America.
Plant domestication is the evolutionary process whereby a
population of plants becomes accustomed to human provision
and control.
For many authors, domestication is generally considered to
be the end-point
of a continuum that starts with
exploitation of wild plants,
continues through cultivation of plants selected from the wild
but not yet genetically different from wild plants,and
ends with the adaptation to the agro ecology through
conscious or unconscious human morphological selection,
and hence genetic differences distinguishing the
domesticated species from its wild progenitor.75
76. Vavilovian Centres
The descriptions of agro-
ecological groups are arranged
according to the centres of
diversity.
According to Vavilov, dominant
alleles would predominate in the
centre of origin of a species,
whereas recessive alleles would
prevail in the periphery.
Vavilov defined about eight
centres of origin for most of our
cultivated plants, each of them
harboring significant genetic
diversity within and between
species.
Most of these Vavilovian centres
are situated in tropical and
subtropical regions of the world,
and their locations fall largely
1924 -Began his collection
trips:
•Afghanistan
•Ethiopia
•Northern Africa
Tailed by spies working for
dictator
Incredibly persuasive and
lucky
He scoured five continents in
the 1920s and 1930s for wild
and cultivated corn, potato
tubers, grains, beans, fodder,
fruits and vegetable seeds.
76
77. Initially, Vavilov proposed five centers of origin in 1924, which developed
into eight in 1935, although his final papers (1992; 1997) discussed
seven major centers with minor additions.
The eight centers of origins are as follows:
1/The Chinese Center
2/The Indian Center
2a/The Indo-Malayan Center
3/The Inner Asiatic Center
4/Asia Minor
5/The Mediterranean Center
6/The Abyssinian
7/The South Mexican and Central American Center
8/South America Andes region
8a/The Chilean Center
8b/Brazilian-Paraguayan Center
77
78. Vavilov’s Centers of Origin – indicated
by Vavilov to be a Center of Plant Domestication
78
79. 79
1/The Chinese Center
138 distinct species of which probably the earlier and most important
were cereals, buckwheats and legumes.
2/The Indian Center (including the entire subcontinent) - based
originally on rice, millets and legumes, with a total of 117 species.
2a. The Indo-Malayan Center (including Indonesia, Philippines, etc.) -
with root crops (Dioscorea spp., Tacca, etc.) preponderant, also with
fruit crops, sugarcane, spices, etc., some 55 species.
3. The Inner Asiatic Center (Tadjikistan, Uzbekistan, etc.) - with
wheats, rye and many herbaceous legumes, as well as seed-sown root
crops and fruits, some 42 species.
80. 80
4/Asia Minor (including Transcaucasia, Iran and
Turkmenistan) - with more wheats, rye, oats,
seed and forage legumes, fruits, etc., some 83
species.
81. 81
5/The Mediterranean Center - of more limited
importance than the others to the east, but including
wheats, barleys, forage plants, vegetables and fruits -
especially also spices and ethereal oil plants, some
84 species.
About 10% of the species of cultivated crops
originated here.
Vavilov (1957) included the entire Mediterranean
coastal area in this centre, covering North Africa
(Egypt, Algeria, Tunisia), Greece with its islands,
Spain, Italy, and western and southwestern parts of
Asia Minor. Syria, Jordan
and Israel in this centre, whereas Vavilov (1957) had
only included the "inner oases of Syria, Morocco and
Algeria". Later, the Arabian Peninsula and even India
82. 6/Abyssinian(Ethiopian) center
82
Abyssinian center produced teff (Eragrostis abyssiniaca
), niger seed oil plant (Guizotia abyssinica ), a false
banana [Ensete ventricosum ], and coffee (Coffea
arabica L.).
Probably about 4% of the world crops originated here.
Harlan (genetist of USA) was the first to scientifically
collect barley in Ethiopia in 1923.
In 1927, Vavilov explored different agricultural regions of
Ethiopia and compiled a unique collection reflecting the
extraordinary botanical diversity of cultivated barleys.
comprises 38 botanical varieties, of which 16 are
endemic.
A larger number of endemic two-rowed botanical
varieties exist than in any other country of the world.
83. Ethiopian centre…
Ethiopia’s ecological diversity is mirrored by her cultural diversity.
The fantastic diversity of cultures and ecology is further mirrored by
the diversity of fauna and flora. As a result Ethiopia is a center of
biological diversity with sizeable endemism.
When the Russian plant geneticist, N.I. Vavilov, came during one of
his collection expeditions to Ethiopia and to neighboring countries in
the 1920s, he was amazed.
In Ethiopia, Eritrea and Somaliland he found so much genetic
diversity that he included the area in the list of the few great centers
of crop plant diversity and called it the Abyssinian gene centre.
Virtually the whole complex of seed crops from the South West
Asian and Mediterranean centers of crop origin were found here.
On wheat variation, Vavilov says that "Abyssinia occupies the first
place" and on barley that there is "an exceptional diversity of forms“
Since these observations of Vavilov, impressive diversity in native
crops such as teff, sorghum, millets and many grain legumes, oil
crops, vegetables, spices and other species have also been found.
83
85. Ethiopian Centre…
85
Ethiopia is a primary gene center for 11 fieldcrops
including
noug (Guizotia abyssinica),
teff (Eragrostis tef),
the Ethiopian mustard (Brassica carinata), and
enset (Ensete ventricosum).
Field crops such as barley, sorghum, durum wheat,
finger millet, faba bean, linseed, sesame, safflower,
chickpea, lentil, cowpea, fenugreek and grass pea
have a large genetic diversity in Ethiopia.
It originated in Ethiopia between 4000 and 1000 BC.
86. List of some important plant genetic resources
of
the Ethiopian Center of origin/Diversity
86
87. 87
7/The South Mexican and Central American
Center - important for maize, Phaseolus and
Cucurbitaceous species, with spices, fruits and fibre
plants, some 49 species.
Staple plants such as maize, cotton, beans,
pumpkins, cocoa, avocados, and subtropical fruits
originated here.
About 8% of the important crops of the world
originated here.
88. 88
8/ South America Andes region (Bolivia, Peru,
Ecuador) - important for potatoes, other root crops,
grain crops of the Andes, vegetables, spices and fruits,
as well as drugs (cocaine, quinine, tobacco, etc.),
some 45 species.
8a. The Chilean Center - only four species - outside
the main area of crop domestication, and one of these
(Solanum tuberosum) derived from the Andean center
in any case.
This could hardly be compared with the eight main
centers.
8b. Brazilian-Paraguayan Center - again outside the
main centers with only 13 species, though Manihot
(cassava) and Arachis (peanut) are of considerable
importance; others such as pineapple, Hevea rubber,
Theobroma cacao were probably domesticated much
later.
89. Why Centre of origin?
89
The following are some of the factors to consider when
explaining this increased BD:
smaller range of climatic conditions: a seasonal
climate, as seen in higher latitudes, results in a shorter
growing season;
physical geography: the presence of a canopy,
subcanopies, and varying mountain altitudes produce
additional niches;
age of the tropics: the tropics remained relatively stable
while the northern and southern land masses
experienced transitions related to
glacial movement;
greater competition: increased competition can lead to
greater specialization;
greater productivity: the sun’s rays hit the tropics more
directly, allowing for more photosynthesis.
90. Criteria
90
According to Cain (1994), many criteria were used for
indicating centre of origin of a tax
1. Location of greatest differentiation of atype ( greatest
nr of spp)
2. Location of dominance or greatestabundance of
individuals
3. Location of synthetic or closely related forms (
primitive & closely related forms)
4. Location of maximum size of individuals.
5. Location of greatest productivity and relative stability.
6. Continuity & convergence of lines of dispersal.
91. Criteria…
91
7. Location of least dependence on a restricted habitat
(generalist)
8. Continuity and directness of individuals variation or
modifications radiating from the center of origin along
highways of dispersal
9. Direction indicated by geographic affinities (e.g., all
southern hemisphere).
10.Direction indicated by the annual migration routes of
birds
11.Direction indicated by seasonal appearance (i.e.
seasonal preferences are historically conserved).
12.Increasing the no of dominant genes towards the center
of origin
92. Megadiversity countries
92
The majority of staple crops used worldwide
originated from few areas, chiefly in Africa, Asia ,
and Latin America, and are often called
“megadiversity” centers.
Megadiversity countries, located largely in the
tropics, which account for a high % of the world's BD
by virtue of containing very large numbers of
species on the basis of congruent patterns of
endemic species diversity for mammals, reptiles,
amphibians, and higher plants.
93. Megadiversity
93
17 ‘‘megadiversity countries’’, political units of high
conservation value.
Example, India is one of the 17 ‘megadiversity’
countries which, together,
possess 60-70% of the world’s total biodiversity.
it has about 7% of the world’s flowering plant
species,
14% of the world’s bird species and, overall, 81,000
species of animals representing 6.4% of the world’s
identified fauna.
1/3 of its 15,000 flowering plants are endemic, plus 14%
of its 1,228 bird species, 32% of 446 reptile species, and
62% of its BDC.
94. 94
The identified Megadiverse Countries are: United States of America, Mexico,
Colombia, Ecuador, Peru, Venezuela, Brazil, Democratic Republic of Congo,
South Africa, Madagascar, India, Malaysia, Indonesia, Philippines, Papua New
Guinea, China, and Australia.
95. In parentheses are rankings for the number of endemic
species among the top 17 countries.
95
96. Biodiversity Hotspots(BHS)
96
A British ecologist Norman Myers (1988), defined the BD
Hotspot approach & places great emphasis on efficiency
of resources and the time-pressure associated with the
global extinction crisis.
BHS are areas under immediate threat and hold the
highest proportions of the world’s BD.
require immediate protection in order to combat the loss of
a significant portion of the world’s species to extinction.
The biological criteria for hotspots is:
a. Endemism as indicated by the number of endemic
plant/animal species (1500+ vascular plants, 0.5% of the
worlds total),
b. based on percent decline of original vegetation;
all hotspots must have lost at least 70% of their primary
vegetation, although many have a much higher
percentage decline.
97. BHS…
97
There are 36 biodiversity hotspots & they hold high
numbers of unique species, yet
The combined area of BHS now covers only 2.3%
of the Earth's land surface. Many encompass
priority areas in multiple countries.
The degradation of critical ecosystems is no less a
threat for the estimated 2 billion people who live in
these fragile places.
Over 50% of the world’s plant species and 42% of
all terrestrial vertebrate species are endemic to the
36 biodiversity hotspots.
98. BHS…
98
The Amazon, represents 53% of all tropical forests and
encompasses the world’s largest river system, which
pours 175,000 m3 of water per second into the Atlantic
Ocean or 1/5 of the total discharge of all other rivers
together.
Amazon- the world's 2nd longest river (4000 miles) next to
Nile (4150 miles) into the Mediterranean.
Conservation efforts should aim at protecting the BD in
these Hotspots and reversing the trends.
Ethiopia harbours 2 of the 36 global biodiversity hotspots,
namely the
1. Eastern Afromontane hotspot,
2. Horn of Africa biodiversity hotspots.
100. IUCN Red List
100
The IUCN Red List of Threatened Species (also
known as the IUCN Red List or Red Data List),
founded in 1964, is the world's most
comprehensive inventory of the global
conservation status of biological species.
103. 103
There are five criteria used by IUCN to evaluate if a taxon belongs to a
threatened category ( critically endangered, endangered , and vulnerable).
There are 260 individuals of very small restricted number of mature individuals
of Oryx in Awash National Park.
108. 3. Conservation strategies
The continued growth of human popns and of per capita
consumption have resulted in: unsustainable
exploitation of Earth’s BD, exacerbated by climate
change, Ocean acidification, and other
anthropogenic environmental impacts.
This calls for conservation strategies.
Most widely accepted scientific methods of
biodiversity conservation are:
In situ methods
Ex situ methods
108
109. This is being done by effecting protection of Natural habitat(s)
so that spp or stock of biological communities in their natural
state is protected from human intervention e.g.
Biosphere reserves,
national Parks (an area of land that is protected by the
government for people to visit because of its natural
beauty and historical or scientific interest ),
wild life sanctuaries (an area where wild birds or animals
are protected and encouraged to breed)
sacred groves or other protected natural ecosystems or
on farm agro diversity.
The idea of establishing protected areas & networks has
been taken a central place in all policy decision process
related to BD conservation both at national and international
levels
109
111. In-situ conservation (ISC)
it is the conservation of BD in place, in its natural
settings.
The CBD defines ISC as “the conservation of
ecosystems and natural habitats and the
maintenance and recovery of viable populations of
species in their natural surroundings and, in the
case of domesticated or cultivated species, in the
surroundings where they have developed their
distinctive properties.”
ISC is often envisaged as taking place in protected
areas or habitats and can either be targeted at spp
or the ecosystem in which they occur.
primary concern: to ensure that the popn sizes
selected are large enough to allow the long-term
maintenance and continuing evolution of the target
popns and their genetic diversity.111
112. 112
To conserve individual species, some effective
approaches are:
Endorsing legal protection for the endangered
species;
improving mgt plans; and
establishing reserves to protect particular
species or unique genetic resources
113. The range of d/t situations covered by
the concept of in- situ conservation
113
1. Conservation of natural or semi-natural
ecosystems in various types of protected
area, with various mgt aims such as:
a. Maintaining ecosystem diversity,
b. BD in general or special landscapes; and
c. Providing habitat for target species such as
megavertebrates, birds, forest species,
medicinal plants, or for concentrations of
endemic species.
114. 114
2. Conservation of agricultural biodiversity, which
may be defined as “the maintenance of the
diversity present in and among popns of the
many species used directly in agriculture, or
used as sources of genes, in habitats where
such diversity arose and continues to grow”.
This includes:
a. Entire agroecosystems, including immediately
useful species (food crops, forages, and agro-
forestry species), as well as their wild and
weedy relatives
b. Maintenance of domesticates such as
landraces or local crop varieties in farmers’
fields, often referred to as ‘on-farm’
conservation
115. 115
3. Conservation and maintenance of selected/target
individual species in their natural habitats/ecosystems
through conservation or mgt plans.
In the case of species of economic importance, the
terms ‘genetic conservation’, ‘gene conservation’ or
‘genetic reserve conservation’ are commonly used.
The areas where such conservation takes place are
also known as gene or genetic reserve mgt units,
gene mgt zones, gene/ genetic sanctuaries, and crop
reservations. E.g., Senkelle Swaynes harte beat
sanctuary , Yayu forest coffee
This type of conservation may be defined as “the
location, management and monitoring of genetic
diversity in natural wild popns within defined areas
designated for active, long-term conservation”
116. 116
4. Recovery programs for nationally or subnationally
threatened, rare or endangered wild species.
Species recovery programs are a special case of in -situ
conservation of target species. They may often
require recovery of their habitats.
5. Restoration, recovery or rehabilitation of habitats.
With the widespread ecological destruction now occurring
around the world, habitat restoration has attracted
growing attention and often environmental legislation
requires habitat rehabilitation or restoration of areas
affected by activities such as mining to be undertaken
to mitigate the damage caused.
117. 117
In-situ cons. therefore covers not only species &
ecosystems but also genetic variability.
In practice, conservation of wild species or popns in-
situ is widely interpreted as meaning their presence
within a protected area or habitat, i.e. with the focus
primarily on the ecosystem.
may also involve the preparation and implementation
of rescue, recovery or mgt plans for target species
that are seriously endangered at the local, national
or global level, to prevent their becoming extinct in
the wild.
Thus, although in situ species conservation is
essentially a species-driven process, it also
necessarily involves habitat protection.
118. Advantages of in situ conservation of landraces
118
Comparative advantages to farmers
1. Conservation of indigenous knowledge —
Farmers are central participants in the in situ effort.
The cons. of crop genetic diversity on farms retains
the diversity within its proper ethnobotanical context.
on-farm conservation maintains indigenous
knowledge about the farming systems and
agricultural practices that retain diversity and
knowledge about direct uses of that diversity.
there is relatively little information about the
dynamics of this kind of indigenous knowledge.
2. Conservation linked with use — On-farm
conservation is closely connected with use directly
by the farmer for food or sale.
119. 119
3. Allelic richness and genotypic diversity-On-farm
popns have the capacity to support a much greater
number of rare alleles and of different (multilocus)
genotypes than accessions in gene banks.
large numbers of individual plants with
autonomous ancestry must be grown over
significant areas
this suggests the need for and importance of
measures of the area devoted to landraces, the nos
of popns and their sizes, and the genetic diversity for
marker loci, disease resistance, and morphological
traits.
120. 120
4. Special adaptations-The in situ strategy conserves a
unique group of germplasm, particularly for marginal or
stress environments.
This provokes the question of how populations on the
farm relate to material already in ex situ collections
generally, and stored accessions from that specific
region.
5. Localized divergence-The in situ strategy conserves
genetic variation on a relatively fine spatial scale, in
theory down to the individual field.
121. Ex-situ conservation
121
The conservation of components of biological diversity
outside their natural habitats (CBD, 1992).
At prehistoric times human being acted as gatherer,
hunter, farmer,
conqueror and eventually on today modified his own
environment as a consequence of his own misdeeds.
From the beginning, his attitude towards the animals was
contradictory; the animals were worshipped,
domesticated, hunted and decimated.
Human relations with animals date back more than ten
thousand years.
As back as 2500 BC in Egypt in zoo type collection the pet
animals like monkeys, antelopes, mongooses etc. were
found.
122. Ex-situ…
122
At about 1100 BC Chinese Emperor Wen Wang
built his “Garden of Intelligence” in an area of
1500 acres to house his animal collection
including Giant Panda.
Several Emperors from Greek, Roman and
Mughal dynasty established their Menagerie to
house their animal collections.
The first recognized Zoo in the world was
established in 1759 in Schonbrunn near Vienna
by the Emperor Francis I.
The Zoo is still operating at the same site and
more than 500 species have found their home at
this Zoo.
123. Ex-situ…
123
Ex-situ (‘off site’) conservation is a set of
conservation techniques involving the transfer of a
target species away from its native habitat.
It is one of two basic conservation strategies,
alongside in-situ conservation.
The main purposes of ex-situ collections are the
rescue and preservation of threatened genetic
material and the breeding of species for
reintroduction in cases where a species’ continued
survival in its native habitat is threatened.
124. Ex-situ…
124
Ex-situ conservation forms the basis of Article 9 of
(CBD), which highlights it should always be
implemented as a complementary (and not as an
alternative) approach to in-situ conservation.
Ex-situ measures should preferentially be put into
practice in the country of species origin.
Ex-situ ('off site', 'out of place') conservation is a set
of conservation techniques involving the transfer of a
target species away from its native habitat to a place
of safety, such as a zoological garden, botanical
garden, seed bank, captive breeding, aquaria,
gene banks,
126. Ex-situ…
126
Its primary objective is to support conservation by
ensuring the survival of threatened species and the
maintenance of associated genetic diversity.
To do so, ex-situ institutions preserve the genetic or
reproductive material of a target species, or take care
of the living target species for the purpose of
reintroduction.
In its simplified form, the concept is likened to Noah’s
ark, wherein species are maintained in a place of
safety until factors threatening their existence in the
wild have been removed and reintroduction is likely to
be successful
127. Techniques for Ex-situ Conservation
127
Ex-situ techniques target plant and animal
populations.
Techniques vary according to the characteristics of
the species to be preserved, which dictates the type
of material to be preserved (e.g. whole animals,
pollen, seeds).
Ex-situ collections of plants are established by
storing seeds, conserving pollen and through the
storage of plant shoots in conditions of slow or
suspended growth (in vitro conservation).
Ex-situ techniques applicable to animal populations
include the storage of embryos, semen/ovule/DNA,
or captive breeding through the establishment of field
gene banks and livestock parks.
128. 128
Lively debate surrounds ex-situ techniques, with much
deliberation over when ex-situ measures are appropriate
and justified.
In particular captive breeding and reintroduction programs have
sparked controversy due to, among others,
the difficulty in establishing self-sustaining captive
populations,
the high costs involved in captive breeding programs,
the poor success of re-introduction attempts and
the negative genetic effects of domestication on
reproductive rates.
Some species are, however, more susceptible to captive-
breeding programs than others.
For example, the global loss of amphibian species is mainly
tackled through captive breeding because the small body size,
low maintenance requirements, repeated breeding and high
fecundity of frogs allows a rapid build-up of captive populations.
Prepared by Talemos Seta
Dilla University, Department of Biology
Notas do Editor
Pbbm_cns@aau.edu.et/tigist.wondimu@aau.edu.et
The peregrine falcon, also known as the peregrine, and historically as the duck hawk in North America, is a widespread bird of prey in the family Falconidae
Economists typically classify ecosystem goods and services according to how they are used. The main framework used is the Total Economic Value (TEV) approach (Figure 3.1) (Pearce and Warford, 1993). The breakdown and terminology vary from analyst to analyst, but generally include(i) direct use value; (ii) indirect use value; (iii) option value; and (iv) non-use value. The first three are generally referred to together as ‘use value’
In various regions of the world, the origin of agriculture dates back 11,000–10,000 years, during a phase in the climate that was accompaniedby fundamental changes in the living conditions of organisms, including humans.
Agriculture developed in the highlands of Ethiopia approximately 6,000 years ago. Several domesticated species, for example coffee (Coffea arabica; finger millet (Eleusine coracana), and the cereal species teff (Eragrostis tef), originate from this region.
How does Habitat fragmentation affects biodiversity? is by reducing the amount of suitable habitat available for organisms. ... As the remaining habitat patches are smaller, they tend to support smaller populations of species. Fragmentation can be caused by natural processes such as fires, floods, and volcanic activity, but is more commonly caused by human impacts.
One of the major ways that habitat fragmentation affects biodiversity
Hunting, especially commercial hunting and poaching, has driven many species to extinction.
Passenger pigeon for meat, snowy egret for fashion, rhinos for their horns.
Bushmeat harvest is a crisis of tropical forests today
W.D. Matthew developed the center of origins-dispersal mode from Darwin and Wallace’s Biogeography and their original concept of “dispersal over a permanent geography”
1920 – went to Petrograd to take over Bureau of Applied Botany
1921-22 – terrible famine in Russia
1923 – went to USA, Europe, met with breeders, geneticists and acquired seed:
6224 packets, 2 tons native corn, 66 boxes from Luther Burbank, 20,000 seeds from Europe
Captive breeding is the process of breeding animals in controlled environments within well-defined settings, such as wildlife reserves, zoos and other commercial and noncommercial conservation facilities.
Botanic Garden- Germany
Prepared by Talemos Seta
Dilla University, Department of Biology