Summary WEC
Wildlife conservation: an act in which people make conscious efforts to protect the global biological
diversity
→ protection of plants and animal species and their habitats
Lecture 1 | Threats to biodiversity
Importance of biodiversity
Convention on Biological diversity (1992):
“At least 40% of the world’s economy and 80% of the needs of the poor are derived from biological
resources. In addition, the richer the diversity of life, the greater the opportunity for medical
discoveries, economic development, and adaptive responses to such new challenges as climate
change.”
Types of biodiversity:
- Genetic diversity
- Species diversity
- Ecosystem diversity
Diversity-stability relationship: species rich communities generally have more stable primary
productivity
→ greater biomass
→ higher resistance
→ different effects on resilience
Species asynchrony: decreases in the productivity of some species are compensated by increases in
the productivity of other species.
Species asynchrony may be caused by:
- Interspecific interactions
- Negative frequency dependence: rare phenotypes are selected → genetic variance increases
(e.g. during a pathogen outbreak)
- Diverse communities containing a wider range of species’ responses to environmental
conditions (e.g. a homogeneous forest versus a heterogeneous forest during a beetle
outbreak)
Extinction
Currently threatened by extinction:
- 25% of all mammal species
- 13% of all bird species
- > 21.000 plants and other organisms
→ current extinction rates are similar to five global mass-extinction events of the past 500 million
years
,Main threats to biodiversity at present (from high to low):
- Habitat destruction
- Overexploitation
- Invasive species, genes & diseases
- Pollution
- Climate change & weather
Main threat context dependent:
- Location
- Habitat
- Taxa
- Time
High risk hotspots
Habitat destruction → Tropics
Overexploitation → Tropics
Invasive species, genes & diseases → Islands in the Pacific and Atalantic
Pollution → Europe
Climate change → High altitudes and latitudes
,A linear regression correlation showed (r = 0.06, p < 0.001) that density of people is a key factor in
species threats
→ but there is not always a relationship
Low genetic diversity can reduce:
- Population viability
- Resistance to disease
What to do:
- More substantial conservation efforts
- Proactive policies e.g. shifts in agricultural practices, increased agricultural trade
- Improved land-use planning
- Shifting diets
, Lecture 2 | Overexploitation
Historical examples
Almost extinction of American Bison
During western times in the USA buffalos were
hunted for the tanning of bison hides, which were
used as belts in big industry.
This was possible because of:
- The defeat of the Sioux people, so modern
man could move more westwards
- Extension of the Northern Pacific Railroad:
hunting bison from the train was
considered a great sport
As a result: rise of the first modern conservation
movement: national park system
→ developed in response to the revulsion to the Slaughter of the Plains
Megafauna extinctions in late Pleistocene
Debate = overhunting or climate change
Lemoine et al. (2023): overhunting is the main cause
→ no megafauna extinctions during earlier interglacial-glacial transitions
→ extreme bias towards large-bodied animals is hard to explain by climate events
Two hypotheses for humans causing megafauna extinctions:
1. Co-adaptation hypothesis: lower extinction rates in areas with longer hominin presence
2. Main hypothesis: development of better hunting techniques
Ecological downsizing: hunted game bodysize decreased throughout the years
Wildlife conservation: an act in which people make conscious efforts to protect the global biological
diversity
→ protection of plants and animal species and their habitats
Lecture 1 | Threats to biodiversity
Importance of biodiversity
Convention on Biological diversity (1992):
“At least 40% of the world’s economy and 80% of the needs of the poor are derived from biological
resources. In addition, the richer the diversity of life, the greater the opportunity for medical
discoveries, economic development, and adaptive responses to such new challenges as climate
change.”
Types of biodiversity:
- Genetic diversity
- Species diversity
- Ecosystem diversity
Diversity-stability relationship: species rich communities generally have more stable primary
productivity
→ greater biomass
→ higher resistance
→ different effects on resilience
Species asynchrony: decreases in the productivity of some species are compensated by increases in
the productivity of other species.
Species asynchrony may be caused by:
- Interspecific interactions
- Negative frequency dependence: rare phenotypes are selected → genetic variance increases
(e.g. during a pathogen outbreak)
- Diverse communities containing a wider range of species’ responses to environmental
conditions (e.g. a homogeneous forest versus a heterogeneous forest during a beetle
outbreak)
Extinction
Currently threatened by extinction:
- 25% of all mammal species
- 13% of all bird species
- > 21.000 plants and other organisms
→ current extinction rates are similar to five global mass-extinction events of the past 500 million
years
,Main threats to biodiversity at present (from high to low):
- Habitat destruction
- Overexploitation
- Invasive species, genes & diseases
- Pollution
- Climate change & weather
Main threat context dependent:
- Location
- Habitat
- Taxa
- Time
High risk hotspots
Habitat destruction → Tropics
Overexploitation → Tropics
Invasive species, genes & diseases → Islands in the Pacific and Atalantic
Pollution → Europe
Climate change → High altitudes and latitudes
,A linear regression correlation showed (r = 0.06, p < 0.001) that density of people is a key factor in
species threats
→ but there is not always a relationship
Low genetic diversity can reduce:
- Population viability
- Resistance to disease
What to do:
- More substantial conservation efforts
- Proactive policies e.g. shifts in agricultural practices, increased agricultural trade
- Improved land-use planning
- Shifting diets
, Lecture 2 | Overexploitation
Historical examples
Almost extinction of American Bison
During western times in the USA buffalos were
hunted for the tanning of bison hides, which were
used as belts in big industry.
This was possible because of:
- The defeat of the Sioux people, so modern
man could move more westwards
- Extension of the Northern Pacific Railroad:
hunting bison from the train was
considered a great sport
As a result: rise of the first modern conservation
movement: national park system
→ developed in response to the revulsion to the Slaughter of the Plains
Megafauna extinctions in late Pleistocene
Debate = overhunting or climate change
Lemoine et al. (2023): overhunting is the main cause
→ no megafauna extinctions during earlier interglacial-glacial transitions
→ extreme bias towards large-bodied animals is hard to explain by climate events
Two hypotheses for humans causing megafauna extinctions:
1. Co-adaptation hypothesis: lower extinction rates in areas with longer hominin presence
2. Main hypothesis: development of better hunting techniques
Ecological downsizing: hunted game bodysize decreased throughout the years
