✅ M6 - Conservation Flashcards
What is meant by biodiversity and what are the 3 levels of biodiversity?
- Biological diversity: the variability among living organisms from all sources and the ecological complexes of which they are part of.
- This includes:
1. Genetic diversity (within-species)
2. Species diversity (between-species)
3. Ecosystem diversity (between-species)
What is meant by genetic diversity?
- The diversity of heritable genes/ alleles within the population of a single species.
- Raw material of evolution
Give an example of genetic diversity?
Example: Heliconius melpomene (a butterfly species)
* Genetic variation produce large phenotype variation across different geographic locations.
* Promote rapid speciation
* Different species in the same location often resemble each other: Müllerian mimicry (all are unpalatable to predators)
What is meant by species diversity?
- The variety and abundance of different types of organisms which inhabit an area.
- Two components:
1. Species richness: the number of different species in a particular area
2. Species evenness: relative abundance with which each species is represented in an area
What is meant by ecosystem diversity?
- The variety of habitats that occur within a region.
- An ecosystem can cover a large area, such as a whole forest, or a small area, like a beach.
What makes species vulnerable to extinction?
- Key factor: loss of genetic variation
- Necessary for responses to environmental change
- Prone to positive feedback loops -> extinction vortex. - Main drivers:
- Habitat loss (e.g. deforestation)
- Climate change
- Polution
- Overexploitation (of humans)
- Invasive species
What is the extinction vortex?
- An increase in the impact of genetic drift, due to the population’s decreased size
- Decreasing genetic diversity = decreasing adaptive potential.
- Leads to a further vortex (continuous) => Eventual extinction
What are the major differences that determine which species are more likely to become extinct?
Most >< Least likely to become extinct:
1. Low >< High population density
2. Found over small >< large area
3. Specialized >< Generalized niche
4. Low >< High reproductive rate
-> Endemic species (species that exist only in one geographic region and nowhere else) are particularly vulnerable to extinction.
How to prevent species from extinction?
Answer: Preserving genetic diversity
- Conserve patches with higher genetic variability for in-situ conservation (protected natural habitat)
- Preserve genetic materials for ex-situ conservation (man-made)
What are some ways to conserve and where? Give 5 examples.
- Prioritize areas for conservation
- Restore damaged areas
- Debt-for-Nature swaps (nation debt is forgiven for the money to be invested in local habitats)
- Captive breeding programs
- Reducing our footprint
Species-wise conservation decision? What species should we prioritise?
Certain species maybe more important that others with respect to ecological function.
- Keystone species: important to prevalence and population levels of other species within the ecosystem. They greatly influence the food webs and define an entire ecosystem.
- Umbrella species: make conservation easier since their conservation indirectly conserves many other species in the ecosystem. They may not play a fundamental role.
-> If remove a keystone species, can drastically change or lose the ecosystem.
Geographical-wise conservation decision?
- Conserving biodiversity using HOTSPOTS
- Normally to qualify as a hotspot, a region should have:
1. Relatively small area
2. High species richness
3. High no. endemics (irreplaceable)
4. Large no. of endangered or rare species
5. Must be threatened (have <30% the original vegetation) - Global hotspots of species richness does not align with endemism or threat.
- 36 areasqualify as hotspots globally. While their intact habitats is only2.5% of Earth’s land surface, but they support >50% of the world’s plant species as endemics.
How can we classify types of species?
Native or non-native (alien) species.
* Native species: existed in ecosystem for a long time and co-evolved with other species
* Non-native species (aka exotic, alien, non-indigenous species) live outside their native range, introduced via human activity => If they establish in their new range, they are naturalized.
* Invasive species are alien species that spread after introduction and cause harm to their environment.
Give 2 examples of an invasive alien species?
- Himalayan Balsam (aka “Policeman’s helmet”)
- 1 of the “big four” introduced from Asia
- Colonises riverbanks and wet woodlands, spreads with explosive seedpods
- Excellent nectar and pollen source (harm local species) - Giant Hogweed
- Seed dispersal
- Rapid growth & spread
- Plant’s sap contains toxic chemicals which causes blistering within 48 hours for human skin -> hard to remove these plants without proper equipment
How do invasives cause harm? Give a few examples for each.
- Disease vectors and competitors: Grey squirrels compete against red, transmits squirrelpox virus.
- Aggressive predators:
- “Killer shrimp” eats aquatic invertebrates and larvae, fish and their eggs; “overkill”
- Feral cats cause for extinctions of most mammals & some bird species in Australia - Economic damage:
- Rabbits: burrowing & grazing damages trees, changes ecosystems, causing £170m crop losses annually in the UK
- Japanese knotweed: eradication legally required, cost £250m annually. - Concerns due to speedy establishment of invasive species in new areas, due to:
- Increased trade
- Increased land degradation
- Climate change
=> Most are harmless, but around 10-15% spread and become invasive non-native species which harm wildlife and the environment.
