11 terms

Biodiversity Loss

1. What is the simple definition of biodiversity and how is it usually measured?
Biodiversity = The biological diversity of life. Measured on a genetic, taxonomic, ecological and spacial level. Often also measured by abundance (population, interactions, turnover), species richness (number of species), and function.
2. Why is that simple definition problematic in terms of: species identification, abundance, proportion/distribution, genetic variation, and diversity of function?
Too simplistic. Fails to acknowledge the importance of interactions, can't actually quantify the number of species well. Also "function" is subjective and difficult to actually quantify. There are also problems quantifying species and determining populations.
About how many species are there on this planet (do we think), and what type of species constitute the majority of our known species?
There have been about 1.7 to 2 billion species identified (though the real number is very uncertain). The most numerous is the beetle (350,000 species identified).
4. What is the difference between local, functional and global extinction?
Local extinction: disappearance of a species from a region/ecosystem.
Functional extinction: loss of ability to interact with an ecosystem--no longer plays a role in ecosystem function.
Global extinction: loss of species from the planet (permanently).
How does current extinction rates compare with background extinction rates?
Current extinction rates are equivalent to mass extinction rates of past 5 mass extinctions ( 1000x higher than historic rates)
What are biodiversity hotspots, as identified by Myers et al?
Biodiversity hotspots = terrestrial regions/biogeographic units of high biodiversity and rapid habitat loss. Regions home to 44% of terrestrial plants and 35% terrestrial animals, but only 1.4% land area. Qualifications: must contain at least .5% of earth's 300,000 endemic plant species and be threatened with at least 10% habitat loss in the next few decades, and be terrestrial terrain.
List some reasons why we value individual species (e.g., food, medicinal value, etc).
Science, recreation, culture/spirituality, medicine, food security, commerce, ethics (intrinsic value)
List some ecosystem services than natural systems provide. What is the estimated economic value of global ecosystem services?
Ecosystem services: 1) Supporting (providing necessities of life like mass, H2O, O2). 2) Regulation services (CO2, O2 regulation, pollution/disease control) -- $33 trillion in services provided (Robert Costanza 1997)
How does biodiversity enhance human security? Give one or two examples.
1) food security 2) protection from disease 3) ecosystem security/water security/gas regulation security 4) climate stability
10. What are the major causes of biodiversity loss for birds? Mammals? Amphibians?
10. Habitat loss is the main reason, then invasive species, overexploitation, climate change.
What are invasive species?
11. Invasive species: non-native species which interfere with the function of native species.