chapter 54 - biodiversity and conservation biology Flashcards
(25 cards)
define genetic diversity
total genetic information contained within all individuals within a population
- number and frequency of all genes (and their alleles) present in a species
breakthroughs in ability to catalogue genetic diversity
- entire genome sequencing
- environmental sequencing
why is genetic diversity important?
represents the adaptive capacity of a group and its ability to persist despite changes in its environment
dna barcoding
uses gene sequences to identify species
- nonspecialists can use it
- researchers can use it to identify leftover tissues
taxonomic diversity
when species are a part of lineages with many species (e.g. Beatles and orchids)
other lineages are species poor (such as the red panda which is the sole species in its lineage) - high targets for conservation
define ecosystem function
sum of the biological and chemical processes (e.g. carbon cycling, primary production) in an environment
how many species are living today?
we don’t know!
estimated 5-100 million. only 1.5 million catalogued
define species richness and species diversity
richness - # of species present in a given ecological community
diversity - variety and relative abundance of species in a. given ecological community
for a given species richness, diversity is high if evenness is high
define endemic species
species that are found in a particular area of the world and nowhere else
common trends in species richness and endemism
- richness highest in the tropics and declines towards the poles
- biodiversity higher on land than at sea
- greater geographic diversity = more diversity
- rainforests high in richness
causes of species endangerment
- habitat loss
- invasive species
- over-exploitation
- pollution
- native species interactions
- natural causes
habitat fragmentation
reducing habitats until they are too small to support some species like top predators
- loss of top predators can cause trophic cascades
- can force species into metapopulations
- leads to small, isolated populations vulnerable to catastrophes
edge effect
biomass decreases sharply along the edges of forest fragments
- quantity and quality of habitat drastically decline
- early succession weedy species replaces large trees
overexploitation
any unsustainable removal or organisms from the natural environment by humans
name major threats to biodiversity
- habitat destruction and degradation
- overexploitation
- invasive species
- pollution
- climate change
difference between exotic and invasive species
exotic - non native species introduced to an area
invasive - exotic species that has grown in size and disrupts native species
species richness increases with ___
habitat area
productivity of ecosystems depends on ____
number and types of species present
define stability in a community and how to measure it
- maintain productivity and other aspects of ecosystem function as conditions change over time
- recover to former levels of productivity and richness after a disturbance
measured by…
- resistance (extend community remains unchanged by disturbance)
- resilience (ability to bounce back)
connection between diversity, resilience and resistance
species diversity increases resistance and resilience!
list ecosystem services
- provisioning (provide raw materials)
- regulating (earth’s life support system)
- cultural
- supporting (enable all other ecosystem services e.g. primary productivity, nutrient cycling, pollination, pest control)
3 arguments to support ethics in preserving the environment
- organisms have intrinsic worth
- industrialized nations are responsible for most harm; should not infect harm on poorer nations
- unethical for current generation to deprive future generations of ecosystem services
impossible to preserve high species diversity if 2 things happen
- population growth to 10 billion or more
- fossil fuel and resource consumption does not decline
strategies to preserve environment
- education campaigns
- genetic restoration
- seed banks
- management plans for invasive species
- management plans for endangered species
- in-situ conservation and reintroduction
- wildlife corridors
- designating protected areas
- ecosystem restoration
- quantifying ecosystem services (paying landowners not to destroy land)
