Biodiversity 2 Flashcards
Types of diversity
Ecosystem diversity
Species diversity
Genetic diversity
What do we know about genetic diversity?
Geographically delineated clusters of genetically distinct population of can have implications for management of species
Based on all georeferenced samples of the mitochondrial gene
cytochrome b from GenBank and BOLD repositories - Relative to the number of samples in each location how much
diversity was observed within that gene
Shows a strong correlation between species richness and genetic diversity
- But also, very limited data and mitochondrial DNA is probably not the best for doing this – but it is all that is currently available
Genetic diversity still plays a minor role in conservation
beyond local projects. But this is changing
Genetic indicators in the CBD (convention of biological diversity)
- The number of populations with effective population size above versus below 500
- The proportion of populations maintained within species
- The number of species and populations in which genetic diversity is monitored using DNA-based methods
Ecological/biophysical ‘habitats’
Defined by rainfall, temperature, geology, soils, history and natural disturbance regimes
Global ecoregion maps
Define ecoregions as relatively large units of land containing a distinct assemblage of natural communities and species, with boundaries that approximate the original extent of natural communities prior to major land-use change
Based on global and regional publications of plant and animal regions
Developed by 100s of experts
Challenges of land use mapping
- Needs to be classified (ultimately just wavelengths)
- Rarely validated/ ground truthed
- Ultimately class-based (discrete) making change analysis difficult
- Evolution of sensors and satellites make comparisons over time difficult.
What do we know about changes in diversity?
Nature across most of the globe has now been significantly altered by multiple human drivers, with the great majority of indicators of ecosystems and biodiversity showing rapid decline
Increasing extinction rates
Living Planet Index data
- Various sources and types of data
- total population size estimates
- density measures (e.g. birds per km of transect)
- biomass estimates (e.g. from fisheries data)
- number of nests (e.g. marine turtles)
- Traceable; geographic location; reputable method; minimum two data points; methods are comparable across years
- > 42,000 time-series
- The index has confidence intervals that vary in size with different regions
Global Forest Watch data
- Global tree cover data at 30x30 m resolution
- Updated annually - and even more frequently since ca. 2000
- BUT only tree cover / “forest”
