WEEK 7 Flashcards
What does urbanisation involves
Habitat loss
Habitat degradation
Habitat fragmentation
Describe remnant vegetation
Surviving patches of natural pre-urban vegetation
Describe managed vegetation
Crop or ornamental plantings maintained by humans, including exotic and native plants. Diversity and structure would not persist without constant human inputs
Describe ruderal vegetation
Early-succession, disturbance-opportunist plants independently colonising vacant growing sites or waste grounds.
Sometimes native but usually wild-breeding exotics.
List two impacts of habitat degradation
Predation (cats)
Light pollution (circadian rhythms)
List the effects of habitat fragmentation
Loss of habitat area
Reduction in patch size
Skewed representation
Change in shape
Edge effects
Isolation
What is a metapopulation
Collection of subpopulations connected by occasional dispersal.
Subpopulations can go extinct but if dispersal is possible they can be repopulated elsewhere within the metapopulation
What are sinks and sources
Sinks are subpopulations where death rates are higher than birth rate
Sources are subpopulations where immigration is higher than death rates
Describe minimum viable populations
Number of individuals required to sustain a breeding population,
This is estimated by using population viability analyses
What is needed to calculate population viability analysis
First age of female reproduction
Number of young produced
mortality rate
Carrying capacity of the environment
frequency and severity of catastrophes
What is an ecological guild
Group of species in a community sharing a similar set of resources. (Nectar-feeding birds, tree-hollow nesting animals).
Not always taxonomically related.
What is a functional group
Group of organisms that perform a similar ecosystem process in a community. (Not always taxonomically related)
