Sustainability Flashcards
What is the population size?
Total number of organisms of a certain species in a habitat.
What is the carrying capacity?
The ability of an ecosystem to carry max stable population size.
Determined by limiting factors.
What do k, a, b and c mean on a population growth curve?
k = carrying capacity
a = lag phase, acclimatise to habitat
b = log phase, high reproduction as adapted
c = stationary phase - carrying capacity
What does it mean to be r or k selected?
r selected - use growth rate to survive, high reproduction, short life, unstable environment eg. bacteria
k selected - maintain carrying capacity, long life, high parental care eg. mammals
What is a predator-prey relationship?
Population of prey increases, predator also as more food, so prey decreases. Negative feedback.
Describe interspecific competition.
Resource availability linked to both populations - insufficient energy so decrease population sizes. Also affects species distribution - competitive exclusion principle.
What is interspecific competition?
Between different species for the same resources.
What is intraspecific competition?
Between organisms of the same species for the same resources.
What is conservation and preservation?
Protect ecosystem so stays the same vs managing the ecosystem so resources are reused.
Why is it important to conserve habitats?
- ethical - right to exist, not be extinct, future generations
- economic - day to day life, trade v important
- social - future generations, appreciate natural processes
What are methods of sustainability for timber production?
Coppicing preserves habitats
Selective felling - disease/unwanted cut down and replanted
Rotational felling - stops leaching
Strip felling
Leave some trees as standards
What are methods of sustainable fishing?
Fishing quotas - species and amount
EU policy - amounts for each country
Mesh size limit - less smaller species and babies caught
Why is sustainability important?
Human activities depleted resources, now needs protection from us. Conflict with preservation and needs.
eg. Galapagos islands - non native animals killed native populations and increased competition. Eradication programmes, border control.
