conservation Flashcards
what is a population
a group of individuals of the same species that are interbreeding freely
what are populations defined by
physical boundaries
what is interspecific competition
the competition for resources between individuals of different species
what is intraspecific competition
competition for resources between members of the same population/species
what are the 3 important concepts of populations
populations have structure
they can expand and contract
they are regulated
what is distribution shaped by
ecology of species
what are the 3 types of distribution
regular/uniform
clumped
random
what defines uniform distribution
the organisms are distributed in regular repeating patterns e.g. planted crops
what defines clumped distribution
the organisms are found in clusters
the resources are also patchy protection form predation - lookout for predators is shared amongst the individuals
what defines random distribution
no underlying resource or predation pattern
is the density of organisms predictable
yes - from factors such as distribution of resources
what does the logistic model of population growth show
that there is a threshold - either the environment or the population itself constrains the population
what are the 2 ways that can force the population to level out
density dependent regulation - a function of the population itself
density independent regulation - environment constrains population
what is a population
an association of populations occupying the same space - they can be any size and are defined by habitat boundaries
species richness
the variety of species within a confined area
.………. …………… varies with latitude (bigger latitude, nearer the equator) and altitude (height from sea level)
species richness
inc latitude - inc species
inc altitude - dec species
what are human pressures on communities
- Pollution
- Habitat loss
- Exploitation of populations
- Species introductions
what are the 2 types of pollution
toxic
nutrient enrichment
what is toxic pollution
acts by poisoning
• Affects total number of organisms present
• may reduce number of species
• can cause total community loss
what is nutrient enrichment pollution
e.g.
• sewage
• food processing waste
• farm silage effluent etc.
what are the effects of habitat loss
- reduced community size
- fragmented populations
- prey populations reduced below threshold to support predators
habitat fragmentation reduces the number of ………. ………..of the food chain
all levels
what are the effects of overexploitation
major reduction in population e.g. overfishing
what are the effects of introducing a new species
- compete with native species
- prey upon native species
- hybridise with native species – red deer and sika deer
- adjust habitats
