Biodiversity Flashcards
What is biodiversity?
The variety of living organisms in an area
What is a habitat?
The place where an organism lives
What is a community?
All the populations of different species in a habitat
What is species richness?
A measure of the number of different species in a community
What is species evenness?
Number of individuals of each species
What is a limitation of species richness?
It doesn’t take into account the number of individuals of each species
Simpsons index of biodiversity?
Takes into account both species richness and evenness
Gives an idea of the number of each species relative to population size
Small and large populations are treated differently
Reasons for maintaining biodiversity?
Moral and ethical
Ecological- increases the stability of ecosystems
Environmental
Economic- range of organisms contribute to medicine, ecotourism, science
Aesthetic- visual effects
Agricultural
What are 2 direct impacts of farming?
Removal of hedgerows
Monoculture
What does the removal of hedgerows do?
Increases the area of farmland by turning lots of small fields into fewer large fields
Destroys habitats- some species could lose their shelter and food source- species will die/ be forced to migrate
What is monoculture?
Farmers have fields only containing one type of plant
A single type of plant reduces biodiversity and will support fewer organisms (as a habitat/food source) which further reduces biodiversity
Indirect impacts of farming?
Pesticides
Escape of silage stores and slurry into water sources
Pesticides?
Chemicals that kill pests that feed on crops
Reduces diversity by directly killing the pests
Any species that feed on the pests will lose a food source- their numbers could decrease too
Escape of silage stores and slurry into water sources?
Pollution- decreases O2 levels
How can biodiversity be increased?
Mature native trees- providing shade and shelter
Pond with varying depth
Species rich grassland
Hedgerows
Water trough
Conservation measures for increasing opportunities for species diversity?
Biological control rather than pesticides
Crop rotations
Natural fertilisers
Reduced risk of eutrophication and slower release to reduce competition
Conservation measures for increasing ecosystem diversity?
Replanting/maintaining hedgerows
Digging ponds
Producing hay from natural meadows (rather than grass)
What is the definition of ecology?
The study of inter-relationships between organisms and their environments
What is an ecosystem?
The living and non-living (abiotic and biotic) parts within an area
Populations?
Group of individuals of one species
Community?
Population of different species living and interacting in a particular place at the same time
Habitat?
The place where an organism lives- characterised by physical conditions
Ecological niche?
Describes how an organism fits within an environment
No 2 species can occupy the same niche (competitive exclusion principle)
Microhabitat?
Part of a habitat e.g. mud at the bottom of a stream
Biosphere/biomes?
A global ecosystem composed of living organisms and the non-living factors from which they derive energy and nutrients
Abiotic/biotic factors?
Non-living (abiotic) and living (biotic) components of an ecosystem
