the impact of human activity on biodiversity

biodiversity

• variety of living organisms present in an area

• includes all the different plants, animals, fungi, microorganism species worldwide

what has correlated with the decrease in biodiversity

• increasing human pop

• suggests activities of human pop are contributing to an increase in extinction rates above natural level and local and global reduction in biodiversity

main problems affecting biodiversity due to increase in human pop

• deforestation

• agriculture

• climate change

how does deforestation affect biodiversity

• decreases species biodiversity

• destroys habitats for animals, plants= further loss of species

• decreased population of species results in further loss of alleles and potential loss of further species

• increase in soil erosion, decreases nutrients available in soil, so less plants survive

how does agriculture affect biodiversity

• removal of hedgerows reduces biodiversity

• use of chemical pesticides and herbicides (loss of species diversity + reduction of genetic diversity within species

• potential loss loss of pollinators due to pesticides= reduction in numbers/ loss of associated plant species

how does monoculture lead to reduction in biodiversity

• only one plant species present and fewer animal species can therefore be supported

• selective breeding, reduces genetic biodiversity

• reduction in species biodiversity/ animals have low genetic diversity

• lack of habitats reduces animals species diversity

green house effect

• greenhouse gases in the atmosphere absorb most of energy radiated by earth

• they then re-radiate this energy back to earth rather than letting it leave the earth’s atmosphere, so the more there are, the warmer earth is

further changes due to greenhouse gases emissions

• global surface temp increases

• global water cycle changes with increases in disparity in wet and dry regions

• oceans will continue to warm which affects circulation patterns

• decrease in artic sea ice cover

• sea level will rise

how melting of polar ice caps and rising sea levels impact biodiversity

• climate change which impacts people and ecosystems

• further risk escalate with every degree of warming

how temperature increase and changing patterns of rainfall impact biodiversity

• changing distributions of plant species eg xerophytes more likely to thrive

• insect life cycles and populations will change, impact on whole ecosystem

typical features of habitats for environments with low biodiversity

• number of successful species= few

• nature of environment= stressful with few niches

• adaptation of species to environment= relatively few species live in the habitat, often with specific adaptations for environment

• types of food webs= relatively simple

• effect of change to ecosystem= major affect

typical features of habitats for environments with high biodiversity

• number of successful species= larger number

• nature of environment= not stressful with niches

• adaptation of species to environment= many species with specific adaptations

• types of food webs= complex

• effect of change to ecosystem= often relatively small effect

how does climate change affect biodiversity

• melting of ice caps and rising sea levels will impact biodiversity

• extinction of artic animals and plants

• migration of other animals which changes distribution of species

• flooding of low lying land= fewer habitats