Populations/ecosystems and human impact

planetary boundary

a threshold value for a global process that is affected by human activity

crossing these boundaries could result in abrupt or irreversible environmental change

biodiversity

a measure of both the number of species present (species richness) and the number of individuals within a species

define endangered species

a species at risk from extinction

extinction

a species which has no living individuals (the extinction rate has increased due to humans)

conservation

the protection, preservation, management and restoration of natural habitats and their ecological communities, to enhance biodiversity while allowing for suitable human activity

reasons for species becoming endangered or extinct (natural, human-induced)

natural selection, deforestation, loss of hedgerows, habitat destruction, pollution, hunting and collecting, competition from domestic animals

schemes to enhance biodiversity

protecting habitats via SSSIs and nature reserves - legal protection

restrictions on trade - imports and exports are all licensed, reduces illegal trade

zoo breeding programmes - ensures there is a healthy number of individuals

sperm/seed banks - act as ‘insurance policy’, can be used in breeding programmes

reintroductions - after species have become extinct, they are reintroduced

agricultural exploitation

the practices used to intensify and improve the efficiency of food production to meet the needs of the growing population often at the cost of biodiversity and the environment

MORE NEEDED ON HUMAN IMPACT - LOOK AT SUMMER WORK

ecology

study of the relationships between living organisms, including humans, and their physical environment

ecosystem

a balanced biological system where all the organisms (community) and the non-living components interact in a particular location. There is energy flow and nutrient cycling.

community

interacting populations of two or more species in the same habitat at the same time

habitat

the place where the organism lives

population

a group of organisms of a single species, interbreeding and occupying a particular habitat at the same time

environment

the factors in a habitat that affect an organism - living and non-living

abiotic

a part of the environment of an organism that is non-living e.g O₂ availability, temperature, pH

biotic

a part of the environment of an organism that is living e.g pathogens, predation, parasitism, competition

niche

the role and position of an organism within its environment, including all the interactions with the biotic and abiotic factors of its environment