challenges to biodiversity Flashcards
biodiversity
variability among living organisms from all sources. includes diversity within and between species and ecosystems.
invasive species
species introduced into an area outside their native range and can cause or has caused harm in that new area.
what do invasive species do that is bad?
they outcompete the native species for resources or habit, altering the structure and potentially leading to extinction.
what’s an example of a native species:
Kudzu and prickly pair.
problems with introducing a species;
numerous, subtle, idiosyncratic.
not sure if they are effective as experiments into their effectiveness are rare.
there’s a time lag between spread and their effects.
2nd greatest cause of species endangerment as they can become invasive.
what are the impacts of invasive species on biodiversity?
predation.
herbivory.
parasites.
competition.
hybridisation.
predation
invaders effect native species, reducing/eliminating them.
causes community level changes.
competition
between native and introduced species.
herbivory
devastates native plants.
hybridisation
infertile hybrids created.
what are some of the characteristics of invasive species?
fast growing,
rapid reproduction,
high dispersal ability,
phenotypic ability,
tolerance of conditions,
live off wide range of foods.
what is urbanisation?
a population shift from rural to urban areas.
what happened in 2007?
there was a turning point in which 50% of the global population lived in cities.
what did the UN predict to happen by 2050?
64% of the developed world and 86% of the developing world will be in cities.
what are 5 effects of urbanisation?
urban heat islands,
ecological degradation,
eutrophication,
light pollution,
health.
what are urban heat islands?
when industrial and urban areas produce and retain heat. this heat is then absorbed into buildings.
as there are no plants to absorb the heat, it leads to an increase in surface temps.
what leads to ecological degradation?
extinction, land-use change, ecosystem processes and ecosystem services.
what does ecological degradation lead to?
highly fragmented, heterogenous and altered environments.
it’s also associated with a decline in animal and plant richness, abundance and diversity.
what is eutrophication?
when rain filters down pollutanta onto ground below. chemical flow into rivers, streams and oceans, causing decline in water quality and damages to marine ecosystems.
it eventually leads to algal bloom.
impacts of light pollution:
compromises health,
disrupts ecosystems,
spoils aesthetic environment,
alters circadian rhythm.
how does urbanisation affect health?
poor urban areas suffer more disease, injury and premature death.
chronic illnesses are also more prevalent.
urban avoiders
sensitive to human habitat disturbance.
