enviro unit 3 why is maintaining biodiversity worth a sustained effort

biodiversty

the variety of life in a particular ecosystem or on the entire Earth. It includes species diversity, genetic diversity, and ecosystem diversity, all of which contribute to ecosystem resilience and human well-being.

genetic diversity

the variation of genes within a species, which enhances adaptability and survival in changing environments.

why genetic diversity matters

Genetic diversity matters because it allows species to adapt to changing environments and resist diseases, ultimately ensuring the survival and resilience of ecosystems. High genetic variation increases the likelihood of beneficial traits emerging in populations. as well as reduced risk of inbreeding

threats to genetic diversity

habitat fragmentation, overharvesting or selective hunting, small population sizes leading to genetic bottlenecks

species diversity

the variety and abundance of species within an ecosystem

having two components:

species richness-the number of different species present

species evenness- how evenly individuals are distributed among these species

why species diversity matters 3 points

ecosystem stability- diverse ecosystems are more resilient to disturbances because ecological roles are spread across many species

functional diversity- different species preform different ecological roles supporting ecosystem processes

Resource availability- high species diversity often means more niches and more efficient use of resources

threats to species diversity

invasive species outcompeting native species

habitat destruction reducing available niches

pollution and climate change

ecosystem diversity

the variety of habitats, ecological communities and ecological processes within a region or across the planet

why ecosystem diversity matters

supports species and genetic diversity

provides ecosystems services

buffers environmental change

Threats to ecosystem diversity

land clearing for ag and unban development

altered fire regimes reducing habitat variety

climate change shifting ecosystem boundaries

genetic drift

when the allele frequency is detained by a random event, some alleles maybe eliminated form a population by chance and rare alleles may also become widespread

this impacts on the population

-population may crash

-reduced genetic variation leading to less chance of survival

inbreeding

when close relatives breed usually happens in a small population

impacts on population

-increase chance for population to have homozygous, as well as rare recessive alleles to become more common

-lower reproductive success

-reduce survival chance

extinction

complete disappearance of a species

genetic swamping

disruption caused by humans that brings a species that were distant close together, causing populations to inbreeding creating hybrids.

impact on population

-genetic diversity of smaller population lost

demographic variation

rate of population growth differences from the average which may affect the demographic measures such as birth rate, death rate and sex ratio

impact on population

-contributes to genetic variation over time

loss of organisms playing a key role

removal of species that are critical for the survival of other organism, these are animals or plants that play a key role in symbiosis including parasitism commensalism and mutualism

impact in population

-loss of biodiversity

-loss of genetic diversity

-loss of life

mutation and natural selection

new alleles arise in a population gradual change in species over time due to natural selection

impact on a population

-increased genetic diversity

-bigger gene pool

-better suited to the environment

-evolution

-new species

provisioning services

are tangible products humans obtain from ecosystems, they directly support human survival and economic systems

key services- food, freshwater, raw materials , medical resources, energy resources

regulating services

ecosystem process that control or moderate natural conditions keeping environments stable and habitable

key services- climate regulation, air quality regulation, water regulation and purification , pollination, erosion control, dieses and pest regulation

cultural services

are non-material benefits that ecosystems provide contributing to mental, social and spiritual wellbeing, they strengthen community identity mental health and economic ablitys’s

key services- recreation and tourism, aesthetic values, spiritual and cultural identity educational scientific research, health and wellbeing

supporting services

underlying ecological processes that make all other ecosystem services possible, they operate over long timescales, without them ecosystems collapse

key services- nutrient cycling, primary production, soil formation, habitat provision

relative dating

is dating based on the layering sequence of rocks and the evolution of life as recorded in the rocks, oldest rocks will have been deposited first and youngest last

absolute dating

absolute dating gives a numerical age usually in millions of years

radiometric dating

based on the natural radioactivity of the rocks

radiometric dating usually dates the rock around the fossil, not the fossil itself especially for older fossils

causes of mass extinction

climate change, volcanic eruptions, sea-level changes, ocean acidification, asteroid impacts changes in atmospheric composition

the 6 mass extinction

end ordovion 448-443mya 86% of organisms lost

end devonian 416-359mya 75% of organisms lost

end permian 299-251mya 96% of organisms lost

end triassic 251-299mya 80% of organisms lost

end cretaceous 65mya 76% of organisms lost

the sixth mass exction happing rn

diversification

the process where the number of species increases over time

endemism, why is it important and what are the vulnerablitys’s

-a species is endemic when it is only found in one place naturally and nowhere else

-endemic species are important as they contribute uniquely to global biodiversity because they represent evolutionary pathways found nowhere else

-endemic species are more vulnerable to habitat loss, climate change, invasive species, disease and human disturbance

random sampling

for results to be statistically valid plots should be placed randomly within the study area, the plots should then be chosen at random to minimize any bias

transect sampling

is where a measure line is laid across the area showing environmental gradient, species that are touching the line are record along the entire line or at specific points on the line

belt transect

gives information on abundance as well as presence or absence of a species

techniques for sampling animals

-indirect signs, such as poo, or prints

-spotlighting

-live trapping

-areial survay using drone technology

species richness

the number of different species present in a particular location

limitations

-ignores genetic variation

-only partly represents ecosystem diversity

-ranks all species present as equal

species evenness

the degree to which the number of individual organism are evenly divided between different species of the community

ICUN categorys

extinct-no reasonable doubt that the last individual has died (after 50 years no sightings)

extinct in the wild

critically endangered- facing an extremely high risk of extinction in the immediate future

endangered- facing a very high risk of extinction in the near future

vulnerable- facing a high risk of extinction in the wild in the median term future

near threatened- close to qualifying for a threatened category

least concern- widespread and abundant, not currently threatened