Species Extinction Flashcards
EG
Evil Quartet/HIPPO
Habitat Loss, Overexploitation, Introduced Species, Extinction, Pollution, Human Population and Overharvesting (Ceballos et al., 2017)
climate change is a social issue
9/10 prescriptions are based on plants -> no ecosystem services will remain, yet these are essential to humanity
extinction rate figures
From 1900 - 69 mammals, 80 birds, 24 reptiles, 146 amphibians and 158 fish went extinct (Ceballos et al., 2015)
177 different mammal species -> lost 40% of their range while ½ had lost 80% (1900-2015) (Ceballos et al., 2015).
Anthropocene - sixth mass extinction (Barnosky et al., 2011)
-> in 100 years we lost 200 vertebrates, should have taken 10,000yrs = biological annihilation and species loss (Ceballos et al., 2017).
Habitat Loss ->
transformation of the earth’s surface in a way which leads to the production of environments species can no longer tolerate -> biodiversity is being ordered and commericalised parts of the habitat.
Overexploitation
species are often targeted for commercial value e.g. sharks for shark fin soup or bluefin tuna -> often leads to illegal purchasing -> or for health reasons e.g. 1/20 forest species in sub-Saharan Africa are at risk of overexploitation -> locals need to consume the organisms to meet protein requirements.
Tipping points
soil exploitation -> lead to permanent environmental damage to the region preventing future regeneration (Lamb et al., 2005)
Introduced species
evolutionary colonisation/globalisation led to species being introduced worldwide -> e.g. ballast water - ships introducing invasive species to new regions.
Chains of extinction -> understudied region
one extinction of a species can lead to further extinctions e.g. passenger pigeon led to the extinction of the parasitic mite as they lived on the pigeons and e.g. northern pike in N. Scandinavia acting as a control on carpe populations (Bellard et al., 2019)
Extinction of Oceania by the British
1800 bird species have been lost (Ceballos et al., 2015)
Climate Change direct impacts
phenology-based changes (activity of species) -> range shifts -> using species-area relationship modelling = 15-37% of species to go extinct by 2050 (Thomas et al., 2004).
Pollution
elemental pollution (N and K), eutrophication (limiting plant growth and causing anoxic dead zones as the algae bloom using all the O) -> no. of dead zones has increased overtime and is based across intensive agricultural systems e.g. eastern N.A.
Drivers of extinction
interactions between C.C. impacts e.g. forest fires then lead to overhunting as the area is more vulnerable = does not lead to secondary succession as hunting limits recovery
captive breeding -> problematic
can the species reacclimatise, have they been screened health wise, do diseases need to be removed from the environment -> farmers avoiding the use of herbicides as they may have wider negative impacts (Griffiths and Pavajeau, 2008)
captive breeding example
Global amphibian crisis -> captive breeding as it is cheap since they breed rapidly -> 110 species considered -> 52 could not be reintroduced, of the 58 that were reintroduced 18 bred successfully but only 13 produced self-sufficient populations (Griffiths and Pavajeau, 2008)
making captive breeding more effective
pilot programmes (Griffiths and Pavajeau, 2008)
Insitu conservation
building fences and producing protected areas = change the behaviour of people who live within the regions -> private NGOs and predominantly the state has spearhead this -> 17% of the earth’s surface is currently a nature reserve
de-extinction programmes - technofix solution
should not be concerned about extinction
taking elephant DNA working back to find the nucleotide differences with mammoths and then using elephants to breed them (Ceballos et al., 2017)
insitu conservation controversy
violent dispossession of land from indigenous communities
effectiveness of insitu conservation
ineffective for the scale of action/change required -> histories of them are controversial -> 0.01% of coral reefs actually protected -> 83% of plants likely to go extinct in New Caledonia are not in protected regions -> proposed that redevelopment could overcome these issues in Australia the plan would increase protection from 18 to 54 species (Fuller et al., 2010)
insitu conservation example
Chagos Marine Protected Area -> Indian Ocean -> 2nd largest protected marine area (545,000km2) = biological resource for the UK
coexistence conservation
matrix conservation without reserves -> modifying the landscape or land use practices to benefit humanity but not impact organisms/environment element of land sharing/sparing e.g. regrowing trees after deforestation but still have impacts (Putz et al., 2001)
coexistence conservation examples (1)
reduced impact logging -> selective cultivation of individual trees = economic value but minimizes the no. of trees chopped/area = better protection biodiversity -> pick areas which will have lower biodiversity impacts, plan the direction of fall, reduce the need for deforestation for roads (Putz et al., 2001; Putz et al., 2008)
coexistence conservation examples (2)
Agroforestry -> tropical rainforests -> involves incorporating species into the agricultural system (Schroth et al., 2004) -> can be conducted across a range of scales -> is effective leading to them holding 2/3 of the species in surrounding reserve regions – lots being saved (Bhagwat, 2008) -> allow species to move between remaining biodiversity sites (Philpott et al., 2008)
plantations
Planting rapid, growth pioneer species -> maintain a canopy cover to protect the soil but facilitate secondary succession -> relies on native species being able to overturn fragmentation (Lamb et al., 2005).
2500 trees planted per hectare -> interspecific competition allowed to take place and produce a selective canopy cover -> more expensive -> used in the Central Amazon with 160 species planted over mining exhausted topsoil -> 130 yrs later the region has recovered (Lamb et al., 2005).
Plantations designed specifically to meet biodiversity demands -> prioritises ecosystem services (Lamb et al., 2005)
Ethnoecology
hybrid ontologies e.g. Uluru-Kata Tjuta National Park -> Aboriginals using scientific methods to identify flora and fauna but using their protection methods (Stevens, 1997)
Market-based approaches
utilitarian valuing -> commodification of the environment to save it -> contradictory in nature (McCauley, 2006)
Finca Sante Fe, Costa Rica -> coffee plantation = native bees were ineffective decrease in yields by 60,000x -> coffee to pineapple cultivation -> no consideration for ecological impacts (McCauley, 2006)
Lake Victoria, Africa -> invasion of Nile with perch impacting biodiversity -> increased profits for fishermen so not considered a problem (McCauley, 2006)
discourse on co2
biodiversity considered a secondary issue to lowering CO2 e.g. deforestation halted in Tanzania, Pemba Islands -> continued hunting of animals e.g. Pemba flying foxes (Caro and Mulder, 2016)
market-incentives with local communities -> demand certain crops for higher value (Lamb et al., 2005)
Silviculture -> planting canopy shading trees with cash crops which mature -> native species being protected while economic incentives being produced (Lamb et al., 2005)
Ecotourism
indigenous communities being financially independent -> brings in revenue -> focus is on people over the environment (Stevens, 1997)
