* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Maintaining Biodiversity (Conservation) PPT CXH
Survey
Document related concepts
Overexploitation wikipedia , lookup
Conservation biology wikipedia , lookup
Occupancy–abundance relationship wikipedia , lookup
Molecular ecology wikipedia , lookup
Introduced species wikipedia , lookup
Theoretical ecology wikipedia , lookup
Island restoration wikipedia , lookup
Latitudinal gradients in species diversity wikipedia , lookup
Biodiversity wikipedia , lookup
Assisted colonization wikipedia , lookup
Reconciliation ecology wikipedia , lookup
Transcript
Objectives: Maintaining Biodiversity • Conservation of animal and plant species – economic, ecological, ethical and aesthetic reasons • Benefits for agriculture in maintaining biodiversity of plants and animals • Consequences of climate change on biodiversity of plants and animals – changing patterns of agriculture and spread of disease • Conservation of endangered species in situ and ex situ – advantages and disadvantages of the two approaches • Role of botanic gardens in the ex situ conservation of rare plant species or extinct species in the wild – use of seed banks • International co-operation in species conservation – CITES; Rio Convention on Biodiversity • Environmental impact assessments – EIA’s (including biodiversity estimates) for local authority planning decisions 1 Maintaining Biodiversity: important for interdependence and survival of all living organisms Actions taken at local, national, and global levels – important for: Economic • Plants and animals as a source of food and drink – part of food chain • Clothing & footwear – cotton (plants) & leather (animals) • Drugs – morphine (analgesic) from poppies • Fuels – from biomass (ethanol, biogas) – renewable • Others – wood, paper, dyes, adhesives, oils, rubber, pesticides Ecological • Disruption of food chains – e.g. herring, salmon, bear – loss of herring causes loss of salmon and bear population • Disruption of nutrient cycles – decomposers (worms, insects, fungi, bacteria) • Loss of habitats – e.g. hedgerows • Habitat destruction – e.g. deforestation leads to climate change Ethical • Moral issues – not to interfere with nature; right to exist; moral responsibility to conserve for future generations • Religious & spiritual – coexistence & harmony with the natural world Aesthetic • Attractive environment – leisure, tourism (economic) 2 Agricultural Benefits of Biodiversity • Source of food – for humans and livestock; wider range of food sources in case of disasters (e.g. potato famine -1845 – 2 varieties of potato – destroyed by disease – caused famine) • Source of plants for cross breeding – desired characteristics ) e.g. drought & disease resistance; faster growth; nutritional characteristics; tolerance to climate change, increase yield • Source of natural predators to pests – e.g. frogs, birds, hedgehogs are predators of pests (e.g. snails) • Pollinators – insects (bees and butterflies) 3 Global Climate Change & Biodiversity Most species have adapted though evolution to survive in a particular climate due to genetic diversity and variation. Threats to a species with low genetic diversity would include – climate change, increase in pollution, new diseases, new pests Changes in the climate – e.g. temperature, rainfall, wind patterns may cause: • • • the migration of species to more suitable areas, or, may cause the extinction of some. changes in the patterns by which diseases are spread. changes in agricultural patterns Climate change occurs naturally, but recently there is consensus that climate change is a result of the impact of human activity on the environment – e.g. global warming due to the increased emissions of greenhouse gases (such as carbon dioxide, methane, NO, H2O vapour, CFC’s, deforestation) Climate change leads to: • • • • • • Increase/decrease in the temperature of the earth The melting of polar ice caps and flooding Emergence and spread of disease Change in agricultural patterns Effects on habitats Global dimming (air pollution – soot) 4 Effects on habitats Uninhabitable area becomes habitable – (and vice versa) – increase or decrease biodiversity Increase or decrease in the range of some species – range limit of Sooty Copper Butterfly has moved 60 miles north in recent decades Migration – to more suitable areas – change in species distribution – usually decrease biodiversity in areas the species migrate from, and increase biodiversity in areas they migrate to If no suitable habitat is available for a species to migrate to, or the species is a plant – which cannot migrate, or if the climate change is too fast, the species may become extinct. This decreases biodiversity – e.g. Corals die if water temperature changes by just 1 or 2 degrees 5 Climate Change and the Spread of Disease Geographical range of some insects might become greater • If area becomes warmer and wetter, mosquitoes (vector of malaria) may spread into the area and spread malaria • Spread of mosquito increases biodiversity, but the spread of the disease could reduce biodiversity • Warmer and wetter conditions encourage spread of fungal disease – could increase or decrease biodiversity Climate Change and Agricultural Patterns Changes in – temperature, rainfall, timings of seasons, frequency of flood and drought, wind patters – will affect patterns of agriculture and biodiversity • Previously unsuitable land becomes suitable for agriculture (and vice versa) – increase or decrease in biodiversity • Crops suitable for growing in new climate will become established – unsuitable crops will not grow – increase or decrease in biodiversity • Extreme weather events (e.g. flood, drought, change in timing of seasons) may cause crop failure – disrupt food chains – reduce biodiversity • Disruption of food chains and webs may occur 6 Conservation & Endangered Species Conservation refers to the attempts by humans to maintain biodiversity by preserving organisms and environments that are at risk as a result of human activity Endangered Species – Definition Species (plant and animal) that are in danger of becoming extinct, unless steps are taken to prevent it – e.g. the panda, gorilla, and black rhino. The numbers are at a critical level (i.e. too low) for continued survival of the species. Extinction – when the last member of a species dies Some species have become extinct – mammoth, dodo, sabre-toothed tiger The survival of species can be threatened for a number of reasons – including: • Climate change • New predators being introduced • Destruction of habitats (e.g. by logging; road building) – destroys food sources and shelter • Hunting • Competition for food, shelter, etc. • Pollutants • Poaching • Killed for food • Killing to prevent damage to farmland and settlements 7 • Low population E.g. Whales Endangered, in danger of extinction. main causes of whale deaths include Entanglement in fishing nets and drowning Pollutants in the sea Colliding with ships during migration Climate change affecting food sources Culling and hunting Money can be made from whales Live whales– as a tourist attraction Dead whales– food, oil, making cosmetics (using blubber) Endangered species can be protected from extinction by • Education – raising awareness • Breeding animals in captivity (e.g. zoos) and returning to natural habitat to create new population • Protecting (conserving) natural habitats • Creating artificial ecosystems (e.g. zoos, aquariums) for the species to live in • Legally protecting endangered species – prevent trapping and captivity • Prohibiting hunting of legally protected species – permits to hunt issued to certain people 8 Conservation – in situ (“on site”) In situ Conservation Involves protecting species in their natural habitat – methods include: Protected areas – national parks; nature reserves - areas are protected from developments (industrial, urban) and farming Control or prevention of species that threaten biodiversity - e.g. grey squirrels (not native) compete with native red squirrel, causing a decline in red squirrel population. Protection of habitats - e.g. conserving wetlands, by controlling water levels; coppicing (trimming trees) to conserve woodlands – allows organisms to live continuously in their natural habitat Restoration of damaged areas – e.g. a coastline polluted by an oil spill. Promoting particular species – by protecting food sources or nesting sites Legal protection for endangered species – prevent hunting, logging; countries may not agree Minimise human impact on the natural environment Advantages All required conditions already present; no special provisions required – well adapted Both species and habitat are conserved; less disruptive; chance of population recovery is greater Disadvantages Difficult to control – poaching, predators, climate change Species not accepted by other members of the species already present if they have been reintroduced. 9 Conservation parks/nature reserves /SSSI’s Choosing of reserve or park • • • How many species represented; prevailing environmental conditions Adequacy – is the area large enough to provide for long-term survival Representativeness - Is there a full range of diversity within each species and set of environmental conditions Advantages of designating an area; • • • • • • • • Conservation of plants and animals in their natural environment Permanent protection of biodiversity and ecosystems Protects elements of natural and cultural heritage Facilitates management of designated area – ensuring ecological integrity Ecologically sustainable land use and associated economic benefits Facilitates scientific research Secure environmental future Enjoyment of natural environment Reserve should meet the needs of indigenous people (hunting; religious; spiritual) – conflict may arise if not considered • • • • protected animals raiding crops continued hunting of protected species for food illegal harvesting of timber and other plant products tourists feeding protected animals or leaving litter 10 Ex situ (“off site”) Conservation Involves removing part of the population from a threatened habitat, and placing it in a new location. Used as a last resort • Relocation of species to safer areas • Breeding species in captivity and reintroducing them into the wild – carried out in animal sanctuaries, and zoos. • Botanic gardens – controlled environments to conserve rare plants and reintroduce them into the wild. • Seed (sperm) banks – frozen (or dried) seeds are stored in seed banks for long periods of time, without losing their fertility. Provides a useful source of seeds if natural reserves are destroyed – in famine conditions. Advantages (reverse arguments for in the wild) • Protect individual animals or plants in a controlled environment – protected from factors causing endangerment • Predation and hunting can be monitored and managed easily; monitor health; treat disease; incubate eggs artificially; hand rear young – reduce mortality; manipulate breeding (hormones, artificial insemination, artificial selection); protect from predation, hunters; reduce competition between individuals / species • Used to reintroduce species that have migrated to other areas • Sperm (frozen) from one male – used to fertilise a large number of females; easy transport; maintains genetic diversity – by importing sperm from another population 11 • Study rare biological organisms at close range Disadvantages • Only a small number of individuals can be catered for. • Difficult and expensive to create and sustain the right environment. • Less successful than in situ methods – many species do not breed successfully in captivity. • Species cannot adapt when introduced to their natural habitat • Problems of acceptance of introduced member by existing members Possible solutions • • • • • Choose individuals from different areas – maintains / increases genetic variation (gene pool) Choose unrelated individuals - reduces risk of inbreeding between related individuals Less risk of losing all individuals due to environmental change (e.g. disease) House in separate centres – less risk of losing all individuals due to natural disasters, human action Select higher proportion of females Preserving of species – long term measures • • • • • • • Legal protection Ban cause of endangerment Protected areas – sanctuaries, reserves – provide breeding sites Prevent habitat destruction Monitoring – tagging Education – to public on importance of the species 12 Sperm and egg banks; seed banks Inbreeding depression is a disadvantage in captive breeding - happens when closely related individuals – e.g. a brother and a sister, mate. Offspring are much less likely to survive and reproduce successfully – due to an increased chance of inheriting harmful recessive alleles from both parents – an offspring with homozygous recessive alleles may lack vital gene products and be less likely to survive and reproduce successfully. Zoos keep detailed records detailing the family trees of all their animals – allowing them to ensure that individuals that mate are as distantly related as possible. Zoos often swap animals with other zoos to promote outbreeding, to maintain genetic diversity of the captive populations Success of release of bred species Healthy before release Adequate food supply Protected reserve Method to monitor population Raise public awareness Prepare animals for survival in the wild Gradual introduction – e.g. via semi-wild habitat 13 Drying and freezing seeds for seed banks • • • • • • • • Inhibits germination Slows down enzymes and rate of decay - prolongs seed survival Drying reduces damage by freezing effect Tested regularly (every 5 years) – to check seed viability/germination success Allows new seeds to be produced - stored seeds may need replacing due to decay/death Seed banks (and zoos) - maintain endangered species in a protected environment – giving protection from predators/poachers Captive breeding programmes are used to reintroduce species into wild; enable scientific research and education. Seed banks (and sperm banks) occupy little space and require little attention 14 CITES (Commission on International Trade in Endangered Species) A number of Governments are signatories to a world-wide programme to protect endangered species by conservation of biological diversity – addresses illegal poaching and illegal trade in endangered species. CITES, agreed in 1973. Some countries do not support conservation programmes. Aims of CITES: • International cooperation in regulating trade and monitoring international trade in selected species of plants and animals • Member countries agree to make it illegal to kill endangered species • Limiting trade in endangered species through licensing • Illegal to trade in products made form endangered species Black rhino - placed on Appendix 1 of CITES. Since then, their number have stabilised and even increased. Endangered due to poaching ; destruction of habitat; shot to protect farmland and settlements; killed for meat and horn Signatory countries agree – illegal to kill/poach rhino Ban on trade in horns/hide Increased cooperation between countries Permits/licences issued to certain people Education; raising awareness Monitor habitats and species on a daily basis (wardens) Legal action (imprisonment, fines, etc) 15 Enforcement of international agreements (e.g. CITES) - problems Not all governments agree with trade policies Some governments corrupt Difficult to stop poaching and hunting in the wild Limited resources or will to police areas effectively Exported species or products may be exported under false documentation or smuggled • Difficult to identify endangered species – e.g. by custom officials • • • • • 16 Environmental Impact Assessment (EIA) and studies of biodiversity In local planning and development it is important to assess the impact of a proposed development (e.g. shopping centre, power station) on the environment and biodiversity – otherwise, there may be destruction of environmentally sensitive habitats that are rich in biodiversity. Need to conserve species that are already protected by law. EIA ensures that decision makers consider the environmental impact of development projects and how projects are to proceed. • To estimate biodiversity on the project site and evaluate how the development might affect biodiversity • To consider impact on wildlife • To identify possible destruction of environmentally sensitive habitats that are rich in biodiversity or where there are rare species • To legally protect particular species of animals and plants 17 If the need to conserve or protect is identified – need to consider whether development should be stopped or whether other measures could be taken to protect the species – e.g. • Providing other suitable (similar) habitats close to the site – e.g. extension of mudflats on shores for the wading and migrating birds that used the habitats that were lost to development. Successful in attracting other bird species as well • Species of animals and plants may be protected by law • Translocation of species • Laws to protect endangered species • Estimate biodiversity on the development site and evaluating the effect of the development on biodiversity 18 Objection to EIA studies An EIA study needs to physically investigate the habitat – this may possibly leading to the destruction of habitats and disturbance of the species in their habitats May cause more disruption than the development itself Damage to environment/ecosystem Habitats best left alone (left to nature) Rare species may be discovered – people stealing species for collectors Need to consider the following in EIA: Water resources Drainage Pollution Damage & disturbance to habitat Loss of species and loss of species diversity Loss of habitat 19 Biodiversity and importance of genetic diversity Genetic diversity makes it possible for a species to evolve Without genetic diversity plant and animals will not be able to adapt to changes in the environment Threats: • Climate change • Increase in the levels of pollution • New disease • Arrival of new pests Humans activity affects the genetic diversity of natural habitats. • Clearing of natural vegetation – reduces size of natural habitat – reduces population size of the species in that habitat; hunting or killing for protection; inadvertent introduction of predators and competitors • Reduces overall gene pool for the species • Decreases genetic variation and hence the ability of the species to adapt and evolve Monoculture and selective breeding reduces variation and genetic diversity of domesticated animals and plants. Leads to extinction of some varieties within a species –termed genetic erosion 20