International conservation and restoring degraded habitats

Non-governmental organisations, such as the World Wide Fund for Nature (WWF) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), play important roles in local and global conservation.

An important part of conservation is restoring degraded habitats so that they may support a flourishing community with high biodiversity.



NGOs in local and global conservation
CITES - Convention on International Trade in Endangered Species of Wild Fauna and Flora

• a signed agreement to control trade of endangered species and their products

            e.g.: fur, skin, ivory,...

• considers evidence presented to it about endangered species

           ---> assigns to 1 of 3 appendices with given criteria and trading regulations

• sometimes CITES listings don't benefit the species:

          - species trade becomes illegal --> price for products increase --> more trade occurs

WWF - World Wide Fund for Nature - the #1 campaigning group for wildlife

• "to stop degradation of the planet's natural environments
• build future where humans and nature live in harmony."

- funds conservation projects

- publicises environmental issues and campaigns

Restoring degraded habitats 

so they may support a flourishing community with high biodiversity

- degradation: human activity or natural catastrophe

- restoration:

• e.g.: small scale - farmer plants trees on land that is no longer needed for food production
• e.g.: replanting mangrove forests

             - provides protection against storm damage, flooding, rising sea levels 

             - important nursery gounds for young fish

                  Planting trees in Haiti

             - after deforestation, soil erosion,.... 

                  Eden project, UK

             - reclamation project

             - educated people in plant biodiversity and the need for conservation

18.3 Conservation Maintaining biodiversity is important for many reasons. Actions to maintain biodiversity must be taken at local, national and global levels.   It is important to conserve ecosystems as well as individual species. a) discuss the threats to the biodiversity of aquatic and terrestrial ecosystems (see 18.1b)  b) discuss the reasons for the need to maintain biodiversity  c) discuss methods of protecting endangered species, including the roles of zoos, botanic gardens, conserved areas (national parks and marine parks), ‘frozen zoos’ and seed banks  d) discuss methods of assisted reproduction, including IVF, embryo transfer and surrogacy, used in the conservation of endangered mammals  e) discuss the use of culling and contraceptive methods to prevent overpopulation of protected and non-protected species  f) use examples to explain the reasons for controlling alien species  g) discuss the roles of non-governmental organisations, such as the World Wide Fund for Nature (WWF) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), in local and global conservation  h) outline how degraded habitats may be restored with reference to local or regional examples

Controlling alien species

Alien or invasive species are those that have moved from one ecosystem to another where they were previously unknown.









Causes:

• humans trading animals and plants
• introduced as biological control agents to control pests
• escapees
• animals introduced for sport

Effects:

• become successful predators
• compete effectively with native organisms of the same niche, pushing them to extinction
• introduce diseases --> spread to organisms that have been exposed to that pathogen

Examples:

Water hyacinth: 

• grow successfully --> covers huge areas of land and water

         ---> blocks sunlight from reaching native aquatic plants

         ---> reduce concentration of oxygen in the water

         ---> kills fish

• habitat for mosquito larvae

Japanese knotweed:

• vigorous root systems --> forces its way through concrete and damaged buildings, roads, walls
• outcompetes native species by reducing space where they grow

Cane toad:

• introduced to Queensland, Australia from Hawaii in 1935
• aim: control insect pest of cane sugar
• the cane toad bred rapidly, spreading across the country
• has few predators in Australia as the toad produces a toxing that kills animals that eat it

Red lionfish:

• native to seas of South-East Asia
• escapee from the Caribbean
• becomes a predator in its new environment; eats local species of coral reefs

Indian mongoose:

• introduced to Jamaica in 1872
• aim: control rats in cane fields
• the mongoose did so well it became a predator to other animal

18.3 Conservation Maintaining biodiversity is important for many reasons. Actions to maintain biodiversity must be taken at local, national and global levels.   It is important to conserve ecosystems as well as individual species. a) discuss the threats to the biodiversity of aquatic and terrestrial ecosystems (see 18.1b)  b) discuss the reasons for the need to maintain biodiversity  c) discuss methods of protecting endangered species, including the roles of zoos, botanic gardens, conserved areas (national parks and marine parks), ‘frozen zoos’ and seed banks  d) discuss methods of assisted reproduction, including IVF, embryo transfer and surrogacy, used in the conservation of endangered mammals  e) discuss the use of culling and contraceptive methods to prevent overpopulation of protected and non-protected species  f) use examples to explain the reasons for controlling alien species  g) discuss the roles of non-governmental organisations, such as the World Wide Fund for Nature (WWF) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), in local and global conservation  h) outline how degraded habitats may be restored with reference to local or regional examples

Assisted reproduction and problems of successful conservation

Assisted reproduction is a solution to the problem of inbreeding.









Assisted reproduction

Sperm bank - freezing collected semen

Sperm samples are collected from males, checked for sperm activity and then diluted with a medium containing a buffer solution and albumen. Small volumes of semen are put into straws (thin tubes) and are stored in liquid nitrogen at -196 degrees Celcius.




Artificial insemination (IA)
- a straw is placed into warm water to activate sperm
- the straw is placed into a catheter --> inserted into the vagina, through the cervis, into the uterus
- resulting embryos are 'flushed out' of the uterus
- embryo transfer: embryo gets transferred to other females (surrogate mothers) that had had hormonal treatment to prepare for pregnancy

• protects endangered animals from pregnancy
• the endangered female becomes the source of many offspring

In-vitro fertilisation (IVF)

- oocyte collected by inserting needle into ovaries --> withdraw mature follicles

- oocyte cultured in a medium --> mixed with semen

- resulting zygotes divide --> form embryos --> cultured for several days

- embryo is placed into the mother or into several females of same or different species

Problems of successful conservation
- organism is saved from extinction has increased in numbers beyond the capacity of the ecosystem to sustain such numbers.
- culling: aim - to reduce numbers

• transferring animals to places with small populations
• birth control: chemical contraceptives: vaccine that targets the region surrounding layer of glycoprotein around egg (vaccine produces immune response --> produce antibodies against glycoproteins)

                   - antibodies attach to glycoprotein and block sperms from fertilising egg

                   - 90% success rate

18.3 Conservation Maintaining biodiversity is important for many reasons. Actions to maintain biodiversity must be taken at local, national and global levels.   It is important to conserve ecosystems as well as individual species. a) discuss the threats to the biodiversity of aquatic and terrestrial ecosystems (see 18.1b)  b) discuss the reasons for the need to maintain biodiversity  c) discuss methods of protecting endangered species, including the roles of zoos, botanic gardens, conserved areas (national parks and marine parks), ‘frozen zoos’ and seed banks  d) discuss methods of assisted reproduction, including IVF, embryo transfer and surrogacy, used in the conservation of endangered mammals  e) discuss the use of culling and contraceptive methods to prevent overpopulation of protected and non-protected species  f) use examples to explain the reasons for controlling alien species  g) discuss the roles of non-governmental organisations, such as the World Wide Fund for Nature (WWF) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), in local and global conservation  h) outline how degraded habitats may be restored with reference to local or regional examples

Protecting endangered species

An endangered species is one that is threatened with extinction. The best way to conserve any species is to keep it in its natural habitat.











National parks - conservation areas with strict limits to protect wildlife and the environment

• alien animal species are removed; invasive plants are dug up and destroyed
• restriction on human activities; tourism raises money and awareness
• marine parks: conserve fragile ecosystems and areas at risk of overfishing, dredging, pollution

Zoos - protection for endangered and vulnerable species; provides enjoyment and interest for visitors

• captive breeding programmes: help reintroduce animals to their natural habitats
• problems: 

            - inbreeding, when breeding animals from a small population

            - some captive bred animals don't know how to avoid predators, find food, rear young

            - animals refuse to breed in captivity; hard to recreate suitable habitat --> animal can't                   be returned to the wild

• for research: understand breeding habits, habitats, how to increase genetic diversity, solution in inbreeding problems

Botanic gardens

• seeds/cuttings are collected from species in the wild and are used to build up a population of plants that can one day be reintroduced into the wild
• sample of cells grown on agar (in sterile conditions) 

          --> cells divide by mitosis to give a mass of cells which can be cloned 

          --> cells transferred to a medium contain an appropriate mixture of plant hormones 

          --> grow stems, roots 

          --> transferred to soil

Roles of botanic gardens:

• protect endangered plant species
• research methods of reproduction and growth
• research conservation methods
• reintroduce species to habitats
• educate the public (roles of plants in the cosystem; economic value)

Frozen zoo

Holds genetic resoures for endangered species in the form of eggs, sperms and embryos

• more genetic diversity
• genetic material is kept for longer periods of time

*eggs are more difficult to freeze as they are more likely damaged by freezing and thawing

Seed banks

Seeds of the same species are collected from different sites, so that the stored samples contain a good proportion of the total gene pool of that species --> genetic diversity is not lost

"Recalcitrant" seeds cannot be dried and frozen. These include seeds of economically important tropical species e.g.: rubber, coffee, cocoa. The only ways to keep the genetic diversity of these species are to

• collect seeds and grow successive generations of plants 
• keep as tissue culture

* seeds can be stored for a long time with little maintenance, anywhere in the world

* seeds are germinated every few years to:

• check if seeds are still viable
• produce new plants to collect new seeds
• find conditions for breaking seed dormancy

18.3 Conservation Maintaining biodiversity is important for many reasons. Actions to maintain biodiversity must be taken at local, national and global levels.   It is important to conserve ecosystems as well as individual species. a) discuss the threats to the biodiversity of aquatic and terrestrial ecosystems (see 18.1b)  b) discuss the reasons for the need to maintain biodiversity  c) discuss methods of protecting endangered species, including the roles of zoos, botanic gardens, conserved areas (national parks and marine parks), ‘frozen zoos’ and seed banks  d) discuss methods of assisted reproduction, including IVF, embryo transfer and surrogacy, used in the conservation of endangered mammals  e) discuss the use of culling and contraceptive methods to prevent overpopulation of protected and non-protected species  f) use examples to explain the reasons for controlling alien species  g) discuss the roles of non-governmental organisations, such as the World Wide Fund for Nature (WWF) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), in local and global conservation  h) outline how degraded habitats may be restored with reference to local or regional examples

need to maintain biodiversity

For some people, the safety of biodiversity is simply a moral or ethical issue. For others it may be for ecological reasons, aesthetic reasons, social and commercial reasons or for other services.







Ecological reasons

• the higher the diversity of an ecosystem, the less likely it is to be unbalanced by changes in conditions or threats such as pollution
• ecosystems are of direct value to humans

                  e.g.: - antibiotics from fungi, bacteria

                          - anti-cancer drugs isolated from plants

Aesthetic reasons

• people gain pleasure from studying or just appreciating the natural work (inspiration to artists, poets, photographers,...)
• ecotourism: wildlife = source of income --> provides employment; contributes to economies

Social and commercial reasons

• wild plants species that are resistant to large numbers of disease of rice known as bacterial blight --> interbreed with cultivated rice (crop plants don't hae much genetic diversity as their wild relatives, because it has been lost by selective breeding for uniform, high-yielding crops)
• microorganisms = source of useful products

                  e.g.: Taq polymerase used for PCR in forensic and DNA analysis

Other services

• forests absorb CO₂ --> lowers the effect of high CO₂ concentration in the atmosphere
• organic waste added in water gets broken down by mircroorganisms
• transpiration of plants: contribute to the water cycle - provides water for drinking and irrigation
• termites, ants, fungi, bacteria recycle elements (C,H,O,N,...)

18.3 Conservation Maintaining biodiversity is important for many reasons. Actions to maintain biodiversity must be taken at local, national and global levels.   It is important to conserve ecosystems as well as individual species. a) discuss the threats to the biodiversity of aquatic and terrestrial ecosystems (see 18.1b)  b) discuss the reasons for the need to maintain biodiversity  c) discuss methods of protecting endangered species, including the roles of zoos, botanic gardens, conserved areas (national parks and marine parks), ‘frozen zoos’ and seed banks  d) discuss methods of assisted reproduction, including IVF, embryo transfer and surrogacy, used in the conservation of endangered mammals  e) discuss the use of culling and contraceptive methods to prevent overpopulation of protected and non-protected species  f) use examples to explain the reasons for controlling alien species  g) discuss the roles of non-governmental organisations, such as the World Wide Fund for Nature (WWF) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), in local and global conservation  h) outline how degraded habitats may be restored with reference to local or regional examples

Threats to biodiversity

Biodiversity is under threat in many aquatic and terrestrial ecosystems as human population continues to increase and we take more resources from the environment and produce more waste.








Threats to biodiversity:

• habitat loss and degradation of the environment
• climate change
• excessive use of fertilisers --> pollution
• overexploitation and unsustainable use of resources
• alien species invasion on native species

1. Habitat loss 

- destruction of natural environment: land clearing for agriculture, housing, transport,...

- e.g.: deforestation --> soil erosion --> sever land degradation

=> habitat fragmentation (habitats become divided)

• most at risk of extinction: endemic species on small islands

2. Climate change

Air pollution: combustion of fuel with high sulfur content leads to high concentrations of atmospheric SO₂

    SO₂  in atmosphere + H₂O = acid rain

• destroys vegetation
• acidification of aquatic ecosystems: animals can't breed/survive in waters of low pH

Industrialisation, extraction and combustion of fossil fuels

    increases concentration of CO₂ and CH₄ in the atmosphere = greenhouse gas --> climate change

    ---> global warming

• change in distribution of terrestrial ecosystems: organisms will migrate north or south to cooler and higher latitudes. There will also be competition between migrating organisms
• acidification of the oceans: destroy CaCO3 mollusc shells
• rise in sea levels
• increase in the frequency of natural catastrophies (hurrican, flooding,...)

                     e.g.: flooding: increases the concentration of nutrients in coastal waters -->                                        increases growth of phytoplanktons which provides food for starfish larvae -->                              adult starfish eats the coral

• coral bleaching: corals provide protection for many coastlines. Corals are very sensitive to temperature increases --> die

3. Fertilisers and pollution

*pollutant: substances that animal bodies are unable to metabolise or excrete

• factory wastes flow into rivers without any treatment --> substance persists --> enters food chains --> weakening of immune systems and reduction in fertility in birds and mammals
• marine pollutant: non-biodegrable plastic

                 e.g.: - animals (dolphins) get caught in discarded fishing nets and die

                         - turtles eat plastic bags, mistaken then for jellyfish --> chokes

• excess fertilisers (not absorbed by crop plants) drain into river --> extra nutrients cause growth of producers, such as algae:

                         -  produce toxic substances

                         - algae growth unbalances food web

18.3 Conservation Maintaining biodiversity is important for many reasons. Actions to maintain biodiversity must be taken at local, national and global levels.   It is important to conserve ecosystems as well as individual species. a) discuss the threats to the biodiversity of aquatic and terrestrial ecosystems (see 18.1b)  b) discuss the reasons for the need to maintain biodiversity  c) discuss methods of protecting endangered species, including the roles of zoos, botanic gardens, conserved areas (national parks and marine parks), ‘frozen zoos’ and seed banks  d) discuss methods of assisted reproduction, including IVF, embryo transfer and surrogacy, used in the conservation of endangered mammals  e) discuss the use of culling and contraceptive methods to prevent overpopulation of protected and non-protected species  f) use examples to explain the reasons for controlling alien species  g) discuss the roles of non-governmental organisations, such as the World Wide Fund for Nature (WWF) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), in local and global conservation  h) outline how degraded habitats may be restored with reference to local or regional examples

Assessing species diversity

There are 2 types of sampling: random sampling and systematic sampling.










Random sampling

• should be used when an area looks reasonably uniform
• there is no clear pattern to the way the species are distributed

--> avoids bias

a) Quadrats
- a square frame that marks off area of ground or water
- used to identify the different species present and/or to measure abundance
- use results to calculate:

• species frequency: measure of chance of a particular species being found within any one quadrat
• species density: measure of how many individuals there are per unit area

- use results to estimate:

• percentage cover: the percentage of area inside the quadrat that is occupied by each species
• abundance scale (e.g.: Braun-Blanquet scale) for number and plant cover

b) Mark-release-recapture: estimating the population size of mobile organisms

1. As many individuals caught as possible
2. Individuals get marked (in a way that will not affect its future chances of survival)
3. Marked individuals are counted (a)
4. Marked individuals are returned to their habitats to mix randomly with their population
5. After enough time has elapsed (at least 24 hours, maximum __ hours), a large sample is recaptured

      6. Number of marked (b) and unmarked individuals are counted

                            |_____________________|

                                                  |

                                                (c)

Systematic sampling

• investigate species distribution where physical conditions change
• e.g.: altitude, soil moisture content, soil pH, exposure/ light intensity

a) Line transect

• record identity of organisms that touch the line at set distances
• data shown as a drawing

b) Belt transect

• place quadrats at regular intervals along line  --> record abundance of species within quadrat
• data plotted as bar chart or kite diagram

Correlation - plot a scatter graph or calculate correlation coefficient (r)

*strength of correlation = how close the points are to the straight line

1. Pearson's correlation coefficient

use with 2 sets of data when data:

• continuous data has been collected
• must be normally distributed
• may be a linear correlation (draw scatter diagram first)
• quantitative data collected as measurements/counts
• number of paired observations is at least 5, ideally 10 or more

2. Spearman's rank correlation

use when data:

• data points are independent of each other
• data is correlated, but not linear (draw scatter diagram first)
• number of paired observations: at least 5, ideally between 10 and 30

- rank data for each variable and assess the difference between the rankings

- make a null hypothesis

Simpson's Index of Diversity

When you have  collected information about the abundance of he species in the are you are studying, use the results to calculate a value for species diversity in that area

• n = total number of organisms in one species
• N = total number of organisms of all species
• D = Index of Diversity

18.1 Biodiversity Biodiversity is much more than a list of all the species in a particular area. a) define the terms species, ecosystem and niche  b) explain that biodiversity is considered at three different levels:  • variation in ecosystems or habitats  • the number of species and their relative abundance  • genetic variation within each species  c) explain the importance of random sampling in determining the biodiversity of an area  d) use suitable methods, such as frame quadrats, line transects, belt transects and mark-release-recapture, to assess the distribution and abundance of organisms in a local area  e) use Spearman’s rank correlation and Pearson’s linear correlation to analyse the relationships between the distribution and abundance of species and abiotic or biotic factors  f) use Simpson’s Index of Diversity (D) to calculate the biodiversity of a habitat and state the significance of different values of D