Module 6-populations and sustainability Flashcards
Define conservation
Maintenance of biodiversity through human action/management
Define coppicing
The process of cutting down trees close to the ground to promote new growth
Define ecosystem
The dynamic interaction between the biotic and abiotic factors in a given area or habitat.
Define grazing
A form of human activity that can interrupt the succession of an ecosystem as animals are grazed on land to prevent growth of vegetation
Define ex situ
The conservation of species outside their natural habitat in a human controlled environment
Define in situ
species are conserved within their natural habitat maintaining biodiversity
Define preservation
The protection of an area by restricting or banning human interference so the ecosystem is kept in its original state.
Define species
2 or more organisms that can produce fertile offspring
Define sustainability
The ability of an ecosystem to maintain biodiversity whilst simultaneously providing humans with resources for long term use.
What ethical reasons do we conserve species for?
-Many people believe we don’t have a right to decide which organisms can stay or become extinct
-All organisms have a right to exist
-We have moral responsibility for future generations
What social reasons do we conserve species for?
-Use them for activities which are beneficial to health by providing a means of relaxation and exercise
-Many people enjoy the natural beauty of ecosystems
What economic reasons do we conserve species for?
-To provide resources that humans need to survive and provide an income for
-E.g rain forest species provide medicinal drugs that can be traded
Describe the process of small scale timber production-coppicing
-Tree trunk is cut close to the ground
-New shoots grow from the cuts surface and mature
-Eventually the shoots are cut and in their place more are produced
-In most managed woodlands rotational copiccing takes place where the woodland is divided into sections and trees are only cut in a particular section until all have been copicced
-Copiccing then begins in a new area allowing time for the newly copicced trees to grow
How does rotational copiccing maintain biodiversity?
the trees never grow enough to block out the light hence succession can’t occur so more species survive
Describe the process of large scale timber production-felling
-large areas of forests are felled
-the felled trees are destroyed and will not regrow
-companies practice selective cutting which involves only removing the largest trees
-they replace trees through replanting rather than waiting for natural regeneration
-this helps to ensure biodiversity and mineral and water cycles are maintained
-they manage pests and pathogens to maximise yields
-main disadvantage is that habitats are destroyed, soil minerals are reduced and the bare soil that is left is susceptible to erosion.
What are some examples of conservation strategies?
-improve public transport around the area to reduce local CO2 emissions
-organise litter picks
-invasive species are being cut back and sprayed with herbicides in attempt to kill them to stop them harming wildlife
-peat land restoration projects and block gullies to stop water draining away
-introduce walker charges to help pay for path restoration and put people off from further eroding the path
-regulated fishing zones
-introduce legislation to limit the numbers of tourists which can operate inside the reserve
-enable locals to have management rights over forests so they can act as stewards and improve biodiversity
Describe the stages of the population growth curve
Phase 1-a period of slow growth, small numbers of individuals that are initially present reproduce, birth rate is higher than death rate so the population increases in size
Phase 2- period of rapid growth s the number of breeding individuals increases, the total population size multiplies exponentially, no constraints act to limit the population
Phase 3- stable state, further population growth is prevented by external constraints, population size fluctuates a bit but overall stays relatively stable, both rates and death rates are relatively equal
What are limiting factors?
-prevent further growth of a population e.g disease or competition between animals
Define carrying capacity
Maximum population size that can be maintained for a long period of time
Describe interspecific variation
-competition between individuals in different species
-can reduce the amount of resources available slowing the rate of population growth
-outcompeting occurs when one organism is better adapted than the other
Define intraspecific competition
-occurs when members of the same species compete for the same resource causes fluctuations in population size
Describe the predator-prey relationship
-sizes of the predator and prey populations are interlinked
-if the prey population is small resources are limited for predators therefore decreasing the population size
-the prey population then increases as there’s less predators
How can succession be managed?
Grazing-animals graze to prevent growth of vegetation
Burning-burning kills vegetation and allows secondary succession to take place
Define sustainable resource
Renewable resource that is being economically exploited in such a way it won’t diminish or run out
