Populations in Ecosystems Flashcards

Question

What is meant by the term climax community?

Answer 1

The climax community contains the best adapted species to the environment (they are the final community, there will be no more succession after them)

Answer 2

The change in a community over time due to changing environmental (abiotic) and biotic factors conditions. Primary succession: when succession begins on an area that has not been inhabited previously (a slow process)

Answer 3

the concept of preservation/maintenance of biodiversity, through sustainable management of resources to maintain forests and the habitats/niches and food they supply that ultimately maintains biodiversity.

Answer 4

Secondary succession occurs on previously inhabited areas by which the ecosystem returns to its climax community through recolonisation. This is much faster as soil already exists and seeds remain alive, the climax community reached may be different to the original. Secondary succession starts from small plants not pioneer species (soil and nutrients already present) and secondary succession is faster (soil, nutrients and seeds already present)

Answer 5

active intervention to manage succession and maintain a wide range of plagioclimaxes (false climax communities) Thinning of woodland to ensure light reaches the ground encouraging shrubs and wildflowers to grow. Hedgerows maintained in farmland, providing ecological corridors for animals to move between areas, nesting sites, food sources, habitats. Grazing by animals, maintains grassland but prevents growth of tress and shrubs Periodic burning to remove saplings and allow fire resistant heather to thrive Cutting back reeds that dominate and dry out fenland, pump water into the fenland to keep it waterlogged

Answer 6

The maximum population size that can be sustainably maintained over a period of time in a particular habitat. No population will grow indefinitely as the availability of resources and competition for these will limit growth.

Answer 7

When species which occupy a similar niche are brought in close contact one will usually out-compete the other, this will be the best adapted. Thus two species cannot occupy the same niche indefinitely, when resources are limited due to interspecific competition.

Answer 8

Pioneer plant species settle, and are adapted to hostile conditions. Over time, land erodes, soil forms, pioneers die and decompose adding humus and nutrients to the soil making the environment less hostile. Small plants with shallow roots can grow and out-compete the pioneer species. Overtime, more soil forms as small plants die and larger plants with deeper roots outcompete etc. Over time, the climax community is reached. Colonisation of area by pioneer species; These organisms changes the environment; This enables new species to colonise; Repetition of this process results in the environment becoming less hostile, Biodiversity increases, providing food, habitat, nesting sites and niches, Eventually a climax community is reached

Answer 9

Their organic material will be decomposed after they die forming basic soil They will make the abiotic conditions less hostile so new organisms can survive there

Answer 10

species diversity increases (peaks just before climax – species in climax will out compete others) habitat diversity increases environment becomes less hostile food chains become more complex & biomass increases

Answer 11

1. Protection of habitat; 2. Legal measures, e.g. quotas, hunting bans; 3. Capture/culling of non-native species; 4. Captive breeding; 5. Surrogacy / artificial insemination / genetic manipulation techniques; 6. Ethical / aesthetic reasons for conservation / tourism; 7. Possible undiscovered benefits, e.g. crop plants, drug sources; 8. Maintaining genetic diversity for future breeding programmes; 9. Avoid damage to food webs / control local pests;

Answer 12

used to prevent formation of woody forests – either on hill sides (for tourism) and farms (space for crops) involves: deforestation, burning trees, grazing, using pesticides