Succession and Conservation

• Both the biotic and abiotic components within ecosystems are dynamic
• There is a constant flow of energy within ecosystems, such as in the process of feeding, which ensures that energy can move between organisms
• Species are constantly fluctuating within ecosystems as populations decline or grow
• Biotic factors mean that the population size of a particular species constantly varies around the carrying capacity depending on factors such as competition, time of year and geographical location
• There is a constant flow of nutrients and water within ecosystems as they are continually recycled
• Aspects of weather can affect communities of species, including abiotic factors such as temperature and wind, which are also very dynamic
• The main implication of the dynamic nature of ecosystems is that it means they can be very complex to study and understand
• Studies into ecosystems must try to take the effects of all factors into account in order to understand how they interact with each other and the different extents to which they affect populations and communities
• Succession is the process by which an ecosystem changes over time, form being very simple to complex through changes in biotic and abiotic conditions
• At each stage in succession, there is certain species that gradually change the local environment so that it becomes more suitable for other species that have not yet colonised the new land, often changing it in such a way that it becomes less suitable for the previous species
• Primary succession occurs when newly exposed or newly formed land is gradually colonised
• What is an example of a location of primary succession?

  Areas where new rock surfaces are formed form volcanic eruptions, when lakes dry up or when new islands emerge from a drop in sea levels
• What are pioneer species?

  The first species to colonise the newly exposed land, as they are specialised to live in harsh abiotic conditions
• What are some examples of pioneer species?

  Seeds or spores that are blown in by the wind and begin to grow
• What are pioneer species role in succession?

  As they die and are decomposed by microorganisms, the organic matter begins to form basic soil, and the environment becomes less hostile as the soil has minerals and the ability to retain water
• After pioneer species have decomposed, seeds of small plants and grasses land on this basic soil and begin to grow, being adapted to survive in shallow, nutrient poor soils
• As larger plants die and decompose, the soil becomes deeper and more nutrient rich
• The roots of larger plants form a network that helps to hold soil in place, meaning that it retains more water and contains more mineral ions
• Larger plants and shrubs that require deeper, more nutrient rich soil begin to grow in the soil, this is because they require more water, which can only be stored and accessed in deeper soils
• At each stage of succession, different organisms that are better adapted for the conditions move into the ecosystem, and sometimes outcompete the previous organisms, these dominant species are the ones that cause the most change to the abiotic environment
• During succession, the biodiversity and biomass of the ecosystem increase
• Secondary succession takes place when parts of an ecosystem are disturbed, typically where the land has been cleared of all plants but the soil still remains
• What are some examples of areas where secondary succession takes place?

  An area where a forest fire or deforestation has taken place
• The pioneer species in secondary succession tend to be larger than those in primary succession
• Why are pioneer species in secondary succession larger than in primary succession?

  The environment is more nutrient rich and they dont have to survive as harsh conditions
• Secondary succession carries on the same process as primary succession, but at a later stage
• What is a climax community?

  When the ecosystem is supporting the largest and most complex community, which exists in a balanced equilibrium
• A climax community is in a stable state and abiotic factors are typically constant over time
• What are some factors that can limit succession?

  Availability of nutrients

  Diseases

  Limited spaces for niches

  Competition for niches
• Conservation is the protection and management of ecosystems in order to maintain biodiversity
• Why can preventing climax communities be a good thing?

  Some ecosystems hold a distinct diversity of plant and animal species that would no longer exist if the climax community was reached

  Both plants and animals may be of conservation importance, for example if they’re rare or threatened
• Some conservation efforts require the deliberate and artificial prevention of succession in order to preserve an ecosystem in its current stage of succession
• How can climax communities be prevented from occuring?

  By temporarily introducing grazing animals or using managed burning of habitats
• What is sustainability?

  When enough resources are taken to meet the current needs of humans without reducing the ability to meet human needs in the future
• There is often a conflict between human needs and conservation, therefore, careful management is needed to find a balance to maintain the sustainability of natural resources
• Conservation is becoming increasingly necessary but also more difficult, as humans need more space and food, meaning that more land is needed for agriculture and development, which expands into space occupied by wildlife
• Conservation efforts like fishing quotas and reduced deforestation can directly impact peoples income and the economy, so people are reluctant
• What are conserved areas?

  Protected areas that have been established for the conservation of the species and environments within them
• What are national parks?

  Areas where wildlife and environment and protected by governments through restrictions such as prohibiting hunting and industrial activities
• What are marine parks?

  Protected areas of water that have been established for the conservation of endangered marine ecosystems, having restrictions to prevent overfishing and pollution