Ocr A2 Biology - Conservation Of Ecosystems (Part 1)

Conservation is the protection and management of ecosystems so that the natural resources in them can be used without running out.

It is constantly changing (due to natural causes and human involvement) so conservation methods need to be adapted.

• Reclamation is restoring ecosystems that have been damaged or destroyed so they can be used again.
  
• An example is restoring a forest that had been cut down so they can be used again.

• Ecosystems provide resources for lots of things humans need (e.g. drugs, materials and food).
• These resources are economically important as they are traded on a local and global scale.
• If ecosystems are not conserved, the resources we use now will be lost, so there will be less trade in the future.

• Many ecosystems bring joy to lots of people because they are attractive to look at and people use them for activities e.g. birdwatching or walking.
• The species and habitats in ecosystems may be lost if they aren't conserved, so future generations won't be able to use and enjoy them.

• Some people think we should conserve ecosystems simply because it is the right thing to do. Most people believe that organisms have a right to exist, so they shouldn't become extinct as a result of human activity.
• Some people think we have a moral responsibility to conserve ecosystems for future generations, so they can use and enjoy them.

• Preservation is the protection of ecosystems so they're kept exactly as they are.
• Nothing is removed from a preserved ecosystem and they are only used for activities that don't damage them.
• An example of a preserved ecosystem is Antartica, which is protected from exploitation by humans. This means only limited tourism and scientific research is carried out there, not mining or other industrial processes.

This means that enough resources are taken to meet the needs of today, without reducing the ability of the people in the future to meet their own needs.

• Trees are cleared up in trips or patches - woodland grows back more quickly in smaller areas of woodland than it does in larger, open areas.
• The cleared strips or patches are not too large or exposed - as this would lead to soil erosion. If the soil is eroded, newly planted trees won't be able to grow.
• Timber is harvested by coppicing - cutting a tree in a way that lets them grow back. This means new tree do not need to be planted.
• Native tree species tend to planted in preference over non-native species. This is better for biodiversity because native species have established interactions with other native species (e.g. plants, fungi, animals), so their presence should help species thrive in the area. Also, some species may not be able to adapt to the presence of a non-native species.
• Planted trees are attached to posts to provide support, and grown in plastic tubes to stop them from being eaten by grazing animals - this increases their survival rate and makes it more likely for them to become mature adults.
• Trees are not planted close together - this stops them from competing with each other for space or resources, so they are more likely to survive.

• Using fishing quotas
• Controlling mesh size of nets.

• Limits to a number of certain fish species that fisherman are allowed to fish.
  
• Fishing quotas are supposed to help to conserve fish species by reducing the numbers that are caught and killed, so the populations aren't reduced too much and the species aren't at risk from being extinct.

Scientists study different species and decide how big their populations need to be to maintain these numbers. Then they decide how much fish is safe to take without reducing the population too much.

• Common Fisheries Policy in the EU
• They state the amount of fish each country can take, and where they are allowed to take them from.

• Fish of the wrong species or size are still caught, but they often end up being thrown back into the sea, dying or dead, as the restrictions do not allow the fishermen to being them ashore.
• However, new rules for the Common Fisheries Policy are banning the discarding of fish and the whole catch will have to be brought to shore and counted against the quota.

• There are different limits to the mesh size of the fishnet, depending on what's being fished.
• To reduce the number of 'unwanted' and discarded fish that are accidently caught, we use nets with bigger mesh sizes.
• This allows the unwanted fish to escape through the net.
• This also allows younger fish to slip through the net, giving them a chance at reaching breeding age.

• It can be difficult to determine exactly how big the mesh size should be in areas where several different fish species are fished for at the same time.
• Two nets could be used one inside each other, reducing the mesh size but still obeying the regulation rules.