Conservation | O-Level Biology

Every organism depends on its surroundings and, directly or indirectly, on other organisms. A fish may depend on smaller animals for food, those animals may depend on producers, and the entire community may depend on a particular habitat providing suitable conditions for survival. This means that conserving biodiversity is about much more than saving individual animals or plants.

Effective conservation looks at the whole system. It protects species, preserves the habitats in which they live and manages resources such as forests and fish populations so that people can continue to benefit from them without destroying the ecosystems that produce them. The central question is therefore not simply “Can humans use this resource?” but “Can we use it in a way that allows the ecosystem and resource to continue into the future?”

Diagnostic Quiz

What Do You Already Know About Conservation?

Try these five questions before reading the chapter. They will test whether you can distinguish conservation, biodiversity and sustainable use before looking at how these ideas are connected.

5 diagnostic questions
Common misconceptions tested
Instant explanation for every answer option

Question 1 of 5

Which statement best describes conservation?

Preventing humans from using any natural resources

Conservation does not necessarily mean preventing all human use. Natural resources may be used if they are managed sustainably.

Protecting species and managing natural resources so that biodiversity can be maintained

Correct. Conservation combines protection with careful management so that species, habitats and natural resources can persist.

Increasing the population of every species in an ecosystem

Conservation does not aim to make every population larger. Populations naturally vary, and excessively large populations can also disturb an ecosystem.

Keeping all populations at exactly the same size

Ecosystems are dynamic. Population sizes naturally rise and fall, so conservation does not attempt to keep them permanently fixed.

Conservation involves protecting biodiversity and managing natural resources responsibly. It is compatible with human use when that use is sustainable.

Which description best explains biodiversity at O-Level?

The total number of individual organisms in an area

A habitat can contain many organisms but very few different species. Number of individuals alone does not describe biodiversity.

The variety of different species present in an area

Correct. At this level, biodiversity is primarily concerned with the variety of species present.

The amount of food produced by an ecosystem

Food production may be an ecosystem function, but it is not the definition of biodiversity.

The amount of land occupied by an ecosystem

The physical size of a habitat does not by itself determine its biodiversity.

Biodiversity describes biological variety. For O-Level questions, focus especially on the variety of different species found in a habitat or ecosystem.

Which example shows the most sustainable use of a renewable natural resource?

Catching as many fish as possible before competitors catch them

Heavy harvesting can reduce the breeding population until the fish population can no longer replace the individuals removed.

Cutting an entire forest and leaving the land bare

Removing the forest without allowing regeneration destroys both the resource and the habitat.

Harvesting trees at a controlled rate while allowing the forest to regenerate

Correct. Sustainable use allows a renewable resource sufficient opportunity to recover or be replaced.

Using a resource rapidly because it is renewable

Renewable does not mean unlimited. A renewable resource can still be depleted if it is removed faster than it can recover.

Sustainable use means using a resource in a way that allows it and the ecosystem supporting it to remain available in the future.

Why can the extinction of one species affect other species in the same ecosystem?

Species are linked through relationships such as feeding, pollination and competition

Correct. Removing one species can change food availability and other ecological relationships throughout the community.

Every species eats every other species

Feeding relationships are specific. Not every organism feeds on every other organism.

Extinction automatically removes all producers

This would only be true in a very unusual situation. The effect depends on which species disappears and its ecological role.

All species in an ecosystem have identical requirements

Different species have different habitats, food sources and other requirements.

Species form interconnected communities. A change to one population can therefore affect predators, prey, competitors and other organisms.

Which action is most directly aimed at conserving an endangered species in its natural habitat?

Increasing hunting during the breeding season

This would remove breeding individuals and could accelerate population decline.

Protecting the habitat in which the species feeds and reproduces

Correct. Protecting the natural habitat preserves the conditions and resources the species needs to survive and reproduce.

Removing all other species from its habitat

Other organisms are part of the ecosystem and may provide food, pollination or other important interactions.

Replacing the natural habitat with buildings

Habitat destruction is a major threat to wild populations rather than a conservation measure.

Protecting habitats is fundamental to conservation because organisms require suitable places to obtain food, shelter and breeding sites.

What Is Conservation?

Conservation is the protection and careful management of species, habitats, ecosystems and natural resources. Its purpose is to reduce the loss of biodiversity while allowing natural systems to continue functioning into the future.

That last part matters. Conservation does not always mean that humans must completely stop using nature. Forests can provide timber, seas can provide fish and natural areas can support tourism. The problem begins when the rate or method of use damages the ecosystem so severely that the resource cannot recover.

Central principle: conservation combines protection with responsible management. The aim is to meet present needs without destroying the biological resources and ecosystems needed in the future.

Conservation is not the same as simply stopping all use

Imagine a fish population that can reproduce fast enough to replace a limited number of fish caught each year. Harvesting some fish may be possible without permanently reducing the population. If far more fish are removed than can be replaced by reproduction, however, the population decreases and may eventually collapse.

The same principle applies to forests. Selective harvesting together with regeneration can preserve much more of the ecosystem than clearing every tree from a large area at once.

Unsustainable use: resources are removed or ecosystems are damaged faster than they can recover.

Sustainable use: resources are managed so that they remain available while the ecosystem continues to function.

Biodiversity and a Balanced Ecosystem

Biodiversity refers to the variety of different species found in an area. A tropical rainforest containing many species of plants, insects, birds, mammals, fungi and microorganisms therefore has high biodiversity.

Do not confuse biodiversity with the total number of organisms. A field containing 10 000 plants of one species may contain more individual organisms than another habitat, but it does not necessarily have greater biodiversity.

Suppose Habitat X contains 5000 organisms belonging to only four species, while Habitat Y contains 2000 organisms belonging to 40 species. Habitat Y has the greater variety of species and therefore the greater species biodiversity.

Why does biodiversity matter?

Species in an ecosystem are connected. Producers supply food to consumers. Predators affect prey populations. Decomposers recycle nutrients. Pollinators help flowering plants reproduce. Organisms may also compete with one another for food, space, light or other resources.

Because of these connections, losing a species can affect organisms other than the species that disappeared. For example, if an important prey species becomes rare, predators that depend heavily on it may also decline.

Greater biodiversity can also provide more alternative pathways within an ecosystem. If one food source decreases, for example, some consumers may be able to use another. This can make an ecosystem better able to continue functioning when environmental conditions change.

Exam idea: biodiversity helps maintain a balanced ecosystem because many species contribute to interconnected food webs, nutrient cycling and other ecological processes.

A balanced ecosystem does not mean that nothing changes

The word balanced can be misleading if it is interpreted as “every population always stays at exactly the same size”. Real ecosystems are dynamic. Births, deaths, migration, seasonal changes, disease and predator–prey interactions cause populations to fluctuate.

A balanced ecosystem is better thought of as one in which organisms and their physical environment continue interacting in a way that allows the ecosystem to persist. Population sizes may change, but the entire system does not repeatedly collapse because key species or resources have been removed.

Why Should Species Be Conserved?

Once a species becomes extinct, that species is permanently lost. Conservation therefore attempts to prevent avoidable extinctions, particularly when populations are declining because of human activities such as habitat destruction, overharvesting or pollution.

There are several reasons for conserving species, and an examination question may ask you to apply more than one of them to a particular situation.

Reason	Why it matters	Example
Ecological	Species interact through food webs and other relationships. Removing one species can affect several others.	Loss of an important prey species may reduce the population of its predators.
Economic	Healthy ecosystems can provide useful resources and support livelihoods.	Fish populations support fisheries, while forests can provide timber when they are managed sustainably.
Scientific and medical	Organisms contain genes and chemical substances that may be useful for research, agriculture or medicine.	A species that disappears before it is studied may contain useful biological information or substances that are then lost.
Ethical	Many people argue that humans have a responsibility to avoid unnecessarily causing the extinction of other species and to preserve biodiversity for future generations.	Protecting threatened species rather than allowing avoidable human activities to eliminate them.

Ecological effects are often interconnected

Consider a flowering plant that provides food for an insect. The insect is then eaten by a bird. If the plant disappears, the insect population may decline because its food source has been lost. The bird may then have less food available.

The important reasoning is not that the disappearance of one species must always destroy an entire ecosystem. Instead, species are connected, so the loss of one species can alter other populations and ecological relationships.

Sustainable Use of Natural Resources

A natural resource is something obtained from the natural environment and used by humans. Examples include timber, fish, freshwater and other biological resources.

Sustainable use means using these resources in a way that does not permanently deplete them or seriously damage the ecosystem that produces them.

Renewable does not mean unlimited

Trees can grow again and fish can reproduce, so both forests and fish populations are renewable resources. However, their ability to renew themselves takes time.

If trees are cut faster than forests regenerate, forest cover decreases. If fish are caught faster than the remaining fish can reproduce, the fish population decreases. A renewable resource can therefore still be exhausted by unsustainable use.

Renewable resource: a resource that can be naturally replaced or regenerated over time.

Sustainable use: managing the rate and method of use so that the resource and its supporting ecosystem can continue into the future.

Sustainable fishing

Fish populations can be conserved by controlling how many fish are removed. Measures may include catch limits, restrictions on catching immature fish, protected breeding areas and temporary restrictions during important breeding periods.

These measures leave enough breeding individuals in the population to reproduce and replace at least some of the fish that are removed.

Sustainable forestry

Forest resources can be managed by limiting the number and type of trees removed, allowing regeneration and replanting where appropriate. This is very different from clearing a large forest completely and repeatedly preventing it from recovering.

Sustainable forestry must also consider the habitat provided by the forest. Conserving only the commercially valuable tree species while destroying the rest of the forest would still cause major biodiversity loss.

Think beyond the resource itself: sustainable use must protect the biological system that produces the resource. A fishery cannot remain sustainable if its breeding grounds are destroyed, and a forest cannot remain biologically healthy if most of its habitat is removed.

Conserving Tropical Rainforests, Mangroves and Coral Reefs

Conservation questions often become easier when you connect the importance of an ecosystem to the organisms and resources that depend on it. The same basic reasoning applies to tropical rainforests, mangroves and coral reefs: protecting the habitat simultaneously protects many species living within it.

Ecosystem	Why it is important	Possible threats	Conservation approaches
Tropical rainforest	Provides habitats for many species, stores carbon, protects soil and supplies biological resources.	Clearing for agriculture or development, excessive logging and habitat fragmentation.	Protected areas, controlled logging, forest regeneration and reforestation.
Mangrove	Provides feeding and nursery habitats for many organisms, traps sediment and helps reduce coastal erosion.	Coastal development, removal of mangrove vegetation and pollution.	Protected coastal areas, limiting destructive development and restoring mangrove vegetation.
Coral reef	Provides habitats for a large variety of marine organisms and can support fisheries, tourism and coastal protection.	Destructive fishing, pollution, sedimentation and environmental changes that damage corals.	Marine protected areas, sustainable fishing practices and reducing pollution and physical damage.

Tropical rainforests

Tropical rainforests contain many different habitats and food sources, allowing large numbers of species to live together. Removing the forest therefore removes far more than trees: it may also remove shelter, breeding sites and food sources for many other organisms.

Forest clearance can also expose soil to greater erosion. Once the original habitat has been severely altered, simply protecting one endangered animal without protecting the forest in which it lives is unlikely to succeed.

Mangroves

Mangroves grow along sheltered tropical and subtropical coastlines. Their root systems provide complex habitats in which many aquatic organisms can shelter and develop. Mangrove areas can therefore act as important nursery grounds for young fish and other organisms.

Their roots also slow moving water and trap sediment. This helps stabilise shorelines and reduce erosion. Conserving mangroves can therefore protect biodiversity while also providing benefits to human coastal communities.

Coral reefs

Coral reefs provide shelter, feeding areas and breeding habitats for many marine species. Damage to the reef structure therefore affects not only corals but also the community of organisms that depends on the reef.

A damaged reef may also provide fewer fishery resources and less coastal protection. Conservation measures are therefore most effective when they protect both the reef habitat and the organisms living within it.

Common reasoning across all three ecosystems: conserve the habitat → more species retain suitable places to feed, shelter and reproduce → biodiversity is more likely to be maintained.

How Is Conservation Carried Out?

There is rarely one conservation method that solves every problem. Different threats require different approaches, and successful conservation often combines several methods.

Protected areas

Governments can designate national parks, nature reserves and marine protected areas where damaging human activities are limited.

Protecting an entire habitat is particularly valuable because many species benefit simultaneously. It also preserves ecological interactions such as feeding and breeding relationships.

Laws and enforcement

Laws can restrict activities such as illegal hunting, collection of protected species, destructive fishing or clearing of protected habitats.

A law by itself, however, does not automatically conserve a species. The law must be enforced. If illegal hunting continues because there is little monitoring or enforcement, the threatened population may continue to decline.

Sustainable harvesting

Where a biological resource is still used, the amount removed can be controlled. Examples include limiting fish catches or regulating timber harvesting.

The purpose is to leave enough organisms and suitable habitat for the population to recover through reproduction and growth.

Captive breeding and reintroduction

When the wild population of an endangered animal becomes very small, individuals may be bred under controlled conditions. The aim is to increase numbers and, where suitable, return individuals to the wild.

Captive breeding cannot replace habitat conservation. Releasing animals back into an environment in which the original threat is still present may simply cause the population to decline again.

If a species became endangered because its forest was destroyed, successfully breeding the species in captivity solves only part of the problem. A suitable forest habitat must still exist before a self-sustaining wild population can be re-established.

Habitat restoration

Damaged ecosystems can sometimes be restored. Examples include replanting native forest vegetation or restoring mangrove areas along a degraded coastline.

Restoration does not instantly recreate the original ecosystem. Complex communities take time to develop, which is one reason preventing severe habitat destruction is usually preferable to trying to repair the damage afterwards.

Education and responsible choices

Conservation also depends on human behaviour. Education can help people understand why ecosystems matter and encourage responsible use of natural resources.

This can support other conservation measures by reducing demand for illegally obtained wildlife products, encouraging sustainable resource use and increasing public support for habitat protection.

Common Mistakes

Common mistake	Why it is wrong	Better approach
Saying that conservation means humans must never use natural resources.	Conservation can include controlled use when the resource and ecosystem are able to recover.	Explain that conservation combines protection with sustainable use.
Defining biodiversity as the number of organisms in an area.	A habitat may contain many organisms belonging to only one or two species.	Refer to the variety of different species present.
Saying that renewable resources cannot run out.	Renewable resources still require time to regenerate or reproduce.	Compare the rate of removal with the rate at which the resource can recover.
Saying that a balanced ecosystem has populations that never change.	Real populations naturally fluctuate because of births, deaths, migration and environmental changes.	Describe a balanced ecosystem as one whose interactions and processes can continue without major disruption.
Assuming captive breeding alone will save an endangered species.	The original threats, such as habitat loss or hunting, may still exist in the wild.	Combine breeding programmes with habitat protection and removal of the original threat.
Explaining conservation only in terms of one endangered animal.	Species depend on habitats and on interactions with many other organisms.	Link species conservation to habitat protection, food webs and maintenance of biodiversity.

What You Should Be Able to Do

Define conservation

I can explain conservation as the protection and careful management of species, habitats and natural resources.

Explain biodiversity

I can describe biodiversity in terms of the variety of different species present in an area.

Connect biodiversity to ecosystems

I can explain how species interact and why loss of biodiversity can disturb food webs and ecosystem processes.

Explain sustainable use

I can distinguish sustainable use from overexploitation and explain why renewable resources can still be depleted.

Apply conservation to rainforests

I can explain why protecting tropical rainforest habitat helps conserve many species and natural resources.

Apply conservation to mangroves

I can relate mangrove conservation to biodiversity, nursery habitats and protection against coastal erosion.

Apply conservation to coral reefs

I can explain why conserving coral reefs protects marine biodiversity and the resources associated with reef ecosystems.

Evaluate conservation methods

I can explain how protected areas, legislation, sustainable harvesting, captive breeding and habitat restoration can work together.

Mastery Quiz

Can You Apply Conservation?

These ten questions test whether you can apply conservation, biodiversity and sustainable-use ideas to unfamiliar ecosystems and management situations.

10 application-focused questions
Real conservation reasoning
Instant explanation for every answer option

Question 1 of 10

A fishing ground produces young fish each year. Which management plan is most likely to keep the fish population available in the long term?

Catch as many fish as possible whenever their selling price is high

The rate of harvesting would be determined by price rather than the population's ability to replace the fish removed.

Limit catches so that enough mature fish remain to reproduce

Correct. Leaving a sufficient breeding population allows new fish to replace individuals that are harvested.

Catch mainly young fish before they can reproduce

Removing fish before reproduction reduces the number contributing offspring to the next generation.

Increase catches whenever the population starts decreasing

Increasing harvesting from an already declining population would worsen the decline.

Sustainable harvesting must leave enough individuals for successful reproduction so that the population can replace organisms that are removed.

A large area of mangrove forest is removed for coastal development. Which pair of consequences is most likely?

Loss of nursery habitats and increased coastal erosion

Correct. Mangroves provide sheltered habitats for many young organisms and their root systems help stabilise coastlines.

Increased nursery habitat and reduced coastal erosion

Removing mangroves removes rather than increases these ecosystem functions.

Greater marine biodiversity and more shelter for young fish

Habitat destruction would normally reduce the shelter available to organisms living in or around the mangroves.

No ecological effect because mangroves occur only on land

Mangroves occur at the land–sea boundary and are closely connected with coastal and aquatic communities.

Conserving mangroves protects both biodiversity and ecosystem services such as shoreline stabilisation.

Why can establishing a marine protected area around a coral reef help conserve many species at once?

It causes every marine organism to reproduce at the same rate

Different species have different reproductive rates and life cycles.

It prevents all natural deaths from occurring

Natural mortality remains part of an ecosystem even when it is protected.

It protects the shared habitat used by many different organisms

Correct. Protecting the reef preserves feeding, shelter and breeding habitats for many species simultaneously.

It changes all marine species into protected coral species

Protection does not change the identity of organisms. It protects the habitat and reduces harmful activities.

Habitat conservation can protect entire communities because many species depend on the same ecosystem.

An endangered mammal is bred successfully in captivity, but the forest where it originally lived continues to be cleared. Why might the programme fail to restore a wild population?

Captive-bred mammals cannot reproduce

Captive breeding works precisely because animals can reproduce under managed conditions.

Endangered species never require habitats

All species require suitable environmental conditions and resources.

A larger captive population always causes extinction

Increasing numbers in captivity does not itself cause extinction. The problem here is the continuing loss of habitat.

There may be too little suitable habitat for released animals to survive and reproduce

Correct. Reintroduction cannot succeed if the original habitat has disappeared or remains unsuitable.

Captive breeding addresses population size, but successful conservation also requires removal of the threats that caused the wild population to decline.

A forest company removes a small number of mature trees from different parts of a forest and allows young trees to grow before further harvesting. What is the main conservation principle being applied?

Complete prevention of all human activity

Timber is still being harvested, so this is not complete prevention of human use.

Sustainable use of a renewable resource

Correct. Harvesting is limited while time is allowed for forest regeneration.

Increasing biodiversity by removing every mature tree

The description states that only a limited number of trees are removed. Removing all mature trees would cause much greater habitat disturbance.

Converting a renewable resource into a non-renewable resource

Trees remain renewable when the forest is able to regenerate.

Sustainable forestry balances resource use with regeneration and habitat protection.

A particular insect is the main food source of several bird species. The insect becomes extinct. Which outcome is most reasonable?

The bird populations must immediately become extinct

The birds may have alternative food sources, so immediate extinction cannot be assumed.

There will definitely be no effect on the birds

Losing their main food source is likely to affect food availability.

Some bird populations may decrease because an important food source has been lost

Correct. Species are linked through food webs, so loss of one species can influence populations that depend on it.

Every organism in the ecosystem will increase in number

Species respond differently to changes in food webs, and a universal population increase would not be expected.

Conservation of biodiversity matters partly because ecological relationships connect the survival of different species.

Scientists discover a wild plant containing a chemical that may be useful in developing a new medicine. Which reason for conserving biodiversity does this best illustrate?

Scientific and medical value

Correct. Wild organisms may contain chemicals, genes or other biological features that have scientific or medical applications.

Conservation prevents all competition between organisms

Competition is a natural ecological interaction and conservation does not aim to eliminate it.

Every wild plant can cure a disease

This is far too broad. Some species may contain useful substances, but this cannot be assumed for every species.

Extinction increases the number of possible medicines

Extinction permanently removes that species and its biological information.

Conserving biodiversity preserves biological material that may have future scientific, medical or technological value.

Hunting an endangered animal is made illegal, but illegal hunting continues and the population keeps falling. What additional conservation measure is most directly needed?

Remove the law because it has not immediately increased the population

The problem is not necessarily the law itself but the fact that illegal hunting continues.

Improve monitoring and enforcement of the hunting restriction

Correct. Legislation is effective only when people comply with it and violations can be detected and controlled.

Allow unlimited hunting for a short period

Additional hunting would remove more individuals from an already declining endangered population.

Destroy the animal's habitat so hunters cannot enter it

Destroying the habitat would threaten the species further.

Conservation laws need effective monitoring and enforcement if they are to reduce illegal activities.

Which statement best explains why restoring mangrove vegetation can benefit both biodiversity and nearby human communities?

Mangroves prevent all waves from reaching a coastline

Mangroves can reduce wave energy and erosion, but they do not completely prevent all waves.

Mangroves remove the need for all other coastal ecosystems

Different coastal ecosystems have different ecological roles.

Mangroves contain only one species, making them easy to manage

Mangrove ecosystems contain many species and complex ecological interactions.

Mangroves provide habitats for organisms while their roots help stabilise the coastline

Correct. Restoration can support biological communities while also helping reduce erosion and protect coastlines.

Conservation can benefit both biodiversity and people because healthy ecosystems provide important ecological functions.

Which conservation plan is most likely to maintain biodiversity in a tropical forest over the long term?

Protect one endangered animal but allow most of its forest habitat to be cleared

Protecting the species without protecting the habitat may leave it without sufficient food, shelter or breeding sites.

Remove all predators so that prey populations can increase

Predators are part of natural food webs. Removing them can create additional ecological disruption.

Protect important habitats, regulate resource use, restore damaged areas and enforce conservation laws

Correct. Combining habitat protection, sustainable use, restoration and enforcement addresses several causes of biodiversity loss.

Harvest every useful species before creating a protected area

Removing useful species first would damage biodiversity and reduce the ecological value of the area being protected.

Long-term conservation usually requires an integrated approach that protects habitats, manages resource use and tackles the human activities responsible for biodiversity loss.

Frequently asked questions

Common Questions About Conservation

Conservation questions often test whether you can connect biodiversity, habitats and sustainable resource use rather than simply memorising a definition. These questions bring those ideas together.

Does conservation mean that humans cannot use natural resources?

No. Conservation can allow natural resources to be used, provided that the rate and method of use are sustainable. For example, a fish population may be harvested if enough breeding individuals remain for the population to recover. Conservation is therefore about responsible management as well as protection.

What is the difference between biodiversity and population size?

Population size refers to the number of individuals of one species, whereas biodiversity concerns biological variety. At O-Level, you should usually discuss biodiversity in terms of the variety of different species present in an area. A habitat can therefore contain a very large number of organisms but still have relatively low biodiversity if most belong to only a few species.

Why does conserving one habitat help many species?

A habitat provides food, shelter, breeding sites and suitable physical conditions for many organisms. Protecting a rainforest, mangrove or coral reef therefore protects entire communities rather than only one selected species. It also preserves interactions such as feeding and reproduction.

Why can a renewable resource still be depleted?

Renewable resources require time to regenerate. Trees require time to grow and fish populations require time to reproduce. If humans remove the resource faster than it can be replaced, its quantity will decrease even though it is technically renewable.

Why is captive breeding not enough on its own?

Captive breeding can increase the number of individuals, but it does not automatically remove the threats affecting the species in the wild. If habitat destruction, hunting or another threat continues, released organisms may still be unable to survive. Effective conservation therefore often combines breeding with habitat protection and management.

Why are mangroves important for conservation?

Mangroves provide habitats and nursery areas for many organisms. Their root systems also trap sediment and help stabilise coastlines. Conserving them can therefore maintain biodiversity while also reducing coastal erosion and supporting nearby fisheries.

Why are coral reefs important even if humans do not live on them?

Coral reefs provide habitats for many marine species and support complex food webs. Healthy reefs can also support fisheries, tourism and coastal protection. Damage to the coral habitat can therefore have ecological and human consequences far beyond the individual coral organisms.

Does a balanced ecosystem mean that every population remains constant?

No. Population sizes naturally fluctuate. Births, deaths, migration, disease, food availability and predator–prey relationships continually change population numbers. A balanced ecosystem is one in which these interactions can continue without major disruption that causes the system to break down.

Conservation becomes much easier to understand when you stop thinking about species in isolation. Every species exists within a habitat and interacts with other organisms. Protecting biodiversity therefore means protecting those connections as well as the organisms themselves. By conserving species, protecting important ecosystems and using natural resources sustainably, humans can continue benefiting from nature without exhausting the biological systems on which those benefits depend.