Rainforest Goods, Services and Climate Change

Physical goods and wider benefits

A tropical rainforest is more than a collection of trees. Its plants, animals, soils and water interact to form an ecosystem that supports people locally and benefits people far beyond the forest. These benefits can be divided into goods, which are physical products, and services, which are benefits provided by the ecosystem's processes or the opportunities it offers.

Foodstuffs include fruits, nuts and spices. These provide food for people and can be collected and sold to earn an income. Timber is another good: wood is used for construction, furniture and fuel for heating or cooking. Rainforest plants also provide products such as rubber and resins.

Medicines are an important example because plant chemicals can be used to develop treatments. The Madagascan rosy periwinkle provides compounds used in medicines to treat childhood leukaemia. This does not mean that eating the plant is a treatment: the plant can be poisonous, and medicinal compounds must be processed and used appropriately. Losing plant species can also mean losing potentially useful medicinal resources.

Recreation is a service rather than a good. People can visit rainforests to enjoy the landscape and observe wildlife. Tourism and recreation can provide employment and income, while the forest also has cultural and spiritual importance for communities who live there.

Services that keep the environment functioning

Rainforests help regulate climate. Trees absorb carbon dioxide during photosynthesis and store carbon in their biomass. A forest acts as a carbon sink when it absorbs more carbon than it releases. This helps limit the accumulation of carbon dioxide in the atmosphere and therefore helps limit global warming.

Rainforests also influence the water cycle. Their canopies intercept rainfall, and trees return water to the atmosphere through transpiration. This moisture contributes to cloud formation and rainfall. In the Amazon, the forest helps generate regional rainfall and lower land-surface temperatures, so its influence extends beyond individual trees or habitats.

Tree roots bind soil together, reducing the amount washed away by rainfall. The forest also provides habitats for many different species. These services are connected: healthy vegetation protects soils, supports wildlife and helps maintain water and carbon cycling. Damage to the forest can therefore reduce several benefits at once.

Three connected ways climate change threatens rainforests

Climate change means long-term changes in temperature and other climate conditions, including rainfall. Rainforests depend on warm, moist conditions, but further warming and changes in rainfall can place them under stress. Some regions face longer or more severe dry periods; the effects are not identical across all tropical rainforests.

To understand the threat, distinguish three aspects of an ecosystem:

• Structure is its physical organisation, such as the canopy, lower vegetation layers and amount of living biomass.
• Functioning means processes such as nutrient cycling, water cycling and carbon storage.
• Biodiversity is the variety of living organisms it supports.

These aspects depend on one another. Losing canopy trees changes the forest's structure, disrupts its processes and removes habitats.

Heat, drought and fire can change forest structure

Higher temperatures combined with reduced moisture can make it harder for plants to grow and survive. Prolonged drought can kill trees, while drier vegetation increases the risk of wildfire. Tree death and fire reduce living biomass and create gaps in the canopy, changing the forest's layered structure.

Where vegetation and roots are lost, soil is less well protected against erosion. The resulting damage to soil can make it more difficult for vegetation to recover. Rising sea levels can also threaten low-lying rainforest areas in river deltas, including the Amazon delta.

Disrupted processes can reinforce forest loss

Dry conditions can slow decomposition, reducing the release of nutrients from dead organic matter. This disrupts nutrient cycling and can limit the nutrients available for plant growth. Slower decomposition and the loss of living biomass are different effects: biomass declines when plant growth is reduced or trees die.

The water cycle can also be disrupted. Fewer trees mean less moisture is returned to the atmosphere, which can reduce the forest's contribution to cloud formation and rainfall. This can reinforce drying and place the remaining vegetation under greater stress.

Carbon regulation is threatened too. Dead or burning trees release stored carbon, while fewer living trees remain to absorb carbon dioxide. A severely damaged forest could change from a carbon sink into a net source of greenhouse gases, reinforcing global warming.

Habitat change threatens biodiversity

Rainforest species are adapted to particular conditions. If temperatures rise and moisture decreases, some species may move to areas with more suitable conditions. Others may be unable to move or adapt quickly enough, increasing their risk of extinction. Species suited to the new conditions may spread into the area, changing the community of organisms.

Tree loss also removes shelter, nesting sites and food sources. A decline in one species can affect others through feeding relationships, so biodiversity loss is not simply a matter of individual species becoming too hot or dry.

The Amazon illustrates how these threats can combine. Warming, drought and fire interact with pressures such as deforestation. Scientists warn that parts of the forest could cross a tipping point, after which extensive dieback could leave degraded forest or more open vegetation. Large-scale collapse is a risk, not a certain prediction. The important connection is that climate change threatens both the rainforest itself and the goods and services people depend on.

Goods and services

• Goods: foodstuffs such as fruits, nuts and spices; medicines, including compounds from Madagascan rosy periwinkle; timber for construction, furniture and fuel.
• Services: recreation and tourism, climate regulation, water cycling, habitat provision and protection against soil erosion.
• A carbon sink absorbs more carbon than it releases.

Climate-change threats

Structure: heat and drought stress plants; tree death and wildfire reduce biomass and open the canopy. Vegetation loss leaves soil more exposed to erosion. Sea-level rise threatens low-lying delta forests.

Functioning: dry conditions slow decomposition and nutrient cycling. Tree loss reduces moisture returned to the atmosphere and carbon uptake; burning and decay release stored carbon.

Biodiversity: changing conditions and habitat loss force migration, alter species communities and increase extinction risk where species cannot adapt quickly enough.

Connected effects

Warming and drought → tree loss → less moisture returned to the atmosphere → further drying.

Severe forest damage can turn a carbon sink into a greenhouse-gas source. Amazon dieback is a potential tipping-point risk, not an inevitable outcome.