Ecosystem Services
Ecosystem services are the benefits that humans receive from nature. It easy to think of clean drinking water, timber, climate regulation or recreational spaces, but there are many, many more.
In fact, scientists have discussed about them for decades, but the concept was popularized in the early 2000s by the Millennium Ecosystem Assessment. Adopting this notion of “services” was an important step to change the perspective on these benefits, provided for free by healthy ecosystems, and to manage them differently.
Ecosystem services encompass a wide range of benefits but they can be grouped into four broad categories:
– Provisioning services
The products obtained from ecosystems. Forests provide us timber, wild food (e.g. mushrooms, Brazilian nuts), fresh water, medicinal resources, etc.
– Regulating Services
The benefits obtained from the regulation of ecosystem processes. Forests regulate the global climate by capturing carbon dioxide from the atmosphere, and help to diminish soil erosion and to moderate extreme events, such as floods, avalanches or landslides. Restoring mangroves, for example, is a well-known tool to protect coastlines from storm damage. In urban environments forests improve local climate and air quality by providing shade and removing air pollutants.
– Cultural services
These include non-material benefits, such as recreation, health, spiritual enrichment, and aesthetic values. Among tourists who enjoy nature and wildlife, forests are an increasingly popular destination. In our daily life, walking or doing other sports in nearby forests helps us to maintain our physical and mental health.
– Supporting services
Refers to the services necessary for the production of all other ecosystem services, such as soil formation, nutrient cycling and primary production.
As we can see, forests – and other ecosystems – provide us numerous services that are vital for our well-being. Yet, many ecosystems have been degraded due to our human activities. Because we do not usually pay a price for ecosystem services, we under-appreciate their value and give them little weight in our decision making.
Here is where the concept of valuation – the process of expressing a value for a particular good or service – comes in handy. We assign a value in terms of money (e.g. by estimating the value of harvested timber or calculating how much would it cost to purify water if a forest is cleared) but we also consider non-market values such as improvements in public health outcomes, societal preferences, and intrinsic value.
The economic valuation of ecosystem services is a complex topic (especially for regulating and cultural services) but methods have improved in recent years and market-based mechanisms are promoting the conservation and sustainable management of natural resources.
Through the payment for ecosystem services scheme, resource users pay the providers for maintaining an ecosystem service. For example, water users or an hydropower company pay farmers who live in the upper watershed to protect and manage it.
The human factor
Humans have had an adverse impact on nature: habitat destruction, pollution, species extinction, climate change, etc. However, humans have also transformed many landscapes in a more sustainable way, creating tight interdependent links between the human and natural systems.
In Europe and elsewhere, humans have been shaping natural landscapes over thousands of years. As such, when we consider the long and broad influence people have on nature, any attempt to restore ecosystems should also consider the relationship between humans and their environment.
Countryside landscapes
Traditional agroforestry systems – any land use system integrating trees and agriculture (crops or pasture/livestock) – are numerous throughout Europe. One of them is a 4,500-year-old system known as Dehesa (in Spain) or Montado (in Portugal).
This system consists of oak woodlands (Quercus ilex and Q. suber) where livestock (sheep, pigs, cattle) is released to feed on the acorn mast that falls from the trees. In addition, the system is also used for the cultivation of cereals and the production of firewood, charcoal and cork. Shade from the trees improves microclimatic conditions in the soil and air (milder radiation, temperature and dryness), which can favour the growth of fodder crops (e.g. oats).
This type of systems represent a productive and integrated land use alternative in the Mediterranean region, where are arable farming is sometimes unprofitable due to the hot and dry climatic conditions. Furthermore, Dehesas provide habitats for many species of conservation interest and have high aesthetic and recreational values (tourism). Still today, this is the most widely-used agroforestry system in Europe.
Nonetheless, the protection of Dehesas and other wood-pastures is challenging. Many of them are being abandoned as people move from rural areas to cities, and dense vegetation grows out of control. The vegetation growth, combined with climate change and the planting of profitable but combustible trees (Eucalyptus), is in turn increasing the extension and intensity of wildfires.
Urban landscapes
Cities, another man-made landscape, are usually seen as isolated from nature. However, as more and more people live in cities, we are realizing that urban nature is critical for our well-being.
Urban forests bring us many benefits: sustainable production of fuelwood, removal of air pollutants, shading and cooling, provision of recreational opportunities, improvement of mental and physical health, among others. For this reason, several cities around the world have launched initiatives and programs to promote green areas. To ensure that citizens are willing to protect and manage their urban forests, it is important to understand their needs of “public space” and to transform spaces into places that people want to visit and enjoy.
Suggested readings:
- Nerlich, K., Graeff-Hönninger, S. & Claupein, W. Agroforest Syst (2013) 87: 475. Available at: https://doi.org/10.1007/s10457-012-9560-2
- Agroforestry in Europe: http://agroforestry.eu/
- A guide to agroforestry: http://www.tubex.com/media/download_gallery/Tubex_AgroforestryGuide_EN.pdf
- FAO Guidelines on urban and peri-urban forestry: http://www.fao.org/3/a-i6210e.pdf
