What are ecosystem services?
Ecosystems are communities formed by the interaction between living (plants, animals, microbes) and non-living organisms (air, water, mineral soil).
Human beings are both part of ecosystems and benefit from ecosystems in many ways. The benefits are known as ECOSYSTEM SERVICES.
Ecosystems contribute to global agricultural productivity in a variety of ways.
For instance, the total economic value of insect pollination worldwide is estimated at EUR€153 billion, representing 9.5% of world agricultural output in 2005.
In a coffee plantation in Costa Rica, services from wild pollinators (honey bees + 10 native species of insects) living in native rainforest patches embedded in the coffee farm were worth $60,000/year.
These forests also provided habitat for birds like the Costa Rican yellow warblers who prey on coffee pests (like the coffee borer beetle), saving a medium-sized coffee farm up to US$9,400 over a year’s harvest — roughly equal to Costa Rica’s average per-capita income. On one farm, hungry birds warded off beetles from coffee beans worth around 4% of the total value of the annual crop. [read more]
Another example of ecosystem services contributing to agricultural productivity can be found in wetlands.
Wetlands provide fresh, clean water, regulate pollution, and reduce climate risk and uncertainty for people, agriculture and aquaculture (fisheries). They are also hotbeds of biodiversity and are home to a vast range of animals, especially bird species.
In the Barotse Floodplain in Zambia, local use of wetland resources was found to have a net economic value of $8.64 million a year. Agricultural cultivation of just 10% of the Barotse floodplain (about 28,000 ha of maize, rice, sweet potato, sugarcane, fruits and vegetables) supports approximately 27,500 households and is estimated to be worth $2.34 million.
Floodplain farming systems are diverse, and include raised gardens (Lizulu), rain-fed village gardens (Litongo), seepage gardens (wet Litongo), drained seepage gardens (Sishango), lagoon gardens (Sitapa) and riverbank gardens (Litunda).
Fish are also an important source of protein, and local fish consumption is 5 times the national average. In Africa, where many people cannot afford to practice aquaculture, the contribution of inland wild fisheries (from lakes, rivers, wetlands) to the livelihoods of people is much greater than that of cultured fisheries. [read more]
In the same area, 265,000 head of cattle (3/4 of the total cattle in the Western Province) that graze on the floodplain are valued at approximately $3 million.
In addition, reeds and papyrus collected from the Barotse floodplain wetland in Zambia are estimated to have a value to local communities of $373,000 y-1.
Agricultural practices can also improve ecosystem services, which leads to a win-win scenario
For instance, rotating maize and wheat in China has resulted in reduced use of chemical pesticides and fertilizers. This in turn provides a habitat for natural pest eaters, like ladybugs that feed on cotton aphids. Cotton farmers benefit from this form of natural pest control, and end up saving an estimated $4.95USD for every ladybug per 100 plants. Just for comparison, chemical pesticides would cost US$8.57/ha for every kg while decreasing the ladybug population density significantly. [read more]
Another example comes from Ecuador, where mixtures of common bean varieties have been found to reduce the severity of common bean rust by up to 50%. Improved drought tolerance from planting mixtures also resulted in yield improvement by up to 32%. This is significant, given that a 1% increase in bean rust severity leads to a yield loss of approximately 19 kg/ha. [read more]
Attracting pollinators is another way to increase agricultural productivity while supporting healthy and more diverse ecosystems.
In India, selected shade trees were planted on coffee and cardamom farms. The temperature control these trees provide in April help to keep pollinators on-farm between flowering of coffee in March and the flowering of cardamom, which starts in May.
Pollinators have different tastes, physiologies, and are active at different times of the year. Birds typically visit red flowers with long, narrow tubes and lots of nectar, while bee proboscis length affects the type of foraging they can do. Accounting for these differences by diversifying crops not only lead to increased agricultural yields: birds can act as natural pest control; bees produce honey; and the buzz frequency of bumblebees actually encourages tomato pollination. [read more]