Ecological/Ecosystem Services

Ecological / Ecosystem Services

Ecosystem services are the many benefits that plant communities and the wider ecosystems they form provide to the environment and to human life, often without any deliberate human effort or payment. These services are frequently taken for granted precisely because they are delivered continuously and invisibly by ordinary, healthy plant communities, yet the wellbeing of both natural ecosystems and human societies depends heavily on them.

One of the clearest examples of an ecosystem service is pollination. A very large proportion of flowering plants — including many of the food crops humans depend on — cannot set seed or fruit without their flowers being pollinated, and this pollination is carried out largely by animal pollinators such as bees, butterflies, and certain birds. In providing nectar and pollen as a reward, plants support stable populations of these pollinators, and in return the pollinators enable the reproduction of both wild plant species and cultivated crops. This is a two-way ecological relationship: plant communities sustain pollinator populations, and pollinator populations, in turn, sustain the reproduction — and therefore the very survival — of the plant communities and crops that depend on them.

Two further vital ecosystem services are delivered directly through photosynthesis: carbon fixation and oxygen release. During photosynthesis, green plants absorb atmospheric carbon dioxide and use it to build organic compounds within their own tissues — in effect locking away, or "fixing," carbon that would otherwise remain in the atmosphere as a greenhouse gas. Carried out across entire forests, grasslands, and other plant communities, this fixation of atmospheric carbon dioxide is one of the most important natural processes moderating the level of greenhouse gases in the atmosphere. At the same time, photosynthesis releases oxygen as a byproduct, and it is this continuously replenished atmospheric oxygen that sustains the aerobic respiration of virtually all animal and plant life, including humans. …