Cooperate Within an Ecosystem
An ecosystem is a community of organisms (plants, animals, and microbes) interacting with one another and the nonliving components of their environment (such as air, water, and mineral soil). This interaction can be passive or active, and can cooperatively enhance the functioning of the ecosystem as a whole. For cooperation to contribute to maintaining communities within an ecosystem, it must be beneficial to at least some members of the community. Cooperation consists of symbiotic relationships, such as mutualism (in which two or more species in an ecosystem benefit) and commensalism (in which one species benefits and the effect on others is neutral). An example of a commensal relationship is that between bromeliad plants and trees: bromeliads live on trees without harming them. Bromeliads have mutualistic relationships with other species, including insects, frogs, and worms. The plants capture water in their base, forming a pond that these organisms join. The nutrients that these organisms excrete in their droppings nourish the bromeliad.
Manage Disturbance in a Community
When environmental conditions change, they can disrupt an ecosystem’s equilibrium. Excessive rain can cause flooding and drought can cause forest fires. An ecosystem must be resilient to such disturbances. Disturbances are unpredictable in location, size, and intensity, so ecosystems must be able to regrow and must have a variety of duplicate forms, processes, or systems that are dispersed in location. For example, a forest ecosystem can recover from fire because diverse organisms play different roles in different ways and in different locations. Many organisms can resprout or grow from seeds triggered by fire, and their dispersed distribution ensures that an entire population isn’t decimated. Though the recovered ecosystem may look totally different from the pre‑fire one, the ecosystem as a whole remains healthy.
Regulate Water Storage
Maintaining water onsite is an important function of ecosystems. Ecosystems and the organisms that comprise them depend upon water for chemical processes, and therefore for life. But because water is subject to gravity, keeping it onsite can be a challenge. The solution to this is some sort of water storage, which can occur in soils, on top of the ground, or within tissues of living or dead organisms. For example, some trees play a role in supporting water storage in their ecosystem. Unlike pine trees (which keep their needles year‑round, losing water to transpiration and evaporation), oak trees lose their leaves during the fall and winter. This leaf loss allows more rain to run down their branches and trunks and into the soil, where much of it will be available to the trees and other organisms in the spring.
Control Erosion and Sediment
Ecosystems must maintain their soils on site and prevent it from being washed away. Organic matter, minerals, and other nutrients in soil support organisms from microorganisms to the largest mammals. But because of the pull of gravity, water flows unless impeded. Therefore, the presence and actions of many, diverse organisms hold soils in place and slow water to allow sediments to settle out rather than be washed downhill. For example, in forests, downed logs that fall crossways to the slope efficiently slow water flow, trapping soils carried by the water and causing water to soak into the soil. In areas lacking logs and other structures, water can flow so fast that it cuts into the soil, causing erosion that washes the soil away.
Pollinate
One of the ways that plants can produce offspring is by making seeds that contain the genetic information to produce a new plant. Seeds can only be produced when pollen grains reach the hidden ovaries within a flower. Flowers have developed wildly diverse forms and activities, such as the production of sweet nectar to attract organisms such as bees and butterflies, that move from flower to flower, transferring pollen. Flowers will also adapt to make use of environmental influences such as wind and water as pollinators.
