The Water Web
Examples
River-Salmon-Bear-Redwood
On the west coast of North America, salmon swim up streams, where they are eaten by bears. The bears then poop, supplying nutrients to the redwood trees. Often, 20-80% of nitrogen in redwood forests comes from salmon.
The redwood forests slow down the rain after it hits the ground. Some of the rainwater seeps underground, where it can come out months later to keep rivers running into the dry season.
The river and the forest help each other in a feedback loop, the river supplying nutrients to the forest via the salmon and the bear, and the forest keeping the river running year round...
The redwood forests also increase rain. They do this by first evapotranspiring enough water vapor that the water in the air increases above the saturation point, and condenses into clouds, and by secondly, slowing the wind, so the water vapor molecules in the air can bump into each other, and nucleate into rain...
The redwood forests evapotranspire water vapor which ‘moisture hops’ inland (moisture hopping is defined as when water moves from land to air, gets carried by the wind, and then rains down onto the land again). The inland forest thus will get extra rain... That rain that falls in the inland forest then traverses rivers and aquifers to feed the closer-to-the-coast redwood forest.[1]