Because of this link, estuarine systems are among the most biologically productive in the world.
Estuaries support many resident species.
Estuaries also provide food, spawning area, and shelter for numerous other species at critical points in their life cycles. Removal of shoreline trees reduces the overall productivity of the estuary by reducing leaf and litter fall, thus depriving the estuary of substrate, and by removing feeding and resting habitat for birds and small mammals. Bog communities are a result of specific hydrologic, soil, and nutrient conditions. Bogs are usually saturated, low in nutrients, and highly acidic. The peat soils have evolved over time.