Wetland Creation, Restoration, and Conservation

Water-dominated landscapes include wetland areas. The term “wetland” has not been commonly used until quite recently. It is believed to be a euphemistic equivalent of “swamp.” Every year on the second day of February, World Wetlands Day marks the adoption of the convention on Wetland by Ramsar, the Iranian city that has a special place in Iranian history. Flood protection, water quality improvement, shoreline erosion control, natural products, recreation, and aesthetics are some of the many advantages of wetlands, as well as the fact that they are vital habitats for a variety of animals and plants. Several studies illustrated the importance of wetlands in reducing carbon emissions and regulating climate on a global scale. In recent years, these advantages of wetlands have been recognized by governments worldwide and have led to legislation, regulations, and management plans creating wetlands for conservation, protection, and restoration. Unfortunately, the destruction of wetlands is a concern since they are among the planet's most productive areas.

Effects of Grazer Exclusion on Carbon Cycling in Created Freshwater Wetlands

Wetland ecosystems play a significant role in the global carbon cycle, and yet are increasingly threatened by human development and climate change. The continued loss of intact freshwater wetlands heightens the need for effective wetland creation and restoration. However, wetland structure and function are controlled by interacting abiotic and biotic factors, complicating efforts to replace ecosystem services associated with natural wetlands and making ecologically-driven management imperative. Increasing waterfowl populations pose a threat to the development and persistence of created wetlands, largely through intensive grazing that can shift vegetation community structure or limit desired plant establishment. This study capitalized on a long-term herbivore exclusion experiment to evaluate how herbivore management impacts carbon cycling and storage in a created wetland in Western New York, USA. Vegetation, above- and belowground biomass, soil carbon, carbon gas fluxes and decomposition rates were evaluated in control plots with free access by large grazers and in plots where grazers had been excluded for four years. Waterfowl were the dominant herbivore at the site. Grazing reduced peak growing season aboveground biomass by over 55%, and during the summer, gross primary productivity doubled in grazer exclusion plots. The shift in plant productivity led to a 34% increase in soil carbon after exclusion of grazers for five growing seasons, but no change in belowground biomass. Our results suggest that grazers may inhibit the development of soil carbon pools during the first decade following wetland creation, reducing the carbon sequestration potential and precluding functional equivalence with natural wetlands.

Outsized effect of predation: Wolves alter wetland creation and recolonization by killing ecosystem engineers

Gray wolves are a premier example of how predators can transform ecosystems through trophic cascades. However, whether wolves change ecosystems as drastically as previously suggested has been increasingly questioned. We demonstrate how wolves alter wetland creation and recolonization by killing dispersing beavers. Beavers are ecosystem engineers that generate most wetland creation throughout boreal ecosystems. By studying beaver pond creation and recolonization patterns coupled with wolf predation on beavers, we determined that 84% of newly created and recolonized beaver ponds remained occupied until the fall, whereas 0% of newly created and recolonized ponds remained active after a wolf killed the dispersing beaver that colonized that pond. By affecting where and when beavers engineer ecosystems, wolves alter all of the ecological processes (e.g., water storage, nutrient cycling, and forest succession) that occur due to beaver-created impoundments. Our study demonstrates how predators have an outsized effect on ecosystems when they kill ecosystem engineers.