Manage forests carefully

Dear Editor,

Producers in the Republican River watershed are facing serious water challenges, with many actions being proposed to save water.

One proposal, which suggests removing the riparian (streamside) forests growing along the Republican River, is based on the assumption that tree removals will increase water flow. Such action needs to be carefully evaluated to make sure unintended consequences do not in fact make the situation worse.

While I recognize the seriousness posed by the continuing drought and pressure to meet Nebraska's water agreements with Kansas, removal of these riparian forests would have severe and lasting impacts on the river. These impacts would extend to the surrounding area's ecology and the residents of the valley. Early explorers and fur traders consistently noted substantial riparian forests along most rivers in the Great Plains, including the Republican River. Trees along streams are a natural, native component of riparian systems in the Plains and provide critically important benefits to people. Riparian trees absorb the energy of rushing floodwaters, reducing erosion damage to levees and crop ground and ensure that more water remains in the immediate area for groundwater recharge.

They substantially improve water quality by filtering both surface and subsurface waters, arresting streambank soil erosion (by 77-97 percent based on studies in Iowa), removing nutrients and pollutants and capturing and storing snow for later recharge. Shade cools the water in the river, protects and enhances fish habitat and reduces evaporation losses. These important forests provide vital habitat to a wide range of wildlife -- both game and non-game. They provide essential stop-over points for migrating wildlife, particularly songbirds and waterfowl, and serve as primary nesting sites for Baltimore orioles and kingbirds.

It is obvious that trees and forests use water, but it would be risky to base large-scale policy claims of extraordinarily high rates of water use by riparian forests. Complete removal of these forests, and eradication of vegetation from the riparian zone, may potentially increase the quantity of the water in the river; however, it would come at a huge cost to the environment and people within the valley. Further, if all trees were removed from the riparian zone, they would be quickly replaced by a dense growth of tree seedlings, shrubs, grasses, forbs -- and potential invasive exotics in the newly exposed areas.

Preliminary research by the U.S. Geological Survey along the Platte River, as well as several other studies in Arizona and Israel, indicate that the lush growth of these riparian plants would use nearly as much water as the larger (but much more widely spaced) trees. And practically speaking, the cost of removing up to 37,500 acres of mature forest in the valley, and then keeping these acres weed-free would be prohibitively expensive.

Would tributary forests be cleared and kept free of trees as well? What about the environmental impacts of using herbicides on a massive scale adjacent to water courses to eliminate the constant regeneration of trees and shrubs?

In the long run, sound management of riparian and upland forests in the watershed is the best course of action. Periodic and environmentally appropriate harvesting of mature cottonwood and other commercial tree species growing in riparian forests would retain the forest community and foster improved and sustainable management of this valuable resource.

It would preserve the many valuable benefits generated by these forests and stimulate rural economic development through the sale and processing of trees for wood products and biofuels. Riparian forest management should also include the aggressive removal of exotic invasive plants, such as saltcedar (Tamarix sp.). This woody species is invading the Republican River Valley, especially the dry lakebeds, and uses far more water than native cottonwoods, outcompetes native plants and degrades habitats

The Nebraska Forest Service, as part of the University of Nebraska, appreciates the complexity of the issues facing producers and landowners in the Republican River watershed. We stand ready to assist landowners and communities in the proper management of the forest resource this region.

Sincerely,

Dr. Scott J. Josiah

State Forester and Director, Nebraska Forest Service

University

of Nebraska-Lincoln