Bioenergy and Biodiversity Together
In the past, conversion of existing land uses and cover types—such as agricultural lands—to poplar bioenergy farms on a large scale benefited biodiversity, and it has the potential to do so again. Poplars have been cultivated in the Northwest for decades. When large-scale tree farms were established previously—such as the nearly 30,000 acres near Boardman, Oregon—positive changes occurred in the abundance and distribution of wildlife. These large tree farms replaced irrigated agricultural and native shrub steppe, often resulting in dramatic increases in biodiversity. Studies showed that tree farms changed the abundance and distribution of deer, elk, songbirds, raptors, small mammals, herpetofauna, and invertebrates. For example, the abundance of deer and elk increased dramatically as the plantations developed. In addition, forest songbirds began breeding in the poplar farms.
We are studying the effects of tree farm establishment on biodiversity by focusing on vertebrate and invertebrate taxa whose populations often respond quickly to changes in their environments. At each of the poplar demonstration sites in Washington, Idaho, Oregon and California, we are comparing songbird and small mammal abundance and reproduction to the adjacent crop types or land uses that these demonstration sites replaced.
We are also sampling for pollinating insects in the poplar demonstration sites and adjacent crops. Preliminary results from the first year at the Idaho and Oregon sites found the abundance of small mammals, birds, and pollinating insects was similar between newly established poplar plantations and adjacent fields.
As the demonstration sites develop, we expect to see more wildlife compared to hay fields and other agricultural lands. Our research is intended to guide management decisions in the future as they pertain to poplar energy farm establishment and biodiversity concerns.