Bird communities and biomass yields in potential bioenergy grasslands

• Published in: PloS one Vol. 9; no. 10; p. e109989
• Main Authors: Blank, Peter J, Sample, David W, Williams, Carol L, Turner, Monica G
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 09.10.2014; Public Library of Science (PLoS)
• Subjects: Agricultural commodities; Agricultural management; Agricultural production; Alternative energy sources; Andropogon gerardii; Animal breeding; Animals; Biodiesel fuels; Biodiversity; Biological diversity conservation; Biology and Life Sciences; Biomass; Biomass energy; Bird populations; Birds; Birds - physiology; Breeding; Climate change; Communities; Conservation; Conservation biology; Conservation of Natural Resources; Corn; Crop; Crop production; Crop yield; Crops; Density; Ecology and Environmental Sciences; Ecosystem; Energy Metabolism; Engineering and Technology; Environmental protection; Grasses; Grassland; Grassland management; Grasslands; Habitats; Landscape preservation; Monoculture; Natural resources; Panicum virgatum; Parcels; Poaceae; Population Dynamics; Raw materials; Renewable energy; Species richness; Studies; Vegetation; Wildlife conservation; Wildlife management; Yield; Zea mays; Zoology; New York; United States > US; Wisconsin
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0109989

Demand for bioenergy is increasing, but the ecological consequences of bioenergy crop production on working lands remain unresolved. Corn is currently a dominant bioenergy crop, but perennial grasslands could produce renewable bioenergy resources and enhance biodiversity. Grassland bird populations have declined in recent decades and may particularly benefit from perennial grasslands grown for bioenergy. We asked how breeding bird community assemblages, vegetation characteristics, and biomass yields varied among three types of potential bioenergy grassland fields (grass monocultures, grass-dominated fields, and forb-dominated fields), and assessed tradeoffs between grassland biomass production and bird habitat. We also compared the bird communities in grassland fields to nearby cornfields. Cornfields had few birds compared to perennial grassland fields. Ten bird Species of Greatest Conservation Need (SGCN) were observed in perennial grassland fields. Bird species richness and total bird density increased with forb cover and were greater in forb-dominated fields than grass monocultures. SGCN density declined with increasing vertical vegetation density, indicating that tall, dense grassland fields managed for maximum biomass yield would be of lesser value to imperiled grassland bird species. The proportion of grassland habitat within 1 km of study sites was positively associated with bird species richness and the density of total birds and SGCNs, suggesting that grassland bioenergy fields may be more beneficial for grassland birds if they are established near other grassland parcels. Predicted total bird density peaked below maximum biomass yields and predicted SGCN density was negatively related to biomass yields. Our results indicate that perennial grassland fields could produce bioenergy feedstocks while providing bird habitat. Bioenergy grasslands promote agricultural multifunctionality and conservation of biodiversity in working landscapes.