Projected gains and losses of wildlife habitat from bioenergy‐induced landscape change

Abstract

Domestic and foreign renewable energy targets and financial incentives have increased demand for woody biomass and bioenergy in the southeastern United States. This demand is expected to be met through purposegrown agricultural bioenergy crops, short-rotation tree plantations, thinning and harvest of planted and natural forests, and forest harvest residues. With results from a forest economics model, spatially explicit state-and-transition simulation models, and species-habitat models, we projected change in habitat amount for 16 wildlife species caused by meeting a renewable fuel target and expected demand for wood pellets in North Carolina, USA. We projected changes over 40 years under a baseline 'business-as-usual' scenario without bioenergy production and five scenarios with unique feedstock portfolios. Bioenergy demand had potential to influence trends in habitat availability for some species in our study area. We found variation in impacts among species, and no scenario was the 'best' or 'worst' across all species. Our models projected that shrub-associated species would gain habitat under some scenarios because of increases in the amount of regenerating forests on the landscape, while species restricted to mature forests would lose habitat. Some forest species could also lose habitat from the conversion of forests on marginal soils to purpose-grown feedstocks. The conversion of agricultural lands on marginal soils to purpose-grown feedstocks increased habitat losses for one species with strong associations with pasture, which is being lost to urbanization in our study region. Our results indicate that landscape-scale impacts on wildlife habitat will vary among species and depend upon the bioenergy feedstock portfolio. Therefore, decisions about bioenergy and wildlife will likely involve trade-offs among wildlife species, and the choice of focal species is likely to affect the results of landscape-scale assessments. We offer general principals to consider when crafting lists of focal species for bioenergy impact assessments at the landscape scale.

Impact of increased wood pellet demand on biodiversity in the south‐eastern United States

“…Wood pellet production was projected to lead to habitat increases for some species but decreases for others, indicating that land‐use transitions will lead to both winners and losers. However, Tarr et al () assessed just one state (North Carolina) within the wood pellet producing region. Studies have identified regions of potential biodiversity risk due to feedstock harvesting for wood pellets, including coastal Georgia and Virginia (Olesen et al, ), Florida and the Atlantic coastal area (Galik & Abt, ).…”

“…Studies have identified regions of potential biodiversity risk due to feedstock harvesting for wood pellets, including coastal Georgia and Virginia (Olesen et al, ), Florida and the Atlantic coastal area (Galik & Abt, ). Species at risk included threatened species such as the Cerulean Warbler (Setophaga cerulean) and Eastern Spotted Skunk (Spilogale putorius) (Evans et al, ; Tarr et al, ). The area of dense, shrubby vegetation may increase in bioenergy scenarios, providing additional habitat for some species including the southeast endemic Oak Toad ( Anaxyrus quercicus ) (Tarr et al, ).…”

“…Species at risk included threatened species such as the Cerulean Warbler (Setophaga cerulean) and Eastern Spotted Skunk (Spilogale putorius) (Evans et al, ; Tarr et al, ). The area of dense, shrubby vegetation may increase in bioenergy scenarios, providing additional habitat for some species including the southeast endemic Oak Toad ( Anaxyrus quercicus ) (Tarr et al, ). Spatially explicit studies on the impacts of woody biomass production on biodiversity in the south‐eastern United States have assessed the impacts either for a limited number of species (Evans et al, ; Olesen et al, ) or for a restricted area in the wood pellet sourcing region (Galik & Abt, ; Tarr et al, ).…”

“…The area of dense, shrubby vegetation may increase in bioenergy scenarios, providing additional habitat for some species including the southeast endemic Oak Toad ( Anaxyrus quercicus ) (Tarr et al, ). Spatially explicit studies on the impacts of woody biomass production on biodiversity in the south‐eastern United States have assessed the impacts either for a limited number of species (Evans et al, ; Olesen et al, ) or for a restricted area in the wood pellet sourcing region (Galik & Abt, ; Tarr et al, ). Using broad taxonomic groups as indicators has been identified as a research need in the study of biodiversity impacts of bioenergy (Fletcher et al, ; Immerzeel et al, ; Riffell, Verschuyl, Miller, & Wigley, ; Verschuyl, Riffell, Miller, & Wigley, ), partly because of contradictory findings for selected species groups as indicators (Dauber et al, ).…”

Alternative biomass strategies for bioenergy: implications for bird communities across the southeastern United States

“…Three major harvest methods for extracting biomass from pine plantations include (i) biomass from thinning conventional pine plantations (‘thinning’); (ii) the harvest of coarse woody debris (CWD) residues from clear‐cuts (‘residue harvest’); and (iii) the conversion of conventional timber stands to short‐rotation energy plantations (‘SREP’) (Munsell & Fox, ). Meta‐analyses and scenario modeling have provided key insights regarding effects of these crops and potential wildlife responses (Fletcher et al ., ; Riffell et al ., ,b; Verschuyl et al ., ; Tarr et al ., ) and some recent investigations have provided useful information for specific alternatives (Homyack et al ., ; Fritts et al ., ; Grodsky et al ., ). Yet the extent to which these harvest methods differentially impact wildlife is largely unknown, as a systematic land‐use comparison across each of these land uses has not yet been done to allow formal comparison among these alternatives.…”