Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida, 32611, USA.
School of Natural Resources and the Environment, University of Florida, Gainesville, Florida, 32611, USA.
Ecol Appl. 2020 Oct;30(7):e02155. doi: 10.1002/eap.2155. Epub 2020 Jun 1.
Human demand for food, fiber, and space is accelerating the rate of change of land cover and land use. Much of the world now consists of a matrix of natural forests, managed forests, agricultural cropland, and urbanized plots. Expansion of domestic energy production efforts in the United States is one driver predicted to influence future land-use and land management practices across large spatial scales. Favorable growing conditions make the southeastern United States an ideal location for producing a large portion of the country's renewable bioenergy. We investigated patterns of bat occurrence in two bioenergy feedstocks commonly grown in this region (corn, Zea mays, and pine, Pinus taeda and P. elliottii). We also evaluated potential impacts of the three major pathways of woody biomass extraction (residue removal following clearcut harvest, short-rotation energy plantations, and mid-rotation forest thinning) to bat occurrence through a priori land-use contrasts. We acoustically sampled bat vocalizations at 84 sites in the Southeastern Plains and Southern Coastal Plains of the southeastern United States across three years. We found that mid-rotation thinning resulted in positive effects on bat occurrence, and potential conversion of unmanaged (reference) forest to managed forest for timber and/or bioenergy harvest resulted in negative effects on bat occurrence when effects were averaged across all species. The effects of short-rotation energy plantations, removal of logging residues from plantation clearcuts, and corn were equivocal for all bat species examined. Our results suggest that accelerated production of biomass for energy production through either corn or intensively managed pine forests is not likely to have an adverse effect on bat communities, so long as existing older unmanaged forests are not converted to managed bioenergy or timber plantations. Beyond bioenergy crop production, mid-rotation thinning of even-aged pine stands intended for timber production, increases to the duration of plantation rotations to promote older forest stands, arranging forest stands and crop fields to maximize edge habitat, and maintaining unmanaged forests could benefit bat communities by augmenting roosting and foraging opportunities.
人类对食物、纤维和空间的需求正在加速改变土地覆盖和土地利用的速度。现在，世界上大部分地区由天然森林、人工林、农业耕地和城市化土地组成的矩阵组成。美国国内能源生产的扩张是预计将影响未来土地利用和土地管理实践的驱动力之一，其影响范围很大。有利的生长条件使美国东南部成为生产该国大部分可再生生物能源的理想地点。我们研究了在该地区常见的两种生物能源饲料（玉米、Zea mays 和松树、Pinus taeda 和 P. elliottii）中蝙蝠出现的模式。我们还通过事先的土地利用对比，评估了木质生物质提取的三种主要途径（清除采伐后的残留物、短轮伐期能源种植园和中轮伐期森林疏伐）对蝙蝠发生的潜在影响。我们在三年内，在美国东南部的东南部平原和南部沿海平原的 84 个地点，通过声学方法对蝙蝠的叫声进行了采样。我们发现，中轮伐期疏伐对蝙蝠的出现有积极的影响，而将未管理的（对照）森林转化为用于木材和/或生物能源收获的管理森林，当所有物种的影响平均化时，对蝙蝠的出现有负面影响。对于所有检查的蝙蝠物种，短轮伐期能源种植园、种植园清除采伐后的残留物去除以及玉米的影响都是不确定的。我们的研究结果表明，只要现有的未管理的旧森林不被转换为管理的生物能源或木材种植园，通过玉米或集约化管理的松树森林加速生产生物质用于能源生产不太可能对蝙蝠群落产生不利影响。除了生物能源作物生产外，即使是为木材生产而进行的同龄松林的中轮伐期疏伐、延长种植园轮作时间以促进较老的林分、安排林分和农田以最大限度地利用边缘生境、以及保持未管理的森林，都可以通过增加栖息和觅食机会，使蝙蝠群落受益。
