ECOLOGICAL Reducing Ecological Impacts of Shale Development: RECOMMENDED PRACTICES BUFFERS FOR THE APPALACHIANS © Mark Godfrey, TNC cological buffers are protected zones established around sensitive or critical areas — such as wildlife E breeding or hibernation habitats, streams, and wetlands — to lessen the impacts of human activity and land disturbance. Well pads, roads and pipelines developed for shale oil and gas development reduce and fragment native forests, rivers and natural grasslands, reducing the quality of migration, foraging and nesting habitats for fish and wildlife. Changes in land cover can also have a negative impact on water quality and watershed health. Ecological buffers may be used to reduce or minimize the risks of land use disturbance and proximity of infrastructure specifically associated with shale energy development. STATE OF THE ant to breeding, rearing and area can be more effective than frag- RESEARCH hibernation.2,4-11 Although these buffers mented buffers in providing fish and Significant research exists fill an important role, studies specific to wildlife habitat and preserving ecosystem documenting the importance and buffer widths needed to protect these health.2,3,6,17 Conservation strategies that effectiveness of maintaining riparian species are relatively limited. target landscape-scale planning, buffers around streams, lakes and including the configuration and connec- wetlands to minimize impacts to water Many factors influence the determina- tivity of buffers and cumulative watershed quality.1–3 Most of this research is derived tion of a buffer width that is effective, development are most effective at from monitoring responses to forestry including the targeted function of the supporting regional biodiversity.2,5,11,18–22 and agricultural practices. In addition to buffer (e.g., to reduce erosion or protect reducing development impacts to water raptor nesting habitat) and landscape Studies specific to habitats and species quality, riparian buffers have also been characteristics, like slope, geology and in the Appalachian region and to shale shown to provide habitat and movement vegetation.6,12–16 Riparian buffers that are energy infrastructure could improve the corridors for many species of birds, effective in maintaining species diversity effectiveness of conservation strategies mammals, reptiles, fish and inverte- are often wider than those required to as development expands. This document brates.4-6 reduce sedimentation. does not address buffers necessary to minimize ecological risks associated with Upland and interior buffers help lessen Width is not the only factor that deter- the transport, use, storage or disposal of impacts to species that rely on other mines buffer effectiveness; buffers that fracturing chemicals, nor does it address habitat types, such as caves or interior are continuous around the perimeter or buffers to minimize for air-quality impacts forest habitat, and protect areas import- along the length of a sensitive habitat associated with shale development. 1 Ecological Buffers | Reducing Ecological Impacts of Shale Development | nature.org/shale-practices | 2015 protect foraging habitat for small and Ecological Buffers semi-aquatic mammals, such as river otter and water shrew, and act as Interior forest and upland buffers can protect interior movement corridors for larger mammals forest areas, provide connectivity between different habitat like bobcat, red fox, deer and black types, and reduce disturbances to critical breeding and INTERIOR FOREST 4–6 nesting areas. BUFFER bear. Upland and interior buffers around caves and bat hibernacula can help lessen the disturbances to bats and other cave-dwelling species.7 Songbirds can be exposed to higher rates of nest predation and lose valuable habitat from the effects of energy CONNECTIVITY OF development.29-32 Riparian buffers of a BUFFERS sufficient width are able to support many riparian and woodland birds and have been associated with lower nest preda- tion rates, however they are unlikely to maintain most forest-interior bird RIPARIAN species that rely on large areas of intact BUFFER forest habitat.4,5 Reptiles and amphibians can lose critical aquatic, riparian and upland 1,300’ Riparian buffers Connectivity of WILDLIFE habitats used for foraging, overwintering, along streams, lakes 300’ buffers is essential ORGANIC MATTER breeding and nesting as a result of and wetlands can help AND DEBRIS in reducing impacts 11,18–20 200’ to lessen the impacts of FLOOD of development and energy development. The benefits CONTROL nearby development. allowing species and effectiveness of buffers around these Riparian areas also to move across the 100’ TEMPERATURE habitats vary widely between species.2,4,33 provide habitat for a landscape and access variety of plant and BUFFER WIDTH EROSION vital resources. Generally, conservation strategies that 0’ animal species and extend beyond riparian buffers and also Effective buffer width depends upon a protect water quality variety of factors, such as slope, vegetation maintain a connected landscape with and aquatic habitats. and function. relatively large areas of natural forest 34-41 Graphic adapted from Figure 2.38 of “Stream Corridor Restoration: Principles, Processes, and Practices” by the Federal Interagency Restoration Working Group and wetlands are more effective. Maintaining healthy stream and wetland habitats is also important to reptiles and amphibians during their aquatic life EVIDENCE OF IMPACT behavior that interferes with feeding and stage. For example, increased sediment rearing behavior or an abandonment of Disturbance to Fish and has been shown to reduce tadpole eggs or young.10,25,26 Development can Wildlife Habitat densities and smother eastern hellbend- also accelerate the spread of invasive Fish and wildlife need stream, riparian er salamander larvae.21,42 and upland habitat for breeding, nesting species that compete with native species and hibernation, as well as the ability to and alter Appalachian ecosystems.27,28 Fish and aquatic invertebrates can move through the landscape.4–6 Effects of be impacted by the effects of energy While buffers can lessen disturbances to energy development — including frag- development near streams, wetlands and wildlife and important habitat areas, mentation, noise and light pollution, vernal pools, including changes to stream many forest-dependent species still human activity, and the spread of invasive characteristics such as temperature, require protection of larger, high-quality species — can result in disturbance to light and sediment that can cause upland or interior habitat areas to survive and loss of these valuable habitat areas, changes in community structure.5,43-45 and reproduce.4–6 which can lead to reduced reproductive Freshwater mussels, which play an rates and changes in behavior.23,24 For Mammals can lose valuable habitat and important part in stream and lake example, disturbance around raptor the ability to move through the land- ecosystems by providing habitat and nests (i.e. hawks and eagles) during the scape as a result of habitat loss and influencing food availability, are one breeding season can result in avoidance fragmentation.4–6 Riparian buffers can example of a species that could be 2 Ecological Buffers | Reducing Ecological Impacts of Shale Development | nature.org/shale-practices | 2015 significantly improve water quality if buffer that does not extend shade to at headwater networks lack adequate least half of the stream or wetland might buffers.6 increase risk to the temperature regime, impacting fish and invertebrate commu- Wetland, vernal and floodplain nities.2,5,21,61 This risk is greater for complexes provide essential ecological cold-cool water habitats and species, functions, such as water storage, such as brook trout, that require cooler groundwater replenishment, and waters to survive and are less tolerant of sediment and nutrient retention that can large temperature fluctuations and be impacted by development.57,58 These therefore might require wider buf- Reptiles, like the eastern box turtle, need a variety of systems also contribute significantly to 5,34,56,62 habitats for foraging, breeding and nesting activities. fers. Maintaining riparian buffers and connectivity between local biodiversity, providing critical habitat areas is important. © Kent Mason habitat for diverse, and in many cases Regulate Sediment, Nutrients and rare, groups of species.59 Organic Matter negatively impacted by inadequate A major function of riparian buffers is to buffers. They are particularly sensitive to Stream Flow and Temperature control erosion and sedimentation by changes in water quality.46 The Appala- Loss of vegetated riparian buffers along stabilizing banks and filtering sediments chian region hosts dozens of freshwater streams, lakes and wetlands can result and nutrients.6,60,63 Sedimentation can mussel species, several of which are in a loss of flood retention and base flow negatively affect water quality and federally endangered. regulation. Without adequate vegetated aquatic species, as well as alter stream buffers, the ability of floodplains to store and wetland characteristics.64 In addition, Disturbance to Aquatic flood flows associated with major storm sedimentation reduces the amount of Ecosystem Processes events and wet seasons might be light in the water column which can Stream, lake and wetland ecosystems significantly reduced, resulting in decrease primary production (i.e. work to retain floods,