Forest Operations and Water Quality in the South

Abstract

n recent years, nonpoint-source (NPS) pollution has been identified as perhaps the greatest threat to the nation's water quality (USEPA, 2003). The Clean Water Act (CWA) of 1977, a result of amendments to the Federal Water Pollution Control Act (FWPCA) of 1972, has two primary goals for the achievement of objectives set forth in the CWA: eliminate discharge of pollutants into the nation's waters, and achieve water quality levels in the nation's waters that are fishable and swimmable. Today, the majority of the nation's waters meet water quality levels set forth in the goals of the CWA. The CWA established the Environmental Protection Agency (EPA) as the chief agency responsible for permitting, enforcing, and administrating the law to states. Section 208 of the CWA identified timber harvesting and silvicultural activities as NPS pollution sources. In Section 208, states were required to establish best management practices (BMPs) for forestry related activities to reduce NPS pollution.Section 303(d) of the CWA also established the Total Maximum Daily Load (TMDL) program in an attempt to achieve "Cleaner Waters across America." The mission of the program is to ensure healthy watersheds and public health protection. The TMDL program identifies impaired waters, determines pollution reductions required for health, and ensures corrections to reduce NPS pollution. As of 1999, 20,000 of the nation's water bodies, including 300,000 river and shore miles and 5 million lake acres, were identified as polluted (USEPA, 1999). The reduction of runoff through more efficient use of water, fertilizer, and pesticides is an action suggested by the EPA for cleaner waters while TMDLs are developed. Within watersheds on 303(d) lists, many nonpoint sources are extremely difficult to pinpoint, measure, and control due to the intertwined land use categories within a given watershed. Possible nonpoint sources of sediments in managed forested lands include harvesting, roads, log decks, skid trails, and site preparation.Intensive management practices have been reported to influence water yield and quality. The use of intensive management practices in the South has made the region one of the most productive in the world (Prestemon and Abt, 2002). The use of intensive management practices in combination with the abundant water resources in the region increases the potential for water quality impacts. In this context, the South would likely be the optimal region to evaluate the extent and nature of the water quality impacts of forest operations. The objective of this article is to provide a review of the watershed research on the nature and extent of NPS pollution attributed to forest operations, specifically harvesting, site preparation, fertilization, and road construction and maintenance, in the South. This article also explores the role of BMPs in NPS issues related to forest operations.

Assessing the Potential Impact of Rising Production of Industrial Wood Pellets on Streamflow in the Presence of Projected Changes in Land Use and Climate: A Case Study from the Oconee River Basin in Georgia, United States

“…Similarly, Sun et al [68] found that water yield increased by 3%, 8%, and 13% when leaf area index was reduced by 20%, 50%, and 80%, respectively, while water yield decreased by 3% when leaf area index increased by 20% across 2100 large basins present in the coterminous United States. Additionally, Grace et al [9] reported that water yields increased on harvested sites due to decreased ET by analyzing the literature across 13 southern states. These studies clearly indicate that an active forest management regime could modify a typical hydrological response associated with an increase in forest cover.…”

“…Isik et al [8] predicted changes in daily streamflow in response to changing land use in 10 watersheds of Georgia and found that the average streamflow decreased with increasing forest cover. In contradiction to existing studies, Grace [9] reviewed the effects of active forest management on water yields and quality in watersheds located in 13 southern states and found that water yield increased in harvested sites due to a decreased evapotranspiration (ET) rate.…”

Eucalyptus Short-Rotation Management Effects on Nutrient and Sediments in Subtropical Streams

“…Water quality of a stream is determined by a range of current and historical influences on catchment, from natural or anthropogenic origin, and is an important indicator of aquatic ecosystem health [1]. Streams draining forested landscapes usually have higher water quality than streams draining other land uses, such as agricultural fields [2][3][4][5][6][7][8]. The high quality of water provided by forested landscapes is partly attributed to a better soil infiltration and a variety of physical and biogeochemical ecosystem processes in the soil that filter particles and chemicals from the water [9].…”

“…Most of these forests are under intensive management, with short rotation cycles (from 6 to 8 years) and presents one of the highest productivity in the world (from 25 to 60 m 3 ha −1 year −1 ) [14]. As a consequence of intensive management, harvesting and other forest management operations can cause shifts in the concentrations and export rates of nutrients and solids, altering the water quality on streams [1][2][3][4]9,[15][16][17].…”

Evaluation of Different Best Management Practices for Erosion Control on Machine Operating Trails

“…Traffic on machine operating trails can alter hillslope hydrology by inducing compaction, which created less permeable soil surfaces that result in decreased infiltration and increased overland water flow, soil erosion, and sedimentation during rain events (Croke and Mockler 2001, Grace 2005, Jackson et al 2002. The magnitude of environmental impacts caused by machine traffic is related to terrain gradient (Akbarimehr and Naghdi 2012a), traffic frequency of forest machines Jaeger 2011, Solgi et al 2014), vegetation cover (Cerdà 2007, Lee et al 2013, applied loads (Battiato et al 2013), seasonality and rainfall intensity (Martínez-Zavala et al 2008), soil texture (Pinard et al 2000, and the time since construction (Fu et al 2010).…”