Browsing by Author "Krenz, Robert J."
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- Establishing Hardwood Forests on Appalachian Mine Sites Using the Forestry Reclamation ApproachZipper, Carl E.; Klopf, Sara K.; Krenz, Robert J.; Evans, Daniel M.; Burger, James A.; Fields-Johnson, Chris W. (Virginia Tech. Powell River Project, 2016)
- Establishing Riparian Woody Vegetation for Constructed Streams Using the Forestry Reclamation ApproachZipper, Carl E.; Krenz, Robert J.; Sweeten, Sara E.; Agouridis, Carmen T.; Barton, Christopher D.; Angel, Patrick N. (Appalachian Regional Reforestation Initiative, 2018-03)Construction and renovation of streams and riparian corridors on mined lands have become common activities in Appalachia. Surface mining for coal can disturb ephemeral and intermittent streams, and may disturb permanent streams in some cases. Under the Clean Water Act, operations that fill or otherwise disturb streams must perform compensatory mitigation. Scientific studies have identified beneficial effects of woody vegetation (trees and shrubs) in riparian areas of streams on mined areas and elsewhere. This advisory describes the reasons for establishing woody vegetation in constructed streams’ riparian areas, and describes proper methods for mine sites.
- Organic Matter Dynamics as Functional Indicators of Stream Condition in Constructed Streams on Virginia Coal Mine SitesKrenz, Robert J.; Schoenholtz, Stephen H. (Virginia Tech. Powell River Project, 2012)The Clean Water Act [section 404; stream mitigation rule] mandates that operations permitted by the U.S. Army Corps of Engineers (COE) must mitigate streams impacted by valley fill and other mining activities (Register April 10, 2008). Agencies regulating coal mining operations are placing increased emphasis on functional measures for stream assessment. Guidance memoranda issued by the U.S. Environmental Protection Agency (EPA) and COE concerning mining permits state that the regulatory process should “ensure that compensatory mitigation adequately replaces lost stream functions” (2011) and that “permitting will not rely exclusively on an evaluation of structure in place of function” (2010). In this context, successful restoration of stream functions is of concern to industry, regulators, and restoration professionals. Additionally, in 2012 EPA released A Function‐Based Framework for Stream Assessments and Restoration Projects, a document aimed at those implementing stream restorations and assessments, and clearly states that it would benefit “from review, comments, and example experiences and applications” (Harman et al. 2012). The research presented in this report is addressing needs of industry and regulators by directly measuring specific ecosystem functions in stream mitigation efforts on coal mine sites in southwestern Virginia, and can contribute as an example experience and application. Organic matter (OM), primarily as leaf litter and detritus input, serves as habitat and an essential energy source for benthic macroinvertebrates within headwater and downstream ecosystems. Alteration of the sources, production rates, or processing rates of OM due to disturbance could have cascading effects throughout these ecosystems. As a result, we see the assessment of OM dynamics as a crucial component to determine the overall functional condition of streams, and as an integral tool to meet the needs of industry and regulators to evaluate mitigation efforts through direct measurement of a crucial stream functions. To address these needs we are measuring litterfall input, leaf litter decomposition, and periphyton biomass accrual for reconstructions of eight low‐order mining‐impacted streams, and evaluating them via comparison to four minimally impacted reference streams. Relationships of these functional measures with physical, chemical, and biological structural measures are also being investigated.
- Reclamation Grading and Seeding Influences on Trees on a Virginia Mine Site after Six YearsZipper, Carl E.; Koropchak, Sara; Krenz, Robert J.; Evans, Daniel M. (Virginia Tech. Powell River Project, 2014)
- Selected Carbon Dynamics as Functional Indicators of Restoration Success: Progress From the First Two YearsKrenz, Robert J.; Schoenholtz, Stephen H.; Zipper, Carl E. (Virginia Tech. Powell River Project, 2011)
- Structural and Functional Characteristics of Mining-impacted Reconstructed StreamsKrenz, Robert J.; Zipper, Carl E.; Schoenholtz, Stephen H. (Virginia Tech. Powell River Project, 2013)The Clean Water Act [section 404; stream mitigation rule] mandates that mining operations permitted by the U.S. Army Corps of Engineers (COE) to impact streams by valley fill or other activities must employ compensatory mitigation (Register April 10, 2008). Reconstructed streams are one means of mitigation and are meant to replace ecosystem structure and function lost due to impacts. With the goal of restoring ecosystem processes and patterns in these headwater streams, reconstruction efforts can serve as an important environmental protection measure. Additionally, in 2012 EPA released A Function-Based Framework for Stream Assessments and Restoration Projects, a document aimed at those constructing and assessing restorations, which states that it would benefit “from review, comments, and example experiences and applications” (Harman et al. 2012). The research we present in this report is addressing these needs by directly measuring specific ecosystem functions of reconstructed streams as mitigation efforts on coal mine sites in southwestern Virginia, and can contribute to the knowledge of stream restoration practices and assessment. Organic matter (OM), primarily as leaf litter and detrital input, serves as an essential energy source and habitat for benthic macroinvertebrates within headwater and larger stream ecosystems. Alteration of the sources, production rates, or processing rates of OM due to disturbance could have cascading effects throughout these ecosystems. As a result, we see the assessment of OM dynamics as important when characterizing and evaluating the overall functional condition of streams, and when identifying restoration practices that improve stream functions. To address these needs we have measured litterfall input, leaf breakdown, and periphyton biomass accrual for eight low-order mining-impacted reconstructed streams, and evaluated them via comparison to four minimally impacted reference streams. Relationships of these functional measures with physical, chemical, and biological structural measures are also being investigated.