Abstract
Logging and mill residues are currently the largest sources of woody biomass for bioenergy in the United States, but short-rotation woody crops (SRWCs) are expected to become a larger contributor to biomass production, primarily on lands marginal for food production. However, there are very few studies on the environmental effects of SRWCs, and most have been conducted at stand rather than at watershed scales. In this manuscript, we review the potential environmental effects of SRWCs relative to current forestry or agricultural practices and best management practices (BMPs) in the southeast United States and identify priorities and constraints for monitoring and modeling these effects. Plot-scale field studies and a watershed-scale modeling study found improved water quality with SRWCs compared to agricultural crops. Further, a recent watershed-scale experiment suggests that conventional forestry BMPs are sufficient to protect water quality from SRWC silvicultural activities, but the duration of these studies is short with respect to travel times of groundwater transporting nitrate to streams. While the effects of SRWC production on carbon (C) and water budgets depend on both soil properties and previous land management, woody crops will typically sequester more C when compared with agricultural crops. The overall C offset by SRWCs will depend on a variety of management practices, the number of rotations, and climate. Effects of SRWCs on biodiversity, especially aquatic organisms, are not well studied, but a meta-analysis found that bird and mammal biodiversity is lower in SRWC stands than unmanaged forests. Long-term (i.e., over multiple rotations) water quality, water use, C dynamics, and soil quality studies are needed, as are larger-scale (i.e., landscape scale) biodiversity studies, to evaluate the potential effects of SRWC production. Such research should couple field measurement and modeling approaches due to the temporal (i.e., multiple rotations) and spatial (i.e., heterogeneous landscape) scaling issues involved with SRWC production.
| Original language | English |
|---|---|
| Pages (from-to) | 554-572 |
| Number of pages | 19 |
| Journal | GCB Bioenergy |
| Volume | 11 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 2019 |
Funding
USDA National Institute of Food and Agriculture, Agriculture and Food Research Initiative Competitive grant (Grant/Award Number: 2013-67009- 21405) to the University of Georgia Research Foundation. U.S. Department of Energy, Grant/Award Number: DE EM0004391 to the University of Georgia Research Foundation; U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Bioenergy Technologies Office. under Award Number DE‐EM0004391 to the University of Georgia Research Foundation. We thank E. Parish, M. Her-nandez, and three anonymous reviewers for comments that greatly improved earlier versions of this manuscript. This manuscript has been authored by UT‐Battelle, LLC, under Contract No. DE‐AC05‐00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid‐up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for the United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (https://energy.gov/downloads/doe-public-access-plan). The views and opinions of the authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. This material is based on work supported by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Bioenergy Technologies Office. Oak Ridge National Laboratory is managed by UT‐Battelle, LLC, for the U.S. Department of Energy under contract DE‐AC05‐00OR22725. This work was also supported by Agriculture and Food Research Initiative Competitive Grant no. 2013‐67009‐21405 from the USDA National Institute of Food and Agriculture and the Department of Energy This material is based on work supported by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Bioenergy Technologies Office. Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. This work was also supported by Agriculture and Food Research Initiative Competitive Grant no. 2013-67009-21405 from the USDA National Institute of Food and Agriculture and the Department of Energy under Award Number DE-EM0004391 to the University of Georgia Research Foundation. We thank E. Parish, M. Hernandez, and three anonymous reviewers for comments that greatly improved earlier versions of this manuscript.
Keywords
- aquatic macroinvertebrates
- best management practices
- bioenergy
- carbon/water tradeoffs
- hydrologic modeling
- soil organic carbon
- southeastern United States
- terrestrial biodiversity
- water quality
- woody feedstocks