Bioenergy harvest, climate change, and forest carbon in the Oregon Coast Range

Abstract

Forests provide important ecological, economic, and social services, and recent interest has emerged in the potential for using residue from timber harvest as a source of renewable woody bioenergy. The long-term consequences of such intensive harvest are unclear, particularly as forests face novel climatic conditions over the next century. We used a simulation model to project the long-term effects of management and climate change on above-and belowground forest carbon storage in a watershed in northwestern Oregon. The multi-ownership watershed has a diverse range of current management practices, including little-to-no harvesting on federal lands, short-rotation clear-cutting on industrial land, and a mix of practices on private nonindustrial land. We simulated multiple management scenarios, varying the rate and intensity of harvest, combined with projections of climate change. Our simulations project a wide range of total ecosystem carbon storage with varying harvest rate, ranging from a 45% increase to a 16% decrease in carbon compared to current levels. Increasing the intensity of harvest for bioenergy caused a 2-3% decrease in ecosystem carbon relative to conventional harvest practices. Soil carbon was relatively insensitive to harvest rotation and intensity, and accumulated slowly regardless of harvest regime. Climate change reduced carbon accumulation in soil and detrital pools due to increasing heterotrophic respiration, and had small but variable effects on aboveground live carbon and total ecosystem carbon. Overall, we conclude that current levels of ecosystem carbon storage are maintained in part due to substantial portions of the landscape (federal and some private lands) remaining unharvested or lightly managed. Increasing the intensity of harvest for bioenergy on currently harvested land, however, led to a relatively small reduction in the ability of forests to store carbon. Climate change is unlikely to substantially alter carbon storage in these forests, absent shifts in disturbance regimes.

Carbon sequestration in managed temperate coniferous forests under climate change

“…Boisvenue and Running, 2010), but are in contrast to other studies that do not show this pattern (e.g. Creutzburg et al, 2016). Carbon stocks tended to follow changes in productivity, increasing in ecoregions with greater productivity and decreasing where productivity was projected to fall, indicating a lower influence of changing decay rates on the stocks over this simulation period.…”

Forest management scenarios in a changing climate: trade‐offs between carbon, timber, and old forest

“…Although there is some debate about the expected effects of increasing temperature on soil C stocks (Davidson and Janssen 2006, Schmidt et al 2011, Bellassen and Luyssaert 2014, our results are consistent with a meta-analysis that found an increase in both soil respiration and plant productivity with warming (Rustad et al 2001). Another related study in a single watershed within the Coast Range found a relatively small decrease in aboveground, soil and detrital C due to climate change (Creutzburg et al 2015). The current study expanded to a broader region with greater overall precipitation (and thus lower summer water limitation), and incorporated improvements to the modeled soil water algorithms.…”

“…Another related study in a single watershed within the Coast Range found a relatively small decrease in aboveground, soil and detrital C due to climate change (Creutzburg et al. ). The current study expanded to a broader region with greater overall precipitation (and thus lower summer water limitation), and incorporated improvements to the modeled soil water algorithms.…”

“…We obtained the supplemental TREE_LIVE database for the GNN map to summarize species-age cohorts in each pixel at 10-yr age intervals. Parameters were derived from the literature where possible (Appendix S1), and the remaining parameters were calibrated to produce growth patterns consistent with the literature, as in Creutzburg et al (2015). Initial simulated levels of aboveground C were calibrated to GNN and U.S. Forest Service Inventory and Analysis (FIA) maps of biomass 5 , using a factor of 0.47 to convert from biomass to C (Fig.…”

Widespread severe wildfires under climate change lead to increased forest homogeneity in dry mixed‐conifer forests

“…Forest succession.-We obtained model parameters from the literature and available datasets including the USDA Fire Effects Information System (Abrahamson; https://www.feis-crs.org/feis/), USGS Vegetation Atlas of North America (Thompson et al 1999; https://pubs.usgs.gov/pp/ p1650-a/), the Northeastern Ecosystem Research Cooperative's Foliar Chemistry Database (NERC 2015; http://www.nercscience.org/), the National Atmospheric Deposition Program (NADP 2015; http://nadp.slh.wisc.edu/data/ntn/), the Oak Ridge National Laboratory database (West 2014; https://daac.ornl.gov/SOILS/guides/West_Soil_Carb on.html), and from previous studies that utilized LANDIS-II species parameterization (Loudermilk et al 2014, Lucash et al 2014, Creutzburg et al 2016.…”