Albedo-induced radiative forcing from mountain pine beetle outbreaks in forests, south-central Rocky Mountains: magnitude, persistence, and relation to outbreak severity

Abstract

Abstract. Mountain pine beetle (MPB) outbreaks in NorthAmerica are widespread and have potentially persistent impacts on forest albedo and associated radiative forcing. This study utilized multiple data sets, both current and historical, within lodgepole pine stands in the south-central Rocky Mountains to quantify the full radiative forcing impact of outbreak events for decades after outbreak (0-60 yr) and the role of outbreak severity in determining that impact. Change in annual albedo and radiative forcing peaked at 14-20 yr post-outbreak (0.06 ± 0.006 and −0.8 ± 0.1 W m −2 , respectively) and recovered to pre-outbreak levels by 30-40 yr post-outbreak. Change in albedo was significant in all four seasons, but strongest in winter with the increased visibility of snow (radiative cooling of −1.6 ± 0.2 W m −2 , −3.0 ± 0.4 W m −2 , and −1.6 ± 0.2 W m −2 for 2-13, 14-20 and 20-30 yr post-outbreak, respectively). Change in winter albedo and radiative forcing also increased with outbreak severity (percent tree mortality). Persistence of albedo effects are seen as a function of the growth rate and species composition of surviving trees, and the establishment and growth of both understory herbaceous vegetation and tree species, all of which may vary with outbreak severity. The establishment and persistence of deciduous trees was found to increase the temporal persistence of albedo effects. MPBinduced changes to radiative forcing may have feedbacks for regional temperature and the hydrological cycle, which could impact future MPB outbreaks dynamics.

Implementation of a Marauding Insect Module (MIM, version 1.0) in the Integrated BIosphere Simulator (IBIS, version 2.6b4) dynamic vegetation–land surface model

“…tions were drier during the growing season. Such positive impacts on lower canopy have often been reported following outbreaks from MPB and other bark beetles (Stone and Wolfe, 1996;Klutsch et al, 2009;Griffin et al, 2011;Simard et al, 2011;Bowler et al, 2012;Brown et al, 2012;Vanderhoof et al, 2014). In the northern and central grid cells, the lower-canopy growth release exceeded the productivity losses coming from the death of NE trees, so that total post-outbreak NPP soon exceeded NPP in the control runs ( Fig.…”

“…Bright et al, 2013;Maness et al, 2013;Mikkelson et al, 2013a;Pugh and Gordon, 2013;Metcalfe et al, 2014;Reed et al, 2014;Seidl et al, 2014;Turcotte et al, 2014;Vanderhoof et al, 2014;Landry and Parrott, 2016). Yet the simulation of insect-induced plant damage in climate models has lagged behind the simulation of fire, even though the two disturbance types were recognized as climate-related phenomena worthwhile of explicit representation in dynamic global vegetation models (DGVMs) more than 15 years ago (Fosberg et al, 1999).…”

Land Surface Albedo Estimation from Chinese HJ Satellite Data Based on the Direct Estimation Approach

“…Due to the scale differences between satellite pixels and footprints of ground measurements, data at finer spatial resolutions are needed to bridge the gap over heterogeneous landscapes for a better understanding of uncertainties of coarse-resolution products [6,7]. Moreover, there is an increasing need for the availability of medium-resolution surface albedo for applications at medium-to-fine scales (<100 m), including forest management [8][9][10], agriculture monitoring [11], and urban environment monitoring [12,13].…”

Spatiotemporal variation of surface shortwave forcing from fire-induced albedo change in interior Alaska

“…First, some trees that might be severely damaged but not killed immediately by the fires could still keep most of the dead needles and branches for 1-2 years before falling to the floor; this structure is similar to the "red attack stage" of the mountain pine beetle (Dendroctonus ponderosae Hopkins, 1902). Existing studies based on Landsat and MODIS (Vanderhoof et al 2014) have documented a decrease in winter albedo in this stage due to needle and litter accumulation on snow (Winkler et al 2010;Pugh and Small 2012). Second, snow might melt faster in some recently burned areas, leading to shorter snow duration and thus a prolonged exposure of burned soil (Liu et al 2005).…”