Can Land Management Buffer Impacts of Climate Changes and Altered Fire Regimes on Ecosystems of the Southwestern United States?

Abstract

Climate changes and associated shifts in ecosystems and fire regimes present enormous challenges for the management of landscapes in the Southwestern US. A central question is whether management strategies can maintain or promote desired ecological conditions under projected future climates. We modeled wildfire and forest responses to climate changes and management activities using two ecosystem process models: FireBGCv2, simulated for the Jemez Mountains, New Mexico, and LANDIS-II, simulated for the Kaibab Plateau, Arizona. We modeled contemporary and two future climates-"Warm-Dry" (CCSM4 RCP 4.5) and "Hot-Arid" (HadGEM2ES RCP 8.5)-and four levels of management including fire suppression alone, a current treatment strategy, and two intensified treatment strategies. We found that Hot-Arid future climate resulted in a fundamental, persistent reorganization of ecosystems in both study areas, including biomass reduction, compositional shifts, and altered forest structure. Climate changes increased the potential for high-severity fire in the Jemez study area, but did not impact fire regime characteristics in the Kaibab. Intensified management treatments somewhat reduced wildfire frequency and severity; however, management strategies did not prevent the reorganization of forest ecosystems in either landscape. Our results suggest that novel approaches may be required to manage future forests for desired conditions.

Large‐scale forest restoration stabilizes carbon under climate change in Southwest United States

“…S12), implying that, despite restoration efforts, biomass loss is still possible. We found similar vegetation type changes as Loehman et al (2018) in a similar time frame but Flatley and Ful e (2016) found that vegetation type changes are possible further into the future.…”

“…Still other studies found that, despite restoration efforts, extreme climate change conditions could result in significant biomass losses and deforestation (Taranc on et al 2014, Flatley and Ful e 2016, Loehman et al 2018. We also saw decreases in TEC and aboveground biomass in the no-harvest and status quo scenarios implying that without restoration there is a strong likelihood that forest biomass will decline with climate change due to high severity fires and low productivity.…”

“…, Flatley and Fulé , Loehman et al. ). We also saw decreases in TEC and aboveground biomass in the no‐harvest and status quo scenarios implying that without restoration there is a strong likelihood that forest biomass will decline with climate change due to high severity fires and low productivity.…”

“…Previous studies have projected that restoration under climate change will result in long-term increases in forest carbon due to reductions in wildfire activity (Loudermilk et al 2016, Hurteau 2017, Krofcheck et al 2017, Liang et al 2018. Mediated in part by low regeneration rates under warmer temperatures, other studies have projected that extreme climate change will result in forest type changes, biomass loss, and deforestation despite restoration treatments (Taranc on et al 2014, Flatley and Ful e 2016, Loehman et al 2018.…”

Is fire “for the birds”? How two rare species influence fire management across the US

“…However, future warming increases uncertainty about maintaining these habitats even if uncharacteristically severe fires can be curtailed (Loehman et al . ).…”