scholarly journals Recent Tree Mortality in the Western United States from Bark Beetles and Forest Fires

2016 ◽  
Vol 62 (2) ◽  
pp. 141-153 ◽  
Author(s):  
Jeffrey A. Hicke ◽  
Arjan J.H. Meddens ◽  
Crystal A. Kolden
Keyword(s):  
United States ◽  
Forest Fires ◽  
Bark Beetles ◽  
Tree Mortality ◽  
Western United States

scholarly journals Over half of western United States' most abundant tree species in decline

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hunter Stanke ◽  
Andrew O. Finley ◽  
Grant M. Domke ◽  
Aaron S. Weed ◽  
David W. MacFarlane
Keyword(s):  
United States ◽  
Tree Species ◽  
Tree Mortality ◽  
Temperate Forests ◽  
Size Structure ◽  
Forest Disturbance ◽  
Population Decline ◽  
Western United States ◽  
Scale Transformation ◽  
Forest Composition

AbstractChanging forest disturbance regimes and climate are driving accelerated tree mortality across temperate forests. However, it remains unknown if elevated mortality has induced decline of tree populations and the ecological, economic, and social benefits they provide. Here, we develop a standardized forest demographic index and use it to quantify trends in tree population dynamics over the last two decades in the western United States. The rate and pattern of change we observe across species and tree size-distributions is alarming and often undesirable. We observe significant population decline in a majority of species examined, show decline was particularly severe, albeit size-dependent, among subalpine tree species, and provide evidence of widespread shifts in the size-structure of montane forests. Our findings offer a stark warning of changing forest composition and structure across the western US, and suggest that sustained anthropogenic and natural stress will likely result in broad-scale transformation of temperate forests globally.

scholarly journals on the prevention of lighting

1969 ◽  
Vol 50 (7) ◽  
pp. 514-521 ◽  
Author(s):  
C. D. Stow
Keyword(s):  
United States ◽  
Forest Fires ◽  
Western United States ◽  
Agricultural Crops ◽  
Loss Of Life ◽  
The World ◽  
Lightning Discharges ◽  
Cloud To Ground Lightning ◽  
Recreational Resources

The destructive nature of cloud-to-ground lightning strokes is well known. Loss of life and damage to buildings and other man-made structures may to a large extent be prevented by the judicial use of lightning conductors and screens but no comparable protection may be offered to expanses of agricultural crops or forests. According to Fuquay (1967) lightning is the greatest single cause of forest fires in the western United States: during the period 1946–1962, 140,000 such fires occurred causing severe losses of timber, wildlife, watershed, and recreational resources. Comparable losses occur regularly in other parts of the world. The only solution is the suppression or modification of cloud-to-ground lightning discharges. Methods of suppression are described, some of which may turn out to be practical ways of achieving this aim.

scholarly journals Biomass burning contribution to black carbon in the Western United States Mountain Ranges

2011 ◽  
Vol 11 (21) ◽  
pp. 11253-11266 ◽  
Author(s):  
Y. H. Mao ◽  
Q. B. Li ◽  
L. Zhang ◽  
Y. Chen ◽  
J. T. Randerson ◽  
...  
Keyword(s):  
United States ◽  
Black Carbon ◽  
Biomass Burning ◽  
Forest Fires ◽  
Transport Model ◽  
Reanalysis Data ◽  
Western United States ◽  
Fire Season ◽  
Carbonaceous Aerosols ◽  
Mountain Ranges

Abstract. Forest fires are an important source to carbonaceous aerosols in the Western United States (WUS). We quantify the relative contribution of biomass burning to black carbon (BC) in the WUS mountain ranges by analyzing surface BC observations for 2006 from the Interagency Monitoring of PROtected Visual Environment (IMPROVE) network using the GEOS-Chem global chemical transport model. Observed surface BC concentrations show broad maxima during late June to early November. Enhanced potassium concentrations and potassium/sulfur ratios observed during the high-BC events indicate a dominant biomass burning influence during the peak fire season. Model surface BC reproduces the observed day-to day and synoptic variabilities in regions downwind of but near urban centers. Major discrepancies are found at elevated mountainous sites during the July-October fire season when simulated BC concentrations are biased low by a factor of two. We attribute these low biases largely to the underestimated (by more than a factor of two) and temporally misplaced biomass burning emissions of BC in the model. Additionally, we find that the biomass burning contribution to surface BC concentrations in the USA likely was underestimated in a previous study using GEOS-Chem (Park et al., 2003), because of the unusually low planetary boundary layer (PBL) heights in the GEOS-3 meteorological reanalysis data used to drive the model. PBL heights from GEOS-4 and GEOS-5 reanalysis data are comparable to those from the North American Regional Reanalysis (NARR). Model simulations show slightly improved agreements with the observations when driven by GEOS-5 reanalysis data, but model results are still biased low. The use of biomass burning emissions with diurnal cycle, synoptic variability, and plume injection has relatively small impact on the simulated surface BC concentrations in the WUS.

scholarly journals The impact of bark beetle infestations on monoterpene emissions and secondary organic aerosol formation in western North America

2013 ◽  
Vol 13 (6) ◽  
pp. 3149-3161 ◽  
Author(s):  
A. R. Berg ◽  
C. L. Heald ◽  
K. E. Huff Hartz ◽  
A. G. Hallar ◽  
A. J. H. Meddens ◽  
...  
Keyword(s):  
United States ◽  
British Columbia ◽  
North America ◽  
Bark Beetle ◽  
Tree Mortality ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Western United States ◽  
Western North America ◽  
The Impact

Abstract. Over the last decade, extensive beetle outbreaks in western North America have destroyed over 100 000 km2 of forest throughout British Columbia and the western United States. Beetle infestations impact monoterpene emissions through both decreased emissions as trees are killed (mortality effect) and increased emissions in trees under attack (attack effect). We use 14 yr of beetle-induced tree mortality data together with beetle-induced monoterpene emission data in the National Center for Atmospheric Research (NCAR) Community Earth System Model (CESM) to investigate the impact of beetle-induced tree mortality and attack on monoterpene emissions and secondary organic aerosol (SOA) formation in western North America. Regionally, beetle infestations may have a significant impact on monoterpene emissions and SOA concentrations, with up to a 4-fold increase in monoterpene emissions and up to a 40% increase in SOA concentrations in some years (in a scenario where the attack effect is based on observed lodgepole pine response). Responses to beetle attack depend on the extent of previous mortality and the number of trees under attack in a given year, which can vary greatly over space and time. Simulated enhancements peak in 2004 (British Columbia) and 2008 (US). Responses to beetle attack are shown to be substantially larger (up to a 3-fold localized increase in summertime SOA concentrations) in a scenario based on bark-beetle attack in spruce trees. Placed in the context of observations from the IMPROVE network, the changes in SOA concentrations due to beetle attack are in most cases small compared to the large annual and interannual variability in total organic aerosol which is driven by wildfire activity in western North America. This indicates that most beetle-induced SOA changes are not likely detectable in current observation networks; however, these changes may impede efforts to achieve natural visibility conditions in the national parks and wilderness areas of the western United States.

scholarly journals Effects of Climate Change on Natural-Caused Fire Activity in Western U.S. National Forests

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 981
Author(s):  
Hadi Heidari ◽  
Mazdak Arabi ◽  
Travis Warziniack
Keyword(s):  
Climate Change ◽  
United States ◽  
Forest Fire ◽  
Forest Fires ◽  
Western United States ◽  
National Forests ◽  
Climate Change Scenarios ◽  
Negative Consequences ◽  
Fire Activity ◽  
The Future

Climate change, with warming temperatures and shifting precipitation patterns, may increase natural-caused forest fire activity. Increasing natural-caused fires throughout western United States national forests could place people, property, and infrastructure at risk in the future. We used the fine K nearest neighbor (KNN) method coupled with the downscaled Multivariate Adaptive Constructed Analogs (MACA) climate dataset to estimate changes in the rate of natural-caused fires in western United States national forests. We projected changes in the rate of minor and major forest fires from historical (1986–2015) to future (2070–2099) conditions to characterize fire-prone national forests under a range of climate change scenarios. The results indicate that climate change can add to the occurrence of forest fires in western United States national forests, particularly in Rocky Mountain, Pacific Southwest, and Southwestern United States Forest Service regions. Although summer months are projected to have the highest rate of natural-caused forest fire activity in the future, the rate of natural-caused forest fires is likely to increase from August to December in the future compared to the historical conditions. Improved understanding of altered forest fire regimes can help forest managers to better understand the potential effects of climate change on future fire activity and implement actions to attenuate possible negative consequences.

Sign in / Sign up

Export Citation Format

Share Document