The complexity of biological disturbance agents, fuels heterogeneity, and fire in coniferous forests of the western United States

Shaw, David C.; Beedlow, P.A.; Lee, E. Henry; Woodruff, David R.; Meigs, Garrett W.; Calkins, Stephen J.; Reilly, Matthew J.; Merschel, Andrew G.; Cline, Steven P.; Comeleo, Randy L.

doi:10.1016/j.foreco.2022.120572

Cited by 6 publications

(3 citation statements)

References 176 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Irrational logging causes alteration in the vegetation structure, which has led to a greater increase and continuity of forest fuels, resulting in a greater possibility of fires [95]. Fuel beds in highly disturbed sites have a higher ignition potential and C emissions through fine fuels (1 and 10 h) and litterfall, while the medium fuels (100 h) spread the fire; coarse fuels (1000 h) are related to their intensity.…”

Section: Discussionmentioning

confidence: 99%

Forest Fuel Bed Variation in Tropical Coastal Freshwater Forested Wetlands Disturbed by Fire

Barrios-Calderón,

Infante Mata,

Flores Garnica

et al. 2024

Forests

View full text Add to dashboard Cite

Tropical coastal freshwater forested wetlands in coastal regions are rapidly disappearing as a result of various disturbance agents, mainly wildfires caused by high accumulations of forest fuels. The objective of this study was to characterize the structure and composition of fuel beds in tropical coastal freshwater forested wetlands with three levels of disturbance at El Castaño, La Encrucijada Biosphere Reserve. Seventeen sampling units were used to describe the structure of the forest’s fuel beds (canopy, sub-canopy, and understory). Fallen woody material and litter (surface and fermented) were characterized using the planar intersection technique. Diversity comprised eight species of trees, two shrubs, five lianas, and two herbaceous species. The vertical strata were dominated by trees between 2 and 22 m in height. The horizontal structure had a higher percentage of trees with normal diameter between 2.5 and 7.5 cm (61.4%) of the total. Sites with low disturbance had the highest arboreal density (2686 ind. ha−1). Diversity of species showed that the Fisher, Margalef, Shannon, and Simpson α indices were higher in the low disturbance sites. The Berger–Parker index exhibited greater dominance in the sites with high disturbance. Pachira aquatica Aubl. Showed the highest importance value index and was the largest contributor to fuel beds. Sites with the highest disturbance had the highest dead fuel load (222.18 ± 33.62 Mg ha−1), with woody fuels of classes 1, 10, and 1000 h (rotten) being the most representative. This study contributes to defining areas prone to fire in these ecosystems and designing prevention strategies.

show abstract

Section: Discussionmentioning

confidence: 99%

Forest Fuel Bed Variation in Tropical Coastal Freshwater Forested Wetlands Disturbed by Fire

Barrios-Calderón,

Infante Mata,

Flores Garnica

et al. 2024

Forests

View full text Add to dashboard Cite

show abstract

“…Recent studies of wildfires in California and Colorado and their hydrological impacts showed an increase in mudslides, flash floods, and debris flows as a hydrological response to wildfire-burned areas [40][41][42]. In the past decade, the severity and frequency of wildfires have increased in forests of the western United States (USA) [43,44], especially in California, where ecosystems are dominated by dry conifers [45,46]. This increase is linked to current shifts in temperature and weather patterns due to vapor pressure deficit [47,48], fuel buildup caused by fire suppression [49,50], and a rapidly changing climate [47,[51][52][53].…”

Section: Introductionmentioning

confidence: 99%

Modification of Soil Hydroscopic and Chemical Properties Caused by Four Recent California, USA Megafires

Samburova,

Schneider,

Rüger

et al. 2023

Fire

View full text Add to dashboard Cite

While it is well known that wildfires can greatly contribute to soil water repellency by changing soil chemical composition, the mechanisms of these changes are still poorly understood. In the past decade, the number, size, and intensity of wildfires have greatly increased in the western USA. Recent megafires in California (i.e., the Dixie, Beckwourth Complex, Caldor, and Mosquito fires) provided us with an opportunity to characterize pre- and post-fire soils and to study the effects of fires on soil water repellency, soil organic constituents, and connections between the two. Water drop penetration time (WDPT) tests performed in the field showed a significant increase (from <1 s up to >600 s) in WDPT from pre- to post-fire soils. This increase in soil water repellency after fires was confirmed by increases in apparent contact angle (ACA) between 1.1 and 9 times from unburned to burned soils. The chemical characterization of burned soils with high resolution mass spectrometry showed the increased abundance of hydrophobic organics (e.g., PAH-like compounds and organic molecules with a low number of oxygen atoms) as well as the correlation of the average H/C ratio and aromaticity index (AI) with ACA. Most likely, these compounds contribute to post-fire soil water repellency that triggers hydrological effects such as landslides, flooding, and debris flows.

show abstract

“…Within these complex forest structures, understory and lower-strata trees are particularly vulnerable to heavy defoliation due to the dispersal of larvae from overstory trees [ 10 ]. WSBW defoliation events may have secondary effects on trees and stands, including alteration of potential fire behavior [ 11 , 12 ] and increase susceptibility to outbreaks of other forest insects, such as Douglas-fir beetle ( Dendroctonus pseudotsugae Hopkins) [ 13 ].…”

Section: Introductionmentioning

confidence: 99%

Western Spruce Budworm Effects on Forest Resilience

Polinko

Rapp

Meador

et al. 2022

Plants

View full text Add to dashboard Cite

Western spruce budworm (Choristoneura freemani Razowski) is the most destructive defoliator of forests in the western US. Forests in northern New Mexico experienced high levels of WSBW-caused defoliation and subsequent mortality between the 1980s and 2010s. The effects of severe western spruce budworm outbreaks on stand dynamics in the US Southwest are still relatively unknown, but understanding the impacts is important to the management and resilience of these forests. To begin addressing this knowledge gap, we conducted a study along two gradients: an elevational gradient from mixed-conifer to spruce-fir forests and a gradient of WSBW-caused defoliation intensity. We recorded overstory and understory stand conditions (size structure, species composition, damaging agents). Western spruce budworm was the primary damaging agent of host trees in all stands andcaused host tree mortality across all size classes, particularly in spruce-fir stands. Results indicate an unsustainable level of mortality in spruce-fir stands and a transition towards non-host species in mixed-conifer stands. Low levels of regeneration coupled with high overstory mortality rates indicate a potential lack of resilience in spruce-fir stands, whereas resilience to future western spruce budworm defoliation events may have increased in mixed-conifer stands affected by these outbreaks.

show abstract

The complexity of biological disturbance agents, fuels heterogeneity, and fire in coniferous forests of the western United States

Cited by 6 publications

References 176 publications

Forest Fuel Bed Variation in Tropical Coastal Freshwater Forested Wetlands Disturbed by Fire

Forest Fuel Bed Variation in Tropical Coastal Freshwater Forested Wetlands Disturbed by Fire

Modification of Soil Hydroscopic and Chemical Properties Caused by Four Recent California, USA Megafires

Western Spruce Budworm Effects on Forest Resilience

Contact Info

Product

Resources

About