A5068905732- Fire effects on ecosystems
- Rangeland and Wildlife Management
- Tree-ring climate responses
- Plant Water Relations and Carbon Dynamics
- Forest ecology and management
- Landslides and related hazards
- Ecology and Vegetation Dynamics Studies
- Forest Ecology and Biodiversity Studies
- Forest Insect Ecology and Management
- Forest Management and Policy
- Cryospheric studies and observations
- Hydrology and Watershed Management Studies
- Climate Change and Environmental Impact
- Hydrology and Drought Analysis
- Scientific Research and Discoveries
- Archaeology and Natural History
- Frailty in Older Adults
- Coastal wetland ecosystem dynamics
- Aeolian processes and effects
- Plant Ecology and Soil Science
- Tree Root and Stability Studies
- Spaceflight effects on biology
- Insect and Pesticide Research
- Environmental Impact and Sustainability
- Hip and Femur Fractures
Humboldt State University
2012-2024
California State Polytechnic University
2022-2024
California Polytechnic State University
2024
John Wiley & Sons (United States)
2016
Ecological Society of America
2016
University of Hawaii at Hilo
2006-2008
University of Colorado Boulder
2001-2008
Gettysburg College
2008
University of Kentucky
2008
University of Colorado System
2007
Abstract Fire is a powerful ecological and evolutionary force that regulates organismal traits, population sizes, species interactions, community composition, carbon nutrient cycling ecosystem function. It also presents rapidly growing societal challenge, due to both increasingly destructive wildfires fire exclusion in fire‐dependent ecosystems. As an process, integrates complex feedbacks among biological, social geophysical processes, requiring coordination across several fields scales of...
There is widespread concern that fire exclusion has led to an unprecedented threat of uncharacteristically severe fires in ponderosa pine (Pinus Dougl. ex. Laws) and mixed-conifer forests western North America. These extensive montane are considered be adapted a low/moderate-severity regime maintained stands relatively old trees. However, there increasing recognition from landscape-scale assessments that, prior any significant effects exclusion, forest structure were more variable these...
Summary Recent bark beetle outbreaks in North America and Europe have impacted forested landscapes the provisioning of critical ecosystem services. The scale intensity many recent are widely believed to be unprecedented. effects on ecosystems often measured terms area affected, host tree mortality rates, alterations forest structure composition. Impacts human systems focus changes property valuation, infrastructure damage from falling trees, landscape aesthetics, quality quantity timber...
Abstract Fire regimes in North American forests are diverse and modern fire records often too short to capture important patterns, trends, feedbacks, drivers of variability. Tree‐ring scars provide valuable perspectives on regimes, including centuries‐long year, season, frequency, severity, size. Here, we introduce the newly compiled tree‐ring fire‐scar network (NAFSN), which contains 2562 sites, >37,000 fire‐scarred trees, covers large parts America. We investigate NAFSN terms geography,...
Abstract Aim Forest restoration in ponderosa pine and mixed pine–Douglas fir forests the US Rocky Mountains has been highly influenced by a historical model of frequent, low‐severity surface fires developed for Southwestern USA. A model, based on this fire focuses thinning prescribed burning to restore forest structure. However, Mountains, research history structure, early reports, suggest may only apply limited geographical areas. The aim article is elaborate new variable‐severity evaluate...
Large recent fires in the western U.S. have contributed to a perception that fire exclusion has caused an unprecedented occurrence of uncharacteristically severe fires, particularly lower elevation dry pine forests. In absence long-term severity records, it is unknown how short-term trends compare prior 20th century exclusion. This study compares historical (i.e. pre-1920) with observed modern and modeled potential behavior across 564,413 ha montane forests Colorado Front Range. We used...
Increasing temperatures have resulted in reduced growth and increased tree mortality across large areas of western North American forests. We use tree-ring isotope chronologies (δ13 C δ18 O) from live dead trees four locations south-central Alaska, USA, to test whether white spruce killed by recent beetle (Dendroctonus rufipennis Kirby) outbreaks showed evidence drought stress prior death. Trees that were more sensitive spring/summer temperature and/or precipitation than survived. At two our...
Abstract We use the historical presence of high‐severity fire patches in mixed‐conifer forests western United States to make several points that we hope will encourage development a more ecologically informed view severe wildland effects. First, many plant and animal species use, have sometimes evolved depend on, severely burned forest conditions for their persistence. Second, evidence from history studies also suggests complex mosaic conifer was common historically West. Third, maintain...
We used tree ring data (AD 1601-2007) to examine the occurrence of and climatic influences on spruce beetle (Dendroctonus rufipennis) outbreaks in south-central southwest Alaska found evidence regional-scale dating from mid-1700s, related climate variability at multiple temporal scales. Over interannual time scales (approximately 1-3 years), El Niño years, combined with severe late-summer drought, appeared contribute significantly study area. multidecadal (up approximately 40 cool-phase...
Forests experiencing moderate- or mixed-severity fire regimes are presumed to be widespread across the western United States, but few studies have characterized these complex disturbance and their effects on contemporary forest structure. Restoration of pre-fire-suppression open-forest structure reduce risk uncharacteristic stand-replacing fires is a guiding principle in management policy, identifying which forests clear candidates for restoration remains challenge. We conducted...
Abstract Question: What is the relative importance of low- and high-severity fires in shaping forest structure across range Pinus ponderosa northern Colorado? Location: Colorado Front Range, USA. Methods: To assess severities historic fires, 24 sites were sampled an elevation 1800 to 2800 m for fire scars, tree establishment dates, mortality, changes tree-ring growth. Results: Below 1950 m, high number scarcity large post-fire cohorts, lack synchronous mortality or growth releases, indicate...
Abstract Question: What is the relative importance of low‐ and high‐severity fires in shaping forest structure across range Pinus ponderosa northern Colorado? Location: Colorado Front Range, USA. Methods: To assess severities historic fires, 24 sites were sampled an elevation 1800 to 2800 m for fire scars, tree establishment dates, mortality, changes tree‐ring growth. Results: Below 1950 m, high number scarcity large post‐fire cohorts, lack synchronous mortality or growth releases, indicate...
Abstract Regional warming has led to increased productivity near the boreal forest margin in Alaska. To date, effects of on seedling recruitment have received little attention, spite forecasted expansion. Here, we used stand structure and environmental data from 95 white spruce ( Picea glauca ) plots sampled across a longitudinal gradient southwest Alaska explore factors influencing establishment western treeline. We total counts live seedlings, saplings, trees, representing five life...
Resource managers rely on knowledge of fire history to guide management decisions, but for the subalpine zone Colorado Front Range little information exists documenting changes in regimes over past several centuries. We examined at 13 high elevation sites detect long-term trends that may be related land use and/or climatic variability. There is a degree spatial and temporal variation across sites; however, most exhibit an increase frequency during 20th century compared 19th century. did not...
Understanding the interactions of climate variability and wildfire has been a primary objective recent fire history research. The present study examines influence El Niño–Southern Oscillation (ENSO), Pacific Decadal (PDO) Atlantic Multidecadal (AMO) on occurrence using fire-scar evidence from 58 sites lower ecotone to upper elevational limits ponderosa pine (Pinus ponderosa) in northern Colorado. An important finding is that at low v. high elevations within montane zone, climatic patterns...
This study examines the influence of grasslands on fire frequency and occurrence in ponderosa pine (Pinus ponderosa)-dominated forests central northern Colorado Front Range. Fire based tree-ring fire-scar data was compared between 34 history sites adjacent to not for time period 1675–1920. Relationships were examined values Palmer Drought Severity Index sea-surface temperatures from NINO3 region tropical Pacific Ocean (positive indicating El Niño-like conditions negative La Niña-like...
Many forest ecosystems with a large pine component in the western United States have experienced environmental stress associated climate change and increased competition densification absence of fire. Information on how changes affect carbon allocation to tree growth defense is needed anticipate vigor and, ultimately, stand structure. This study retrospectively examined influence annual measures 113 sugar pines (Pinus lambertiana) mixed-conifer central Sierra Nevada California. We found that...
Dendroecology is the science that dates tree rings to their exact calendar year of formation study processes influence forest ecology (e.g., Speer 2010 [1], Amoroso et al., 2017 [2]) [...]
Abstract Warming temperatures are having a disproportionate effect on boreal ecosystems, influencing the establishment and growth of tree species across their respective ranges. However, less is known about how competitive interactions influence growth–climate relationships. We used tree‐ring data from 26 study plots (836 trees) to investigate patterns white spruce ( Picea glauca ) respond variation in competition climate southwest Alaska. Using linear mixed‐effects models, we compared...
Abstract Many fire‐maintained savannas and woodlands are suffering the effects of fire exclusion concomitant invasion fire‐sensitive trees. In Pacific West, dominated by either Oregon white oak ( Quercus garryana ) or California black kelloggii have transitioned from oak‐dominated to conifer‐dominated (primarily native Douglas‐fir; Pseudotsuga menziesii forest conditions with corresponding losses plant animal biodiversity. spite prevalence this transition, few studies documented these...
Drought, coupled with rising temperatures, is an emerging threat to many forest types across the globe. At least a degree, we expect management actions that reduce competition (e.g., thinning, prescribed fire, or both) improve growth of residual trees during drought. The influences and drought on individual tree may be measured high precision using tree-rings. Here, summarize tree-ring-based assessments effectiveness thinning fire as adaptation tools, special consideration for how these...