Phillip van Mantgem
- Ph.D., Ecology, University of California, Davis, CA 2001
- M.S., Plant Biology, University of California, Davis, CA 1996
- B.S., Botany, University of Iowa, Iowa City, IA 1991
- Conservation biology
- Fire ecology
- Forest ecology
- Research Ecologist, USGS, Redwood Field Station, Arcata, CA, 2008 - Present
- Ecologist, USGS, Sequoia and Kings Canyon Field Station, Three Rivers, CA, 2000 - 2008
Science and Products
USGS WERC's Dr. Phil van Mantgem and his collaborators are using plot-based methods to describe change and vulnerability to drought in the forests of the western United States. A focus of this work is the installation and maintenance of large (1 ha) monitoring plots. Many other vegetation monitoring strategies are based on small (0.1 ha) plots, which may not be sufficient to detect changes in forest tree populations and communities. Earlier work has established the climatic sensitivity of temperate forests, but many questions remain as to where and how forests in the western United States will respond to drought.
Long-term monitoring of forest resources in the western U.S. is an essential part of understanding biological responses to drought. Using the current severe drought in the southwestern U.S. as a natural experiment, USGS scientists and partners are combining direct measurements of tree mortality with tree-ring indices of tree health—providing the first large-scale assessment of prescribed fire as a management tool to increase forest resistance to severe drought.
This project uses new and existing field data to assess forest restoration treatment effects across broad spatial and temporal scales. WERC's Dr. Phil van Mantgem and project partners are considering the effects of restoration treatments in terms of forest structure, forest stand development, subsequent tree mortality patterns mortality, and how climate influences the success or failure of restoration treatments. Findings from this work allow managers to better predict the outcomes of restoration activities. The management of forests is becoming ever more contentious, and it is only with these detailed data that our Department of Interior (DOI) client agencies will be able to effectively plan and manage for the future of these forests.
How will increased drought affect forest fire severity? WERC’s Dr. Phil van Mantgem is testing the idea increased drought stress may affect forest fire severity independent of fire intensity. Drought stress prior to fire can affect tree health, potentially resulting in a higher sensitivity to fire-induced damage. Thus, with drought there may be ongoing increases in fire severity (the number of trees killed), even when there is no change in fire intensity (the amount of heat released during a fire). Dr. Phil van Mantgem and his collaborators are considering this question at a subcontinental scale by synthesizing existing information from plot-based prescribed fire monitoring databases across the western United States of America.
Characterizing interactions between fire and other disturbances and their impacts on tree mortality in western U.S. Forests
Increasing evidence that pervasive warming trends are altering disturbance regimes and their interactions with fire has generated substantial interest and debate over the implications of these changes. Previous work has primarily focused on conditions that promote non-additive interactions of linked and compounded disturbances, but the spectrum of...Kane, Jeffrey M.; Varner, J. Morgan; Metz, Margaret R.; van Mantgem, Phillip J.
Higher sensitivity and lower specificity in post-fire mortality model validation of 11 western US tree species
Managers require accurate models to predict post-fire tree mortality to plan prescribed fire treatments and examine their effectiveness. Here we assess the performance of a common post-fire tree mortality model with an independent dataset of 11 tree species from 13 National Park Service units in the western USA. Overall model discrimination was...Kane, Jeffrey M.; van Mantgem, Phillip J.; Lalemand, Laura; Keifer, MaryBeth
Forest restoration at Redwood National Park: exploring prescribed fire alternatives to second-growth management: a case study
Almost half of Redwood National Park is comprised of second-growth forests characterized by high stand density, deficient redwood composition, and low understory biodiversity. Typical structure of young redwood stands impedes the recovery of old-growth conditions, such as dominance of redwood (Sequoia sempervirens (D. Don) Endl.), distinct canopy...Engber, Eamon; Teraoka, Jason; van Mantgem, Phillip J.
Low thinning and crown thinning of two severities as restoration tools at Redwood National Park
Interest in the restoration of second-growth forests has continued to increase in the redwood region, which has further increased the importance of evaluating restoration-based silvicultural strategies. This study assessed the short-term effectiveness of four silvicultural treatments (two silvicultural thinning methods, low thinning and crown...Teraoka, Jason R; van Mantgem, Phillip J.; Keyes, Christopher R.
The relative contributions of disease and insects in the decline of a long-lived tree: a stochastic demographic model of whitebark pine (Pinus albicaulis)
Pathogens and insect pests have become increasingly important drivers of tree mortality in forested ecosystems. Unfortunately, understanding the relative contributions of multiple mortality agents to the population decline of trees is difficult, because it requires frequent measures of tree survival, growth, and recruitment, as well as the...Jules, Erik S; Jackson, Jenell I.; van Mantgem, Phillip J.; Beck, Jennifer S.; Murray, Michael P.; Sahara, E. April
Duration of fuels reduction following prescribed fire in coniferous forests of U.S. national parks in California and the Colorado Plateau
Prescribed fire is a widely used forest management tool, yet the long-term effectiveness of prescribed fire in reducing fuels and fire hazards in many vegetation types is not well documented. We assessed the magnitude and duration of reductions in surface fuels and modeled fire hazards in coniferous forests across nine U.S. national parks in...van Mantgem, Phillip J.; Lalemand, Laura; Keifer, MaryBeth; Kane, Jeffrey M.
Does prescribed fire promote resistance to drought in low elevation forests of the Sierra Nevada, California, USA?
Prescribed fire is a primary tool used to restore western forests following more than a century of fire exclusion, reducing fire hazard by removing dead and live fuels (small trees and shrubs). It is commonly assumed that the reduced forest density following prescribed fire also reduces competition for resources among the remaining trees, so...van Mantgem, Phillip J.; Caprio, Anthony C.; Stephenson, Nathan L.; Das, Adrian J.
Increasing elevation of fire in the Sierra Nevada and implications for forest change
Fire in high-elevation forest ecosystems can have severe impacts on forest structure, function and biodiversity. Using a 105-year data set, we found increasing elevation extent of fires in the Sierra Nevada, and pose five hypotheses to explain this pattern. Beyond the recognized pattern of increasing fire frequency in the Sierra Nevada since the...Schwartz, Mark W.; Butt, Nathalie; Dolanc, Christopher R.; Holguin, Andrew; Moritz, Max A.; North, Malcolm P.; Safford, Hugh D.; Stephenson, Nathan L.; Thorne, James H.; van Mantgem, Phillip J.
The influence of prefire tree growth and crown condition on postfire mortality of sugar pine following prescribed fire in Sequoia National Park
Tree mortality is a vital component of forest management in the context of prescribed fires; however, few studies have examined the effect of prefire tree health on postfire mortality. This is especially relevant for sugar pine (Pinus lambertiana Douglas), a species experiencing population declines due to a suite of anthropogenic factors....Nesmith, Jonathan C. B.; Das, Adrian J.; O'Hara, Kevin L.; van Mantgem, Phillip J.
Structure, diversity, and biophysical properties of old-growth forestsin the Klamath region, USA
The diverse old-growth forests in Klamath region of northern California and southern Oregon provide valuable ecosystem services (e.g., maintaining watersheds, wildlife habitat, recreation), but may be vulnerable to a wide range of stressors, including invasive species, disrupted disturbance regimes, and climatic change. Yet our understanding of...van Mantgem, Phillip J.; Starr, Daniel A
An individual-based growth and competition model for coastal redwood forest restoration
Thinning treatments to accelerate coastal redwood forest stand development are in wide application, but managers have yet to identify prescriptions that might best promote Sequoia sempervirens (Lamb. ex D. Don) Endl. (redwood) growth. The creation of successful thinning prescriptions would be aided by identifying the underlying...van Mantgem, Phillip J.; Das, Adrian J.
Rate of tree carbon accumulation increases continuously with tree size
Forests are major components of the global carbon cycle, providing substantial feedback to atmospheric greenhouse gas concentrations. Our ability to understand and predict changes in the forest carbon cycle—particularly net primary productivity and carbon storage - increasingly relies on models that represent biological processes across several...Stephenson, N.L.; Das, A.J.; Condit, R.; Russo, S.E.; Baker, P.J.; Beckman, N.G.; Coomes, D.A.; Lines, E.R.; Morris, W.K.; Rüger, N.; Álvarez, E.; Blundo, C.; Bunyavejchewin, S.; Chuyong, G.; Davies, S.J.; Duque, Á.; Ewango, C.N.; Flores, O.; Franklin, J.F.; Grau, H.R.; Hao, Z.; Harmon, M.E.; Hubbell, S.P.; Kenfack, D.; Lin, Y.; Makana, J.-R.; Malizia, A.; Malizia, L.R.; Pabst, R.J.; Pongpattananurak, N.; Su, S.-H.; Sun, I-F.; Tan, S.; Thomas, D.; van Mantgem, P.J.; Wang, X.; Wiser, S.K.; Zavala, M.A.
- Tree death rates have more than doubled over the last few decades in old-growth forests of our western states, possibly reflecting increasing temperatures, with potentially serious consequences for wildlife, fire risks, and the global carbon cycle
- Rising regional temperatures have lengthened the summer drought, likely stressing trees and leading to higher death rates
- Is this alarming trend a harbinger of larger, more abrupt changes in our forests?
Speaker: Phillip van Mantgem, USGS Ecologist