David Wahl, PhD
David is a research scientist at the Geology, Minerals, Energy, and Geophysics Science Center. He received a PhD in Geography from UC Berkeley in 2005. Since joining the USGS in 2004, his research has focused on understanding drivers and impacts of Quaternary environmental change, specifically droughts, floods, and wildfire, in North America and the Pacific Islands.
Professional Experience
2004 - Present, Research Geographer, US Geological Survey, Menlo Park, CA
2011 - Present, Assistant Adjunct Professor, Geography Department, UC Berkeley
Education and Certifications
Ph.D., Geography, University of California, Berkeley, 2005
M.A., Geography, University of California, Berkeley, 2000
B.A., History, Cal Poly, San Luis Obispo, 1996
Science and Products
Filter Total Items: 38
Methods for robust estimates of tree biomass from pollen accumulation rates: Quantifying paleoecological reconstruction uncertainty
Pollen accumulation rates (PAR, grains cm–2 year–1) have been shown to be a reliable but methodologically complex bioproxy for quantitative reconstruction of past tree abundance. In a prior study, we found that the PARs of major tree taxa – Pseudotsuga, Pinus, Notholithocarpus, and the pollen group TC (Taxaceae and Cupressaceae families) – were robust and precise estimators of...
Authors
Clarke Alexandra Knight, John J. Battles, M. Jane Bunting, Marie Rhondelle Champagne, James A. Wanket, David B. Wahl
Late Holocene human-environment interactions on the central California coast, USA, inferred from Morro Bay salt marsh sediments
Coastal salt marshes and estuaries provide valuable ecosystem services, yet are susceptible to alteration from human activities. Records of past environmental change in these ecosystems can elucidate relationships between human activities, such as land-use practices, and physical and ecological processes, such as sediment accretion and vegetation changes. To reconstruct the environmental...
Authors
Ellie Broadman, Liam M. Reidy, David B. Wahl
Land management explains major trends in forest structure and composition over the last millennium in California’s Klamath Mountains
For millennia, forest ecosystems in California have been shaped by fire from both natural processes and Indigenous land management, but the notion of climatic variation as a primary controller of the pre-colonial landscape remains pervasive. Understanding the relative influence of climate and Indigenous burning on the fire regime is key because contemporary forest policy and management...
Authors
Clarke Alexandra Knight, Lysanna Anderson, M. Jane Bunting, Marie Rhondelle Champagne, Rosie M. Clayburn, Jeffrey N. Crawford, Anna Klimaszewski-Patterson, Eric E. Knapp, Frank K. Lake, Scott A. Mensing, David B. Wahl, James A. Wanket, Alex Watts-Tobin, Matthew D. Potts, John J. Battles
Understanding rates of change: A case study using fossil pollen records from California to assess the potential for and challenges to a regional data synthesis
Insights into the rates at which ecosystems and vegetation respond to a changing climate is fundamental to anticipating impacts of projected climate change. Characterization of vegetation change over millennia to centuries has potential to make an important contribution toward this goal, and regional scale syntheses of fossil pollen data can provide the foundation for this understanding...
Authors
Lysanna Anderson, David B. Wahl, T. Bhattacharya
Linking modern pollen accumulation rates to biomass: Quantitative vegetation reconstruction in the western Klamath Mountains, NW California, USA
Quantitative reconstructions of vegetation abundance from sediment-derived pollen systems provide unique insights into past ecological conditions. Recently, the use of pollen accumulation rates (PAR, grains cm−2 year−1) has shown promise as a bioproxy for plant abundance. However, successfully reconstructing region-specific vegetation dynamics using PAR requires that accurate assessments...
Authors
Clarke Alexandra Knight, Mark Baskaran, M. Jane Bunting, Marie Rhondelle Champagne, Matthew D. Potts, David B. Wahl, James A. Wanket, John J. Battles
A multiproxy database of western North American Holocene paleoclimate records
Holocene climate reconstructions are useful for understanding the diverse features and spatial heterogeneity of past and future climate change. Here we present a database of western North American Holocene paleoclimate records. The database gathers paleoclimate time series from 184 terrestrial and marine sites, including 381 individual proxy records. The records span at least 4000 of the...
Authors
Cody C. Routson, Darrell S. Kaufman, Nicholas P. McKay, Michael Erb, S. H. Arcusa, Kendrick Brown, Matthew E. Kirby, Jeremiah Marsicek, R. Todd Anderson, Gonzalo Jimenez-Moreno, Jessica R. Rodysill, M. S. Lachniet, Sherilyn Fritz, Joseph R. Bennett, Michelle F. Goman, Sarah E. Metcalfe, J. M. Galloway, Gerrit H.W. Schoups, David B. Wahl, Jesse L. Morris, F. Staines-Urias, A. Dawson, B. N. Shuman, Daniel G. Gavin, Jeffrey S. Munroe, Brian F. Cumming
Non-USGS Publications**
Hansen, R., S. Bozarth, J. Jacob, Wahl D. and T. Schreiner (2002) “Climatic and Environmental Variability in the Rise of Maya Civilization.” Ancient Mesoamerica 13: 273-295.
Wahl, D., R. Byrne, T. Schreiner and R. Hansen (2006) “Holocene Vegetation Change in the Northern Peten and its Implications for Maya Prehistory.” Quaternary Research 65:380-389.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 38
Methods for robust estimates of tree biomass from pollen accumulation rates: Quantifying paleoecological reconstruction uncertainty
Pollen accumulation rates (PAR, grains cm–2 year–1) have been shown to be a reliable but methodologically complex bioproxy for quantitative reconstruction of past tree abundance. In a prior study, we found that the PARs of major tree taxa – Pseudotsuga, Pinus, Notholithocarpus, and the pollen group TC (Taxaceae and Cupressaceae families) – were robust and precise estimators of...
Authors
Clarke Alexandra Knight, John J. Battles, M. Jane Bunting, Marie Rhondelle Champagne, James A. Wanket, David B. Wahl
Late Holocene human-environment interactions on the central California coast, USA, inferred from Morro Bay salt marsh sediments
Coastal salt marshes and estuaries provide valuable ecosystem services, yet are susceptible to alteration from human activities. Records of past environmental change in these ecosystems can elucidate relationships between human activities, such as land-use practices, and physical and ecological processes, such as sediment accretion and vegetation changes. To reconstruct the environmental...
Authors
Ellie Broadman, Liam M. Reidy, David B. Wahl
Land management explains major trends in forest structure and composition over the last millennium in California’s Klamath Mountains
For millennia, forest ecosystems in California have been shaped by fire from both natural processes and Indigenous land management, but the notion of climatic variation as a primary controller of the pre-colonial landscape remains pervasive. Understanding the relative influence of climate and Indigenous burning on the fire regime is key because contemporary forest policy and management...
Authors
Clarke Alexandra Knight, Lysanna Anderson, M. Jane Bunting, Marie Rhondelle Champagne, Rosie M. Clayburn, Jeffrey N. Crawford, Anna Klimaszewski-Patterson, Eric E. Knapp, Frank K. Lake, Scott A. Mensing, David B. Wahl, James A. Wanket, Alex Watts-Tobin, Matthew D. Potts, John J. Battles
Understanding rates of change: A case study using fossil pollen records from California to assess the potential for and challenges to a regional data synthesis
Insights into the rates at which ecosystems and vegetation respond to a changing climate is fundamental to anticipating impacts of projected climate change. Characterization of vegetation change over millennia to centuries has potential to make an important contribution toward this goal, and regional scale syntheses of fossil pollen data can provide the foundation for this understanding...
Authors
Lysanna Anderson, David B. Wahl, T. Bhattacharya
Linking modern pollen accumulation rates to biomass: Quantitative vegetation reconstruction in the western Klamath Mountains, NW California, USA
Quantitative reconstructions of vegetation abundance from sediment-derived pollen systems provide unique insights into past ecological conditions. Recently, the use of pollen accumulation rates (PAR, grains cm−2 year−1) has shown promise as a bioproxy for plant abundance. However, successfully reconstructing region-specific vegetation dynamics using PAR requires that accurate assessments...
Authors
Clarke Alexandra Knight, Mark Baskaran, M. Jane Bunting, Marie Rhondelle Champagne, Matthew D. Potts, David B. Wahl, James A. Wanket, John J. Battles
A multiproxy database of western North American Holocene paleoclimate records
Holocene climate reconstructions are useful for understanding the diverse features and spatial heterogeneity of past and future climate change. Here we present a database of western North American Holocene paleoclimate records. The database gathers paleoclimate time series from 184 terrestrial and marine sites, including 381 individual proxy records. The records span at least 4000 of the...
Authors
Cody C. Routson, Darrell S. Kaufman, Nicholas P. McKay, Michael Erb, S. H. Arcusa, Kendrick Brown, Matthew E. Kirby, Jeremiah Marsicek, R. Todd Anderson, Gonzalo Jimenez-Moreno, Jessica R. Rodysill, M. S. Lachniet, Sherilyn Fritz, Joseph R. Bennett, Michelle F. Goman, Sarah E. Metcalfe, J. M. Galloway, Gerrit H.W. Schoups, David B. Wahl, Jesse L. Morris, F. Staines-Urias, A. Dawson, B. N. Shuman, Daniel G. Gavin, Jeffrey S. Munroe, Brian F. Cumming
Non-USGS Publications**
Hansen, R., S. Bozarth, J. Jacob, Wahl D. and T. Schreiner (2002) “Climatic and Environmental Variability in the Rise of Maya Civilization.” Ancient Mesoamerica 13: 273-295.
Wahl, D., R. Byrne, T. Schreiner and R. Hansen (2006) “Holocene Vegetation Change in the Northern Peten and its Implications for Maya Prehistory.” Quaternary Research 65:380-389.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.