Current Research

My research spans multiple systems, from the forests of the Northeastern US to the street tree populations in our cities. My overarching research question is: what drives changes in urban and wildland forests? To address this, I utilize and contribute to long-term data sets on tree demography, forest biomass, and spatially-explicit tree growth.

Current studies include:

- Urban tree database and allometric equations
- Climate-ready trees for Southern California communities
- Street tree demography in Claremont and Santa Monica, California
- Structure, function and value of street trees in California

- Understanding neighborhood effects on forest growth and tree competition in a temperate forest
- Demography of decline, disturbance and recovery in a northern hardwood forest
- Best practices and quantified error rates for long-term tagged-tree inventories

Research Interests

- urban forest resilience
- multiple disturbances
- neighborhood dynamics of forest ecosystems
- tree demography
- dendroecology
- long-term data

Past Research

I graduated with a PhD in Environmental Science, Policy and Management from the Forest Ecology & Ecosystem Dynamics Lab at UC Berkeley. The title of my dissertation is “Patterns and process of forest growth: the role of neighborhood dynamics and tree demography in a northern hardwood forest”. The sustainability of the northern hardwood forest is threatened by disturbances and perturbations including chronic air pollution, invasive pests, and rare catastrophic events. Hubbard Brook Experimental Forest (HBEF) in New Hampshire is a prime example of a forest experiencing multiple environmental stressors with serious but subtle impacts. Long-term studies at HBEF have documented a decline in forest biomass accumulation that seems to be the result of reduced growth of the dominant tree species: sugar maple (Acer saccharum Marsh.) and beech (Fagus grandifolia Ehrh.). Previous studies have linked soil calcium depletion resulting from acidic deposition to reduced health in sugar maple. In addition, the spread of the exotic scale insect, Cryptococcus fagisuga Lind., that produces bark cankering has reduced growth rates in beech trees. Each of these perturbations may influence species competitive hierarchies. My dissertation focused on teasing apart these complex competitive interactions in relation to tree growth and examines the role of chronic acid deposition and an ice storm on demographic processes that affect forest productivity. In addition, I synthesized best practices for evaluating changes in forest dynamics through tagged-tree inventories.

Education

• University of California at Berkeley, Ph.D. Environmental Science, Policy and Managament 2014
• University of California at Berkeley, M.S. Environmental Science, Policy and Management 2007
• University of California at Berkeley, B.S. Resource Management (emphasis in forestry) 2004

Professional Organizations

• International Association for Landscape Ecology, Member (2017 - Current)
• Society of American Foresters (SAF), Member (2003 - Current)

Featured Publications & Products

• van Doorn, Natalie S.; McPherson, E. Gregory. 2018. Demographic trends in Claremont California s street tree population.
• McPherson, E. Gregory; van Doorn, Natalie S.; Peper, Paula J. . 2016. Urban tree database and allometric equations.
• McPherson, E. Gregory; Xiao, Qingfu; van Doorn, Natalie S.; de Goede, John; Bjorkman, Jacquelyn; Hollander, Allan; Boynton, Ryan M.; Quinn, James F.; Thorne, James H. 2017. The structure, function and value of urban forests in California communities.
• McPherson, E. Gregory; van Doorn, Natalie; de Goede, John. 2016. Structure, function and value of street trees in California, USA.
• McPherson, E.Gregory; Berry, Alison M.; van Doorn, Natalie S. 2018. Performance testing to identify climate-ready trees.
• Roman, Lara A.; Pearsall, Hamil; Eisenman, Theodore S.; Conway, Tenley M.; Fahey, Robert T.; Landry, Shawn; Vogt, Jess; van Doorn, Natalie S.; Grove, J. Morgan; Locke, Dexter H.; Bardekjian, Adrina C.; Battles, John J.; Cadenasso, Mary L.; van den Bosch, Cecil C. Konijnendijk; Avolio, Meghan; Berland, Adam; Jenerette, G. Darrel; Mincey, Sarah K.; Pataki, Diane E.; Staudhammer, Christina. 2018. Human and biophysical legacies shape contemporary urban forests: A literature synthesis.
• Levine, Carrie R.; Krivak-Tetley, Flora; van Doorn, Natalie S.; Ansley, Jolie-Anne S.; Battles, John J. 2016. Long-term demographic trends in a fire-suppressed mixed-conifer forest.
• Li, Xiang; Xiao, Qingfu; Niu, Jianzhi; Dymond, Salli; van Doorn, Natalie S.; Yu, Xinxiao; Xie, Baoyuan; Lv, Xizhi; Zhang, Kebin; Li, Jiao. 2016. Process-based rainfall interception by small trees in Northern China: The effect of rainfall traits and crown structure characteristics.

Publications

• McPherson, E. Gregory; Xiao, Qingfu; van Doorn, Natalie S.; Johnson, Nels; Albers, Shannon; Peper, Paula J. 2018. Shade factors for 149 taxa of in-leaf urban trees in the USA.
• McPherson, E.G. ; Berry, A.M. ; van Doorn, N.S. ; Downer, J. ; Hartin, J. ; Haver, D. ; Teach, E. . 2017. Climate-ready tree study update for Central Valley communities.
• Li, Xiang; Xiao, Qingfu; Niu, Jianzhi; Dymond, Salli; McPherson, E. Gregory; van Doorn, Natalie; Yu, Xinxiao; Xie, Baoyuan; Zhang, Kebin; Li, Jiao. 2017. Rainfall interception by tree crown and leaf litter: an interactive process.
• McPherson, E. Gregory; Xiao, Q.; van Doorn, Natalie; Peper, P.; Teach, E. 2017. Surface storage of rainfall in tree crowns: not all trees are equal.
• Li, Xiang; Niu, Jianzhi; Zhang, Linus; Xiao, Qingfu; McPherson, Gregory E.; van Doorn, Natalie; Yu, Xinxiao; Xie, Baoyuan; Dymond, Salli; Li, Jiao; Meng, Chen; Luo, Ziteng. 2016. A study on crown interception with four dominant tree species: a direct measurement.

Citations of non US Forest Service Publications

• Pietrzykowski, M., J. Socha, N.S. van Doorn. 2015. Scots pine (Pinus sylvestris L.) site index in relation to physico-chemical and biological properties in reclaimed mine soils. New Forests 46: 247-266. doi: 10.1007/s11056-014-9459-z
• Pietrzykowski, M., J. Socha, N.S. van Doorn. 2014. Linking heavy metal bioavailability (Cd, Cu, Zn, and Pb) in Scots pine needles to soil properties in reclaimed mine areas. Science of the Total Environment 470: 501-510. doi: 10.1016/j.scitotenv.2013.10.008

• van Doorn, N.S., J.J. Battles, T.G. Siccama, P. Schwarz, T.J. Fahey. 2011. Links between biomass and tree demography in a northern hardwood forest: A decade of stability and change in Hubbard Brook Valley, New Hampshire. Canadian Journal of Forest Research 41: 1369-1379. doi: 10.1139/x11-063

• Fonti, Patrick; Solomonoff, Natalie; García-González, Ignacio 2007. Earlywood vessels of Castanea sativa record temperature before their formation. New Phytologist 173: 562–570. doi: 10.1111/j.1469-8137.2006.01945.x