Research Topics
| Donald L PhillipsSummaryAffiliation: U.S. Environmental Protection Agency Country: USA Publications
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Detail Information
Publications
Estimating the timing of diet shifts using stable isotopesDonald L Phillips
National Health and Environmental Effects Research Laboratory, U S Environmental Protection Agency, 200 SW 35th St, Corvallis, OR 97333, USA
Oecologia 147:195-203. 2006....- Source partitioning using stable isotopes: coping with too many sourcesDonald L Phillips
U S Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, 200 SW 35th St, Corvallis, OR 97333, USA
Oecologia 136:261-9. 2003..A computer program (IsoSource) to perform these calculations for user-specified data is available at http://www.epa.gov/wed/pages/models.htm... - Combining sources in stable isotope mixing models: alternative methodsDonald L Phillips
US Environmental Protection Agency, Office of Research and Development, Western Ecology Division, National Health and Environmental Effects Research Laboratory, 200 SW 35th St, Corvallis, OR, 97333, USA
Oecologia 144:520-7. 2005..In this case, a posteriori aggregation of sources allowed strong conclusions about temporal shifts in marine versus terrestrial diets that would not have otherwise been discerned... - CO2 and N-fertilization effects on fine-root length, production, and mortality: a 4-year ponderosa pine studyDonald L Phillips
U S Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Western Ecology Division, 200 SW 35th St, Corvallis, OR, 97333, USA
Oecologia 148:517-25. 2006..This study showed the potential for juvenile ponderosa pine to increase fine-root C pools and C fluxes through root mortality in response to elevated CO2... 
Elevated CO2 and O3 effects on fine-root survivorship in ponderosa pine mesocosmsDonald L Phillips
National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Corvallis, OR 97333, USA
Oecologia 160:827-37. 2009..These results indicate the potential for elevated CO(2) to increase the number of fine roots and their residence time in the soil, which is also affected by root diameter, root depth, and phenology...- Seasonal and long-term effects of CO2 and O3 on water loss in ponderosa pine and their interaction with climate and soil moistureE Henry Lee
US Environmental Protection Agency, Western Ecology Division, 200 SW 35th Street, Corvallis, OR 97333, USA
Tree Physiol 29:1381-93. 2009..O3-induced reductions in ET under ambient CO2 were likely transpirational changes via reduced conductance because needle area and root biomass were not affected by exposures to elevated O3 in this study... - Elevated CO(2) and temperature alter net ecosystem C exchange in a young Douglas fir mesocosm experimentDavid T Tingey
US Environmental Protection Agency, Western Ecology Division, 200 SW 35th St, Corvallis, OR 97330, USA
Plant Cell Environ 30:1400-10. 2007..In contrast, the degree of light inhibition of respiration was greater in AC than EC. In our system, respiration was the primary control on NEE, as EC and ET caused greater changes in respiration than photosynthesis... - Bole water content shows little seasonal variation in century-old Douglas-fir treesPeter A Beedlow
U S Environmental Protection Agency, 200 SW 35th Street, Corvallis, OR 97333, USA
Tree Physiol 27:737-47. 2007..Seasonal changes in bole RWC corresponded to cambial phenology, although decreasing AWS appeared to trigger the shift from earlywood to latewood formation... 
The shifting baseline of northern fur seal ecology in the northeast Pacific OceanSeth D Newsome
Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington, DC 20015, USA
Proc Natl Acad Sci U S A 104:9709-14. 2007..P., long before European contact. The relative roles of human hunting versus climatic factors in explaining this ecological shift are unclear, as more paleoclimate information is needed from the coastal zone...