Barbara Allen-Diaz

Professor
Ph.D.  Wildland Resource Science    University of California, Berkeley, 1980
A.B.   Anthropology    Anthropology, 1975

311 Hilgard Hall
Berkeley, California 94720-3114
ballen@nature.berkeley.edu
office: 510-642-7125   lab: 510-642-7125   fax:  510-643-5438

Web site         Recent publications      People

I study how rangeland ecosystems respond to herbivory, fire, and management. I ask questions about how rangeland plant community distribution is related to physical site variables such as elevation, slope, aspect, soil type, and climate, as well as to biological and management variables such as grazing and fire history, etc. Then I examine whether the patterns in community response are predictable at various scales. I develop plant community models of ecosystem response which are intended to improve land management decision making.

My current research focus addresses political and management issues of livestock grazing contribution to nonpoint source pollution. Common belief is that livestock are a major source of degradation to riparian vegetation, streambanks, and water quality. Furthermore, livestock grazing in the uplands is believed to be a significant source of pollution in rangeland watersheds.

I have several projects, at different scales, examining rangeland watershed functioning. With other colleagues, I am studying spring systems in oak woodland/annual grass dominated rangelands to determine spring type, relationship to site, and response to herbivory. I am experimentally manipulating cattle grazing intensity in replicated sub-watersheds containing springs and riparian areas to determine vegetation, channel, and water quality response. I am simultaneously monitoring an ungrazed watershed to determine the yearly cycle of water movement in and through the system. I am also interested in grazing season and fire effects on plant community composition, native plant distribution, and water quality and runoff. I continue to study the effects of spatial and temporal scale on plant community dynamics, biodiversity, and ecosystem productivity.

Students working with me are interested in general questions of ecosystem response to various disturbances and effects of management activities My students are specifically interested in oak woodland, riparian, wetland, and meadow rangeland ecosystems and approach research questions from plant community, landscape, and ecosystem points of view. All the students working with me are interested in rangeland vegetation change and the mechanisms involved in predicting change as well as options for good and/or better management of resources.

Jackson, R.D. and B.Allen-Diaz. In press. Grazing removal disturbs the equilibrium of spring-fed plant communities in Californian oak savanna-annual grassland. J. Applied Ecology.

Wenk, R.C., J.J. Battles, R.D. Jackson, J.W. Bartolome, and B. Allen-Diaz. 2006. An accurate and efficient method for sorting biomass extreacted from soil cores using point-intercept sampling. Soil Sci Soc Am J 2006 70: 851-855.

Kelly, M., B. Allen-Diaz, and N. Kobzina. 2005.Digitization of a historic dataset: the Wieslander California Vegetation Type Mapping project. Madrono 52:191-201.

Jackson, R.D., B. Allen-Diaz, L.G. Oates, and K.W. Tate. 2006. Spring-water nitrate increased with removal of livestock grazing in a California oak savanna. Ecosystems 9: 1-15.

Kluse, Jennifer S. and Barbara H. Allen-Diaz. 2005.Importance of soil moisture and its interaction with competition and clipping for two montane meadow grasses. Plant Ecology 176: 87-99.

Allen-Diaz, B., R. Jackson, J. Bartolome, K. Tate, and G. Oates. 2004. Grazing management of spring-fed wetlands in Californian oak woodlands: summary of results of a long term study. California Agriculture 58: 144-148.

Bartolome, J.W., J.S. Fehmi, R.D. Jackson, and B.Allen-Diaz. 2004. Response of a native perennial grass stand to disturbance in California’s Coast Range grassland. Restoration Ecology 12(2): 279-289.

Merenlender, A.M., K.L. Heise, J.W. Bartolome, and B.H. Allen-Diaz. 2001. Monitoring shows vegetation change at multiple scales. California Agriculture 55(6): 42-46.

Bartolome, J.W., M.P. McClaran, B. Allen-Diaz, J.Dunne, L.Ford, R. Standiford, N. McDougald, and L. Forero. 2002. Effects of fire and browsing on regeneration of blue oak. . In: Proc. 5th Oak Symposium: Oaks in California’s Changing Landscape. San Diego, CA.Gen. Tech. Rep. PSW-GTR-184:281-286.

Jackson, R.D. and B. Allen-Diaz. 2002. Nitrogen dynamics of spring-fed wetland ecosystems of the Sierra Nevada foothills oak woodland. In: Proc. 5th Oak Symposium: Oaks in California’s Changing Landscape. San Diego, CA.Gen. Tech. Rep. PSW-GTR-184:119-130.

Allen-Diaz, B.H., R.D. Jackson, and C. Phillips.2001. Spring communities of the East Bay Hills oak woodland, Contra Costa and Alameda Counties, California. Madrono 48:98-111.

Fernandez-Gimenez, M. and B. Allen-Diaz. 2001.Vegetation change along gradients from water sources in three grazed Mongolian ecosystems. Plant Ecology 157: 101-118.

Battles, John J., Ayn J. Shlisky, Reginald H. Barrett, Robert C. Heald, and Barbara H. Allen-Diaz. 2001. The effects of forest management on plant species diversity in a Sierran conifer forest. Forest Ecology and Manage. 146:211-222.

Salve, Rohit and B. Allen-Diaz. 2001.Variations in soil moisture content in a rangeland catchment. J. Range Manage. 54(1): 44-51.

Vayssieres, Marc P.; R.E. Plant, and B. Allen-Diaz. 2000.Classification trees: An alternative non-parametric approach for predicting species distributions. J. Vegetation Science 11: 679-694.