Kevin L. O'Hara

Professor
Ph.D.  
  

207 Mulford Hall
Berkeley, California 94720-3114
ohara@nature.berkeley.edu
office: 510-642-2127   lab: 510-642-2127   fax:  510-643-5438

     Recent publications     

My research involves integrating stand dynamics into stand- and landscape-level decision-making. Stand dynamics generally refers to changes in stand structure and related processes over time. With a good understanding of stand structure and stand development, silviculturists and other forest managers can anticipate changes in structure and make appropriate interventions to meet management objectives. These management objectives may involve enhancing wildlife habitat, restoring ecosystem function, or growing trees for timber production.

One area of my research involves using leaf area to represent the occupied growing space of trees. Leaf area is useful for representing rates of energy and material exchange in tree canopies, and it is limited by site quality variables. By examining rates of tree increment per unit of leaf area, differences in the efficiency (or growing space efficiency) of trees based on crown class, age, or species can be measured. This work enables the identification of stand components that are making large contributions to stand increment and those that are not. For example, in even-aged stands, codominant trees appear to be most efficient. In multiaged ponderosa pine, the oldest age classes appear to be most efficient. This information is useful for silviculturists trying to maximize volume increment or examining the volume increment implications of changes in forest stand structure.

Other research has involved reconstruction of mixed-species stand development to compare growth rates of different species. Patterns of height growth development can vary between species enabling mixed-species stands to form multistrata canopies. These multistrata canopies can meet some management objectives not met by single-species stands that under many management regimes lack structural variability. Pruning of forest trees to enhance wood quality is another area of interest.

Finally, a major portion of my research effort is focused on decision support tools to assist managers making silvicultural decisions. These decision support systems include models which predict stand growth, decision keys for prioritizing stands for precommercial thinning treatments, expert systems for prioritizing silvicultural treatments, and the development of stocking guidelines for single-species, mixed-species, and multiaged stands.

Add here.

Keyes, C.R., and K.L. O'Hara. 2002. Quantifying stand targets for silvicultural prevention of crown fires. Western Journal of Applied Forestry 17(2): 101-109.

Nagel, L.M., and K.L. O'Hara. 2002. Diurnal fluctuations of gas exchanged and water potential in different stand structures of Pinus ponderosa. Trees: Structure and Function 16:281-290.

O'Hara, K.L. 2002. The historical development of uneven-aged silviculture in North America. Forestry 75(4): 339-346.

O'Hara, K.L., N.I. Valappil, and L.M. Nagel. 2003. Stocking control procedures for multiaged ponderosa pine stands in the Inland Northwest. Western Journal of Applied Forestry 18(1): 5-14.

O'Hara, K.L., and R.F. Gersonde. 2004. Stocking control concepts in uneven-aged silviculture. Forestry 77(2): 131-143.

Gersonde, R.F., J.J. Battles, and K.L. O'Hara. 2004. Characterizing the light environment in Sierra Nevada mixed-conifer forests using a spatially explicit light model. Canadian Journal of Forest Research 34: 1332-1342.

O'Hara, K.L., and K.M. Waring 2005. Forest restoration practices in the Pacific Northwest and California. Pp. 445-461 in Restoration of Boreal and Temperate Forests. (J.A. Stanturf and P.Madsen, editors). CRC Press. Boca Raton, FL.

Waring, K.M., and K.L. O'Hara. 2005. Silvicultural strategies in forest ecosystems affected by introduced pests. Forest Ecology and Management 209: 27-41.

Stancioiu, P.T., and K.L. O'Hara. 2005. Sapwood area - leaf area relationships for coast redwood. Canadian Journal of Forest Research 35: 1250-1255.

Gersonde, R.F., and K.L. O'Hara. 2005. Comparative tree growth efficiency in Sierra Nevada mixed-conifer forests. Forest Ecology and Management 219: 95-108

Stancioiu, P.T., and K.L. O'Hara. 2006. Leaf area and growth efficiency of regeneration in mixed-species, multiaged forests of the Romanian Carpathians. Forest Ecology and Management 222:55-66.

Carnus, J.-M., J. Parrotta, E. Brockerhoff, M. Arbez, H. Jactel, A. Kremer, D. Lamb, O'Hara, K. L., B. Walters, 2006. Planted Forests and Biodiversity. Journal of Forestry 104 (2) 65-77.

Stancioiu, P.T., and K.L. O'Hara. 2006. Regeneration dynamics in different light environments of mixed species, multiaged, mountainous forests of Romania. European Journal of Forest Research 125: 151-162.

O'Hara, K.L. 2006. Multiaged forest stands for protection forests: concepts and applications. Forest Snow and Landscape Research 80: 45-55.

O’Hara, K.L., and L.M. Nagel. 2006. A functional comparison of productivity in even-aged and multiaged stands: A synthesis for Pinus ponderosa. Forest Science 52: 290-303.

Waring, K.M., and K.L. O’Hara. 2006. Estimating relative error in growth ring analysis of second growth coast redwood (Sequoia sempervirens). Canadian Journal of Forest Research 36: 2216-2222.

Berrill, J.-P., and K.L. O'Hara. 2007. Patterns of leaf area and growing space efficiency in young even-aged and multiaged coast redwood stands. Canadian Journal of Forest Research 37: 617-626.

O’Hara, K.L., H. Hasenauer, and G. Kindermann. 2007. Sustainability in multiaged stands: An analysis of long-term plenter systems. Forestry 80(2): 163-181.

O’Brien, M.J., K.L. O’Hara, N. Erbilgin, and D.L. Wood. 2007. Overstory and shrub effects on natural regeneration processes in native Pinus radiata stands. Forest Ecology and Management 240: 178-185.

O'Hara, K.L. 2007. Bridging the generation gap: Science is helping second- and third-growth redwoods come into their own. California Forests 11(1): 12-13.

O’Hara, K.L. 2007. Pruning wounds and occlusion: A long-standing conundrum in forestry. Journal of Forestry 105(3): 131-138.

Berrill, J.-P., and K.L. O’Hara. 2007. Redwood in California: An overview of silvicultural systems. New Zealand Tree Grower 28(1): 11-13.

O’Hara, K.L., P.T. Stancioiu, M.A. Spencer. 2007. Understory stump sprout development under variable canopy density and leaf area in coast redwood. Forest Ecology and Management 244: 76-85.

Peracca, G.G., and K.L. O’Hara. 2007. Effects of growing space on growth for 20-year-old giant Sequoia, ponderosa pine and Douglas-fir in the Sierra Nevada. Western Journal of Applied Forestry (in press).