USGS National Wetlands Research Center: Jim Grace profile

James B. Grace, Ph.D.

James B. Grace, Ph.D. 1980. Michigan State University. Complex systems analysis.

In recent years, Grace's research has evolved to emphasize the study of complex interrelationships in natural systems. This focus has grown out of the recognition that the study of systems (as opposed to individual processes) requires methods that are quite different from the time-honored procedures recommended for experimentation and monitoring. In brief, if we are to understand and predict the behavior of systems, we need to develop and evaluate multivariate hypotheses. One approach to the evaluation of multivariate hypotheses involves the use of structural equation modeling (SEM) and this has been the primary method we are using at present. SEM represents a methodology by which we can develop models about complex networks of relationships and subsequently evaluate the degree to which data are consistent with various models. The use of SEM allows researchers to address a whole new set of questions about how system parts interact, the relative importances of different processes, and how systems will behave under a wide variety of conditions. SEM allows for the evaluation of multivariate models using both experimental and nonexperimental data. As a model-centered approach (versus the conventional null hypothesis-centered approach), SEM provides a uniquely powerful and flexible approach for progressive learning about systems. A brief introduction to SEM can be found in Chapter 30 of McCune and Grace (2002).

While SEM holds great promise for use in the study of natural systems, there are a number of capabilities of the method that are currently underdeveloped. In particular there is a need to deal readily with complex variables and to this end, Grace has been working with other SEM specialists to develop procedures for including composite variables in structural equation models. Composite variables are particularly useful in representing nonlinear relationships as well as for representing the general relationships that emerge from complex models. Another aspect of SEM that Grace is currently studying has to do with how to best extract general predictive information out of model results. One example of this work can be found in Grace and Bollen (2005).

Finally, Grace has been collaborating with a great number of researchers to determine the range of utility of SEM in studying natural systems. Such studies include studies of plant diversity, wetland conservation, grazing, disturbance, biological control of weeds, climate change, sea level rise, fire ecology, and wildlife habitat.

In the past Grace's research program has dealt with a variety of particular applications, including the ecology of coastal plant ecosystems, especially coastal prairie and coastal wetlands. These ecosystems are currently at risk from a variety of forces, especially exotic plants but also fire suppression. Research efforts have been centered on predicting the effects of fire on coastal communities with a special emphasis on the impacts on exotic species, particularly Chinese tallow tree. Of special interest in this work have been the mechanisms of interaction among plants that determine the long-term responses to fire. For more information about the NWRC Coastal Prairie Research Program, click here.

Select Publications:

The following is only a list of recent publications (plus books published previously). For a complete list of publications, please click here (PDF, 77 KB). For assistance with obtaining reprints, please contact the NWRC Library.

Clark, C, Cleland, E, Fargione, J.E., Gough, L., Gross, K.L., Pennings, S.C., Suding, K.N. and Grace, JB. 2007. Environmental and plant community determinants of species loss following nitrogen enrichment. Ecology Letters.10:000-000 [published early online].
Owens, A, Proffitt, E, and Grace, JB. 2007. Prescribed fire and cutting as tools for managing woody plant succession in a created salt marsh. Wetlands Ecology and Management. 00:000-000. [published early online].
Grace, J.B., Anderson, T.M., Smith, M., Seabloom, E., Andelman, S., Meche, G., Weiher, E., Allain, L.K., Jutila, H., Sankaran, M., Harpole, W.S., Knops, J., Ritchie, M.E. and Willig, M.R. 2007. Does species diversity limit productivity in natural grassland communities. Ecology Letters. 10:000-000 [published early online].
Anderson, T.M., Ritchie, M.E., Mayemba, E., Eby, S., Grace, J.B., and McNaughton, S.J. 2007. Forage nutritive quality in the Serengeti ecosystem: the roles of fire and hervbivory. American Naturalist. (in press).
Grace, J.B., Safford, H., and Harrison, S. 2007. Large-scale causes of variation in the serpentine vegetation of California. Plant and Soil [early online pub. # DOI 10.1007/s11104-007-9196-6].
Harrison, S. and Grace, JB. 2007. Biogeographic affinity contributes to our understanding of productivity-richness relationships at regional and local scales. American Naturalist (in press).
Grace, J.B. 2007. A brief overview of structural equation modeling. Journal of Wildlife Management (in press).
Laughlin, D.C., Abella, S.R., Covington, W.W., Fulé, P., and Grace, J.B. 2007. A structural equation modeling analysis of plant species richness and soil properties in a ponderosa pine forest ecosystem. Journal of Vegetation Science 18:231-242.
Larson, D.L., Grace, J.B., Rabie, P.A., and Andersen, P. 2007. Short-term disruption of a leafy spurge (Euphorbia esula) biocontrol program following herbicide application. Biological Control 40:1-8.
Grace, J.B. and Zouhar, K. 2007. Central region. In: Smith, J., Sutherland, S., and Brooks, M. (eds.) Wildland Fire and Ecosystems: Fire and Non-native Invasive Species, Forest Service Report. (in press).
Grace, J.B. and Bollen, KA. 2007. Representing general theoretical concepts in structural equation models: the role of composite variables. Environmental and Ecological Statistics (in press).
Baldwin, H.Q., Grace, J.B., Barrow, W., Rohwer, F.C. 2007. Association of overwintering grassland birds with time since burn and vegetation characteristics in coastal tallgrass prairie. Wilson Journal of Ornithology 119:188-196.
Drake, D.L., Altig, R., Grace, J.B. and Walls, S.C. 2007. Occurrence of oral defects in larval anurans from protected sites. Copeia 2007(2):449-458.
Grace, J.B. and Bollen, K.A. 2006. The Interface between Theory and Data in Structural Equation Models. USGS Open-File Report 2006-1363. 37 p.
Grace, J.B. 2006. Structural Equation Modeling and Natural Systems. Cambridge University Press. 365 p.
Lichtenberg, J.S., King, S.L., Grace, J.B., and Walls, S. 2006. Habitat associations of chorusing anurans in the lower Mississippi river alluvial valley. Wetlands 26:736-744.
Laughlin, D.C. and Grace, J.B. 2006. A multivariate model of plant species richness in forested systems: old-growth montane forests with a long history of fire. Oikos 114:60-70.
Whitbeck, M. and Grace, J.B. 2006. Estimating biomass in marshes of the upper Texas coast. Wetlands 26:278-282.
Harrison, S., Grace, J.B. Davies, K.F., Safford, H.D., and Viers, J.H. 2006. Exotic invasion in a diversity hotspot: disentangling the direct and indirect relationships of exotic cover to native richness in the californian serpentine flora. Ecology 87:695-703.
Harrison, S., Safford, H.D. Grace, J.B. Viers, J.H. and Davies, K.F. 2006. Regional and local species richness in an insular environment: Serpentine plants in California. Ecological Monographs 76:41-56.
Grace, JB and Keeley, JE. 2006. A structural equation model analysis of postfire plant diversity in California shrublands. Ecological Applications 16:503-514.
Allain, L., Smith, L, Allen, C. Vidrine, M.F. and Grace, J.B. 2006. A floristic quality assessment system for the coastal prairie of Louisiana. Proceedings of The 19th North American Prairie Conference, pp. 1-18.

Books Published Previously:

McCune, B. and J.B. Grace. 2002. Analysis of Ecological Communities. MJM Press, 302 pages.
Grace, J.B. and D. Tilman (eds.) 1990. Perspectives in Plant Competition. Academic Press, New York. 484 pages.

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