Environmental Relationships of Native Garry Oak (Quercus garryana) Communities at Their Northern Margin

Knowledge of relationships among plant communities and environmental variables can be used in restoration, ecological assessments, predictive mapping and conservation planning. This information would be particularly important in the conservation of endangered ecosystems, such as those of Garry oak in British Columbia. To investigate relationships,
sixteen environmental variables were examined for a plant community framework using Detrended Correspondence Analysis and interpretive graphing. Overall, the variables and the degree of differentiation were adequately represented by the framework of 26 native communities. Most of the environmental multivariate space from DCA was covered by the communities, but not all communities were associated with variables. Fifteen communities were distinct, and many of the remaining eleven had special circumstances. Thirteen of the variables were associated with particular communities, a total of 26 times. Most important
were site mineral soil exposure, soil coarse fragments and geographic area. The results could be used to develop environmental keys to plant community sites for practical field application.