Analysis of vegetation-environment relationships using a simultaneous equations model

The simultaneous equations model based on regression analysis was adopted to analyse relations between vegetation and environment in a forest reserve in the eastern part of Poland. It allowed a direct analysis of the vegetational variation caused by both environmental factors and interactions between species. In the system sampled several significant interrelations were found, and the ecological importance of particular factors and species was determined. Similar analysis performed by reciprocal averaging did not yield such satisfactory results, because of the equivocal correlation pattern between ecological variables and ordination axes, the dominance of the first axis and the exclusion of interspecific relations.