Potentials and limitations of ecological classification as a tool for forest management: a case study of disturbed deciduous forests in Québec

Abstract

The forest ecosystems of the most southern part of Québec have been influenced by activities of various intensities and spatial distribution (harvesting, agriculture, pastureland, etc.) since the beginning of settlement. These activities have changed the natural relationships between soil and vegetation characteristics. The aims of this study were (1) to identify, with a concrete example, the difficulties encountered by a forest ecological classification program in disturbed deciduous forests and (2) to evaluate the efficacy, for forest managers, of the products derived from that classification. We first show, by a complete linkage cluster analysis, that the forest type concept is not appropriate for the disturbed deciduous forests context because of the great variability in forest composition and the low relationships between soil and vegetation. By comparing information required to manage effectively the disturbed deciduous forest to the information provided by the Québec Forest Ecological Classification Program (FECP), we demonstrate, in the second part of the study, some shortcomings of this program at the site scale. Three main reasons are given to explain the weaknesses encountered. The first one is that the disturbed characteristics of these forests increase the complexity of forest and ecological mapping. The second main reason is that some vegetation and soil characteristics are so variable that it is almost impossible to predict them with ecological classification. Deficiencies in the methodology used in the Québec FECP constitute the third main reason explaining the weaknesses encountered. From these results, we propose some solutions to enhance the support that the Québec FECP can bring to forest managers in disturbed deciduous forests. Finally, shortcomings of ecological classification at the site scale do not necessarily limit its potential at the regional scale.