A multifactor ecological classification of the northern hardwood and conifer ecosystems of Sylvania Recreation Area, Upper Peninsula, Michigan

Abstract

An ecological method of multifactor ecosystem classification was applied in the Sylvania Recreation Area, an 8500-ha tract of old-growth northern hardwood – conifer forests in upper Michigan. The uplands and wetlands were subjectively classified into 25 ecosystems by a method combining reconnaissance, plot sampling, data analysis, and ecosystem mapping. Each ecosystem was a characteristic combination of physiography, ecological species groups (ground vegetation), and soil. Discriminant analysis was used to evaluate the distinctness of the upland ecosystems and to compare the discriminating abilities of different ecosystem components (physiography, ground vegetation, and soil). The classification was corroborated in the multivariate analyses. The lowest estimated error rate (9.4%) in discriminant analysis was obtained by a model based on a combination of physiographic and soil characteristics and ecological species groups. The estimated error rates based on the species groups alone and physiography and soil alone were 42.2 and 25.0%, respectively. The discriminant analyses indicate that neither vegetation alone nor physiography and soil alone could be used with high reliability in classifying and mapping ecosystems. An additional discriminant analysis of the three ecosystem components indicated that the ecosystems could be distinguished by field characteristics without information from soil laboratory analyses. This analysis also demonstrated the particular value of the vegetation component as a readily observed, acceptable substitute for soil laboratory data in identifying and mapping ecosystem units.

Can understory vegetation accurately predict site index? A comparative study using floristic and abiotic indices in sessile oak (Quercus petraea Liebl.) stands in northern France

“…However, mF was a poorer predictor of site index compared to SWC. This is consistent with the hypothesis that soil water capacity is better assessed by soil parameters than floristic indices, especially because tree productivity can be affected by deeper soil horizons whereas the shallow-rooted herb-layer vegetation is not [37,50].…”

“…This is consistent with the hypothesis that neither vegetation nor physiography alone are sufficient to classify ecosystems or to reliably predict site index [17,27,50,58]. Nieppola [43] showed that the inclusion of soil type in the prediction model increases the accuracy of site index estimation by about 15%.…”

“…(1) The connection between vegetation data and site quality has been studied by examining vegetation-site relationships [4,15,28,50]. Understory vegetation has become the fundamental component of many forest site classifications in several European countries [4,12,61].…”

“…However, the environmental relationships and predictive values of individual understory species can vary geographically in response to climatic, physiographic and genetic differences [7,30,39,51]. Understory vegetation can also reflect differences in canopy cover or disturbance history [50]. All these sources of variation explain why some studies across large areas fail to accurately predict site index variations using understory vegetation exclusively [51] and why understory vegetation is often only used within small areas with a homogeneous climate, especially in France [4,12].…”

A discrimlnant function approach to ecological site classification in northern New England

“…Quantitative analysis of patterns of soil-site factors in relationship to plant communities has proven valuable in the development of ecological classifications in similar ecological regions in the province of New Brunswick, Canada (Zelazny et al 1989) and in the Lake States (Pregitzer and Barnes 1984;Spies and Barnes 1985;Host et al 1988). This methodology is being used to help delineate units of land with a unique combination of potential natural community, soil, landscape features, and climate, and which differ from other units in their ability to produce vegetation and respond to management.…”