Forest Ecosystem Classification Research Articles

Multifactor classification and analysis of upland hardwood forest ecosystems of the Kickapoo River watershed, southwestern Wisconsin

An ecological multifactor approach was used to develop a hierarchical classification of upland hardwood forest ecosystems of the Kickapoo River watershed, southwestern Wisconsin. This method was chosen from among the variety available because of its utility in this area of heavily disturbed forests. Eleven major ecosystem units were distinguished for the 67 plot areas sampled. Each ecosystem unit is characterized by a distinct combination of physiography (aspect and slope position and steepness), soil (parent material depth and type), and vegetation (canopy tree species and groups of ground cover species), and occurs in a unique position in the landscape. The canopies of most units are dominated by combinations of northern red oak (Quercusrubra L.), white oak (Q. alba L.), and sugar maple (Acersaccharum Marsh.). The results of several discriminant analyses indicate a high level of association between plots within some units. A combination of physiographic, soil, and vegetational variables resulted in the highest overall percentage of correct classification of the plots. These 11 ecosystem units ranged in estimated productivity (average site index for northern red oak) from 12 to 21 m, with the two extremes significantly different at the 5% level.

Alternate Strip Clearcutting in Upland Black Spruce: VIII. Shallow-soil Ecosystems and Their Classification

Shallow-soil sites in the Nipigon-Beardmore area of northern Ontario are widespread and pose unique operational problems for forest managers. Several working definitions of shallow soils are used in Ontario. More accurate regional definitions are required in order that silvicultural decisions for these sometimes fragile sites may be refined or new ones developed. Harvesting and silvicultural options for shallow-soil sites are limited in the North Central Region.A program of Forest Ecosystem Classification (FEC) for the North Central Region has been designed to provide better understanding of shallow sites and a framework of standardized definitions. The FEC describes several shallow-soil types that occur over boulder pavement or bedrock, and differentiates mainly on the basis of depth-to-rock contact, surface organic material thickness and texture of the primary mineral soil particles. Operational application of this classification may require identification of complexes of shallow-soil types.

Evaluating Soil Nutrient Regime for Black Spruce in the Ontario Claybelt by Fertilization

Fertilization screening trials testing a standard NPK application were conducted in 29 mature black spruce stands growing on diverse Claybelt sites. The objective was to evaluate several methods of predicting soil nutrient regime, and validate a nutrient-related ordination axis of the regional Forest Ecosystem Classification (FEC) system. Diagnosis by vector analysis of current needle responses in dry weight and macronutrient concentration and content suggested that of all nutrients added N was most limiting for black spruce growth. Potential fertilizer response was measured by the change in unit needle N uptake (content) occurring in the first season after treatment. Significant increases (as high as 63% over the control) were detected in about half the trials suggesting that the stands were established on sites varying in soil fertility. Foliar N response was subsequently correlated against more rapid predictors of site productivity such as stand growth parameters site index, stem analysis, and chemical analysis of unfertilized soil and foliage. Of these only measures of fall-sampled, current needle N content correlated adequately (r = −0.72) with potential fertilizer response. This response factor was also significantly correlated (r = 0.71) with the coordinate values of the FEC-ordination diagram indicative of site nutrient regime, supporting evidence that the axis reflects a continuum of soil N availability. Key words: Nitrogen, foliar analysis, response prediction, site evaluation, forest fertilization, Picea mariana

The prediction of understory vegetation by environmental factors for the purpose of site classification in forestry: an example from northern Ontario using residual ordination analysis

Problems arise in the use of understory vegetation as an indicator of site condition in that impermanent factors such as microclimate, succession, and chance may play significant roles in determining local composition. Residual ordination analysis is a method which facilitates quantification of the sources of variation in understory vegetation over a landscape. Here it is applied to survey data, representing 250 stands upon which the forest ecosystem classification programme for the Clay Belt portion of northeastern Ontario is based, to test the premise that vegetation types will differentiate soil conditions for forestry purposes. Ordination of the data by detrended correspondence analysis yielded a bivariate scatterplot which, through visual appraisal, seemed readily interpretable in terms of site-related nutrient and moisture gradients. Formal exploration, using canonical redundancy analysis, yielded the following predictive model: understory vegetation (detrended correspondence analysis axes 1 and 2) = soils (67%) + canopy (8%) + succession (1%) + error (24%). Extraction of residual ordinations confirmed this general model and demonstrated that although canopy and successional influences are minor in the data, they are significant. Because the nonsite-related, predictable components account for only 9% of the variation at most, the premise of the existing forest ecosystem classification system is judged to be sound insofar as the data upon which it is based adequately describe the range of commercial stand conditions normally encountered. The results are discussed in relation to vegetation survey design and the performance of residual ordination analysis on a large data set is assessed.

De la nécessité d'un inventaire forestier écologique

To meet our growing needs for wood products will require several million dollars of investment in forest management without assured success, unless we have an appropriate knowledge of forest ecosystems.This paper proposes a simple approach to laying down an "ecological" forest map. Physical habitats which can be related to landform, position on the slope, drainage, etc., within an ecological region, are mapped with their actual stands. This approach leads to a rapid classification and mapping of the different forest ecosystems. It is then possible to work out different chronological sequences or seres by relating the stands occupying similar habitats. Knowledge of seres and of actual stand allows the manager to foresee the evolution of a particular stand. In the same way, by the integrated mapping of forest stands and physical habitats, results of sylvicultural treatments can be related to habitat factors, and subsequently can be applied to similar ecosystems.Added costs of mapping data relative to habitats are rapidly compensated by avoiding costly management errors. Furthermore, the supplementary exercise of determining the habitat increases the precision of photo interpretation for stand mapping. The cost is also compensated by the fact that map contours are permanent since they are based on natural and stable features. Only vegetation data will have to be brought up to date periodically.