An ecological land classification approach to modeling the production of forest biomass

Abstract

Forest site classification is a prerequisite to successful integrated forest resources planning and management. Traditionally, site classification has emphasized a phytocentric approach, with tools such as the site index having a rich and long history in forest site evaluation. The concept of site index was primarily devised to assess site productivity of an even-aged, single-species stand. Site index has been the primary method of forest site evaluation in support of management for traditional forest products. However, this method of site classification has been criticized as the needs, perspectives and social values of the public regarding forest management have changed the emphasis from timber production to multiplevalue forestry practices. There are alternative approaches to forest site classification that have the potential to meet the growing demands placed on forest information for inventory and modeling purposes. Ecological Land Classification (ELC), is a phytogeocentric approach that stratifies the landscape into ecologically meaningful units (ecosites) based on substrate characteristics, moisture regime and canopy composition. This approach offers a more holistic view of site productivity evaluation; however, until recently it has been difficult to acquire data to support widespread mapping of ecosites. Remote sensing technology along with predictive modeling and interpretive mapping techniques make the application of an ecosite-based approach at the forest landscape level possible. As forest management moves towards the consideration of a broader set of resources (e.g., woody biomass), there is an opportunity to develop new tools for linking forest productivity to the sustainable production of forest bioproducts with forest ecosites as a solid foundation for segmenting the landscape.Key words: forest site classification, site index, site productivity, Ecological Land Classification (ELC), ecosites, forest biomass, bioproducts RÉSUMÉLa classification des sites forestiers est un pré-requis au succès de la planification et de l'aménagement des ressources forestières. Habituellement, la classification des sites a mise en évidence une approche phytocentrique, comptant sur des outils comme l'indice de qualité de la station qui affiche un historique riche et durable de l' évaluation des sites forestiers. Le concept d'indice de la qualité de station a été établi principalement pour évaluer la productivité de la station dans le cas d'un peuplement équienne composé d'une seule espèce. L'indice de la qualité de station a été la principale méthode d' éva-luation d'un site forestier utilisée dans le cas de l'aménagement pour les produits forestiers traditionnels. Cependant, cette méthode de classification du site a fait l' objet de critiques compte tenu que les besoins, les perspectives et les valeurs sociales du public relativement à l'aménagement forestier ont réorienté l'accent mis sur la production de bois vers des pratiques forestières considérant les multiples valeurs du milieu. Il existe des approch...

Assessing Forest Classification in a Landscape-Level Framework: An Example from Central European Forests

“…Our study revealed issues that contradict expert knowledge based concepts respected for decades with respect to approaches via formal quantification of available data, which is consistent with a recent call for advanced classifications in Europe [46,92,93], and in North America [86,87,[94][95][96]. Findings of this study may point to similar problems accompanying other classifications where landscape units may not be as strong as expected.…”

An analysis of the Modeling and Inventory Support Tool: Yield curves vary with Forest Ecosystem Classification

“…It is thus not particularly surprising that there would be differences in productivity. We quantified these differences using site index, which is widely employed to assess overall stand productivity or quality (Pokharel and Dech 2011), but which has some recognized limitations. Site index is an indirect measurement due to the fact that the top height at age 50 can only be directly meas- For personal use only.…”

“…Wang and Huang (2000) observed height and growth patterns of white spruce for the five major natural subregions in Alberta, and found that height was significantly different for one of the subregions, resulting in volume estimation errors up to 25% when the provincial height and site index curve was applied to this subregion. We are aware of no prior studies that examine ecosite classification with growth and yield model outputs from MIST; however, Pokharel and Dech (2011) have argued more broadly that a phytogeocentric approach to ecological land classification is essential to stratifying landscapes into ecologically meaningful units for management decision-making.…”

Modeling Wood Fibre Length in Black Spruce (Picea mariana (Mill.) BSP) Based on Ecological Land Classification

“…Relationships between ecosite, growth rate and wood anatomy may be quantified by a model that links microscopic properties (e.g., wood fibre length) to the landscape scale (e.g., site quality indicators) [16]. The use of ecosites as a base unit for modeling can be viewed as a more holistic (sensu Billings [17]) approach to creating growth and yield models in forestry, as ecosite classification captures many aspects of the complex environment [18]. Nonparametric hierarchical classification models such as regression tree analyses and random forests [19] provide a good approach for developing models that make predictions about wood fibre attributes for specific ecosites at the landscape scale.…”