Modified site index equations for major Canadian timber species

Self Cite

Plonski's yield tables have been used extensively in forest management, economic evaluation, and as a basis for management planning in Ontario. However, because these tables are based on site classes, they are not directly applicable to uneven-aged mixed-wood cover types. A four-parameter nonlinear model was employed to express various stand attributes as a function of stand age and recently developed basal area indices for the major species in Ontario. The resulting variable stocking yield functions will be applicable to even-aged stands as well as the boreal mixedwood. Basal area index proved superior to site index for estimating both merchantable basal area and volume for the James River/Marathon data set representing boreal mixed from Northcentral Ontario. In addition, stand basal area index may be determined easily and inexpensively via horizontal point sampling or prism cruising. Key word: Basal area index, sigmoidal growth curve, variable stocking

Section: Methodsmentioning

confidence: 99%

Variable stocking version of Plonski's yield tables formulated

Payandeh¹,

Wang²

1996

Self Cite

“…For the last few decades, a number of efforts including Heger (1968), Payandeh (1974a, b), Plonski (1974), Newnham (1988), Carmean and Lenthall (1989) Carmean and Li (1998), Carmean (1996, Goelz and Burk (1992), Payandeh and Wang (1994a, b;1995), Woods and Miller (1996) and Carmean et al (1998;2001;2006a, b) were made to develop site index curves for major tree species in Ontario. However, to date no complete site index equations have been developed for the major tree species in Ontario; therefore many of the species share site index equations developed elsewhere , Alemdag 1991, Carmean 1996.…”

Section: The Phytocentric Approachmentioning

confidence: 99%

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

Pokharel¹,

Dech²

2011

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...

“…Site index (SI) values at age 50 (Payandeh 1977) were calculated for each plot using the mean height of dominant trees in 1985 and 2002.…”

Section: Height and Volume Calculationsmentioning

confidence: 99%

Upland black spruce stand development 17 years after cleaning and precommercial thinning

Fleming¹,

Mossa²,

Marek³

2005

Density management is often used by silviculturists to guide stand composition and development. We examined the effects of cleaning (hardwood removal) and four levels of precommercial thinning (0, 20, 35 and 50% basal area removal) on stand development in a dense, 24-year-old upland black spruce (Picea mariana [Mill.] BSP) plantation near Beardmore, Ontario. Immediately before treatment, stand densities and basal areas for all species and for black spruce averaged 7375 and 6415 stems ha -1 , and 27.9 and 20.5 m 2 ha -1 , respectively. Seventeen years after treatment, black spruce total stand volume (V T ) was higher in the cleaned, unthinned plots (243 m 3 ha -1 ) than in the untreated controls (171 m 3 ha -1 ) while total stand volume increment of all species combined was similar in these two treatments. Compared with cleaning alone, thinning cleaned plots from below increased quadratic mean diameters (D Q ) by up to 9% but decreased V T by up to 28%. At plantation age 41, increases in black spruce densities of 1000 stems ha -1 resulted in mean decreases of 0.6 cm in D Q and mean increases of 43 m 3 ha -1 in V T . Endemic black spruce stem mortality rates decreased with thinning intensity, with mortality concentrated in the smallest size classes. In some plots, mortality was increased by wind or snow damage, and by root rots. Height increment of dominant trees was unaffected by thinning. Projected yields at age 55 (the physical rotation age-the age at which maximum mean annual increment occurs) suggest the heaviest precommercial thinning could increase quadratic mean diameter from 16.1 to 17.7 cm, but decrease merchantable stand volume from 292 to 225 m 3 ha -1 . Results indicate that total black spruce fibre yields and product value on these sites will be maximized in denser stands. Cleaning appears to offer greater benefits for black spruce fibre production than precommercial thinning.Key words: black spruce, precommercial thinning, cleaning, density management, projected yields Tout juste avant le traitement, les densités du peuplement et les surfaces terrières pour toutes les espèces et pour l'épinette noire atteignaient respectivement en moyenne 7 375 et 6 415 tiges ha -1 et 27,9 et 20,5 m 2 ha -1 . Dix-sept ans après le traitement, le volume total du peuplement d'épinette noire (VT) était supérieur dans les parcelles dégagées et non éclaircies (243 m 3 ha -1 ) par rapport aux parcelles-témoins (171 m 3 ha -1 ) tandis que l'accroissement total en volume du peuplement, toutes espèces combinées, était semblable dans ces deux traitements. Par comparaison avec seulement le dégagement, les parcelles éclaircies par le bas et dégagées ont connu une augmentation des diamètres quadratiques moyens (DQ) atteignant jusqu'à 9 % mais une diminution du VT allant jusqu'à 28 %. Dans la plantation à l'âge de 41 ans, les accroissements des densités d'épinette noire de 1 000 tiges ha -1 ont entraîné des diminutions de 0,6 cm du DQ et des accroissements moyens du VT de 43 m 3 ha -1 . Les taux de mortalité endémique de...