The effect of site quality on growth efficiency of upper crown class Picea rubens and Abies balsamea in Maine, USAPublication 3046 of the Maine Agricultural and Forestry Experiment Station.

2009 ◽  
Vol 39 (4) ◽  
pp. 777-784 ◽  
Author(s):  
R. Justin DeRose ◽  
Robert S. Seymour
Keyword(s):  
Leaf Area ◽  
Abies Balsamea ◽  
Growth Efficiency ◽  
Site Index ◽  
Picea Rubens ◽  
Site Quality ◽  
Experiment Station ◽  
Volume Increment

The influence of site index on growth efficiency was studied for 411 dominant and codominant Abies balsamea (L.) Mill. and Picea rubens Sarg. from 10 sites across Maine, USA. Young A. balsamea (n = 204) were from stands precommercially thinned 15–20 years ago and ranged in site index from 18.4 to 24.3, while the older P. rubens (n = 207) were from stands that were not precommercially thinned and ranged in site index from 13.1 to 17.8. We hypothesized that site index positively influences growth efficiency. The results showed that volume increment – leaf area relationships and growth efficiency increased significantly with site index for A. balsamea but were unaffected by site index for P. rubens. A monotonic decreasing pattern of growth efficiency over increasing leaf area was found for both species. When standardized per unit site index, growth efficiency behaved nonlinearly for both species.

scholarly journals Leaf Area and Structural Changes after Thinning in Even-AgedPicea rubensandAbies balsameaStands in Maine, USA

2012 ◽  
Vol 2012 ◽  
pp. 1-9
Author(s):  
R. Justin DeRose ◽  
Robert S. Seymour
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Structural Changes ◽  
Abies Balsamea ◽  
Picea Rubens ◽  
Area Index ◽  
Precommercial Thinning ◽  
Density Reduction

We tested the hypothesis that changes in leaf area index (LAI m2 m−2) and mean stand diameter following thinning are due to thinning type and residual density. The ratios of pre- to postthinning diameter and LAI were used to assess structural changes between replicated crown, dominant, and low thinning treatments to 33% and 50% residual density in even-agedPicea rubensandAbies balsameastands with and without a precommercial thinning history in Maine, USA. Diameter ratios varied predictably by thinning type: low thinnings were <0.7, crown thinnings were >0.7 but <1.0, and dominant thinnings were >1.0 . LAI change was affected by type and intensity of thinning. On average, 33% density reduction removed <50% of LAI, whereas 50% density reduction removed >50% of LAI. Overall reduction of LAI was generally greatest in dominant thinnings (54%), intermediate in crown thinnings (46%), and lowest in low thinnings (35%). Upon closer examination by crown classes, the postthinning distribution of LAI between upper and lower crown classes varied by thinning history, thinning method, and amount of density reduction.

Size–density metrics, leaf area, and productivity in eastern white pine

2005 ◽  
Vol 35 (10) ◽  
pp. 2469-2478 ◽  
Author(s):  
J C Innes ◽  
M J Ducey ◽  
J H Gove ◽  
W B Leak ◽  
J P Barrett
Keyword(s):  
Leaf Area ◽  
Stand Density ◽  
Growth Efficiency ◽  
Site Index ◽  
Stand Age ◽  
White Pine ◽  
Eastern White Pine ◽  
Area Index ◽  
Linear Predictor ◽  
Density Indices

Size–density metrics are used extensively for silvicultural planning; however, they operate on biological assumptions that remain relatively untested. Using data from 12 even-aged stands of eastern white pine (Pinus strobus L.) growing in southern New Hampshire, we compared size-density metrics with stand productivity and its biological components, including leaf area index (LAI) and measures of crown morphology. Density indices included Reineke's stand density index (SDI), a –3/2 relative density law, and trees per hectare. We examined models with and without site index and stand age as components, to predict total stand accretion (PAI), LAI, and growth efficiency (GE). LAI was a strong linear predictor of PAI (R2 = 0.89). However, of the indices tested only SDI was a significant predictor of accretion, and none were significantly related to LAI or GE. Site index was not a significant predictor of any variable when used alone, but in combination with SDI and stand age did lead to significant relationships with PAI (R2 = 0.84), LAI (R2 = 0.67), and GE (R2 = 0.92). Of the density indices tested only trees per hectare was strongly correlated with crown attributes. These results demonstrate that size-density metrics combined with other stand attributes are reasonably correlated with biological measures of stand growth.

Patterns of change of saturated sapwood permeability and sapwood conductance with stand development

1989 ◽  
Vol 19 (4) ◽  
pp. 432-439 ◽  
Author(s):  
David Pothier ◽  
Hank A. Margolis ◽  
Richard H. Waring
Keyword(s):  
Leaf Area ◽  
Ground Level ◽  
Growth Efficiency ◽  
Poor Quality ◽  
Height Growth ◽  
Site Quality ◽  
Stand Development ◽  
Sapwood Area ◽  
Negative Exponential Function ◽  
Age Related

The saturated sapwood permeability (k) of jack pine (Pinusbanksiana Lamb.) from stands of different ages and site qualities was measured using a constant water flow apparatus. Saturated sapwood permeability at the base of the live crown (BLC) increased with age and reached a plateau just beyond 4 × 10−12 m2. The rate at which this plateau was reached, however, was dependent on site quality. Such age-related increases in k can partially explain how trees can maintain similar daytime leaf water potentials at different stages of stand development. Within age-classes 15 and 35, k at BLC was greater on the better-quality sites and was strongly correlated with both diameter and height growth. For age-class 120, k at BLC was not significantly different among sites. Saturated sapwood permeability at BLC could be predicted from age and site quality, using a negative exponential function (R2 = 0.66). The ability to predict changes in k with stand development has potential for improving leaf area estimates derived from sapwood area -leaf area correlations. Sapwood conductance from ground level to the upper third of the crown decreased with age for good-quality sites and increased with age for poor-quality sites. It corresponded to the pattern of average annual height growth over the last 5 years (R2 = 0.61). The number of annual rings contributing to the sapwood at a given age was independent of site quality. This suggests that the historical reconstruction of a tree's leaf area and growth efficiency is possible even after the formation of significant amounts of heartwood.

Patterns of leaf area index during stand development in even-aged balsam fir – red spruce stands

2010 ◽  
Vol 40 (4) ◽  
pp. 629-637 ◽  
Author(s):  
R. Justin DeRose ◽  
Robert S. Seymour
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Abies Balsamea ◽  
Stand Density ◽  
Red Spruce ◽  
Balsam Fir ◽  
Research Network ◽  
Site Quality ◽  
Area Index ◽  
Commercial Thinning

Leaf area index (LAI) strongly controls forest stand production. Silviculturists can easily manage this biologically important variable by quantifying its relationship to more directly manageable stand elements, such as density. Hypothesized patterns of LAI development over relative stand density (RD) in even-aged stands of balsam fir ( Abies balsamea (L.) Mill.) and red spruce ( Picea rubens Sarg.) were examined using 78 plots from the Cooperative Forestry Research Unit’s Commercial Thinning Research Network located in the Acadian forest zone in Maine. Nonlinear regression indicated that LAI was significantly related to RD, site quality, and stand top height. LAI increased nonlinearly with increasing RD holding stand top height constant. At a given RD, LAI peaked at approximately 13 m in stand top height. Site quality positively and linearly influenced LAI, but this was only apparent after crown closure, which in turn was influenced by initial stand density. Five-year trajectories of LAI–RD remeasurement data showed an increase in LAI and RD for all stands that varied by stand top height and site quality. Taken together, RD, stand top height, and site quality are strong predictors of LAI and can be used by silviculturists to manage for LAI.

Leaf area - sapwood area relations of lodgepole pine as influenced by stand density and site index

1988 ◽  
Vol 18 (2) ◽  
pp. 247-250 ◽  
Author(s):  
James N. Long ◽  
Frederick W. Smith
Keyword(s):  
Leaf Area ◽  
Forest Ecology ◽  
Lodgepole Pine ◽  
Stand Density ◽  
Site Index ◽  
Site Quality ◽  
Cross Sectional ◽  
Sapwood Area ◽  
Pine Trees ◽  
Stand Conditions

Leaf area to sapwood area ratios for a given species are believed to vary with factors such as site quality, stand density, early stand growth rates, and crown class. Based on data from 55 mature lodgepole pine trees (Pinuscontorta var. latifolia Dougl.) from 10 plots in southeastern Wyoming, we conclude that putative density and site effects on leaf area - sapwood area relations are actually a consequence of the increase in the leaf area to sapwood area ratio with increasing sapwood area. When leaf area is estimated with a nonlinear model that includes tree size and distance to the live crown, the apparent effects of stand density and site index disappear. We consider a constant ratio of leaf area and sapwood cross-sectional area to be inappropriate for the estimation of leaf area aross the range of stand conditions included in most studies of forest ecology.

Comparing site quality indices and productivity in ponderosa pine stands of western Montana

1988 ◽  
Vol 18 (3) ◽  
pp. 346-352 ◽  
Author(s):  
Scott D. McLeod ◽  
Steven W. Running
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Ponderosa Pine ◽  
Volume Growth ◽  
Stand Density ◽  
Site Index ◽  
Site Quality ◽  
Area Index ◽  
Water Index ◽  
Available Water

Four indices of site quality were compared with volume growth of pure, ideal ponderosa pine (Pinusponderosa Laws.) stands in western Montana. Indices based on quantifying the biophysical factors or physiological processes that control productivity (available water index and a relative index of seasonal photosynthesis from computer simulations) worked as well as those based on tree or stand measurements (site index and leaf area index). The following correlations of mean annual stem volume increment were found: with leaf area index, R2 = 0.93; with available water index, R2 = 0.95; with site index, R2 = 0.98; with gross photosynthesis R2 = 0.96. The available water and photosynthesis indices were also highly correlated to site index (R2 > 0.95). However, the tree-dependent site quality indices varied by stand density. Leaf area index and volume growth increased with stand density while site index decreased. Simulations indicated that depletion of soil water effectively halted transpiration and photosynthesis by midsummer and illustrated that even with adequate water, cold spring and fall temperatures ultimately defined the length of the growing season and hence site quality. We conclude that an ecosystem process model can provide an index to site quality independent of tree or stand measurements.

Influence of age on growth efficiency of Tsuga canadensis and Picea rubens trees in mixed-species, multiaged northern conifer stands

2002 ◽  
Vol 32 (11) ◽  
pp. 2032-2042 ◽  
Author(s):  
Robert S Seymour ◽  
Laura S Kenefic
Keyword(s):  
Leaf Area ◽  
Volume Growth ◽  
Growth Efficiency ◽  
Tsuga Canadensis ◽  
Picea Rubens ◽  
Tree Age ◽  
Tree Level ◽  
Mixed Species ◽  
Fundamental Relationship ◽  
Negative Effect

Well-known patterns in the fundamental relationship between tree-level stemwood volume increment (VINC) and projected leaf area (PLA) are examined and quantified for Tsuga canadensis (L.) Carrière (eastern hemlock) and Picea rubens Sarg. (red spruce) growing in managed, mixed-species, multiaged stands in east-central Maine, U.S.A. Both species follow a sigmoid pattern, suggesting a peak growth efficiency (GE, stemwood volume growth per unit of PLA) in mid- to upper-canopy trees with PLAs of less than half that of the largest trees sampled. Tree age negatively influenced the VINC–PLA relationship in the expected manner: at a given PLA, older trees produce less stemwood than younger ones. The combined effect of leaf area and age is accurately modeled with a Weibull-like function in which the asymptote is an index of tree maturity defined as tree age relative to an estimated maximum for the species. Although previous studies have independently documented both the sigmoid relationship between VINC and PLA and the negative effect of age, their conclusions have been confounded by the strong correlation between age and mean tree PLA. This study addresses both issues simultaneously, and is the first to demonstrate a decline in GE with age independent from the effect of increasing PLA.

Stand level volume increment in relation to leaf area index of Austrocedrus chilensis and Nothofagus dombeyi mixed forests of Patagonia, Argentina

2021 ◽  
Vol 494 ◽  
pp. 119337
Author(s):  
Marina Caselli ◽  
Gabriel Ángel Loguercio ◽  
María Florencia Urretavizcaya ◽  
Guillermo Emilio Defossé
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Austrocedrus Chilensis ◽  
Mixed Forests ◽  
Area Index ◽  
Volume Increment ◽  
Nothofagus Dombeyi

The effect of local stand structure on growth and growth efficiency in heterogeneous stands of ponderosa pine and lodgepole pine in central Oregon

2004 ◽  
Vol 34 (11) ◽  
pp. 2217-2229 ◽  
Author(s):  
Douglas B Mainwaring ◽  
Douglas A Maguire
Keyword(s):  
Leaf Area ◽  
Ponderosa Pine ◽  
Lodgepole Pine ◽  
Volume Growth ◽  
Basal Area ◽  
Growth Efficiency ◽  
Projection Area ◽  
Sapwood Area ◽  
Negative Effect ◽  
Crown Projection Area

Basal area and height growth were analyzed for individual trees in uneven-aged ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and lodgepole pine (Pinus contorta Dougl. ex. Loud.) stands in central Oregon. Basal area growth was modeled as a function of other stand and tree variables to address three general objectives: (1) to compare the predictive ability of distance-dependent versus distance-independent stand density variables; (2) to determine the degree to which small trees negatively affect the growth of overstory trees; and (3) to test for differences in growth efficiency between species and between indices of spatial occupancy used to define efficiency (area potentially available, crown projection area, and a surrogate for total tree leaf area). Distance-dependent variables were found to improve growth predictions when added to models with only distance-independent variables, and small trees were found to have a quantifiably negative effect on the growth of larger trees. While volume growth efficiency declined with increasing levels of spatial occupancy for lodgepole pine, ponderosa pine volume growth efficiency was greatest at the highest levels of crown base sapwood area and crown projection area. The behavior in ponderosa pine resulted from the previously recognized correlation between tree height and total leaf area or crown size. The final statistical models distinguished between the positive effect of relative height and the negative effect of increasing tree size.

scholarly journals A Novel Approach to Modelling Stand-Level Growth of an Even-Aged Forest Using a Volume Productivity Index with Application to New Zealand-Grown Coast Redwood

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1155 ◽  
Author(s):  
Mark O. Kimberley ◽  
Michael S. Watt
Keyword(s):  
New Zealand ◽  
Growth Model ◽  
Growth Models ◽  
Stand Density ◽  
Site Index ◽  
Growth And Yield ◽  
Productivity Index ◽  
Site Quality ◽  
Spatial And Temporal Variation ◽  
Coast Redwood

Empirical growth models are widely used to predict the growth and yield of plantation tree species, and the precise estimation of site quality is an important component of these models. The most commonly used proxy for site quality in growth models is Site Index (SI), which describes the mean height of dominant trees at a specified base age. Although SI is widely used, considerable research shows significant site-dependent variation in height for a given volume, with this latter variable more closely reflecting actual site productivity. Using a national dataset, this study develops and describes a stand-level growth and yield model for even-aged New Zealand-grown coast redwood (Sequoia sempervirens). We used a novel modelling approach that quantifies site quality using SI and a volume-based index termed the 300 Index, defined as the volume mean annual increment at age 30 years for a reference regime of 300 stems ha−1. The growth model includes a number of interrelated components. Mean top height is modelled from age and SI using a polymorphic Korf function. A modified anamorphic Korf function is used to describe tree quadratic mean diameter (Dq) as a function of age, stand density, SI and a diameter site index. As the Dq model includes stand density in its formulation, it can predict tree growth for different stand densities and thinning regimes. The mortality model is based on a simple attritional equation improved through incorporation of the Reineke stand density index to account for competition-induced mortality. Using these components, the model precisely estimates stand-level volume. The developed model will be of considerable value to growers for yield projection and regime evaluation. By more robustly describing the site effect, the growth model provides researchers with an improved framework for quantifying and understanding the causes of spatial and temporal variation in plantation productivity.

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