Climate sensitivity of trembling aspen radial growth along a productivity gradient in northeastern British Columbia, Canada

2008 ◽  
Vol 38 (5) ◽  
pp. 1211-1222 ◽  
Author(s):  
Giovanni Leonelli ◽  
Bernhard Denneler ◽  
Yves Bergeron
Keyword(s):  
British Columbia ◽  
Populus Tremuloides ◽  
Radial Growth ◽  
Site Index ◽  
Future Climate Change ◽  
Trembling Aspen ◽  
Tree Ring Chronology ◽  
Index Model ◽  
Productivity Gradient ◽  
Site Index Model

Growth–climate relationships were analyzed for 15 stands of trembling aspen ( Populus tremuloides Michx.) along a productivity gradient in northeastern British Columbia. Productivity was evaluated with a site index model whose values varied between 6.65 and 26.93 m height at age 50 years. To assess the role of climate on radial growth, we built a tree-ring chronology for each site and then performed a dendroclimatic analysis by means of bootstrapped correlation functions using monthly and annual climatic variables. We found that trembling aspen sensitivity to climate varied across stands with different productivities in the study area. At the more productive sites, trees were more sensitive to climate, and ring widths were positively correlated, particularly with summer month precipitation prior to the year of growth. The different responses to climate along the productivity gradient are likely related to the differences in substrate properties; substrates at the more productive sites are richer in nutrients and have a better water holding capacity than those of the less productive sites. Our study suggests that the effects of future climate change on tree growth may not only increase towards the limit of a species distribution, but also towards richer and wetter stands.

scholarly journals A system for estimating height and site index of western hemlock in the interior of British Columbia

1998 ◽  
Vol 74 (4) ◽  
pp. 588-596 ◽  
Author(s):  
Gordon D. Nigh
Keyword(s):  
British Columbia ◽  
Site Index ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Index Model ◽  
Breast Height ◽  
Age Model ◽  
Site Index Model ◽  
Growth Intercept ◽  
Height Model

The focus of recent site productivity research in British Columbia has been to develop height-breast height age, growth intercept, and ecosystem-site index models. These models, together with a years-to-breast-height model, form a system for estimating site index and height. This system is described for western hemlock (Tsuga heterophylla (Raf.) Sarg.) in the interior of British Columbia. Forty-four western hemlock stem analysis plots were used in the construction of this system. As there are three models for estimating site index, the appropriate model for a given stand depends largely on the stand condition and the precision of the models. A graph of model precision against breast height age gives some assistance in deciding which model should be used to estimate site index. Key words: western hemlock, site index, height-age model, growth intercept model, years-to-breast-height model, ecosystem-site index model, model precision

Variation of the understory composition and diversity along a gradient of productivity in Populus tremuloides stands of northern British Columbia, Canada

2004 ◽  
Vol 82 (9) ◽  
pp. 1314-1323 ◽  
Author(s):  
Han YH Chen ◽  
Sonia Légaré ◽  
Yves Bergeron
Keyword(s):  
British Columbia ◽  
Populus Tremuloides ◽  
Diversity Index ◽  
Light Availability ◽  
Basal Area ◽  
Site Index ◽  
Understory Vegetation ◽  
Forest Understory ◽  
Vegetation Composition ◽  
Productivity Gradient

Although various conceptual models exist to explain the pattern of diversity along a productivity gradient, studies of forest understory vegetation along a natural gradient of productivity are often confounded with changes in overstory cover types. We investigated how understory vegetation composition, cover, structure, and diversity change along a productivity gradient in 60 monodominant Populus stands in northeastern British Columbia. A partial canonical correspondence analysis indicated that understory vegetation composition was significantly related to aspen site index – dominant aspen tree height at breast-height age 50 years and several climate and soil variables, but not to stand basal area, density, or aboveground biomass, values that served as an index of light availability to forest understory. Indicator species analysis showed that Cornus sericea, Galium trifidum, and Equisetum pratense were associated with the higher productivity class, while Geocaulon lividum, Vaccinium vitis-idaea, Vaccinium myrtilloides, and bryophytes like Polytrichum juniperinum and Pleurozium schreberi occurred only on poor sites. Total cover of all understory plants, woody plants, and herbaceous species did not vary, but that of bryophytes and lichens decreased from poor to intermediate sites, and diversity indices of total, woody, and herbaceous plants increased significantly with the site index. The greater diversity on more productive sites may be associated with greater spatial and resource heterogeneity.Key words: trembling aspen, forest productivity, site index, understory vegetation, species composition, diversity index.

A height-growth and site-index model for interior spruce in the Sub-Boreal Spruce biogeoclimatic zone of British Columbia

2010 ◽  
Vol 40 (6) ◽  
pp. 1175-1183 ◽  
Author(s):  
Zhengjun Hu ◽  
Oscar García
Keyword(s):  
British Columbia ◽  
Full Range ◽  
Site Index ◽  
Height Growth ◽  
Site Quality ◽  
Growth Equation ◽  
Index Model ◽  
Interior Spruce ◽  
Height Prediction ◽  
Site Index Model

Height growth was modelled for spruce-dominated, even-aged stands in the Sub-Boreal Spruce biogeoclimatic zone of British Columbia, Canada, using both stem analysis (SA) and permanent sample plot (PSP) data. The model is based on a stochastic differential equation (SDE) formulation of the Bertalanffy–Richards growth equation. The SDE approach accounts for serial correlation and heterogeneous variance and makes hypothesis testing possible. Statistically significant differences in height–age trends between SA and PSP data were found that may be attributed to bias caused by dominance changes in SA trees. Error structure in SA and PSPs was also significantly different. Combining both data sources in a way that respects these different error structures reduced bias and increased precision. Four parametrizations were tested; the best was a polymorphic version. The final model fit the data well with no appreciable bias over the full range of ages and site qualities. The currently used spruce site-index model was found to underestimate growth and overestimate site index in young stands. The new model can be recommended for height prediction and site-quality assessment in interior spruce.

Height growth and site index models for trembling aspen (Populus tremuloides Michx.) in northern British Columbia

1998 ◽  
Vol 102 (2-3) ◽  
pp. 157-165 ◽  
Author(s):  
Han Y.H. Chen ◽  
Karel Klinka ◽  
Richard D. Kabzems
Keyword(s):  
British Columbia ◽  
Populus Tremuloides ◽  
Site Index ◽  
Height Growth ◽  
Trembling Aspen

scholarly journals A Site Index Model for Lodgepole Pine in British Columbia

2014 ◽  
Vol 60 (5) ◽  
pp. 982-987 ◽  
Author(s):  
Adrian Batho ◽  
Oscar García
Keyword(s):  
British Columbia ◽  
Lodgepole Pine ◽  
Site Index ◽  
Index Model ◽  
Site Index Model ◽  
A Site

Within-tree patterns of wood stiffness for white spruce (Picea glauca) and trembling aspen (Populus tremuloides)

2014 ◽  
Vol 44 (2) ◽  
pp. 162-171 ◽  
Author(s):  
Derek F. Sattler ◽  
Philip G. Comeau ◽  
Alexis Achim
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Radial Growth ◽  
Tree Height ◽  
White Spruce ◽  
Vertical Position ◽  
Trembling Aspen ◽  
Mixed Effect ◽  
Cambial Age ◽  
Rate Of Increase

Radial patterns of modulus of elasticity (MOE) were examined for white spruce (Picea glauca (Moench) Voss) and trembling aspen (Populus tremuoides Michx.) from 19 mature, uneven-aged stands in the boreal mixedwood region of northern Alberta, Canada. The main objectives were to (1) evaluate the relationship between pith-to-bark changes in MOE and cambial age or distance from pith; (2) develop species-specific models to predict pith-to-bark changes in MOE; and (3) to test the influences of radial growth, relative vertical height, and tree slenderness (tree height/DBH) on MOE. For both species, cambial age was selected as the best explanatory variable with which to build pith-to-bark models of MOE. For white spruce and trembling aspen, the final nonlinear mixed-effect models indicated that an augmented rate of increase in MOE occurred with increasing vertical position within the tree. For white spruce trees, radial growth and slenderness were found to positively influence maximum estimated MOE. For trembling aspen, there was no apparent effect of vertical position or radial growth on maximum MOE. The results shed light on potential drivers of radial patterns of MOE and will be useful in guiding silvicultural prescriptions.

scholarly journals SITE QUALITY ESTIMATIONS BASED ON THE GENERALIZED ALGEBRAIC DIFFERENCE APPROACH: A CASE STUDY IN ÇANKIRI FORESTS

2018 ◽  
Vol 42 (3) ◽  
Author(s):  
Ugur Akbas ◽  
Muammer SENYURT
Keyword(s):  
Site Index ◽  
Site Quality ◽  
Model Parameters ◽  
Successful Model ◽  
Index Model ◽  
Prediction Technique ◽  
Algebraic Difference ◽  
Pine Stands ◽  
Site Index Model ◽  
Generalized Algebraic Difference Approach

ABSTRACT In this study, it is aimed that the dynamic site index models were developed for Crimean Pine stands in Sarikaya-Cankiri forests located in middle northern Turkey. The data for this study are 153 sample trees obtained from the Crimean Pine stands. In modeling relationships between height and age of dominant or co-dominant trees, some dynamic site index equations such as Chapman-Richards (M1, M2, M3), Lundqvist (M4 and M6), Hossfeld (M5), Weibull (M7) and Schumacher (M8) based on the Generalized Algebraic Difference Approach (GADA) were used. The estimations for these eight-dynamic site index model parameters with well as various statistical values were obtained using the nonlinear regression technique. Among these equations, the Chapman-Richards’s equation, M3, was determined to be the most successful model, with accounted for 89.03 % of the total variance in height-age relationships with MSE: 1.7633, RMSE: 1.3279, SSE: 1165.6, Bias: -0.0380. After determination of the best predictive model, ARMA (1, 1) autoregressive prediction technique was used to account autocorrelation problems for time-series height measurements. When ARMA autoregressive prediction technique was applied to the Chapman-Richards function for solving autocorrelation problem, these success statistics were improved as SSE: 868.7, MSE: 1.3183, RMSE: 1.1482, Bias: -0.06369, R2: 0.918. Also, Durbin-Watson statistics displayed that autocorrelation problem was solved by the use of ARMA autoregressive prediction technique; DW test value=1.99, DW<P=0.5622, DW>P=0.4378. The dynamic site index model that was developed has provided results compatible with the growth characteristics expected in the modeling of height-age relations, such as polymorphism, multiple asymptote, and base-age invariance.

Development of Site Index Model for Styrax japonica

2019 ◽  
Vol 53 (4) ◽  
pp. 13-18
Author(s):  
Joon Hyung Park ◽  
◽  
Kwang Soo Lee ◽  
Yeong Mo Sonk ◽  
Su Young Jung ◽  
...  
Keyword(s):  
Site Index ◽  
Index Model ◽  
Site Index Model ◽  
Styrax Japonica

A calibrateable site index model for Pinus kesiya plantations in southeastern Africa

2002 ◽  
Vol 32 (11) ◽  
pp. 1916-1928 ◽  
Author(s):  
Kalle Eerikäinen ◽  
Danaza Mabvurira ◽  
Ladislaus Nshubemuki ◽  
Jussi Saramäki
Keyword(s):  
Random Parameter ◽  
Site Index ◽  
Stand Age ◽  
Random Parameters ◽  
Index Model ◽  
Forest Inventories ◽  
Pinus Kesiya ◽  
Dominant Height ◽  
Random Parameter Model ◽  
Site Index Model

The aim of the study was to develop a site index model for Pinus kesiya Royle ex Gordon plantations in southeastern Africa based on the relationship between the dominant height and stand age. Conversely, analysis of dominant height and age data showed that the growth patterns of plantations were different. In addition, the asymptotes and forms of standwise dominant height curves varied within plantations. In developing a common site index model, instead of using the more common approach of estimating separate dominant height–age models for different plantations or sites, a mean curve approach based on a linear random parameter model with fixed and random parameters was applied. The random parameter model of this study was calibrated by predicting random parameters for the plantation and stand effects, in accordance with the standard linear prediction theory. The analyses showed that the calibration of the dominant height model was an efficient method to obtain reliable dominant height predictions of a stand, particularly when several dominant height–age observations from different stands of a plantation and at least one measured dominant height and stand age of a target stand are available. This is the case in many forest inventories based on temporary samples, i.e., cross-sectional data. The new site index model is a useful tool for use in different mensurational applications, and its properties can efficiently be utilized for example in forest inventories of P. kesiya plantations in southeastern Africa.

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