Quantifying the interrelationship between tree stand growth rate and water table level in drained peatland sites within Central Finland

2008 ◽  
Vol 38 (7) ◽  
pp. 1775-1783 ◽  
Author(s):  
Hannu Hökkä ◽  
Jaakko Repola ◽  
Jukka Laine
Keyword(s):  
Growth Rate ◽  
Water Table ◽  
Scots Pine ◽  
Prediction Models ◽  
Volume Growth ◽  
Water Levels ◽  
Stand Volume ◽  
Stand Growth ◽  
Water Table Level ◽  
Bivariate Regression

The quantitative relationship between stand growth rate and water table level in peatland forest sites has not been fully ascertained in the literature. In this study, we investigated this relationship by means of a bivariate regression model. Tree and stand attributes, including volume and past 5-year volume growth as well as median water table depth (WTM) during the 1984 growing season, were observed in 69 Scots pine ( Pinus sylvestris L.) sample stands with three subplots established in each stand. All stands were located in deep-peated, moderately rich to poor organic soil sites in Central Finland (61°45′–62°26′N, 22°40′–28°29′E) that had been ditched for forestry about 25 years earlier (1959–1961). Prediction models for the fixed mean functions for 5-year volume growth and WTM as well as estimates for variances and the correlation of random effects at plot and subplot levels were estimated simultaneously using bivariate regression methods. The correlation of model residuals at the plot level was highly significant. The model was applied to simulate stand volume development for a period of 20 years. Simulations illustrated the dynamic interaction of stand volume, volume growth, and soil water levels: deep initial WTM resulted in stand growth and volume-development increases and subsequently further deepened the WTM in the stand. The model can be applied to southern boreal drained Scots pine peatlands to estimate the WTM in different stand volume conditions and to assess the effect of stand management on WTM.

scholarly journals Comparison of granulated and loose ash in fertilisation of Scots pine on peatland

Silva Fennica ◽  
2020 ◽  
Vol 54 (2) ◽  
Author(s):  
Jyrki Hytönen ◽  
Hannu Hökkä
Keyword(s):  
Scots Pine ◽  
Volume Growth ◽  
Wood Ash ◽  
Control Treatment ◽  
Initial Increase ◽  
Stand Volume ◽  
Growth And Nutrition ◽  
Growth Increase ◽  
The Mean ◽  
Poor Site

The effects of wood ash fertilisation on tree nutrition and growth on forested peatlands has been studied using loose ash, but in practice, ash fertilisation is done almost exclusively with granulated ash. In this study, the effects of granulated ash and loose ash (both 5 Mg ha) on the growth and nutrition of Scots pine ( L.) stands were compared between a nitrogen-poor and a nitrogen-rich site over 15 years. On the nitrogen-rich site, wood ash application was also compared with commercial PK fertilisation. On the nitrogen-rich site, mean stand volume growth increase over unfertilised control treatment during the 15 year study period using granulated ash and commercial PK fertiliser was of the same magnitude (on average, 2.2–2.3 m ha a). However, when loose ash was used growth increase over control was higher (3.7 m ha a). On the nitrogen-poor site, the mean growth increase gained by loose or granulated ash (1.4–1.5 m ha a) over the unfertilised control treatment was not significant. Fertilisation with loose ash or PK increased foliar P, K and B concentrations already in the first or second growing season, following fertilisation on both sites. Granulated ash increased foliar P concentrations on the nitrogen-rich site less than loose ash. After an initial increase, foliar P, K and B concentrations decreased at the end of study period. On the nitrogen-poor site, foliar P concentrations were below the deficiency limit by the end of the study period.–1Pinus sylvestris3–1–13–1–13–1–1

scholarly journals Effects of Thinning Practice, High Pruning and Slash Management on Crop Tree and Stand Growth in Young Even-Aged Stands of Planted Silver Birch (Betula pendula Roth)

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 225
Author(s):  
Jens Peter Skovsgaard ◽  
Ulf Johansson ◽  
Emma Holmström ◽  
Rebecka McCarthy Tune ◽  
Clémentine Ols ◽  
...  
Keyword(s):  
Betula Pendula ◽  
Volume Growth ◽  
Stem Diameter ◽  
Silver Birch ◽  
Stand Volume ◽  
Annual Increase ◽  
Stand Growth ◽  
Thinning Intensity ◽  
Betula Pendula Roth ◽  
Increased Risk

The objective was to quantify the influence of thinning, high pruning and slash management on crop tree and stand growth in young even-aged stands of planted silver birch (Betula pendula Roth). This study was based on two field experiments, aged six and eleven years at initiation and re-measured after six and eight years, respectively. Treatments included the unthinned control, moderate thinning mainly from below (removing 28–33% of standing volume), point thinning to favor 300 trees per ha and with no thinning elsewhere in the plot (removing 16–25%), and heavy thinning leaving 600 evenly distributed potential future crop trees per ha (removing 64–75%). Slash management (extraction or retention) was applied to heavily thinned plots. High pruning removing 30–70% of the green crown was carried out in some plots with point or heavy thinning on 300 or 600 trees per ha, respectively. Stand volume growth increased with increasing pre-treatment mean annual volume increment and decreased with increasing thinning intensity as compared to the unthinned control. LS-means estimates indicated a reduction for moderate thinning by 14%, for point thinning by 12% and for heavy thinning (combined with pruning) by 62%. However, in the youngest experiment, heavy thinning (without pruning) reduced growth by 54%. Combining these results with results from a similar experiment in Canada, the reduction in stand volume growth (RedIv%) depending on thinning removal (RemV%), both expressed as a percentage of the unthinned control, was quantified as RedIv% = −23.67 + 1.16·RemV% (calibration range: 30–83%). For heavy thinning (large quantities of slash), slash extraction resulted in no reduction in stand volume growth as compared to slash retention. The instantaneous numeric reduction in the average stem diameter of the 300 thickest trees per ha (D300) due to thinning was 3.5, 15–21% and 955–11% with moderate, point and heavy thinning, respectively. The subsequent average annual increase in D300 during the observation period was 8.5%, 25 and 18%, respectively. In the youngest experiment, pruning in unthinned plots led to a reduction in the annual increase of D300 by 14%, and heavy thinning in unpruned plots led to an increase by 30%. The growth of pre-selected potential future crop trees increased with increasing thinning intensity. In heavily thinned plots, pruning reduced growth increasingly with increasing pruning severity; LS-means estimates indicated 21% larger growth on stem diameter for unpruned trees and 3% for pruned trees. As an adverse side effect, heavily thinned plots with only 600 trees per ha were at increased risk of windthrow for some years after the thinning intervention. In the oldest experiment, 95–21% of the trees in these plots were damaged by wind.

scholarly journals Comparing Tree and Stand Volume Growth Response to Low and Crown Thinning in Young Natural Douglas-fir Stands

2007 ◽  
Vol 22 (2) ◽  
pp. 124-133 ◽  
Author(s):  
Wm Emmingham ◽  
Rick Fletcher ◽  
Stephen Fitzgerald ◽  
Max Bennett
Keyword(s):  
Growth Response ◽  
Volume Growth ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Oregon Coast ◽  
Stand Volume ◽  
Stand Growth ◽  
Growing Stock ◽  
Crown Thinning ◽  
Well Differentiated

Abstract We consider tree and stand response to low, crown, and no thinningof well-differentiated, naturally regenerated even-aged Douglas-firstands over 15 years on a moderately productive Cascade Mountains siteand over 10 years on a highly productive Oregon Coast Range site.Regardless of treatment, trees in dominant and codominant crown classescontinued growing at preinitiation rates and contributed 92–100% ofstand growth 5–15 years later. Most leave trees in suppressed crownclasses died during the first 10 years and suppressed and intermediatecrown classes contributed little to stand growth because survivorscontinued to grow slowly. Low thinning remains the most reliablethinning method for increasing stand volume in high-quality trees.Crown or selection thinning may be used to achieve certain objectivesif managers carefully use information about response of trees invarious crown classes. Growth rates of residual stands will depend onthe amount of residual growing stock and the degree to which it iscomprised of vigorously growing dominant and codominant trees.Residual subordinate trees may provide snags but few living trees insmall-diameter classes. Implications for management of the Douglas-firare discussed.

scholarly journals Developing Growth Models of Stand Volume for Subtropical Forests in Karst Areas: A Case Study in the Guizhou Plateau

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 83
Author(s):  
Yuzhi Tang ◽  
Quanqin Shao ◽  
Tiezhu Shi ◽  
Guofeng Wu
Keyword(s):  
Growth Models ◽  
Volume Growth ◽  
Site Quality ◽  
Rocky Desertification ◽  
Stand Volume ◽  
Subtropical Forests ◽  
Karst Areas ◽  
Growth Equations ◽  
Global Carbon ◽  
Guizhou Plateau

Forest stand volume is one of the key forest structural attributes in estimating and forecasting ecosystem productivity and carbon stock. However, studies on growth modeling and environmental influences on stand volume are still rare to date, especially in subtropical forests in karst areas, which are characterized by a complex species composition and are important in the global carbon budget. In this paper, we developed growth models of stand volume for all the dominant tree species (groups) (DTSG) in a subtropical karst area, the Guizhou Plateau based on an investigation of the effects of various environmental factors on stand volume. The Richards growth function, space-for-time substitution and zonal-hierarchical modeling method were applied in the model fitting, and multiple indices were used in the model evaluation. The results showed that the climatic factors of annual temperature and precipitation, as well as the site factors of stand origin, elevation, slope gradient, topsoil thickness, site quality degree, rocky desertification type and rocky desertification degree, have significant influences on stand volume, and the topsoil thickness and site quality degree have the strongest positive effect. A total of 959 growth equations of stand volume were fitted with a five-level stand classifier (DTSG–climatic zone–site quality degree–stand origin–rocky desertification type). All the growth equations were qualified, because all passed the TRE test (≤30%), and the majority of the R2 ≥ 0.50, above 70% of the RMSE were between 5.0 and 20.0, and above 80% of the P ≥ 75%. These findings provide updated knowledge about the environmental effect on the stand volume growth of subtropical forests in karst areas, and the developed stand volume growth models are convenient for forest management and planning, further contributing to the study of forest carbon storage assessments and global carbon cycling.

Height growth rate of Scots pine in Central Europe increased by 29% between 1900 and 2000 due to changes in site productivity

2021 ◽  
Vol 490 ◽  
pp. 119102
Author(s):  
Jarosław Socha ◽  
Svein Solberg ◽  
Luiza Tymińska-Czabańska ◽  
Piotr Tompalski ◽  
Patrick Vallet
Keyword(s):  
Growth Rate ◽  
Central Europe ◽  
Scots Pine ◽  
Height Growth ◽  
Site Productivity

Modelling response of infiltration loss toward water table depth using RBFN, RNN, ANFIS techniques

2021 ◽  
Vol 25 (2) ◽  
pp. 227-234
Author(s):  
Sandeep Samantaray ◽  
Abinash Sahoo
Keyword(s):  
Neural Network ◽  
Mean Square Error ◽  
Water Table ◽  
Environmental Sustainability ◽  
Model Development ◽  
Water Table Depth ◽  
Water Levels ◽  
Coefficient Of Determination ◽  
Mean Square ◽  
Inference System

Accurate prediction of water table depth over long-term in arid agricultural areas are very much important for maintaining environmental sustainability. Because of intricate and diverse hydrogeological features, boundary conditions, and human activities researchers face enormous difficulties for predicting water table depth. A virtual study on forecast of water table depth using various neural networks is employed in this paper. Hybrid neural network approach like Adaptive Neuro Fuzzy Inference System (ANFIS), Recurrent Neural Network (RNN), Radial Basis Function Neural Network (RBFN) is employed here to appraisal water levels as a function of average temperature, precipitation, humidity, evapotranspiration and infiltration loss data. Coefficient of determination (R2), Root mean square error (RMSE), and Mean square error (MSE) are used to evaluate performance of model development. While ANFIS algorithm is used, Gbell function gives best value of performance for model development. Whole outcomes establish that, ANFIS accomplishes finest as related to RNN and RBFN for predicting water table depth in watershed.

Role of tree stand evapotranspiration in maintaining satisfactory drainage conditions in drained peatlands

2010 ◽  
Vol 40 (8) ◽  
pp. 1485-1496 ◽  
Author(s):  
Sakari Sarkkola ◽  
Hannu Hökkä ◽  
Harri Koivusalo ◽  
Mika Nieminen ◽  
Erkki Ahti ◽  
...  
Keyword(s):  
Bulk Density ◽  
Water Table ◽  
Interactive Effect ◽  
Late Summer ◽  
Water Table Depth ◽  
Separate Analysis ◽  
Tree Stand ◽  
Stand Volume ◽  
Linear Effect ◽  
Subsequent Decrease

Ditch networks in drained peatland forests are maintained regularly to prevent water table rise and subsequent decrease in tree growth. The growing tree stand itself affects the level of water table through evapotranspiration, the magnitude of which is closely related to the living stand volume. In this study, regression analysis was applied to quantify the relationship between the late summer water table depth (DWT) and tree stand volume, mean monthly summertime precipitation (Ps), drainage network condition, and latitude. The analysis was based on several large data sets from southern to northern Finland, including concurrent measurements of stand volume and summer water table depth. The identified model demonstrated a nonlinear effect of stand volume on DWT, a linear effect of Ps on DWT, and an interactive effect of both stand volume and Ps. Latitude and ditch depth showed only marginal influence on DWT. A separate analysis indicated that an increase of 10 m3·ha–1 in stand volume corresponded with a drop of 1 cm in water table level during the growing season. In a subsample of the data, high bulk density peat showed deeper DWT than peat with low bulk density at the same stand volume.

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