Tree growth and mortality after small-group harvesting in New Zealand old-growth Nothofagus forests

2005 ◽  
Vol 35 (10) ◽  
pp. 2323-2331 ◽  
Author(s):  
Susan K Wiser ◽  
Robert B Allen ◽  
Udo Benecke ◽  
Gordon Baker ◽  
Duane Peltzer
Keyword(s):  
New Zealand ◽  
Tree Growth ◽  
Growth Models ◽  
Forest Growth ◽  
Major Influence ◽  
Growth Responses ◽  
Old Growth ◽  
Diameter Increment ◽  
Large Trees ◽  
The Impact

In New Zealand uncertainty about how silvicultural systems influence growth and mortality of residual beech trees has caused controversy surrounding sustainable beech management. We assess the impact of group-selection harvesting on residual-tree growth and mortality in old-growth hard beech (Nothofagus truncata (Col.) Ckn.) and mixed red beech – silver beech (Nothofagus fusca (Hook. F.) Oerst. – Nothofagus menziesii (Hook. F.) Oerst.) forests. Proximity to cuts had a major influence on growth that varied with both species and initial tree diameter. For all three beech species, diameter increment of small trees (<60 cm DBH) in intact forest was less than that of large trees, but smaller trees grew two- to four-fold faster along cut edges than in intact forest. In contrast, growth of large hard beech and silver beech and intermediate-sized red beech trees did not vary with cut proximity, suggesting that these main canopy trees were growing at a maximum potential rate. Edge trees were more likely to die as their level of Platypus beetle infection increased, but overall mortality rates were unrelated to harvest proximity. These results demonstrate that complex mortality and growth responses to harvesting should be incorporated into forest growth models upon which silvicultural systems that sustain the structural, compositional, and functional characteristics of forests are based.

scholarly journals Effect of Competition and Climatic Conditions on the Growth of Beech in the Mixed Pine Beech Stand: Lithuanian Case Study

2020 ◽  
Vol 3 (1) ◽  
pp. 49
Author(s):  
Edgaras Linkevičius ◽  
Gerda Junevičiūtė
Keyword(s):  
Intraspecific Competition ◽  
Tree Species ◽  
Forest Growth ◽  
Competition Effect ◽  
Diameter Increment ◽  
Cart Analysis ◽  
Crown Width ◽  
Beech Stand ◽  
Negative Effect ◽  
The Impact

Climate change and warming will potentially have profound effects on forest growth and yield, especially for pure stands in the near future. Thus, increased attention has been paid to mixed stands, e.g., pine and beech mixtures. However, the interaction of tree species growing in mixtures still remains unknown. Thus, the aim of this study was to investigate the impact of the interspecific and intraspecific competition to diameter, height, and crown width of pine and beech trees growing in mixtures, as well as to evaluate the impact of climatic indicators to the beech radial diameter increment. The data was collected in 2017 at the mixed mature pine beech double layer stand, located in the western part of Lithuania. The sample plot of 1.2 hectare was established and tree species, diameter at the breast height, tree height, height-to-crown base, height-to-crown width, and position were measured for all 836 trees. Additionally, a representative sample of radial diameter increments were estimated only for the beech trees by taking out core discs at the height of 1 m when the stand was partially cut. Competition analysis was based on the distance-dependent competition index, which was further based on crown parameters. Climatic effect was evaluated using classification and regression tree (CART) analysis. We found almost no interspecific competition effect to diameter, height, or crown width for both tree species growing in the first layer. However, it had an effect on beeches growing in the second layer. The intraspecific competition effect was important for pine and beech trees, showing a negative effect for both of them. Our results show the possible coexistence of these tree species due to niche differentiation. An analysis of climatic indicators from 1991–2005 revealed that precipitation from February–May of the current vegetation year and mean temperatures from July to September expressed radial diameter increment effects for beech trees. Low temperatures during March and April, as well as high precipitation during January, had a negative effect on beech radial increments. From 2006–2016, the highest effect on radial diameter increments was the mean temperatures from July to September, as well as the precipitation in January of the current year. From 1991–2016, the highest effect on radial diameter increments was the temperature from July to September 1991–2016 and the precipitation in June 1991–2016. Generally, cool temperatures and higher precipitation in June had a positive effect on beech radial increments. Therefore, our results show a sensitivity to high temperatures and droughts during summer amid Lithuanian’s growth conditions.

scholarly journals HETEROFOR 1.0: a spatially explicit model for exploring the response of structurally complex forests to uncertain future conditions. II. Phenology and water cycle

2019 ◽  
Author(s):  
Louis de Wergifosse ◽  
Frédéric André ◽  
Nicolas Beudez ◽  
François de Coligny ◽  
Hugues Goosse ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Balance ◽  
Tree Growth ◽  
Leaf Development ◽  
Forest Growth ◽  
Spatially Explicit ◽  
Model Assessment ◽  
Pearson's R ◽  
The Impact ◽  
Pearson’S R

Abstract. Climate change affects forest growth in numerous and sometimes opposite ways and the resulting trend is often difficult to predict for a given site. Integrating and structuring the knowledge gained from the monitoring and experimental studies into process-based models is an interesting approach to predict the response of forest ecosystems to climate change. While the first generation of such models operates at stand level, we need now individual-based and spatially-explicit approaches in order to account for structurally complex stands whose importance is increasingly recognized in the changing environment context. Among the climate-sensitive drivers of forest growth, phenology and water availability are often cited as crucial elements. They influence, for example, the length of the vegetation period during which photosynthesis takes place and the stomata opening, which determines the photosynthesis rate. In this paper, we describe the phenology and water balance modules integrated in the tree growth model HETEROFOR and evaluate them on six Belgian sites. More precisely, we assess the ability of the model to reproduce key phenological processes (budburst, leaf development, yellowing and fall) as well as water fluxes. Three variants are used to predict budburst (Uniforc, Unichill and Sequential), which differ regarding the inclusion of chilling and/or forcing periods and the calculation of the coldness or heat accumulation. Among the three, the Sequential approach is the least biased (overestimation of 2.46 days) while Uniforc (chilling not considered) best accounts for the interannual variability (Pearson’s R = 0.68). For the leaf development, yellowing and fall, predictions and observation are in accordance. Regarding the water balance module, the predicted throughfall is also in close agreement with the measurements (Pearson’s R = 0.856, bias = −1.3 %) and the soil water dynamics across the year is well-reproduced for all the study sites (Pearson’s R comprised between 0.893 and 0.950, and bias between −1.81 and −9.33 %). The positive results from the model assessment will allow us to use it reliably in projection studies to evaluate the impact of climate change on tree growth and test how diverse forestry practices can adapt forests to these changes.

scholarly journals Divergent Growth Responses to Warming between Stand-Grown and Open-Grown Trees in a Dryland Montane Forest in Northwestern China

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1133 ◽  
Author(s):  
Lei Zhang ◽  
Hao Shi ◽  
Pengtao Yu ◽  
Yanhui Wang ◽  
Shufen Pan ◽  
...  
Keyword(s):  
Climate Change ◽  
Tree Growth ◽  
Elevation Gradient ◽  
Montane Forest ◽  
Growth Patterns ◽  
Forest Growth ◽  
Northwestern China ◽  
Growth Responses ◽  
Internal Factors ◽  
High Elevations

Dryland montane forests conserve water for people living in the fluvial plains. The fate of these forests under climate warming is strongly affected by local environmental factors. The question remains of how internal factors contribute to climate change impacts on forest growth in these regions. Here, we investigated tree ring records for similar-aged stand-grown trees and their neighboring open-grown trees at elevation in a dryland montane forest (Picea crassifolia Kom.) in northwestern China. The growth rate of open-grown trees is much higher than their neighboring stand-grown trees across the entire elevation gradient, and the lower the altitude, the greater the difference. Open-grown trees at different elevations showed similar growth patterns, as tree growth at all sites was accelerated over time. In contrast, growth patterns of stand-grown trees were divergent at different altitudes, as growth at high elevations (3100–3300 m a.s.l.) was accelerated, whereas growth at low elevations (2700–2900 m a.s.l.) became stable after the year 1990. Analysis of growth–climate relationships indicated that warming promoted open-grown tree growth across the entire altitude gradient, and also stand-grown tree growth at high elevations, but negatively affected the growth of stand-grown trees at low elevations. Water scarcity can be exacerbated by competition within forests, inhibiting the warming-induced benefits on tree growth. Moving window correlation analysis suggested the negative effect of warming on tree growth at low elevations was diminished after the late 1990s, as the drought stress was alleviated. Our research shows the divergent growth responses to warming of stand-grown and open-grown trees along elevation. It reveals effects of internal factors in determining tree growth response to warming and holds the potential to aid forest management and ecosystem models in responding to climate change.

The impact of deer on relationships between tree growth and mortality in an old-growth beech-maple forest

2007 ◽  
Vol 252 (1-3) ◽  
pp. 230-238 ◽  
Author(s):  
Zachary T. Long ◽  
Thomas H. Pendergast ◽  
Walter P. Carson
Keyword(s):  
Tree Growth ◽  
Old Growth ◽  
The Impact

scholarly journals Size‐, species‐, and site‐specific tree growth responses to climate variability in old‐growth subalpine forests

Ecosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Elizabeth M. Campbell ◽  
Steen Magnussen ◽  
Joseph A. Antos ◽  
Roberta Parish
Keyword(s):  
Climate Variability ◽  
Tree Growth ◽  
Growth Responses ◽  
Old Growth ◽  
Subalpine Forests ◽  
Site Specific

scholarly journals Variation in Water Supply Leads to Different Responses of Tree Growth to Warming

2021 ◽  
Author(s):  
Pengfei Zheng ◽  
Dandan Wang ◽  
Xinxiao Yu ◽  
Guodong Jia ◽  
Ziqiang Liu ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Supply ◽  
Climate Warming ◽  
Tree Growth ◽  
Structural Equation Models ◽  
Growing Season ◽  
Forest Growth ◽  
Arid Ecosystems ◽  
Carbon Sinks ◽  
The Impact

Abstract Background: Global climate change, which includes changes in precipitation, prolonged growing seasons, and drought stress caused by overall climate warming, is putting increased pressure on forest ecosystems globally. Understanding the impact of climate change on drought-prone forests is a key objective in assessing forest responses to climate change.Results: In this study, we assessed tree growth trends and changes in physiological activity under climate change based on patterns in tree rings and stable isotopes. Additionally, structural equation models were used to analyze the climate drivers influencing tree growth, with several key results. (1) The climate in the study area showed a trend of warming and drying, with the growth of tree section areas decreasing first and then increasing, while the water use efficiency showed a steady increase. (2) The effects of climate warming on tree growth in the study area have transitioned from negative to positive. The gradual advance of the growing season and the supply of snowmelt water in the early critical period of the growing season are the key factors underlying the reversal of the sensitivity of trees to climate. (3) Variation in water supply has led to different responses of tree growth to warming, and the growth response of Pinus tabuliformis to temperature rise was closely related to increased water availability.Conclusions: Our study indicates that warming is not the cause of forest decline, and instead, drought caused by warming is the main factor causing this change. If adequate water is available during critical periods of the growing season, boreal forests may be better able to withstand rising temperatures and even exhibit increased growth during periods of rising temperatures, forming stronger carbon sinks. However, in semi-arid regions, where water supply is limited, continued warming could lead to reduced forest growth and even death, which would dramatically reduce carbon sinks in arid ecosystems.

scholarly journals Comparison of Spatially and Nonspatially Explicit Nonlinear Mixed Effects Models for Norway Spruce Individual Tree Growth under Single-Tree Selection

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1338
Author(s):  
Simone Bianchi ◽  
Mari Myllymaki ◽  
Jouni Siipilehto ◽  
Hannu Salminen ◽  
Jari Hynynen ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Tree Growth ◽  
Cross Validation ◽  
Growth Models ◽  
Forest Growth ◽  
Individual Tree ◽  
Selection Cutting ◽  
Single Tree ◽  
Individual Tree Growth ◽  
Single Tree Selection

Background and Objectives: Continuous cover forestry is of increasing importance, but operational forest growth models are still lacking. The debate is especially open if more complex spatial approaches would provide a worthwhile increase in accuracy. Our objective was to compare a nonspatial versus a spatial approach for individual Norway spruce tree growth models under single-tree selection cutting. Materials and Methods: We calibrated nonlinear mixed models using data from a long-term experiment in Finland (20 stands with 3538 individual trees for 10,238 growth measurements). We compared the use of nonspatial versus spatial predictors to describe the competitive pressure and its release after cutting. The models were compared in terms of Akaike Information Criteria (AIC), root mean square error (RMSE), and mean absolute bias (MAB), both with the training data and after cross-validation with a leave-one-out method at stand level. Results: Even though the spatial model had a lower AIC than the nonspatial model, RMSE and MAB of the two models were similar. Both models tended to underpredict growth for the highest observed values when the tree-level random effects were not used. After cross-validation, the aggregated predictions at stand level well represented the observations in both models. For most of the predictors, the use of values based on trees’ height rather than trees’ diameter improved the fit. After single-tree selection cutting, trees had a growth boost both in the first and second five-year period after cutting, however, with different predicted intensity in the two models. Conclusions: Under the research framework here considered, the spatial modeling approach was not more accurate than the nonspatial one. Regarding the single-tree selection cutting, an intervention regime spaced no more than 15 years apart seems necessary to sustain the individual tree growth. However, the model’s fixed effect parts were not able to capture the high growth of the few fastest-growing trees, and a proper estimation of site potential is needed for uneven-aged stands.

Predicting growth of plantation conifers in the Adirondack Mountains in response to climate change

1995 ◽  
Vol 25 (1) ◽  
pp. 48-56 ◽  
Author(s):  
Yude Pan ◽  
Dudley J. Raynal
Keyword(s):  
Climate Change ◽  
Tree Growth ◽  
Climate Models ◽  
Growth Models ◽  
Future Climate Change ◽  
Adirondack Mountains ◽  
Growth Responses ◽  
Conifer Species ◽  
Climatic Effects ◽  
Extrinsic Factors

Three conifer species grown in plantations in the southeastern Adirondack Mountains of New York were chosen to model tree growth. Annual growth of trees was decomposed into several components that reflect various intrinsic or extrinsic factors. Growth signals indicative of climatic effects were used to construct growth-climate models using both multivariate regression analysis and Kalman filter methods. Two growth models were used to simulate tree growth response to future climate change projected by GCMs. The consistent results of both models indicate that different conifer species have individualistic growth responses to future climatic change. The response behaviors of trees are affected greatly by local stand conditions and species tolerance to drought.

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