Linking forest growth with stand structure: Tree size inequality, tree growth or resource partitioning and the asymmetry of competition

2019 ◽  
Vol 447 ◽  
pp. 139-157 ◽  
Author(s):  
David I. Forrester
Keyword(s):  
Tree Growth ◽  
Resource Partitioning ◽  
Stand Structure ◽  
Forest Growth ◽  
Tree Size ◽  
Size Inequality ◽  
Structure Tree ◽  
The Asymmetry

Tree growth across the Nepal Himalaya during the last four centuries

2017 ◽  
Vol 41 (4) ◽  
pp. 478-495 ◽  
Author(s):  
UK Thapa ◽  
S St. George ◽  
DK Kharal ◽  
NP Gaire
Keyword(s):  
Tree Ring ◽  
Tree Growth ◽  
Environmental Changes ◽  
Ring Width ◽  
High Elevation ◽  
Forest Growth ◽  
Tree Ring Width ◽  
Early 19Th Century ◽  
Tree Ring Data ◽  
Instrumental Records

The climate of Nepal has changed rapidly over the recent decades, but most instrumental records of weather and hydrology only extend back to the 1980s. Tree rings can provide a longer perspective on recent environmental changes, and since the early 2000s, a new round of field initiatives by international researchers and Nepali scientists have more than doubled the size of the country’s tree-ring network. In this paper, we present a comprehensive analysis of the current tree-ring width network for Nepal, and use this network to estimate changes in forest growth nation-wide during the last four centuries. Ring-width chronologies in Nepal have been developed from 11 tree species, and half of the records span at least 290 years. The Nepal tree-ring width network provides a robust estimate of annual forest growth over roughly the last four centuries, but prior to this point, our mean ring-width composite fluctuates wildly due to low sample replication. Over the last four centuries, two major events are prominent in the all-Nepal composite: (i) a prolonged and widespread growth suppression during the early 1800s; and (ii) heightened growth during the most recent decade. The early 19th century decline in tree growth coincides with two major Indonesian eruptions, and suggests that short-term disturbances related to climate extremes can exert a lasting influence on the vigor of Nepal’s forests. Growth increases since AD 2000 are mainly apparent in high-elevation fir, which may be a consequence of the observed trend towards warmer temperatures, particularly during winter. This synthesis effort should be useful to establish baselines for tree-ring data in Nepal and provide a broader context to evaluate the sensitivity or behavior of this proxy in the central Himalayas.

scholarly journals Tree growth-competition relationships in thinned Eucalyptus plantations vary with stand structure and site quality

2012 ◽  
Vol 132 (2) ◽  
pp. 241-252 ◽  
Author(s):  
David I. Forrester ◽  
Stephen R. Elms ◽  
Thomas G. Baker
Keyword(s):  
Tree Growth ◽  
Stand Structure ◽  
Site Quality ◽  
Eucalyptus Plantations

scholarly journals A 406-year non-growing-season precipitation reconstruction in the southeastern Tibetan Plateau

2021 ◽  
Vol 17 (6) ◽  
pp. 2381-2392
Author(s):  
Maierdang Keyimu ◽  
Zongshan Li ◽  
Bojie Fu ◽  
Guohua Liu ◽  
Fanjiang Zeng ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Tree Ring ◽  
Tree Growth ◽  
Ring Width ◽  
Growing Season ◽  
Climatic Conditions ◽  
Forest Growth ◽  
Drought Severity ◽  
Precipitation Reconstruction ◽  
Southeastern Tibetan Plateau

Abstract. Trees record climatic conditions during their growth, and tree rings serve as proxy to reveal the features of the historical climate of a region. In this study, we collected tree-ring cores of hemlock forest (Tsuga forrestii) from the northwestern Yunnan area of the southeastern Tibetan Plateau (SETP) and created a residual tree-ring width (TRW) chronology. An analysis of the relationship between tree growth and climate revealed that precipitation during the non-growing season (NGS) (from November of the previous year to February of the current year) was the most important constraining factor on the radial tree growth of hemlock forests in this region. In addition, the influence of NGS precipitation on radial tree growth was relatively uniform over time (1956–2005). Accordingly, we reconstructed the NGS precipitation over the period spanning from 1600–2005. The reconstruction accounted for 28.5 % of the actual variance during the common period of 1956–2005. Based on the reconstruction, NGS was extremely dry during the years 1656, 1694, 1703, 1736, 1897, 1907, 1943, 1982 and 1999. In contrast, the NGS was extremely wet during the years 1627, 1638, 1654, 1832, 1834–1835 and 1992. Similar variations of the NGS precipitation reconstruction series and Palmer Drought Severity Index (PDSI) reconstructions of early growing season from surrounding regions indicated the reliability of the present reconstruction. A comparison of the reconstruction with Climate Research Unit (CRU) gridded data revealed that our reconstruction was representative of the NGS precipitation variability of a large region in the SETP. Our study provides the first historical NGS precipitation reconstruction in the SETP which enriches the understanding of the long-term climate variability of this region. The NGS precipitation showed slightly increasing trend during the last decade which might accelerate regional hemlock forest growth.

scholarly journals No growth stimulation of Canada’s boreal forest under half-century of combined warming and CO2 fertilization

2016 ◽  
Vol 113 (52) ◽  
pp. E8406-E8414 ◽  
Author(s):  
Martin P. Girardin ◽  
Olivier Bouriaud ◽  
Edward H. Hogg ◽  
Werner Kurz ◽  
Niklaus E. Zimmermann ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Boreal Forest ◽  
Spatial Patterns ◽  
Tree Growth ◽  
Hydrological Cycle ◽  
Forest Growth ◽  
Spatiotemporal Variability ◽  
Late 20Th Century ◽  
Growth Trends ◽  
Growth Variability

Considerable evidence exists that current global temperatures are higher than at any time during the past millennium. However, the long-term impacts of rising temperatures and associated shifts in the hydrological cycle on the productivity of ecosystems remain poorly understood for mid to high northern latitudes. Here, we quantify species-specific spatiotemporal variability in terrestrial aboveground biomass stem growth across Canada’s boreal forests from 1950 to the present. We use 873 newly developed tree-ring chronologies from Canada’s National Forest Inventory, representing an unprecedented degree of sampling standardization for a large-scale dendrochronological study. We find significant regional- and species-related trends in growth, but the positive and negative trends compensate each other to yield no strong overall trend in forest growth when averaged across the Canadian boreal forest. The spatial patterns of growth trends identified in our analysis were to some extent coherent with trends estimated by remote sensing, but there are wide areas where remote-sensing information did not match the forest growth trends. Quantifications of tree growth variability as a function of climate factors and atmospheric CO2 concentration reveal strong negative temperature and positive moisture controls on spatial patterns of tree growth rates, emphasizing the ecological sensitivity to regime shifts in the hydrological cycle. An enhanced dependence of forest growth on soil moisture during the late-20th century coincides with a rapid rise in summer temperatures and occurs despite potential compensating effects from increased atmospheric CO2 concentration.

Does forest growth acceleration lead to denser stands? Insights from Swiss forests and mechanistic modelling

2021 ◽  
Author(s):  
Laura Marques ◽  
Ensheng Weng ◽  
Harald Bugmann ◽  
David I. Forrester ◽  
Martina Hobi ◽  
...  
Keyword(s):  
Tree Growth ◽  
Carbon Balance ◽  
Tree Mortality ◽  
Forest Growth ◽  
Growth Enhancement ◽  
Carbon Sinks ◽  
Terrestrial Carbon ◽  
Model Simulations ◽  
Leaf Level ◽  
Use Efficiency

<p>Forest demographic processes - growth, recruitment and mortality - are being altered by global change. The changing balance between growth and mortality strongly influences forest dynamics and the carbon balance. Elevated atmospheric carbon dioxide (eCO<sub>2</sub>) has been reported to enhance photosynthesis and tree growth rates by increasing both light-use efficiency (LUE) and water-use efficiency (WUE). Tree growth enhancement could be translated into an increase in biomass stocks or could be associated with a reduction in the longevity of trees, thus reducing the ability of forest ecosystems to act as carbon sinks over long timescales. These links between growth and mortality, and the implications for forest stand density and self-thinning relationships are still debated. Scarce empirical evidence exists for how changing drivers affect tree mortality due to existing data and modelling limitations. Understanding the causes of observed mortality trends and the mechanisms underlying these processes is critical for accurate projections of global terrestrial carbon storage and its feedbacks to anthropogenic climate change.</p><p>Here, we combine a mechanistic model with empirical forest data to better understand the causes of changes in tree mortality and the implications for past and future trends in forest tree density. Specifically, we test the Grow-Fast-Die-Young hypothesis to investigate if a leaf-level CO<sub>2</sub> fertilization effect may lead to an increase in the biomass stock in forest stands. We use a novel vegetation demography model (LM3-PPA) which includes vegetation dynamics with biogeochemical processes allowing for explicit representation of individuals and a mechanistic treatment of tree mortality. The key links between leaf-level assimilation and stand dynamics depend on the carbon turnover time. In this sense, we investigate alternative mortality assumptions about the functional dependence of mortality on tree size, tree carbon balance or growth rate. These formulations represent typical approaches to simulate mortality in mechanistic forest models. Model simulations show that increasing photosynthetic LUE leads to higher biomass stocks, with contrasting behavior among mortality assumptions. Empirical data from Swiss forest inventories support the results from the model simulations showing a shift upwards in the self-thinning relationships, with denser stands and bigger trees. This data-supported mortality-modelling helps to identify links between forest responses and environmental changes at the leaf, tree and stand levels and yields new insight into the causes of currently observed terrestrial carbon sinks and future responses.</p>

scholarly journals The effect of coppice management on the structure, tree growth and soil nutrients in temperate Turkey

2016 ◽  
Vol 61 (No. 1) ◽  
pp. 27-34 ◽  
Author(s):  
Šrámek Martin ◽  
Volařík Daniel ◽  
Ertas Aytekin ◽  
Matula Radim
Keyword(s):  
Soil Nutrients ◽  
Tree Growth ◽  
Coppice Management ◽  
Structure Tree

Relative impact of stand structure, tree composition and climate on mountain bird communities

2007 ◽  
Vol 247 (1-3) ◽  
pp. 72-79 ◽  
Author(s):  
Frédéric Archaux ◽  
Noémie Bakkaus
Keyword(s):  
Stand Structure ◽  
Bird Communities ◽  
Relative Impact ◽  
Structure Tree ◽  
Tree Composition

scholarly journals Understanding the Evolution of Tree Size Diversity within the Multivariate Nonsymmetrical Diffusion Process and Information Measures

Mathematics ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 761 ◽  
Author(s):  
Rupšys
Keyword(s):  
Differential Equation ◽  
Stochastic Differential Equation ◽  
Probability Density ◽  
Forest Growth ◽  
Tree Size ◽  
Growth And Yield ◽  
State Variables ◽  
Data Set ◽  
Interaction Information ◽  
Information Measures

This study focuses on the stochastic differential calculus of Itô, as an effective tool for the analysis of noise in forest growth and yield modeling. Idea of modeling state (tree size) variable in terms of univariate stochastic differential equation is exposed to a multivariate stochastic differential equation. The new developed multivariate probability density function and its marginal univariate, bivariate and trivariate distributions, and conditional univariate, bivariate and trivariate probability density functions can be applied for the modeling of tree size variables and various stand attributes such as the mean diameter, height, crown base height, crown width, volume, basal area, slenderness ratio, increments, and much more. This study introduces generalized multivariate interaction information measures based on the differential entropy to capture multivariate dependencies between state variables. The present study experimentally confirms the effectiveness of using multivariate interaction information measures to reconstruct multivariate relationships of state variables using measurements obtained from a real-world data set.

Clonal variation in shoot respiration and tree growth of Eucalyptus hybrids

2007 ◽  
Vol 37 (8) ◽  
pp. 1404-1413 ◽  
Author(s):  
Andrew N. Callister ◽  
Peter K. Ades ◽  
Stefan K. Arndt ◽  
Mark A. Adams
Keyword(s):  
Respiration Rate ◽  
Tree Growth ◽  
Isothermal Calorimetry ◽  
Intraclass Correlation ◽  
Genetic Correlations ◽  
Volume Growth ◽  
Eucalyptus Camaldulensis ◽  
Tree Size ◽  
Balance Model ◽  
Clonal Variation

Respiration rate and efficiency in growing tissues are major determinants of plant growth. We measured apical shoot respiration and tree growth in 3-year-old clones of Eucalyptus camaldulensis Dehnhardt × Eucalyptus grandis W. Hill ex Maid. and Eucalyptus camaldulensis × Eucalyptus globulus Labill. Respiration was measured by isothermal calorimetry and the oxidation state of newly formed biomass was determined by elemental analysis. We found that the enthalpy change due to conversion of carbon substrate to biomass was too small for determining specific growth rate by an enthalpy balance model of respiration and growth. Negative phenotypic correlations were significant between respiration rate and basal area, height, volume, and volume growth. Genetic correlations between respiration rate and tree size or growth were mostly significant and estimates ranged from –0.55 to –1.02. Repeatability of the clone means was around 0.80 for respiration rate, 0.71–0.91 for summer growth, and in excess of 0.80 for tree size traits. The intraclass correlation for clones (within families) was 0.33 for rate of CO2 evolution and 0.45 for rate of metabolic heat evolution. Our results suggest considerable potential for altering respiration rate in breeding populations by selection, although the mechanisms linking respiration with growth require further investigation.

Influence of rootstocks on Navel orange yield and tree growth at Mildura, Victoria

1972 ◽  
Vol 12 (55) ◽  
pp. 203 ◽  
Author(s):  
LM Stafford
Keyword(s):  
Fruit Quality ◽  
Tree Growth ◽  
Soil Type ◽  
Sweet Orange ◽  
Tree Size ◽  
Irrigation District ◽  
Navel Orange ◽  
Trifoliate Orange ◽  
Rough Lemon

Two experiments with Navel orange scions (CV. Washington and Leng) on a number of rootstocks were done on three sandy Mallee soils in the Mildura irrigation district. Rootstocks included sweet orange (eight cultivars), rough lemon, mandarin (two cultivars), trifoliate orange, and citrange (two cultivars). In experiment 1 (1949 to 1963) eight sweet orange rootstocks gave similar results in terms of yield and tree size. Leng produced more but smaller fruit than Washington, but total weights were similar. In experiment 2 (1959 to 1969 and continuing) Leng trees were larger, produced more fruit, and on one soil a greater weight of fruit per tree than Washington. Sweet orange rootstocks were usually superior to other rootstocks on each soil type, although rough lemon gave results that were similar and, for a few combinations, superior. Trees on mandarin rootstocks were low producers and small in the early part of the experiment, but by the end of the period were yielding as much fruit as those on sweet orange. Trifoliate rootstocks were unsatisfactory, and citrange intermediate between sweet orange and trifoliate. No fruit quality differences ascribable to rootstock were detected.

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