Topographic variation and stand heterogeneity in a wet evergreen forest of India

2003 ◽  
Vol 19 (6) ◽  
pp. 697-707 ◽  
Author(s):  
Audrey Robert ◽  
Marie-Agnès Moravie
Keyword(s):  
Tree Growth ◽  
Stand Structure ◽  
Evergreen Forest ◽  
Tree Level ◽  
Spatial Distributions ◽  
Trunk Diameter ◽  
Diameter Increment ◽  
Large Trees ◽  
Steep Slopes ◽  
Diameter Distributions

We investigated the links between slope variation and heterogeneity in tree growth and stand structure. The study was conducted in an undisturbed wet evergreen forest in India. We selected three plots situated on gentle slopes and three plots situated on steep slopes. Tree growth was considered as mean annual diameter increment. Stand structure was considered in relation to several characteristics: trunk diameter distributions, tree heights, and spatial distributions of stems and crowns. Except for the spatial structure, analyses were performed on samples including either all the species or only the dominant species (Vateria indica L.). Diameter growth varied according to slope intensity and to tree size: growth of large trees was clearly higher on steep slopes whereas growth of small trees proved lower or similar. Diameter distributions were different among the six plots, but the difference cannot be related to slope intensity. On the contrary, tree heights differed according to slope intensity: for a given diameter, trees were taller on gentle slopes than on steep slopes. Finally, stem spatial distributions showed strong regularity on gentle slopes whereas they were random on steep slopes. The observed changes between gentle and steep slopes suggest differences at tree level through a modification of its shape, but also differences in the major processes responsible for stand dynamics: competition, establishment and survival.

scholarly journals Complementarity effects on tree growth are contingent on tree size and climatic conditions across Europe

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jaime Madrigal-González ◽  
Paloma Ruiz-Benito ◽  
Sophia Ratcliffe ◽  
Joaquín Calatayud ◽  
Gerald Kändler ◽  
...  
Keyword(s):  
Large Scale ◽  
Stand Structure ◽  
Tree Size ◽  
Tree Level ◽  
Permanent Plots ◽  
Growth Responses ◽  
Niche Complementarity ◽  
Growth Increments ◽  
Large Trees ◽  
Complementarity Effects

Abstract Neglecting tree size and stand structure dynamics might bias the interpretation of the diversity-productivity relationship in forests. Here we show evidence that complementarity is contingent on tree size across large-scale climatic gradients in Europe. We compiled growth data of the 14 most dominant tree species in 32,628 permanent plots covering boreal, temperate and Mediterranean forest biomes. Niche complementarity is expected to result in significant growth increments of trees surrounded by a larger proportion of functionally dissimilar neighbours. Functional dissimilarity at the tree level was assessed using four functional types: i.e. broad-leaved deciduous, broad-leaved evergreen, needle-leaved deciduous and needle-leaved evergreen. Using Linear Mixed Models we show that, complementarity effects depend on tree size along an energy availability gradient across Europe. Specifically: (i) complementarity effects at low and intermediate positions of the gradient (coldest-temperate areas) were stronger for small than for large trees; (ii) in contrast, at the upper end of the gradient (warmer regions), complementarity is more widespread in larger than smaller trees, which in turn showed negative growth responses to increased functional dissimilarity. Our findings suggest that the outcome of species mixing on stand productivity might critically depend on individual size distribution structure along gradients of environmental variation.

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 Threshold Response to Extreme Drought Shifts Inter-Tree Growth Dominance in Pinus sylvestris

2021 ◽  
Vol 4 ◽  
Author(s):  
Thomas S. Ovenden ◽  
Mike P. Perks ◽  
Toni-Kim Clarke ◽  
Maurizio Mencuccini ◽  
Alistair S. Jump
Keyword(s):  
Pinus Sylvestris ◽  
Tree Growth ◽  
Stand Structure ◽  
Mixed Effects ◽  
Extreme Drought ◽  
Tree Level ◽  
Drought Severity ◽  
Drought Impact ◽  
Threshold Response ◽  
Growth Change

Many studies quantify short-term drought impact on tree growth relative to pre-drought growth averages. However, fewer studies examine the extent to which droughts of differing severity differentially impact tree growth or shape stand dynamics. Focusing on three droughts in high and low density stands of Pinus sylvestris in Scotland, we calculated pre-drought growth averages using climatically standardized antecedent growth years to assess tree level drought and post-drought growth performance as percentage growth change (PGC). We then used mixed-effects models to understand how droughts of differing severity impact tree growth and calculated indices of growth dominance (Gd), size inequality (Si), and size asymmetry (Sa) to detect changes in stand structure. Mixed-effects model results indicate that the magnitude and duration of the growth reduction during and following the more extreme drought was significantly larger compared to less severe droughts, for which we found limited evidence of drought impact. While no changes in Si or Sa were noted following any drought, we found evidence of a difference in Gd after the most extreme drought in both stand densities indicative of a threshold response, with smaller trees contributing proportionally more to stand growth relative to their size. Under less severe droughts, inter-tree variability may have partially buffered against stand-level growth change, however, a small increase in drought severity was associated with a significant reduction in average tree growth, an increase in the number of trees growing at &gt;2SD below pre-drought levels and a shift in Gd toward smaller trees, indicating that a drought severity threshold in P. sylvestris may have been exceeded.

scholarly journals A protocol for sampling vascular epiphyte richness and abundance

2009 ◽  
Vol 25 (2) ◽  
pp. 107-121 ◽  
Author(s):  
Jan H. D. Wolf ◽  
S. Robbert Gradstein ◽  
Nalini M. Nadkarni
Keyword(s):  
Tree Height ◽  
Dry Weight ◽  
Mantel Test ◽  
Tree Size ◽  
Tree Level ◽  
Trunk Diameter ◽  
Host Trees ◽  
Epiphyte Communities ◽  
Vascular Epiphyte

Abstract:The sampling of epiphytes is fraught with methodological difficulties. We present a protocol to sample and analyse vascular epiphyte richness and abundance in forests of different structure (SVERA). Epiphyte abundance is estimated as biomass by recording the number of plant components in a range of size cohorts. Epiphyte species biomass is estimated on 35 sample-trees, evenly distributed over six trunk diameter-size cohorts (10 trees with dbh > 30 cm). Tree height, dbh and number of forks (diameter > 5 cm) yield a dimensionless estimate of the size of the tree. Epiphyte dry weight and species richness between forests is compared with ANCOVA that controls for tree size. SChao1 is used as an estimate of the total number of species at the sites. The relative dependence of the distribution of the epiphyte communities on environmental and spatial variables may be assessed using multivariate analysis and Mantel test. In a case study, we compared epiphyte vegetation of six Mexican oak forests and one Colombian oak forest at similar elevation. We found a strongly significant positive correlation between tree size and epiphyte richness or biomass at all sites. In forests with a higher diversity of host trees, more trees must be sampled. Epiphyte biomass at the Colombian site was lower than in any of the Mexican sites; without correction for tree size no significant differences in terms of epiphyte biomass could be detected. The occurrence of spatial dependence, at both the landscape level and at the tree level, shows that the inclusion of spatial descriptors in SVERA is justified.

scholarly journals Modelling Tree Growth in Monospecific Forests from Forest Inventory Data

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 753
Author(s):  
Guadalupe Sáez-Cano ◽  
Marcos Marvá ◽  
Paloma Ruiz-Benito ◽  
Miguel A. Zavala
Keyword(s):  
Tree Growth ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Carbon Sink ◽  
Size Variation ◽  
Biotic Interactions ◽  
Richards Equation ◽  
Tree Level ◽  
Forest Inventories ◽  
Large Scale Data

The prediction of tree growth is key to further understand the carbon sink role of forests and the short-term forest capacity on climate change mitigation. In this work, we used large-scale data available from three consecutive forest inventories in a Euro-Mediterranean region and the Bertalanffy–Chapman–Richards equation to model up to a decade’s tree size variation in monospecific forests in the growing stages. We showed that a tree-level fitting with ordinary differential equations can be used to forecast tree diameter growth across time and space as function of environmental characteristics and initial size. This modelling approximation was applied at different aggregation levels to monospecific regions with forest inventories to predict trends in aboveground tree biomass stocks. Furthermore, we showed that this model accurately forecasts tree growth temporal dynamics as a function of size and environmental conditions. Further research to provide longer term prediction forest stock dynamics in a wide variety of forests should model regeneration and mortality processes and biotic interactions.

Using saline reclaimed water on almond grown in Mediterranean conditions: deficit irrigation strategies and salinity effects

2019 ◽  
Vol 19 (5) ◽  
pp. 1413-1421 ◽  
Author(s):  
Gaetano Alessandro Vivaldi ◽  
Salvatore Camposeo ◽  
Giuseppe Lopriore ◽  
Cristina Romero-Trigueros ◽  
Francisco Pedrero Salcedo
Keyword(s):  
Tree Growth ◽  
Deficit Irrigation ◽  
Management Practices ◽  
Water Productivity ◽  
Maximum Yield ◽  
Control Treatment ◽  
Irrigation Season ◽  
Regulated Deficit Irrigation ◽  
Trunk Diameter ◽  
Almond Trees

Abstract The main objective of this study was to acquire agronomic knowledge about the effects of irrigation with saline reclaimed (RW) and desalinated DESERT (DW) water and different irrigation strategies: control full irrigation (FI) and regulated deficit irrigation (RDI) on leaf nutrients, tree growth and fruit quality and yield of almond trees in pots. Our results showed that RW had the highest concentration of some valuable agronomic nutrients such as N, but also of phytotoxic elements (Na and Cl−). Na leaf concentration on RW treatments reached toxic levels, especially under RDI, and toxicity symptoms were shown. Regarding tree growth, cumulate trunk diameter on RW-RDI was significantly lower than on the control treatment and shoot growth was reduced from the beginning of the irrigation season in RW treatments. Maximum yield was reached on RW-FI, 18% higher than the control treatment. However, RDI strategies influenced negatively on yield, being 23% less in RW and 7% less in DW although water productivity was not significantly reduced by water stress. These findings manifest that the combination of RW and RDI can be a promising future practice for almond irrigation, but long-term studies to establish suitable management practices must be developed.

Forest structure altered by mountain pine beetle outbreaks affects subsequent attack in a Wyoming lodgepole pine forest, USA

2011 ◽  
Vol 41 (12) ◽  
pp. 2403-2412 ◽  
Author(s):  
Daniel M. Kashian ◽  
Rebecca M. Jackson ◽  
Heather D. Lyons
Keyword(s):  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Climate Change Scenarios ◽  
Cone Production ◽  
Mountain Pine ◽  
Large Trees ◽  
Pine Beetle ◽  
The 1960S

Extensive outbreaks of the mountain pine beetle ( Dendroctonus ponderosae Hopkins) will alter the structure of many stands that will likely be attacked again before experiencing a stand-replacing fire. We examined a stand of lodgepole pine ( Pinus contorta var. latifolia Engelm. ex S. Watson) in Grand Teton National Park currently experiencing a moderate-level outbreak and previously attacked by mountain pine beetle in the 1960s. Consistent with published studies, tree diameter was the main predictor of beetle attack on a given tree, large trees were preferentially attacked, and tree vigor, age, and cone production were unimportant variables for beetle attack at epidemic levels. Small trees killed in the stand were killed based mainly on their proximity to large trees and were likely spatially aggregated with large trees as a result of the previous outbreak. We concluded that the driving factors of beetle attack and their spatial patterns are consistent across outbreak severities but that stand structure altered by the previous outbreak had implications for the current outbreaks in the same location. This study should catalyze additional research that examines how beetle-altered stand structure affects future outbreaks — an important priority for predicting their impacts under climate change scenarios that project increases in outbreak frequency and extent.

scholarly journals Microclimates and Tree Growth in Three Urban Spaces

1992 ◽  
Vol 10 (3) ◽  
pp. 139-145 ◽  
Author(s):  
Roger K. Kjelgren ◽  
James R. Clark
Keyword(s):  
Tree Growth ◽  
The Other ◽  
Urban Spaces ◽  
Urban Site ◽  
Soil Conditions ◽  
Evaporative Demand ◽  
Diameter Increment ◽  
Shade Acclimation ◽  
Air Temperatures ◽  
Crown Size

Abstract Microclimates characteristic of urban park, plaza, and canyon spaces were related to physiology and growth of even-aged sweetgum (Liquidambar styraciflua L.) street trees. Microclimates, tree growth, and physiological responses were characterized diurnally and seasonally. Park and plaza sites received unobstructed sunlight while the canyon was limited to four hours of direct solar radiation in midsummer. Potential seasonal insolation was 44% of the potential maximum at the canyon and over 90% at the park. Afternoon air temperatures and vapor pressure deficits were somewhat greater at the plaza than the other two sites, and potential pan evaporation was nearly 50% greater over the season. Tree growth at the plaza and canyon acclimated physiologically and developmentally to the prevailing environmental conditions. Thinner leaves and less trunk growth when compared with the park were indications of shade acclimation in the canyon trees. This did not, however, appear to affect crown size or shoot growth of canyon trees. In contrast, plaza trees were sparse and stunted, exhibiting diminished crown size and diameter increment when compared with tree at the other sites. Less favorable water relations suggested that chronically higher evaporative demand and limited soil resources restricted growth of the plaza trees. Park, plaza, and canyon designations of urban spaces can provide a useful framework for predicting microclimatic factors that can affect tree growth for an urban site. Long-term growth and development, however, with in any of these urban spaces will depend on interactions with existing soil conditions.

Evaluating the influence of stem form and damage on individual-tree diameter increment and survival in the Acadian Region: implications for predicting future value of northern commercial hardwood stands

2018 ◽  
Vol 48 (9) ◽  
pp. 1007-1019 ◽  
Author(s):  
Mark Castle ◽  
Aaron Weiskittel ◽  
Robert Wagner ◽  
Mark Ducey ◽  
Jereme Frank ◽  
...  
Keyword(s):  
Growth And Yield ◽  
Tree Level ◽  
Permanent Plots ◽  
Stem Form ◽  
Individual Tree ◽  
Tree Diameter ◽  
Diameter Increment ◽  
Hardwood Species ◽  
Future Value

Northern hardwood species display a variety of forms and defects that can reduce stem quality and complicate their timber management. However, for the most part, growth and yield models do not account for the influence of stem form and damage. This study determined the influence of stem form and damage on growth, survival, and projected future sawlog value among several northern commercial hardwood species. To accomplish this, hardwood trees on 112 permanent plots across three long-term research sites in Maine were assigned stem form and risk classes using a tree classification system developed in New Brunswick. A highly significant influence of stem form and risk on annualized individual-tree diameter increment and survival was found. Inclusion of these equations into a regional growth and yield model highlighted the importance of stem form and defects on long-term simulations as projected stand-level future value was significantly reduced by over 17%, on average (range of 13% to 28%), when compared with projections that did not include that tree-level information. The results highlight the importance of stem form and defects, as well as the need to account for them, in growth and yield applications that assess the forecasted value of commercially important hardwood stands.

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