Growth and yield of tropical moist forest for forest planning: an inquiry through modeling

2003 ◽  
Vol 33 (3) ◽  
pp. 521-535 ◽  
Author(s):  
R Glauner ◽  
T Ditzer ◽  
A Huth
Keyword(s):  
Timber Harvesting ◽  
Forest Growth ◽  
Growth And Yield ◽  
Forest Reserve ◽  
Dipterocarp Forest ◽  
Management Standards ◽  
Moist Forest ◽  
Undisturbed Forest ◽  
Lowland Dipterocarp Forest ◽  
Diameter Outside Bark

For the forest growth and yield calculations presented here, the process-based model FORMIX was applied in combination with a geographic information system. The study was carried out for the 55 084 ha of the Deramakot Forest Reserve, which consists of heavily logged and degraded lowland dipterocarp forest. FORMIX was used to assess forest development with and without timber harvesting. Three scenarios were compared: undisturbed forest growth and two reduced-impact timber harvesting scenarios ("textbook" and "borderline"). The latter differ in the number of seed trees retained after harvesting. The simulations reveal that timber harvesting is feasible, although stands are presently degraded. Achievable harvesting levels differ widely from 200 to 10 000 m3·year–1 for the next 40 years for the textbook and borderline scenario, respectively. A future increase up to 80 000 m3·year–1 is possible if all silvicultural and management standards are strictly observed. An analysis of stand development reveals that the portion of commercial dipterocarps decreases with time, while the portion of pioneer and understorey species increases. Future stands do not contain as many trees >60 cm DBH (diameter outside bark at 1.3 m height above ground), whereas they contain more trees in lower diameter classes, ensuring adequate potential for future harvests.

Regeneration of a Clear-Cut Plot in a Lowland Dipterocarp Forest in Pasoh Forest Reserve, Peninsular Malaysia

Pasoh ◽  
2003 ◽  
pp. 559-568 ◽  
Author(s):  
Kaoru Niiyama ◽  
Abdul Rahman Kassim ◽  
Shigeo Iida ◽  
Katsuhiko Kimura ◽  
Azizi Ripin ◽  
...  
Keyword(s):  
Peninsular Malaysia ◽  
Forest Reserve ◽  
Dipterocarp Forest ◽  
Clear Cut ◽  
Lowland Dipterocarp Forest ◽  
Pasoh Forest Reserve

Recruitment, growth and mortality of tree species in a lowland dipterocarp forest in Peninsular Malaysia

1987 ◽  
Vol 3 (4) ◽  
pp. 315-330 ◽  
Author(s):  
N. Manokaran ◽  
K. M. Kochummen
Keyword(s):  
Basal Area ◽  
Mortality Rates ◽  
Peninsular Malaysia ◽  
Recruitment Rate ◽  
Size Class ◽  
Tree Density ◽  
Pioneer Species ◽  
Forest Reserve ◽  
Dipterocarp Forest ◽  
Lowland Dipterocarp Forest

ABSTRACTChanges in the lowland dipterocarp forest structure and composition are described for a 34-year period between 1947 and 1981 in Sungei Menyala Forest Reserve, Peninsular Malaysia. Although tree density declined by about 10%, basal area changed little, averaging 32.4 m2 ha−1. Size class distributions in 1947 and 1981 were not significantly different. Mortality rates were independent of size class. Mortality exceeded recruitment during the first 16 years to 1963, but was thereafter almost exactly balanced by recruitment. Recruitment rate increased significantly for the latter part of the study.Mortality was greater than average for understorey species and lower for emergents. Pioneer and late seral species together showed significantly higher mortality rates. Amongst the commoner species, emergent, late-seral and pioneer species showed the highest annual diameter growth rates with species averages over all size classes exceeding 3 mm yr−1; rates for main-canopy species were between 1.5 and 2.5 mm yr−1, and understorey species generally less than 2 mm yr−1.Species richness was almost identical in 1947 and 1981 (243, 244 species), but a clear decline (to 229 species) between 1953 and 1971 was recovered by 1981. Most species showed little net change in density over the 34-year period, but eight of the 32 commoner species showed significant changes, all unidirectional. These changes in species composition are not negligible, but further analysis is needed to determine if, for example, they are related to disturbance of part of the plot in 1917.

Optimization of irregular-grid cellular automata and application in risk management of wind damage in forest planning

2010 ◽  
Vol 40 (6) ◽  
pp. 1064-1075 ◽  
Author(s):  
Hongcheng Zeng ◽  
Timo Pukkala ◽  
Heli Peltola ◽  
Seppo Kellomäki
Keyword(s):  
Cellular Automata ◽  
Damage Model ◽  
Timber Harvesting ◽  
Forest Growth ◽  
Wind Damage ◽  
Growth And Yield ◽  
Planning Problem ◽  
Risk Minimization ◽  
Yield Model ◽  
Forest Management Planning

This study demonstrated how cellular automata, using irregular grids, can be used to minimize the risk of wind damage in forest management planning. The development of a forest in central Finland was simulated for a 30-year period with three subplanning periods. A forest growth and yield model in association with a mechanistic wind damage model was applied to simulate forest growth and to calculate the length of stand edges at risk. Irregular cellular automata were utilized to optimize the harvest schedules for reducing the risk and maintaining a sustainable harvest level. The cellular automata produced rational results, i.e., new clearcuts were often placed next to open gaps, thereby, reducing the amount of vulnerable stand edges. The algorithms of the cellular automata rapidly converged and optimized the harvest schedules in an efficient way, especially when risk minimization was the only objective. In a planning problem that included even-flow timber harvesting objectives (harvest level equal to the total timber growth), the targets were almost achieved. Although the cellular automaton had slightly larger deviations of harvesting from the targets compared with other tested heuristic approaches (simulated annealing, tabu search, and genetic algorithms), it had the best performance when minimizing the expected wind damage.

Decay classes of coarse woody debris in a lowland Dipterocarp forest: implications for volume, density, and carbon estimates

Biotropica ◽  
2021 ◽  
Author(s):  
Ekaterina Shorohova ◽  
Ekaterina Kapitsa ◽  
Andrey Kuznetsov ◽  
Svetlana Kuznetsova ◽  
Valentin Lopes de Gerenuy ◽  
...  
Keyword(s):  
Coarse Woody Debris ◽  
Woody Debris ◽  
Volume Density ◽  
Dipterocarp Forest ◽  
Lowland Dipterocarp Forest

A Blind Spot in the Use of the Weibull Function for Modeling Diameter Distributions

2020 ◽  
Author(s):  
Adrian Norman Goodwin
Keyword(s):  
Lower Bound ◽  
Blind Spot ◽  
Forest Growth ◽  
Growth And Yield ◽  
Diameter Distribution ◽  
Absolute Difference ◽  
Weibull Function ◽  
Distribution Models ◽  
Difference Statistic ◽  
Diameter Distributions

Abstract Diameter distribution models based on probability density functions are integral to many forest growth and yield systems, where they are used to estimate product volumes within diameter classes. The three-parameter Weibull function with a constrained nonnegative lower bound is commonly used because of its flexibility and ease of fitting. This study compared Weibull and reverse Weibull functions with and without a lower bound constraint and left-hand truncation, across three large unthinned plantation cohorts in which 81% of plots had negatively skewed diameter distributions. Near-optimal lower bounds for the unconstrained Weibull function were negative for negatively skewed data, and the left-truncated Weibull using these bounds was 14.2% more accurate than the constrained Weibull, based on the Kolmogorov-Smirnov statistic. The truncated reverse Weibull fit dominant tree distributions 23.7% more accurately than the constrained Weibull, based on a mean absolute difference statistic. This work indicates that a blind spot may have developed in plantation growth modeling systems deploying constrained Weibull functions, and that left-truncation of unconstrained functions could substantially improve model accuracy for negatively skewed distributions.

scholarly journals Mixed Regional Shifts in Conifer Productivity under 21st-Century Climate Projections in Canada’s Northeastern Boreal Forest

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 248
Author(s):  
Tyler Searls ◽  
James Steenberg ◽  
Xinbiao Zhu ◽  
Charles P.-A. Bourque ◽  
Fan-Rui Meng
Keyword(s):  
Climate Change ◽  
Model Validation ◽  
21St Century ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Acer Rubrum ◽  
Forest Growth ◽  
Balsam Fir ◽  
Growth And Yield ◽  
Climate Projections

Models of forest growth and yield (G&Y) are a key component in long-term strategic forest management plans. Models leveraging the industry-standard “empirical” approach to G&Y are frequently underpinned by an assumption of historical consistency in climatic growing conditions. This assumption is problematic as forest managers look to obtain reliable growth predictions under the changing climate of the 21st century. Consequently, there is a pressing need for G&Y modelling approaches that can be more robustly applied under the influence of climate change. In this study we utilized an established forest gap model (JABOWA-3) to simulate G&Y between 2020 and 2100 under Representative Concentration Pathways (RCP) 2.6, 4.5, and 8.5 in the Canadian province of Newfoundland and Labrador (NL). Simulations were completed using the province’s permanent sample plot data and surface-fitted climatic datasets. Through model validation, we found simulated basal area (BA) aligned with observed BA for the major conifer species components of NL’s forests, including black spruce [Picea mariana (Mill.) Britton et al.] and balsam fir [Abies balsamea (L.) Mill]. Model validation was not as robust for the less abundant species components of NL (e.g., Acer rubrum L. 1753, Populus tremuloides Michx., and Picea glauca (Moench) Voss). Our simulations generally indicate that projected climatic changes may modestly increase black spruce and balsam fir productivity in the more northerly growing environments within NL. In contrast, we found productivity of these same species to only be maintained, and in some instances even decline, toward NL’s southerly extents. These generalizations are moderated by species, RCP, and geographic parameters. Growth modifiers were also prepared to render empirical G&Y projections more robust for use under periods of climate change.

The consequences of selective logging for Bornean lowland forest birds

1992 ◽  
Vol 335 (1275) ◽  
pp. 443-457 ◽  
Keyword(s):  
Population Dynamics ◽  
Bird Species ◽  
Selective Logging ◽  
Forest Birds ◽  
Primary Forest ◽  
Bird Conservation ◽  
Lowland Forest ◽  
Dipterocarp Forest ◽  
Logged Forest ◽  
Lowland Dipterocarp Forest

In lowland dipterocarp forest in Sabah, Malaysia, most primary forest bird species were present in areas selectively logged eight years previously. However, certain taxa, notably flycatchers, woodpeckers, trogons and wren-babblers, became comparatively rare. In contrast, nectarivorous and opportunistic frugivorous species were significantly more abundant. Few species appeared to change foraging height, but netting rates suggest that the activity of some species had increased, or that some birds ranged over larger areas after logging. Although there is still much to be learned about the survival of birds in logged forest, large areas of this habitat are important for bird conservation. However, the susceptibility of logged forest to fire, and our present incomplete understanding of bird behaviour and population dynamics in logged forests mean that they should not be considered by conservationists as alternatives to reserves of primary forest.

Ontario's forest growth and yield modelling program: Advances resulting from the Forestry Research Partnership

2008 ◽  
Vol 84 (5) ◽  
pp. 694-703 ◽  
Author(s):  
Mahadev Sharma ◽  
John Parton ◽  
Murray Woods ◽  
Peter Newton ◽  
Margaret Penner ◽  
...  
Keyword(s):  
Tree Species ◽  
Stand Density ◽  
Forest Growth ◽  
Growth And Yield ◽  
Research Partnership ◽  
Wood Supply ◽  
Permanent Sample Plots ◽  
Forestry Research ◽  
Research Activities ◽  
Forest Growth And Yield

The province of Ontario holds approximately 70.2 million hectares of forests: about 17% of Canada’s and 2% of the world’s forests. Approximately 21 million hectares are managed as commercial forests, with an annual harvest in the early part of the decade approaching 200 000 ha. Yield tables developed by Walter Plonski in the 1950s provide the basis for most wood supply calculations and growth projections in Ontario. However, due to changes in legislation, policy, and the planning process, they no longer fully meet the needs of resource managers. Furthermore, Plonski`s tables are not appropriate for the range of silvicultural options now practised in Ontario. In October 1999, the Canadian Ecology Centre- Forestry Research Partnership (CEC-FRP) was formed and initiated a series of projects that collectively aimed at characterizing, quantifying and ultimately increasing the economically available wood supply. Comprehensive, defensible, and reliable forecasts of forest growth and yield were identified as key knowledge gaps. The CEC-FRP, with support from the broader science community and forest industry, initiated several new research activities to address these needs, the results of which are outlined briefly in this paper. We describe new stand level models (e.g., benchmark yield curves, FVS Ontario, stand density management diagrams) that were developed using data collected from permanent sample plots and permanent growth plots established and remeasured during the past 5 decades. Similarly, we discuss new height–diameter equations developed for 8 major commercial tree species that specifically account for stand density. As well, we introduce a CEC-FRP-supported project aimed at developing new taper equations for plantation grown jack pine and black spruce trees established at varying densities. Furthermore, we provide an overview of various projects undertaken to explore measures of site productivity. Available growth intercept and site index equations are being evaluated and new equations are being developed for major commercial tree species as needed. We illustrate how these efforts are advancing Ontario’s growth and yield program and supporting the CEC-FRP in achieving its objective of increasing the supply of fibre by 10% in 10 years while maintaining forest sustainability. Key words: permanent sample plots (PSPs), permanent growth plots (PGPs), normal yield tables, sustainable forest management, NEBIE plot network, forest inventory, Forest Vegetation Simulator

scholarly journals Habitat use by a primate community in a lowland dipterocarp forest in Danum Valley, Borneo

2020 ◽  
Vol 82 (8) ◽  
Author(s):  
Goro Hanya ◽  
Tomoko Kanamori ◽  
Noko Kuze ◽  
Siew Te Wong ◽  
Henry Bernard
Keyword(s):  
Habitat Use ◽  
Dipterocarp Forest ◽  
Lowland Dipterocarp Forest ◽  
Primate Community

scholarly journals How random are predictions of forest growth? The importance of weather variability

2020 ◽  
Author(s):  
Joanna Horemans ◽  
Olga Vindušková ◽  
Gaby Deckmyn
Keyword(s):  
Climate Change ◽  
Uncertainty Analysis ◽  
Climate Models ◽  
Global Climate ◽  
Basal Area ◽  
Random Order ◽  
Forest Growth ◽  
Global Climate Models ◽  
Growth And Yield ◽  
Weather Variability

Quantifying the output uncertainty and tracking down its origins is key to interpreting the results of model studies. We perform such an uncertainty analysis on the predictions of forest growth and yield under climate change. We specifically focus on the effect of the inter-annual climate variability. For that, the climate years in the model input (daily resolution) were randomly shuffled within each 5-year period. In total, 540 simulations (10 parameter sets, 9 climate shuffles, 3 global climate models and 2 mitigation scenarios), were made for one growing cycle (80 years) of a Scots pine forest growing in Peitz (Germany). Our results show that, besides the important effect of the parameter set, the random order of climate years can significantly change results such as basal area and produced volume, and the response of these to climate change. We stress that the effect of weather variability should be included in the design of impact model ensembles, and the accompanying uncertainty analysis. We further suggest presenting model results as likelihoods to allow risk assessment. For example, in our study the likelihood of a decrease in basal area of >10% with no mitigation was 20.4%, while the likelihood of an increase >10% was 34.4%.

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