Influences of Forest Management Activity on Growth and Diameter Distribution Models for Larix kaempferi Carriere Stands in South Korea

2018 ◽  
Vol 52 (6) ◽  
pp. 37-47 ◽  
Author(s):  
Sun Joo Lee ◽  
Young Jin Lee
Keyword(s):  
Forest Management ◽  
South Korea ◽  
Diameter Distribution ◽  
Larix Kaempferi ◽  
Distribution Models ◽  
Management Activity

scholarly journals Forest Diversity and Modeling Diameter Distribution of the Tropical Dryforest in East Nusa Tenggara, Indonesia

2020 ◽  
Vol 9 (1) ◽  
pp. 21-28
Author(s):  
Aah Ahmad Almulqu ◽  
Keyword(s):  
Forest Management ◽  
Stand Structure ◽  
Likelihood Function ◽  
Dry Forest ◽  
Diameter Distribution ◽  
Structure Model ◽  
Distribution Models ◽  
Forest Diversity ◽  
Product Regulation ◽  
Forest Conditions

The variation of forest conditions shows structural differences, species composition, and potential value as well as stand density. The need and important role of stand structure model in forest management, particularly in forest-based product regulation become the supply demands quantitatively for various forest conditions in Indonesia. The objective of the study was to determine the stand structure model of dry forest. The study was conducted at the dry forest of Binafun, Bonmuti, Letkole and Oelbanu, East Nusa Tenggara Province. Determination of the best stand structure model based on maximum likelihood function of family distribution that tested including the function of exponential, gamma, lognormal and Weibull. A total of 2097 tree individuals, its representing 94 species, 72 genera and 45 families, were found in the research sites. Eucalyptus urophylla were found to be the most dominant species in the research sites and Elattostachys verrucosa have potential to replace Dryobalanops aromatic. Most of family distribution models can describe the stand structure in research sites. The models presented here are the basis for further developments toward the tree diversity for general purpose in tropical dry forest management of East Nusa Tenggara, Indonesia.

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.

Compatible taper and stem volume equations for Larix kaempferi (Japanese larch) species of South Korea

2017 ◽  
Vol 14 (7) ◽  
pp. 1341-1349 ◽  
Author(s):  
Nova D. Doyog ◽  
Young Jin Lee ◽  
Sun Joo Lee ◽  
Jin Taek Kang ◽  
Sung Yong Kim
Keyword(s):  
South Korea ◽  
Japanese Larch ◽  
Stem Volume ◽  
Larix Kaempferi ◽  
Larch Species ◽  
Volume Equations

Performance of Weibull function as a diameter distribution model for Pinus thunbergii stands in the eastern coast of South Korea

2016 ◽  
Vol 13 (5) ◽  
pp. 822-830 ◽  
Author(s):  
Azyleah Cañizares Abino ◽  
Sung Yong Kim ◽  
Roscinto Ian Canicosa Lumbres ◽  
Mi Na Jang ◽  
Ho Joong Youn ◽  
...  
Keyword(s):  
South Korea ◽  
Pinus Thunbergii ◽  
Distribution Model ◽  
Diameter Distribution ◽  
Eastern Coast ◽  
Weibull Function

scholarly journals Towards a Characterization of Working Forest Conservation Easements in Georgia, USA

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 635 ◽  
Author(s):  
Tyler Reeves ◽  
Bin Mei ◽  
Jacek Siry ◽  
Pete Bettinger ◽  
Susana Ferreira
Keyword(s):  
Land Use ◽  
Forest Management ◽  
Forest Conservation ◽  
Natural Habitat ◽  
Bottomland Hardwoods ◽  
Conservation Easements ◽  
Management Activity ◽  
Land Use Types ◽  
Conservation Values ◽  
Food Plots

We examine the attributes of working forest conservation easements in Georgia. Easement contracts and baseline reports are inspected to investigate easement themes, land use types, recreation opportunities, hydrological features, and forest management activity. Easement themes are heavily weighted towards themes of protecting natural habitat and preserving the conservation values of properties. Predominant land use types include wildlife food plots, bottomland hardwoods, and planted pine stands. Common hydrological features found were small creeks/streams and ponds. Lastly, forest management was characterized as having small amounts of restrictions present, with forest management being largely similar to other unencumbered property in the southeastern USA. This information can be used as a reference for landowners interested in establishing a working forest conservation easement (WFCE) on their property as well as a tool for comparison for researchers investigating easement characteristics in other regions.

scholarly journals A New Diameter Distribution Model for Unmanaged Loblolly Pine Plantations in East Texas

2006 ◽  
Vol 30 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Young-Jin Lee ◽  
Dean W. Coble
Keyword(s):  
Loblolly Pine ◽  
Pine Plantations ◽  
Growth And Yield ◽  
Distribution Model ◽  
Diameter Distribution ◽  
Yield Prediction ◽  
East Texas ◽  
Distribution Models ◽  
Parameter Recovery ◽  
Diameter Classes

Abstract A parameter recovery procedure for the Weibull distribution function based on four percentile equations was used to develop a diameter distribution yield prediction model for unmanaged loblolly pine (Pinus taeda L.) plantations in East Texas. This model was compared with the diameter distribution models of Lenhart and Knowe, which have been used in East Texas. All three models were evaluated with independent observed data. The model developed in this study performed better than the other two models in prediction of trees per acre and cubic-foot volume per acre (wood and bark, excluding stump) across diameter classes. Lenhart’s model consistently underestimated the larger-diameter classes because it was developed originally with data mostly collected in young plantations. Knowe’s model overestimated volume in sawtimber-sized trees, which could lead to overestimations of volume in older loblolly pine plantations found in East Texas. An example also is provided to show users how to use this new yield prediction system. These results support the recommendation that forest managers should use growth and yield models designed and/or calibrated for the region in which they are implemented.South. J. Appl.For. 30(1):13–20.

Spatial prediction of diameter distribution models

2002 ◽  
Vol 161 (1-3) ◽  
pp. 147-158 ◽  
Author(s):  
Nikos Nanos ◽  
Gregorio Montero
Keyword(s):  
Spatial Prediction ◽  
Diameter Distribution ◽  
Distribution Models

scholarly journals Diversity of beetles in Gariwangsan Mountain, South Korea: Influence of forest management and sampling efficiency of collecting method

2014 ◽  
Vol 7 (3) ◽  
pp. 319-346 ◽  
Author(s):  
Cheol Min Lee ◽  
Tae-Sung Kwon ◽  
Young Kyu Park ◽  
Sung-Soo Kim ◽  
Joo Han Sung ◽  
...  
Keyword(s):  
Forest Management ◽  
South Korea ◽  
Sampling Efficiency
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