Logging damage to residual trees is one of the fundamental components in evaluating the sustainability of tropical selective logging in terms of timber production, carbon retention and biodiversity conservation. Although many studies have taken an area-based approach to tropical rain forests, we adopted a tree-based approach to quantify the dependence of residual tree damage on the size of residual and felled trees. We used data from 179 plots, each 25 m x 40 m, covering the stump and crown of one felled tree in Cambodian tropical semi-evergreen forests. We used the mixed-effects multinomial logistic regression model to predict the probability of a residual tree sustaining severe, slight or no damage. Increasing size of residual trees decreased the probability of severe damage and increased that of slight damage. The probability of total damage (severe plus slight) was nearly constant, regardless of the size of residual trees. Increasing size of the felled tree caused greater probability of severe damage, but did not influence the probability of slight damage. Interestingly, our prediction of total damage rate from the tree-based modeling approach of the Cambodian semi-evergreen forests is very consistent with the findings of previous studies using the area-based approach in Indonesia. The departure of our study results from those of other studies may be explained by differences in felled tree size and terrain slope. The inclusion of tree-size dependence in logging damage estimation would increase its accuracy and comparability across different types of tropical forests. (C) 2015 Elsevier B.V. All rights reserved.

Understanding carbon stocks relative to tree species is important for managing tropical forests in a way that will result in the carbon emission reductions and biodiversity conservation required under the REDD+ scheme. Here we analyse inventory data from 179 sample plots in semi- evergreen forests of three provinces in Cambodia. Across all study sites, 5,995 trees with a diameter at breast height (DBH) >= 10 cm, comprising 79 species from 38 families, were analysed. Tree species of the Dipterocarpaceae were most common (10 species), followed by the species of Caesalpinaceae, Combretaceae and Ebenaceae. Analysis of relative carbon stocks (RCS) suggested that Lagerstroemia calyculata Kurz (RCS = 14.3%), Syzygium sp. (6.8%), Shorea vulgaris (5.0%), Irvingia malayana (4.8%), Anisoptera costata Kort (4.6%), Vatica astrotricha (4.2%), and Dehaasia cuneata Blume (3.8%) together accounted for 43.6% of the total average carbon stocks of 99.8 +/- 4.8 MgC ha(-1). We found that carbon stock is highly correlated to basal area (R-2 = 0.993) but not to stem density (R-2 = 0.153). Using carbon stock values, we estimated the carbon emission due to deforestation of semi-evergreen forests to be 8.3 TgCO(2) year(-1) in Cambodia between 2002 and 2010. These emissions and the loss of 79 tree species in our study sites could be avoided if financial incentives were available for protecting semi-evergreen forests in Cambodia. (C) 2015 The Authors. Published by Elsevier B.V.

Information on tree and stand growth is essential to ensure sttstained timber yield in tropical natural forests, but very liule is known about stand dynamics of tropical seasonal forests, especially in the main]and Southeast Asia, Stand dynamics of seasonal evergreen forest in central Cambodia were estimated from 20 sarnple plots measured in 1998 and 2003. Data for all trees with diameter at breast height (DBH) l 10cm arid for commercial species DBH 2 10cm or DBH ). minimum diameter cutting limit (MDCL) were evaluated. In 1998, 67 species, of which 19 were commercial trees with DBH l MDCL, were found at tree densities of 544.5 and 23,4 treeslha, basal areas oE 23,8 and 6.3m21ha, and stem volumes et 192.9 and 64.3m31ha. The mean diameter increment between 1998 and 2003 was O.33 for all species andi O,32cm for cormnercial species; mean mortality rates were 2,4% and O,5%, mean recruitment rates were 2.5% and 1,4% and volume increments were 1.09 and O,86mS!ha, 'lhese values are similar to those reported trom tropical rain forests in Arriazon and Southeast Asia. Estimated velume increment (O.86mSlhalyea!) for commercial trees with DBH ) MDCL was signhicantiy 1arger than the dgure (O,33m:/ha/yeai) previously used in Cambodian management systems, KlaywoniS:

Information on tree and stand growth is essential to ensure sustained timber yield in tropical natural forests, but very little is known about stand dynamics of tropical seasonal forests, especially in the mainland Southeast Asia. Stand dynamics of seasonal evergreen forest in central Cambodia were estimated from 20 sample plots measured in 1998 and 2003. Data for all trees with diameter at breast height (DBH)≧10cm and for commercial species DBH≧10cm or DBH≧minimum diameter cutting limit (MDCL) were evaluated. In 1998, 67 species, of which 19 were commercial trees with DBH≧MDCL, were found at tree densities of 544.5 and 23.4 trees/ha, basal areas of 23.8 and 6.3m^2/ha, and stem volumes of 192.9 and 64.3m^3/ha. The mean diameter increment between 1998 and 2003 was 0.33 for all species and 0.32cm for commercial species; mean mortality rates were 2.4% and 0.5%, mean recruitment rates were 2.5% and 1.4% and volume increments were 1.09 and 0.86m^3/ha. These values are similar to those reported from tropical rain forests in Amazon and Southeast Asia. Estimated volume increment (0.86m^3/ha/year) for commercial trees with DBH≧MDCL was significantly larger than the figure (0.33m^3/ha/year) previously used in Cambodian management systems.

Forest fragmentation results because the spatial scales of resource extraction do not match the scales of natural disturbance that shaped the evolution of the landscape. Tropical deforestation was still proceeding at 14.2 million hectares per annum in the 1990s, and only 5.5% of all forest in developing countries was under formal management plans in the year 2000. The Cambodian tropical forests contain partly continuous tropical forest in the world. However, it has suffered serious deforestation 0.6% annually since the last 30 years because of road- building, logging, mining, mismanagement- decision, and agricultural raising expansion. This paper aims at scaling and forecasting the problem in Cambodian forest concession management to fulfill the gape of sustainable forest management decision. To scale and forecast problems of forest management, we used data from CFC company in Cambodia to compare the modern forest management Montreal criteria. The work responds to the need to assess progress toward sustainable forest management as established by the Montreal Process of Criterion 2 and its Indicators. The focus is on a single criterion ( commonly referred to as indicator 10 to 14) , which addresses the "maintenance of the productive capacity of forest ecosystems" to compare with data of 25- year strategic sustainable forest concession management level. There were 33 sub-indicators of Criterion 2 in Montreal and only 52 %e quivalent to17 sub-indicators were fulfilled. We found that 3 indicators (48%) of management indicators were not in the plan yet. We suggested that growing stock of plantation and non- timber forest products have made the forest management into terrible condition because the forest area in CFC Company was mainly studied only on the timber production. The CFC Company is not alone in facing the challenge of sustainable renewable resource management. The results of this study on assessment of forest concession in Cambodia are applicable for tropical forest management. The assessment was more accurate using a forest concession planning and the Montreal criteria and indicators. Because the sustainable forest management remedies are based on specific knowledge of criteria and indicators, our results may be useful for the future establishment and management of sustainable yields at tropical forests.