Long-term dynamics of fire-affected pine-dipterocarp forest in Northern Thailand

Introduction: Tree ferns are significant components of temperate, tropical and subtropical forests, contributing to shape complex forest stand structures. Objectives: 1) to describe the population structure of Cyathea costaricensis in a remnant cloud forest of West-central Mexico; 2) to characterize and relate the floristic composition and the structure of the most important tree species associated to the C. costaricensis population and; 3) to describe the environment where C. costaricensis occurs. Methods: We estimated the Importance Value Index (IVI) to select the most important canopy-dominant species associated to C. costaricensis; we constructed height and Diameter at Breast Height (DBH) frequency distributions for those selected species according to IVI as well as for C. costaricensis population; we computed the asymmetry of the frequency distributions through the coefficient of skewness and the probability density function via the Kernel density estimation. We tested for differences between canopy-dominant tree species and C. costaricensis population structure by the non-parametric Wilcoxon rank sum test. Results: C. costaricensis individuals presented the smallest heights and intermediate DBH sizes as compared with the canopy-dominant species, with statistically significant differences for height but not for DBH according to the Wilcoxon test. Most of the tree fern individuals were located in uneven terrains and over the base slope of the terrain; canopy openness and Total Radiation Under the Canopy values were similar to those reported for Cyathea species elsewhere. Conclusions: We confirm the hypothesis of comparable structure between the canopy-dominant species and the C. costaricensis population only for DBH; on the contrary, for trunk height, there were statistically significant differences; the small heights of C. costaricensis suggest their coexistence in the understory through sheltering from the taller canopy-dominants. Mostly all individuals of C. costaricensis were confined to local environmental conditions, particularly to physiography.

Climate change has become a prominent topic, particularly regarding plant adaptation and migration within mountain ecosystems. This study aimed to clarify forest dynamics by focusing on sapling and tree stages in relation to microclimate changes across a permanent plot along an altitudinal gradient. In 2012, a permanent transect plot (50 m × 600 m) was established at the forest ecotone between the deciduous dipterocarp forest (DDF) and lower montane forest (LMF). All trees with a diameter at breast height ≥ 1 cm were tagged, measured, and identified. Monitoring occurred every 2 years between 2012, 2014, 2016, and 2018, with a final census conducted in 2023. Microclimatic factors were recorded automatically, and rainfall data were obtained from a meteorological station. The dynamics of all trees were analyzed in relation to micro-climate changes. Our results showed that environmental changes significantly affected species coexistence, particularly in the forest ecotone between the DDF and LMF, where intermediate environmental factors were observed. High mortality rates were observed in the dominant evergreen species, with significant positive correlations with decreased rainfall and increased temperature, suggesting that drought conditions strongly influence tree mortality. In contrast, the deciduous species showed increased density, particularly in the forest ecotone zone, indicating their better adaptation to drought conditions and their potential to occupy the forest ecotone at a higher rate than LMF species. Understanding the ecological niches of coexisting species along altitudinal gradients is crucial for developing effective restoration programs in mountainous ecosystems.

High stocks of coarse woody debris in a tropical rainforest, East Kalimantan: Coupled impact of forest fires and selective logging

Fruits are a major food resource for wildlifes and have evolved different traits which attract specific frugivores and facilitate seed dispersal. This study examines the quantity of the frequency of fruit tree species, distribution amongst fruit traits and estimates the potential availability of the fruit resource for frugivores in a 16-ha permanent forest plot at Doi Suthep–Pui, Thailand. The similarity amongst traits for fleshy fruited species was explored using Principal Component Analysis (PCA). Fleshy fruited species comprised 122 of 208 tree species >2 cm diameter at breast height (DBH) recorded in the permanent plot. Amongst fleshy fruited species, small fruits (length <20 mm) were most common (63.16% of species) while large fruits were rare (4.1%). Black was the most common fruit colour (43.4%). Principal Component Analysis of fruit traits explained 57% of total variance on the first three axes, and allowed identification of three species groups. Litsea martabanica and Persea gamblei are the greatest density and represented the major PCA group; black, small-sized and thin husk indehiscent fruits. These fruiting trees scattered throughout the permanent plot and were of good regeneration status. Indicating fleshy fruit can be a food resource for frugivores especially small-sized fruit. Furthermore, large-fruited species such as Madhuca floribunda is low density but important to preserve for food resource of large frugivores. This finding is very important not only for forest protection policy but also for wildlife conservation as food resources.

Abstract. Thinkampheang S, Nakashizuka T, Suksavate W, Kachina P, Hermhuk S, Asanok L, Phumphuang W, Chouibumroong B, Wu J, Kurokawa H, Marod D. 2024. Impacts of climate change on forest restoration dynamics in the lower montane forest of Doi Suthep-Pui National Park, Northern Thailand. Biodiversitas 25: 4829-4845. Lower montane forest ecosystems are rich in biodiversity but prone to anthropogenic and natural disturbances. Forest restoration aims to emulate natural succession, particularly concerning tree species composition. In this study, we investigated the effects of different forest restoration practices on tree regeneration and the impact of climate change on forest dynamics following restoration in a natural lower montane forest. Three forest dynamics plots (100 m × 100 m) were established in the forest, and two artificial forest restoration approaches were simulated based on mono-species and multi-species plantations, respectively. All trees with a diameter at breast height > 2 cm were tagged, measured, identified, and monitored every 2 years from 2011 to 2021. Forest dynamics, including mortality and recruitment rates, were analyzed in relation to climate change. The results show that recovery varied among restoration practices. The mono-species plantation had the highest species diversity (114 species), followed by the natural forest and multi-species plantation. The mean mortality rate was higher than the net mean recruitment rate in mono-species and multi-species plantations, with significant variation in forest dynamics across species and periods. These fluctuations were closely linked to environmental changes, particularly droughts related to El Niño. Environmental factors exert a substantial influence on forest structure and species composition. In particular, the interplay between forest dynamics and ecological changes underscores the susceptibility of certain species to drought. Our findings imply that multi-species planting, with its potential to mirror the natural climax state of a forest closely, is a highly effective forest restoration strategy that can inspire and motivate further research and action in this field.

Long-term studies of the dynamics of managed forests in tropical regions are lacking. This study aimed to evaluate the dynamics of a tropical forest, over a 25-year period, that was experimentally logged in 1987 and 1988 and submitted to three different cutting intensities. All trees with diameter at breast height (DBH) ≥ 10 cm have been measured annually since 1990. The three logging intensities that were applied were: light (T1)-trees harvested with DBH ≥ 55 cm; medium (T2)-DBH ≥ 50 cm; and heavy (T3)-DBH ≥ 40 cm. Control plots (T0) were also monitored. The highest mean annual mortality rates (1.82% ± 0.38), recruitment rates (2.93% ± 0.77) and diameter increments (0.30 ± 0.02 cm) occurred in the T3 treatment. Shifts in dynamics of the forest were mainly caused by a striking increase in a fast-growing pioneer species and their high mortality rates. The loss in stocking caused by mortality was greater than to that of replacement by recruitment. The results demonstrated that selective logging altered the natural dynamics of the forest through increased: mortality rates, recruitment and growth rates of the residual trees.

Background and AimsEpiphytes are an important component of tropical forests, also they are sensitive to disturbance and deforestation caused by humans, since they depend on their host trees and the micro environmental conditions that these provide. The aim of this study was to analyze the differences in species richness, composition, and vertical distribution of epiphytic angiosperms between areas with natural and disturbed forest at the Northern Coast of Jalisco state, Mexico.MethodsThe presence/absence of epiphytic angiosperms was evaluated in each vertical zone of a selected tree, as well as those present in the understory, both in natural and disturbed sites in three types of vegetation (gallery forest, oak forest, tropical semideciduous forest) with a total of 30 plots of 20 m × 20 m in six sites. Alpha diversity was calculated for each site, as well as species turnover (beta diversity) between habitats. An analysis of variance was performed to determine if there was a significant difference in species richness between sites and, also to compare the height and diameter at breast height (DBH) of the host trees. Multivariate analyzes were used to group the sites according to their floristic composition. Furthermore, a linear regression was performed to detect any relationship between the number of species and the phorophyte structure.ResultsWe recorded 45 species, 29 genera and nine families of epiphytic angiosperms. The most diverse families were Bromeliaceae and Orchidaceae and the richest genus was Tillandsia. Although the disturbed sites had more species, a significant difference in richness was not found, except for the disturbed gallery forest. Epiphytic angiosperms presented a high beta diversity, since the sites shared only between 2 and 18% of the recorded species. The inner portion of the canopy (Z3 and Z4) hosted most of the species in all sites and the understory had a high representation of epiphytes except for the disturbed oak forest, where these were absent. A relationship between the DBH and the number of species was found only at the disturbed sites, however, it was highly influenced by the high number of taxa registered in disturbed gallery forest. Therefore, the size of the trees could not be considered a factor in determining the diversity of epiphyte species.ConclusionThe diversity of epiphytic angiosperm species from the North Coast of Jalisco has not been severely affected by the human disturbance. Most of the species have morphological and physiological adaptations that allow their establishment and survival in adverse climatic conditions. Our results suggest that epiphytic angiosperms cannot be considered as a good indicator for natural or disturbed environments in this region but should be considered in environmental conservation, as they present a high beta diversity.

Background and Purpose: Romania’s forests are of globally significant value due to their natural characteristics, as similar forests in some other parts of the world have been lost forever. These types of forests, so-called "virgin" and "quasi-virgin (old growth)" forests, are also identified in the Buzau Mountains, which are part of the Eastern Carpathians in Romania (Curvature Region). Materials and Methods: To study and understand the structure and dynamics of primeval forest, four permanent one-hectare research plots were installed in the Penteleu Mountains, part of the Buzau Mountains. All trees with a diameter at breast height (DBH) greater than 80 mm were measured and their main dendrometric characteristics (DBH, height and social position) registered. The forest structure was analysed by fitting different theoretical distribution functions (beta, gamma, gamma 3P, gamma 3P mixt, loglogistic 3p, lognormal 3P and Weibull 3p). The structural homogeneity of the permanent research plots was tested using the Camino index (H) and Gini index (G). Results: For the smaller DBH categories, Norway spruce was relatively shorter in height, but with increasing DBH, the heights of Norway spruce exceeded those of European beech. Stand volume varied between 615 and 1133 m3 per hectare. The area of maximum stability where we encountered the lowest tree height variability was recorded between the 60 cm and 100 cm diameter categories. The Lorenz curve and the Gini index indicated that the studied stands have high structural biodiversity. Conclusions: The results showed that the studied forests have an optimal structural diversity, assuring them a higher stability and multifunctionality. Thus, these forests are models for managed forests.

Spatial patterns of species at different life stages are an important aspect for understanding causal mechanisms that facilitate species co-existence. Using Ripley's univariate L(t) and bivariate L(12)(t) functions, we analyzed the spatial patterns and interspecific associations of three canopy species at different life history stages in a 20-ha subtropical forest plot in Dinghushan Nature Reserve. Based on diameter at breast height (DBH), four life stages were distinguished. Castanopsis chinensis and Schima superba showed a unimodal DBH distribution. Engelhardtia roxburghiana showed a bimodal curve. L(t) function analysis showed significantly aggregated distributions of all three species at later life stages and random distribution at early life stages at some scales. From the analysis of L(12)(t) function, the results showed the positive association was a dominant pattern for most species pairs at most scales but the intensity of association decreases with the increase of life stages. Juveniles of the three species had no negative intra- and interspecific associations with the older life stages. Only premature trees were suppressed by overmature trees at some scales. Considering these results, we found three canopy-dominant species that lacked regeneration. There was no direct competition occurring between understorey individuals. Young trees can grow well under conspecific species with two other species. Longevity and lack of regeneration led to a large number of trees stored in mature and overmature stages, therefore, intra- and inter-competition can be strong at later life stages.

PDF HTML阅读 XML下载 导出引用 引用提醒 天然次生林蒙古栎种群空间格局 DOI: 10.5846/stxb201707101243 作者: 作者单位: 中国林业科学研究院资源信息研究所,中国林业科学研究院资源信息研究所,中国林业科学研究院资源信息研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家"十三五"重点研发计划项目（2017YFC0504101） Spatial pattern of Quercus mongolica in natural secondary forest Author: Affiliation: Research Institute of Forest Resources Information Techniques,Chinese Academy of Forestry,Research Institute of Forest Resources Information Techniques,Chinese Academy of Forestry,Research Institute of Forest Resources Information Techniques,Chinese Academy of Forestry Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以蒙古栎天然次生林中的蒙古栎（Quercus mongolica）种群为研究对象，在吉林省汪清林业局塔子沟林场设置了2块1hm2群落组成和结构存在差异的样地（样地A、样地B）。采用相邻网格调查法将每块样地划分为100个10m×10m的调查单元，精确定位单元内每株林木的空间坐标（X，Y），调查所有胸径（DBH）≥1cm的林木基本信息。采用径阶替代年龄的方法，将蒙古栎划分为4个不同的生长阶段：Ⅰ龄级（1cm≤DBH < 10cm），Ⅱ龄级（10cm≤DBH < 20cm），Ⅲ龄级（20cm≤DBH < 30cm），Ⅳ龄级（DBH≥30cm）。运用单变量、双变量成对相关函数、标记相关函数、标记变异函数，分析了不同群落中蒙古栎种群在不同空间尺度上的分布格局。结果显示：（1）两块样地中蒙古栎在大尺度上均呈随机分布，聚集分布主要集中在中小尺度，这主要是由Ⅰ、Ⅱ龄级的蒙古栎在中小尺度上的强度聚集所致，两块样地均未出现均匀分布的格局；样地A中蒙古栎聚集的尺度和强度均明显大于样地B中蒙古栎的聚集；（2）样地A中Ⅰ、Ⅱ、Ⅲ龄级的蒙古栎之间在中小尺度上呈正关联，高龄级与低龄级之间则呈负关联，尤其是Ⅳ龄级与Ⅰ、Ⅱ龄级之间；而样地B中几乎未出现负关联的格局，各龄级之间以无关联为主，伴随以小尺度和低强度的正关联；（3）样地A中蒙古栎的空间自相关性较强，尤其体现在林木胸径方面；相比之下，样地B中胸径和树高的空间自相关得以减弱。上述结果表明，研究的空间尺度大小、物种的生长阶段、群落的发育程度均会给蒙古栎种群的空间分布格局造成影响。该研究有助于深入了解蒙古栎及蒙古栎次生林的现状、生长特性和发展趋势，可为东北林区大面积的蒙古栎天然次生林的可持续经营提供参考。 Abstract:Spatial signatures often reveal ecological processes, and spatial pattern analysis is an important method for studying population characteristics, interspecies relationships, and the relationships between population and the environment. Due to the distinctive characteristics and the current situation of Quercus mongolica in China, it is necessary to investigate the ecological processes in Q. mongolica stands. To realize the status and development tendency of the Q. mongolica population in the Q. mongolica natural secondary forest, its spatial patterns were studied based on two permanent sample plots(plot A and plot B) with different compositions and structures(i.e.,different coenotypes) over an area of 1hm2(100m×100m) in Tazigou Forest Farm of Wangqing Forestry Bureau, Jilin province. The essential features, which include species identity, diameter at breast height(DBH), tree height, clear bole height, crown breadth, and coordinate information of each tree(DBH ≥ 1), of the two plots were surveyed by the adjacent grid method(10m×10m). Using the method of diameter class(instead of the age), Q. mongolica was divided into four different growth stages:stage I(1cm ≤ DBH < 10cm), stage Ⅱ(10cm ≤ DBH < 20cm), stage Ⅲ(20cm ≤ DBH < 30cm), stage IV(DBH ≥ 30cm). In accordance with the spatial point pattern theory, univariate pair-correlation function g1(r), bivariate pair-correlation function g12(r), mark correlation function kmm(r), and mark variogram function γ(r) were adopted to evaluate the spatial patterns of Q. mongolica in different communities at various scales. The results showed that(1) All Q. mongolica populations in the two plots showed random spatial distribution at large scales, and the aggregated distribution was mainly concentrated at medium and small scales. The aggregated distribution at stages I and Ⅱ at medium and small scales was the primary cause for the above phenomenon. Uniform distribution was not observed in the two plots at all scales. The aggregated distribution of Q. mongolica in plot A is stronger than that in plot B.(2) The spatial associations of Q. mongolica among the stages I, Ⅱ, and Ⅲ in plot A are positive at medium and small scales. The spatial associations between older age and younger age classes were negative, especially between the stages IV, I, and Ⅱ. In plot B, however, negative spatial association was scarcely observed at all scales. The relationships between different stages were mostly uncorrelated with positive spatial association at small scale and low intensity.(3) The spatial autocorrelation of plot A is stronger than that of plot B, and the conspicuous expression mainly appears at DBH. The spatial autocorrelation of plot B for DBH and height is weakened to some extent compared to that of plot A. These results demonstrated that the spatial patterns of Q. mongolica are affected by the space scale of the sample plot, the growth stage of species, and the developmental stage of the community. This helps us to understand the current situation, growth characteristics, and developmental tendency of Q. mongolica population and its natural secondary forest, and can provide an important reference for sustainable forest management and ecosystem conservation in the Q. mongolica natural secondary forest area of northeast China. 参考文献 相似文献 引证文献

The study aimed to evaluate the annual variation in fruits and seed productivity of Brazil nut trees and to determine the association between diameter structure and fruit/seed productivity in a semi-deciduous seasonal forest undergoing logging in Mato Grosso, Brazil. Data were collected in two permanent plots (300 m x 300 m) spaced 3.5 km apart. All trees ( n = 279) with diameter at breast height (DBH) ≥ 10 cm were tagged and productivity was monitored from October to February during each of the five harvest seasons between 2012 and 2017. Associations between seed dry weight (SDW) per tree and DBH, crown position, crown shape and fruit number were established using stepwise regression analysis. The model based on DBH was a good predictor of seed production and revealed that SDW tree -1 increased by 1.3 kg on average for every 10 cm increase in DBH. Trees reached the reproductive phase with DBH < 50 cm. Characteristics and mean SDW values of the diameter classes were: 10 cm ≤ DBH < 30 cm - dominated/suppressed trees/malformed crowns (0.12 kg tree -1 year -1 ); 30 cm ≤ DBH < 70 cm - dominant/co-dominant/good crown shape (1.23 kg tree -1 year -1 ); DBH ≥ 70 cm - dominant/co-dominant/well-formed crowns (4.8 kg tree -1 year -1 ). DBH explained 34% of the variation in the mean SDW. Our results are important for the sustainable management of the study stands, allowing the assessment of current and future yields of Brazil nuts for the purpose of improving the economy of forest-dependent communities and associated enterprises.

Abstract. Marod D, Sungkaew S, Thinkampaeng S, Wachrinrat C, Hermhuk S, Thongsawi J, Phumphuang W, Yarnvudhi A, Yatar C, Cheysawat S, Sawasmongkol C. 2024. Natural tree regeneration after selective cutting in a dry evergreen forest in Northeastern Thailand. Biodiversitas 25: 4074-4085. Forest degradation is a serious problem caused by anthropogenic disturbance, nevertheless, forest recovery rates vary among forest ecosystems. We investigated forest regeneration after selective cutting in a dry evergreen forest at the Wang Nam Khiao Forestry Research and Training Station (WFRS), Nakhon Ratchasima Province, Thailand. In 2002, a 1-ha permanent plot was established in the forest. All woody plant (sapling and trees) in the plot with Diameter at Breast Height (DBH) &gt;2 cm were identified, and their DBHs and positions were recorded. Data on environmental and topographic factors and soil properties were collected to analyze their relationships with tree spatial distribution. Tree monitoring was conducted in 2004, 2018, and 2020 and forest dynamics were analyzed for the periods 2002-2004, 2004-2018, and 2018-2020. In 2020, we identified 3,669 trees of 91 species, 81 genera, and 36 families. Based on importance index values, the dominant tree species (all with DBH ?4.5 cm) were Walsura pinnata Hassk., Dialium cochinchinense Pierre, Hopea ferrea Laness., Hydnocarpus ilicifolius King and Vitex scabra Wall. ex Schauer. Based on the DBH class distribution, the natural regeneration of all woody plants tended toward a reverse J-shaped, indicating a good regeneration condition. The results of forest dynamics analysis showed that the net recruitment rate (2.75±1.70% year-1) was higher than the mortality rate (2.14±0.73% year-1) throughout the study period. Tree spatial distributions varied among species and across environmental factors which were strongly influenced by soil texture followed by topographic and can be divided into generalist and specialist species. This indicates that the forest is going toward a positive regeneration trajectory after the disturbances. Nonetheless, additional information based on forest monitoring is required. Additionally, an understanding of the relationships between species niches and environmental changes is important for tree regeneration research and forest restoration programs; it will allow better matching of tree species to their optimal environmental conditions, thereby increasing the likelihood of plant community success.

In order to supply biomass energy in Thailand, fast-growing trees like Eucalyptus and Acacia are large plantations in the region. However, there are few studies on related topics such as biomass growth versus time and tree partitioning. The objectives of the study are to develop biomass equations and characterize biomass dynamics accumulation for E. camaldulensis , E. camaldulensis coppice, and A . hybrid. The study plantation area is 960 hectares in Lampang and Lamphun province, Northern Thailand. The planted density is 1666 trees ha -1 . A total of 221 trees for destructive sampling were randomly selected from thirteen sites. Allometric biomass equations for tree components are developed by regressing the diameter at breast height (DBH), tree height (H) and a combination of these. The results show that DBH alone is an optimal predictor variable for all studied species. However, the combination of DBH and H is more accurate than DBH alone. The models show that the total estimated above-ground biomass (AGB) production is 62.78 t ha -1 and 48.87 t ha -1 at the age of 5 years of E. camaldulensis and A . hybrid, respectively. The total estimated AGB production of E. camaldulensis coppice is 18.21 t ha -1 at 3 years of age. The equations developed in the study can be used to estimate the growth of the three species under the same growing conditions: topography, tree growth dimensions, and plantation density.

Aims Our objective was to elucidate the trajectory and pattern of tree succession on lands abandoned after mul-tiple cycles of shifting cultivation in comparison to old-growth communities.Methods We established seven 100 m × 100 m plots in lowland sites.There were two old-growth forest plots,one 12-year-old fallow plot,two 25-year-old fallow plots,and two 55-year-old fallow plots.We recorded species,diameter at breast height(DBH),and height of all woody stems(excluding lianas) ≥1 cm DBH in 100 subplots(10 m × 10 m) in each plot.Analysis methods included non-metric multidimensional scaling(NMS).Important findings NMS showed large differences in community composition between fallow and old-growth forest,even after 55 years of natural recovery.Saplings(DBH 5 cm) showed more convergence with old-growth forest composition than did adult trees(DBH ≥10 cm).Species accumulation rates for all three ages of fallow plots were slower than for old-growth forests.The recovery of community structure was relatively faster,espe-cially for tree height,but structural complexity did not reach that of old-growth forests.Sprouting stems accounted for 39.9% of density and 55.9% of basal area in the 12-year-old fallow plot,but less in older plots.The proportion of three functional groups(pioneer,non-pioneer light-demanding and shade-tolerant species) showed directional patterns of change during succession,indicating that pattern of recovery was determined by life-history traits.However,cessation of recovery during mid succession indicated that return to pre-disturbance species composi-tion may take centuries or never occur.This should be considered when structuring successional models and pre-dicting carbon accumulation in tropical forest.

The Reducing Emissions from Deforestation and Forest Degradation in Developing Countries (REDD) initiative requires accurate estimates of carbon stock changes in forested areas. However, estimating carbon emissions from stumps of various heights left by illegal loggers is difficult. To remedy this problem, we examined two methods of estimating diameter at breast height (DBH) from a reference diameter observation measured at any stump height. The one-reference diameter (OD) observation model estimates DBH from a single diameter observation using empirical coefficients derived mainly from emergent dipterocarp trees. The two-reference diameter (TD) observation model estimates DBH from two diameter observations and assumes a logarithmic relationship between diameter and height. Prediction data to establish the models were collected in Cambodian lowland evergreen forests that are undergoing intensive illegal logging of emergent dipterocarp trees for timber. The OD model performed better than the TD model in predicting DBH and is extremely practical, as it requires only a single diameter observation. Validation data previously collected in the Southeast Asian tropical forests established the general validity of the OD model. This study may improve the reliability of the REDD scheme by providing a reliable method to assess carbon emissions from Southeast Asian tropical forests.