Disturbance gradients strongly influence biodiversity, stand structure, and regeneration dynamics... more Disturbance gradients strongly influence biodiversity, stand structure, and regeneration dynamics in Shorea robusta (Sal) forests. This study provides the first empirical assessment of such impacts in Dharmapur National Park, Bangladesh, one of the last remaining Sal Forest remnants in the region. Despite its ecological importance, the disturbance ecology of Dharmapur has remained unexamined. To quantify disturbance effects, 105 plots (20 × 20 m) were established across low-(LD), moderate-(MD), and high-disturbance (HD) categories, classified using a composite Disturbance Index. Within each plot, trees (DBH ≥ 5 cm), saplings, and seedlings were inventoried, and diversity, structure, regeneration, and community composition were analyzed using diversity indices, non-metric multidimensional scaling (NMDS), and PERMANOVA. A total of 39 tree species (29 genera, 20 families) were recorded. Species richness declined from 35 species in LD plots to 17 in HD plots, while Shannon diversity decreased from 2.36 to 2.12 (p < 0.001). Basal area dropped from 25.7 to 13.4 m 2 ha-1 and tree density from 802 to 397 individuals ha-1 between LD and HD plots. Regeneration of S. robusta remained relatively strong, but late-successional and shade-tolerant associates declined sharply. NMDS ordination (stress = 0.14) revealed significant compositional turnover, with HD plots dominated by S. robusta and disturbance-tolerant taxa. Overall, disturbance gradients in Dharmapur's Sal forests reduce diversity, simplify structure, and constrain regeneration of non-Sal species, emphasizing the urgent need for disturbance-sensitive management and restoration strategies.
Juri is a biodiversity-rich primary forest in Bangladesh, which remains ecologically unexplored. ... more Juri is a biodiversity-rich primary forest in Bangladesh, which remains ecologically unexplored. We identified tree species and examined the richness, alpha (a) diversity and floristic similarity patterns within the identified communities. Vegetation and environmental data were sampled in 120 (0.04 ha) study plots. Tree communities were delimited by two-way indicator species analysis (TWINSPAN). In total, 78 tree species of 35 families and 58 genera were identified. TWINSPAN identified six tree communities: A-Tricalysia singularis; B-Kydia calycina-Castanopsis tribuloides; C-Polyalthia simiarum-Duabanga grandiflora; D-Ficus roxburghii; E-Artocarpus lacucha; F-Artocarpus lacucha. Mean richness, Shannon and Gini-Simpson indices were highest for the Polyalthia simiarum-Duabanga grandiflora community, while Ficus roxburghii showed lowest diversity. Significant differences (p = 0.05) in three diversity indices were recorded between Polyalthia simiarum-Duabanga grandiflora and Ficus roxburghii. Tree compositional similarity was greatest between Kydia calycina-Castanopsis tribuloides and Polyalthia simiarum-Duabanga grandiflora (0.712).
Madhupur National Park is renowned for severe resource ownership conflicts between ethnic communi... more Madhupur National Park is renowned for severe resource ownership conflicts between ethnic communities and government authorities in Bangladesh. In this study, we applied the Institutional Analysis and Development framework to identify: (i) past and present informal institutional structures within the ethnic Garo community for land resource management; (ii) the origin of the land ownership dispute; (iii) interaction mechanisms between formal and informal institutions; and (iv) change in land management authority and informal governance structures. We identify that the informal institutions of the traditional community have undergone radical change due to government interventions with implications for the regulation of land use, informal institutional functions, and joint decision-making. Importantly, the government's persistent denial of the role of existing informal institutions is widening the gap between government and community actors, and driving land ownership conflicts in a cyclic way with associated natural resource degradation.
Juri is a biodiversity-rich primary forest in Bangladesh, which remains ecologically unexplored. ... more Juri is a biodiversity-rich primary forest in Bangladesh, which remains ecologically unexplored. We identified tree species and examined the richness, alpha (a) diversity and floristic similarity patterns within the identified communities. Vegetation and environmental data were sampled in 120 (0.04 ha) study plots. Tree communities were delimited by two-way indicator species analysis (TWINSPAN). In total, 78 tree species of 35 families and 58 genera were identified. TWINSPAN identified six tree communities: A-Tricalysia singularis; B-Kydia calycina-Castanopsis tribuloides; C-Polyalthia simiarum-Duabanga grandiflora; D-Ficus roxburghii; E-Artocarpus lacucha; F-Artocarpus lacucha. Mean richness, Shannon and Gini-Simpson indices were highest for the Polyalthia simiarum-Duabanga grandiflora community, while Ficus roxburghii showed lowest diversity. Significant differences (p = 0.05) in three diversity indices were recorded between Polyalthia simiarum-Duabanga grandiflora and Ficus roxburghii. Tree compositional similarity was greatest between Kydia calycina-Castanopsis tribuloides and Polyalthia simiarum-Duabanga grandiflora (0.712). Keywords Two-way indicator species analysis (TWINSPAN) Á Richness index Á Shannon index Á Gini-Simpson index Á Tropical forest Á Conservation
The seed germination of pre-sowing treatments of Aquilaria agallocha and Shorea robusta seeds was... more The seed germination of pre-sowing treatments of Aquilaria agallocha and Shorea robusta seeds was conducted in the nursery of Bangladesh Agricultural University. The seeds were collected from 18 to 26 years old matured and healthy trees from various locations in Bangladesh and subjected to different pre-sowing treatments, i.e., control, soaking in normal and hot water (for different times), immersion in 80 % concentrated H SO (for 20 minutes) and so on. Seed 2 4 germination was carried out in poly bags with a mixture of topsoil and cow dung in the ratio of 3:1. The result of analysis of variance (ANOVA) showed no significant differences between seed sources but the germination percentage among the treatment of the selected species was strongly significant with each another.
The diversity-productivity relationship has received considerable attention during the past two d... more The diversity-productivity relationship has received considerable attention during the past two decades, largely because of the continuous loss of biodiversity. The positive relationship between species diversity and productivity is significant as a credible argument for the conservation of biodiversity. This research was conducted in the central region of Bangladesh to exemplify the relationship between tree species diversity and stand productivity at four mixed plantations. In total 112 sample plots (size-0.09 ha/plot) of four different mixed species plantations were systematically selected for data collection. After that, regression analysis explained a significantly positive relationship between tree species diversity and productivity at four mixed plantations. This research suggests that having more tree species generally raises plantation productivity. Therefore, this result indicates that mixed species plantations could be the better choice in the degraded and fallow forest lands of Bangladesh.
This research was conducted at the Agroforestry Research Farm, Hajee Mohammad Danesh Science and ... more This research was conducted at the Agroforestry Research Farm, Hajee Mohammad Danesh Science and Technology University to quantify the effects of pruning height in Jatropha curcas L. (Jatropha) and fertility levels of the recommended dose of NPK in Glycine max L. (Soybean) on crop growth parameters and yield in the agri-silviculture system of Agroforestry. The pruning in Jatropha and fertility level favored growth parameters with varying magnitudes. Six growth indices CGR, RGR, NAR, LAI, RLGR, and SLW were observed to be higher under various pruning heights and reduced under no pruning. After that, the scale of yield varied with pruning heights and fertility levels. Grain, straw, and biological yield of 100 cm pruning height in Jatropha increased by 15.38 %, 13.74 %, and 14.61 % respectively compared to sole crop and other pruning height levels. At that time, it showed that these three yields of 100 % of the recommended dose of NPK (100 % RDF) in Soybeans are comparatively higher than other fertility levels. Hence, a proper pruning system and optimum fertility level are important for improving Soybean yield under the agri-silviculture system. It ensures higher income to the farmers and efficient land management compared to its sole cropping.
Leaf area and leaf biomass estimation are significant prerequisites to studying tree physiologica... more Leaf area and leaf biomass estimation are significant prerequisites to studying tree physiological processes and modeling in the forest ecosystem. The objective of this study was to develop allometric models for estimating A0 and M0 of Swietenia mahagoni L. from different tree parameters such as DBH and tree height of mahogany plantations in the northeastern region of Bangladesh. A total of 850 healthy and well formed trees were selected randomly for sampling in the five study sites. Then, twenty two models were developed based on different statistical criteria that propose reliable and accurate models for estimating the A0 and M0 using non-destructive measurements. The results exposed that model iv and xv were selected on a single predictor of DBH and showed more statistically accuracy than other models. The selected models were also validated with an additional test data set on the basis of linear regression and t-test for mean difference between observed and predicted values. After that, a comparison between the best logarithmic and non-linear allometric model shows that the non-linear model produces systematic biases and underestimates A0 and M0 for larger trees. As a result, it showed that the bias-corrected logarithmic model iv and xv can be used to help quantify forest structure and functions, particularly valuable in future research for estimating A0 and M0 of S. mahagoni in this region.
International Journal of Forest Usufructs Management, 2014
Non-timber forest products (NTFPs) play significant roles in the livelihoods of forest dependent ... more Non-timber forest products (NTFPs) play significant roles in the livelihoods of forest dependent community and forest conservation. It also plays a key function in forest management for most tropical countries. This study is conducted in the Habiganj-2 forest range in the northeastern region of Bangladesh purposely based on a semi structured questionnaire since the nontimber resources of this forest are very rich. The study reveals the dependency level of the community on non-timber forest resources and thus figures out the importance of NTFPs management. It was found from the study that most of the respondents collected the non-timber forest products for the selling purposes. The dependency of forest community on NTFPs in the study area was higher during the winter season and low during the rainy season. Here, it is exposed that the people of the surrounding areas of the forest are highly dependent on the non-timber forest products for their livelihood. So we concluded that forest communities are involved in the management system of the forest then it will give a harmony to the sustainable management of this forest.
The seed germination of seed sources and presowing treatments of Acacia catechu and Elaeocarpus f... more The seed germination of seed sources and presowing treatments of Acacia catechu and Elaeocarpus floribundus seeds were conducted in the nursery of Bangladesh Agricultural University. The seeds were collected from matured and healthy trees from four different locations in Bangladesh and treated with six presowing methods. The germination test was conducted in polybags with a mixture of topsoil and cow dung in a ratio of 3 : 1. The results of ANOVA showed no significant differences among seed sources but statistically significant differences among the presowing treatments for both species. Thus the presowing methods affected the germination process of seeds, and then the highest germination success was found to be 91.26% in hot water (80 ∘ C for 10 min), treatment in Acacia catechu and the highest germination success (89.81%) of Elaeocarpus floribundus was found in H 2 SO 4 treatment followed by 86.35% and 78.42% in treatments with hot water (100 ∘ C for 12 min) and scarification. The study also revealed that the interactions between seed source variation and presowing methods effect significantly differed in seed germination percentages. Therefore, it is concluded that hot water treatment can be suggested on seed germination of both species for developing nurseries and rural Bangladesh.
Leaf area and leaf biomass have an important influence on the exchange of energy, light intercept... more Leaf area and leaf biomass have an important influence on the exchange of energy, light interception, carbon cycling, plant growth, and forest productivity. This study showed the development and comparison of models for predicting leaf area and leaf biomass of Lagerstroemia speciosa based on diameter at breast height and tree height as predictors. Data on tree parameters were collected randomly from 312 healthy, well-formed tree species that were considered specifically for full tree crowns. Twenty-four different forms of linear and power models were compared in this study to select the best model. Two models (M 10 and M 22) for the estimation of leaf area and leaf biomass were selected based on 2 , adjusted 2 , root mean squared error, corrected akaike information criterion, Bayesian information criterion and Furnival's index, and the three assumptions of linear regression. The models were validated with a test data set having the same range of DBH and tree height of the sampled data set based on linear regression Morisita's similarity index. So, the robustness of the models suggests their further application for leaf area and biomass estimation of L. speciosa in the West Vanugach reserve forest of Bangladesh.
Estimation of leaf area (LA) and leaf biomass (LB) is important to understand plant physiological... more Estimation of leaf area (LA) and leaf biomass (LB) is important to understand plant physiological and carbon assimilation processes, and tree growth models. The aim of this study was to develop and compare allometric equations for predicting LA and LB of Artocarpus chaplasha Roxb. taking diameter at breast height (DBH) and tree height as predictors. Data of tree parameters were collected randomly from 200 healthy and well-formed trees. Among all the models developed, models I and IX were based on only a single predictor of DBH and showed more statistical accuracy. Both models were also validated with a distinct data set having the same range of DBH and tree height of the previous data set on the basis of linear regression and t-test for mean difference between observed and predicted LA and LB. These models produced a range of prediction values closer to the upper and lower limits of the observed mean values and suggest their application for LA and LB estimation of A. chaplasha in this region.
The diameter and height distribution of the growing stock is an essential starting point in many ... more The diameter and height distribution of the growing stock is an essential starting point in many forest management planning problems. There are several methods for predicting the diameter and height distribution of a stand, varying from methods which utilize theoretical distribution functions to non-parametric methods. Data from 160 plots, established of Swietenia mahagoni L. plantations (sample size-20 m x 20 m) were stratified by year into eight different ages plantations planted in the northeastern region of Bangladesh from 1999-2013. The parameters of the Weibull distribution were calculated using maximum likelihood estimation (MLE) and moment estimation (ME) methods. The goodness of fit of normal, lognormal, Weibull MLE and Weibull ME were tested using one-sample Kolmogorov-Smirnov (KS) tests. After that, The MLE and ME of the Weibull distribution was best fit to be suitable and the lognormal distribution was also found as fit for 1 to 7 years of plantations but the normal distribution did not provide a satisfactory description of the data. The results suggest that the Weibull distributions were effective for describing the diameter and height distributions which derived were statistically and biologically acceptable and could be satisfactorily used for stands of Mahagony plantations grown in Bangladesh.
The experiment was conducted to determine the effects of light intensity on the seed germination ... more The experiment was conducted to determine the effects of light intensity on the seed germination and early growth of Spondias mombin L. under four light-intensity treatments (40%, 60%, 100%, and under a closed natural forest canopy) in polybags containing a mixture of topsoil and cow dung in a 3:1 ratio. The results showed that the closed natural forest canopy and 100% light intensity treatments resulted in unsatisfactory germination of S. mombin seeds. The 40% light intensity treatment (medium shading) significantly increased seed germination, with the highest cumulative seed germination at 40% light intensity (71.61%) and the lowest at 100% light intensity (26.58%). Intense light delayed germination. Light intensity significantly (P ≤0.05) affected most of the morphological and physiological parameters of the seedling early growth. The early growth phase of seedlings did not perform well under heavy shade, indicating that S. mombin requires shading during early growth. Seedlings under 100% light intensity died shortly after emergence. The findings demonstrated that the best growth and most stable seedlings were obtained under 60% light intensity. Therefore, adequate exposure to light at the nursery stage is necessary for the optimum growth performance of S. mombin seedlings for agroforestry and afforestation purposes in Bangladesh.
The species diversity, floristic composition, and structural characteristics of tree species in K... more The species diversity, floristic composition, and structural characteristics of tree species in Kadigarh National Park, Mymensingh, Bangladesh, where the forest is of the tropical moist deciduous type, were explored. The study was carried out by randomly sampling 20 m × 20 m plots to record and identify trees in the area, resulting in 87 species belonging to 70 genera and 34 families. Additionally, the stem density, Basal area, diversity indices, and importance value index of tree species with a Diameter at Breast Height (DBH) of ≥5 cm were assessed in this protected area. The basal area of tree species and stem density were 18.105±1.06 m 2 ha-1 and 1373.07±44.83 stems ha-1 , respectively. The diversity indices, such as the Shannon-Wiener diversity, Simpson diversity, Margalef's richness, and Pielou's evenness index, showed poor diversity compared to other protected areas in Bangladesh. The structural composition based on DBH and height indicated higher regeneration and recruitment, but the trees of large-growth classes were removed. Sal (Shorea robusta Gaertn.) was identified as the most dominant and native tree species, accounting for 72% of the tree individuals. However, some rare tree species, such as Sidha (Lagerstroemia parviflora Roxb.), Mahua (Madhuca longifolia (J.Koenig ex L.) J.F.Macbr.), and Thona (Oroxylum indicum (L.) Kurz), showed the presence of Sal. Therefore, this research will support future policymakers in formulating a forest resource management plan for Kadigarh National Park.
Forests are among the most biologically rich ecosystems on Earth, providing vital services that s... more Forests are among the most biologically rich ecosystems on Earth, providing vital services that sustain biodiversity, regulate climate, and support livelihoods. However, increasing deforestation, habitat fragmentation, and climate change threaten the stability of these ecosystems. This book offers a comprehensive exploration of forest biodiversity, bridging scientific research with conservation practice to address these challenges.
This book delves into the ecological and genetic foundations of biodiversity, examining species interactions, ecosystem resilience, and evolutionary adaptation. It highlights emerging technologies such as remote sensing and artificial intelligence in biodiversity monitoring, alongside policy frameworks like the Convention on Biological Diversity and REDD+ programs that shape global conservation strategies. Through detailed graphical data, tables, and case studies, it provides a multi-disciplinary perspective essential for understanding forest dynamics.
Designed for academics, researchers, conservation professionals, and policymakers, this work integrates quantitative ecological modeling, sustainability principles, and economic valuation of biodiversity conservation efforts. Whether exploring species adaptation, forest restoration strategies, or international conservation policies, this book serves as a valuable resource for advancing biodiversity research and practical applications. A must-read for those committed to understanding and safeguarding forest ecosystems, this book presents rigorous scientific insights while offering actionable solutions for biodiversity conservation in a rapidly changing world.
Table of Contents 1 Chapter One modeling 7. Parameter estimation of Weibull distribution 8. Compa... more Table of Contents 1 Chapter One modeling 7. Parameter estimation of Weibull distribution 8. Comparison among Normal, Lognormal and Weibull distribution in tree Diameter and Height distribution modeling Chapter Three Material and methods Site description Species description Sampling design Data collection and measurement Data analysis 1. Fitting normal and lognormal distribution 2. Estimation of Weibull parameters 2.1.Maximum likelihood method 2.2. Moments method 3. Model evaluation Chapter Four Results Descriptive statistics of tree diameters Diameter distribution models Model evaluation References
Leaf area and biomass estimation has important influence on the exchange of energy, light interce... more Leaf area and biomass estimation has important influence on the exchange of energy, light interception, carbon cycling, plant growth and productivity. The objective of this study was to develop allometric relationships for estimating leaf area (LA) and foliar biomass (FB) of Swietenia mahagoni L. from different tree parameters such as DBH and tree height of mahogany plantations in Bangladesh. A total of eight hundred fifty healthy and well formed trees were selected randomly for sampling in the five study sites. Then, we evaluate several models and based on different statistical criteria for allometric relationships, we propose reliable and accurate models for estimating the LA and FB. The results exposed that Model IV and XV were selected on a single predictor of DBH and showed more statistically accuracy and validity than other models. Thus, we expect these allometric models to predict LA and FB to prove valuable in future research.
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This book delves into the ecological and genetic foundations of biodiversity, examining species interactions, ecosystem resilience, and evolutionary adaptation. It highlights emerging technologies such as remote sensing and artificial intelligence in biodiversity monitoring, alongside policy frameworks like the Convention on Biological Diversity and REDD+ programs that shape global conservation strategies. Through detailed graphical data, tables, and case studies, it provides a multi-disciplinary perspective essential for understanding forest dynamics.
Designed for academics, researchers, conservation professionals, and policymakers, this work integrates quantitative ecological modeling, sustainability principles, and economic valuation of biodiversity conservation efforts. Whether exploring species adaptation, forest restoration strategies, or international conservation policies, this book serves as a valuable resource for advancing biodiversity research and practical applications. A must-read for those committed to understanding and safeguarding forest ecosystems, this book presents rigorous scientific insights while offering actionable solutions for biodiversity conservation in a rapidly changing world.