Forest Of Bangladesh Research Articles

<i>Neurozerra conferta</i> Walker. (Beehole Borer) on <i>Aquilaria malaccensis</i> Lamk. in Assam

Neurozerra conferta Walker. (syn. Zeuzera conferta) a lepidopteran wood borer belonging to the family Cossidae, is an important insect pest on Aquilaria malaccensis Lamk. in Northeast India. It is commonly known as beehole borer. The eggs are laid on the upper portion of the trunk near the branch. The newly hatched larvae enter into the branches or twigs of the tree by making hole through bark. They bore inside the tree trunk making zig-zag tunnels in upward direction, feeding within the tunnel and complete their larval and pupal stages inside the plant and emerge as adults and fly away. The duration of life cycle is 5 to 6 months depending on the temperature. Although Neurozerra conferta is a polyphagous pest of mangrove forests in Bangladesh, in Assam its infestation has been observed only on A. malaccensis . This tree species is renowned for its black oleoresin and its oil which has very high price in international market. Generally, agar wood is harvested by felling the tree and then cutting it down for making chips. Indiscriminate cutting of agar tree in search of agar wood by unskilled persons, has led to its decline in wild. Natural formation of agarwood happens mostly in areas where N. conferta is present, and in other areas artificial induction becomes necessary drilling holes on the tree. To ascertain the role of N. conferta on agarwood formation and to explore possibilities of its cultivation for release in areas where natural agarwood formation does not take place, the biology of the insect was studied in detail. Paucity of information on bio-ecology of N. conferta on A. malaccensis necessitated more observations. The same is presented with illustrations.

Status of Illegal Bird Hunting in Bangladesh: Online news portal as the source

ABSTRACT Illegal wildlife hunting, especially birds are a major global conservation concern for many dwindling species. This article attempted to collate the illegal bird hunting incidents in Bangladesh from 2010 to 2020 (until June) by searching articles published in online news portals. Three hunting hotspots have been identified, which are typically wetland habitats. Birds from the Ardeidae family (herons, egrets, bitterns, night herons) (118 cases) were hunted mostly preferred by trapping (40%) and netting (27%) hunting techniques. To generate some easy income (77% cases) during the winter season was the main motivation for hunting. Existing Wildlife Crime Control Unit of Bangladesh Forest Department should be strengthened and laws should be implemented to halt the further illegal killing of birds in Bangladesh. The country is strategically an important stopover site for bird migration where two migratory flyways (East Asian-Australasian and Central Asian) run over.

The potential perils of Sal forests land grabbing in Bangladesh: an analysis of economic, social and ecological perspectives

The increased demand for foods and commercialization of the commodity markets has resulted in enormous interest in arable land resources, leading to a rapid expansion of forest land into arable land. The Sal forests of Bangladesh have been rapidly grabbed into commercial purposes, which made the forests a threatened ecosystem. Therefore, the objective of the study was to identify the economic, social and ecological impacts of land grabbing on the sustainable development of Sal forests in Bangladesh. Using different qualitative and quantitative data collection techniques from the Madhupur and Bhawal Sal forests of Bangladesh, the study clearly identified that the forestland grabbing has taken place with the assistance of state institutions. The economic outcomes of forestland grabbing were mainly seized by the state institutions and local elites, and a number of industries have been set up in and around the Sal forest areas which created huge pressure on forest biodiversity. Consequently, the ecological analysis showed that a significant number of plant species had lost and the remaining species were facing a critical situation. The study also found a violation of human rights and displacement of almost all ethnic respondents from their ancestral forestland. Therefore, the negligible economic gain of Sal forest land grabbing has not taken precedence over social and ecological consideration; a coordinated approach leading by the government level could stop land grabbing and ensure the sustainable development of Sal forests in Bangladesh.

Farmers’ Perceptions and Attitudes Toward Aquasilviculture in the Periphery of the Sundarbans Forest of Bangladesh

The Sundarbans is a protected forest ecosystem in Bangladesh. A large number of people depend on this forest for their livelihoods and income. Many farmers in the region are now adopting fish farming—specifically, aquasilviculture (multi-purpose production system that allows production of fish and perennial plants mostly trees), one of the most profitable agroforestry systems in many countries. The present study aimed to study the status, benefits, and farmers’ perceptions of and attitudes towards the practice of aquasilviculture in the periphery of the Sundarbans. It was conducted in the Shyamnagar upazilla (administrative district) in the southwestern part of Bangladesh, which is recognized as the most vulnerable upazilla on the coast. About 10% of the area’s shrimp farms were randomly selected and their farmers were interviewed using a semi-structured questionnaire. Most farmers (87%) had a positive attitude toward and clear perception of aquasilviculture practices. Farmers also perceived that trees helped increase their income and provide sources of fuelwood, timber, and fodder for their livestock. The respondents mainly preferred to plant Albizia procera, Acacia nilotica, Azadirachta indica, Psidium guajava, Excoecaria agallocha, and Avicennia officinalis on the dikes of fishponds. Farmers considered increased levels of salinity in water and soils, lack of access to capital, and inadequate technical assistance the main barriers to the practice of aquasilviculture in the region. Aquasilviculture could be an environmentally friendly and climate-smart aquaculture practice in the area, one that increases green coverage on fishponds’ dikes while also improving the livelihoods of local farmers.

The soil quality of the world's largest refugee campsites located in the Hill forest of Bangladesh and the way forward to improve the soil quality

The Rohingya refugee camps in Bangladesh are located in the forest areas of the Cox's Bazar South Forest Division. The construction of refugee camps has caused detrimental changes in the natural vegetation and soil quality of the campsites. The objectives of this study were to develop a database on the soil quality of the block plantation sites and to prescribe native species for plantation and site quality improvement. A total of 204 soil samples from 34 sites of block plantations and control-denuded hill sites were collected from the refugee camps. Soil physical properties (depth of humus layer, bulk density, soil texture) and chemical properties (pH, electrical conductivity (EC), organic carbon, and nutrients (N, P, and K) of the collected samples were measured. Depth of soil humus layer was varied from 0.6 to 2.5 cm and only 4% sampling points possessed the humus layer. Comparatively (p < 0.05) higher bulk density (1.64 g/cm3) was observed for the control-denuded sites. Soil EC found to vary significantly (p < 0.05) among the plantations types and the control-denuded hill sites. Comparatively lower concentration of soil organic carbon and nutrients (N, P, and K) were observed for the control-denuded hill sites. While comparatively higher stocks of carbon and nutrients were observed for block plantations without terraces. This study has prescribed 40 native tree species for plantation in the campsites. However, periodic monitoring of the soil quality properties and carbon stock and sequestration are at a time interval are needed to track the restoration performance of the studied areas.

A multi-purpose National Forest Inventory in Bangladesh: design, operationalisation and key results

BackgroundNational forest inventory and forest monitoring systems are more important than ever considering continued global degradation of trees and forests. These systems are especially important in a country like Bangladesh, which is characterised by a large population density, climate change vulnerability and dependence on natural resources. With the aim of supporting the Government’s actions towards sustainable forest management through reliable information, the Bangladesh Forest Inventory (BFI) was designed and implemented through three components: biophysical inventory, socio-economic survey and remote sensing-based land cover mapping. This article documents the approach undertaken by the Forest Department under the Ministry of Environment, Forests and Climate Change to establish the BFI as a multipurpose, efficient, accurate and replicable national forest assessment. The design, operationalization and some key results of the process are presented.MethodsThe BFI takes advantage of the latest and most well-accepted technological and methodological approaches. Importantly, it was designed through a collaborative process which drew from the experience and knowledge of multiple national and international entities. Overall, 1781 field plots were visited, 6400 households were surveyed, and a national land cover map for the year 2015 was produced. Innovative technological enhancements include a semi-automated segmentation approach for developing the wall-to-wall land cover map, an object-based national land characterisation system, consistent estimates between sample-based and mapped land cover areas, use of mobile apps for tree species identification and data collection, and use of differential global positioning system for referencing plot centres.ResultsSeven criteria, and multiple associated indicators, were developed for monitoring progress towards sustainable forest management goals, informing management decisions, and national and international reporting needs. A wide range of biophysical and socioeconomic data were collected, and in some cases integrated, for estimating the indicators.ConclusionsThe BFI is a new information source tool for helping guide Bangladesh towards a sustainable future. Reliable information on the status of tree and forest resources, as well as land use, empowers evidence-based decision making across multiple stakeholders and at different levels for protecting natural resources. The integrated socio-economic data collected provides information about the interactions between people and their tree and forest resources, and the valuation of ecosystem services. The BFI is designed to be a permanent assessment of these resources, and future data collection will enable monitoring of trends against the current baseline. However, additional institutional support as well as continuation of collaboration among national partners is crucial for sustaining the BFI process in future.

Determination of Financial Rotation of Acacia nilotica (L.) Plantations: A Case Study in Faridpur District of Bangladesh

Knowing the rotation age of farming trees is important to urge maximum return from it. Acacia nilotica (Babla) may be a widely planted farming tree especially in modern agroforestry practice mainly in northern, north western and south western region of Bangladesh. Farmers have little idea about optimum age of the trees to be cut. So, they fail to realize maximum enjoy it. No study has been undertaken to work out the optimum rotation age for A. nilotica in Bangladesh. during this study, an effort has been taken to unravel this problem. Plantations done by Bangladesh Forest Department (BFD) in Faridpur district has taken into consideration as study area. Total cost and total benefit for every plantation site was identified first. Then, Present Value of Benefit (PVB), Present Value of Cost (PVC) and Net Present Value of Benefit (NPVB) were determined to live the Land Expectation Value (Le), Internal Rate of Return (IRR) and Benefit-Cost Ratio (B/C). Using those parameters during this study, it's found that 11 to 14 years old plantations provided highest benefit to the farmers and this could be the acceptable rotation age for Babla trees in Faridpur district. Keywords: Babla, Financial rotation, Forest Management, Faridpur, Bangladesh. DOI: 10.7176/JESD/12-4-05 Publication date: February 28 th 2021

Assessing the Progress and Pitfalls of the Ministry of Environment, Forest, and Climate Change in Achieving SDGs in Bangladesh

The study strived to assess the performance of the Ministry of Environment, Forest, and Climate Change in achieving environmental sustainability in Bangladesh. The overarching pitfalls, shortcomings, and associated challenges were critically examined. The research used both primary and secondary data, which was collected following several research approaches. It was found that the Ministry is actively working to achieve 25 targets of SDGs. Nothing is mentioned about climate change in its mandates though it is nodal Ministry in climate adaptation and mitigation. Due to its ambiguous and viscous mandates, jurisdictional overlapping followed by the conflict of interests has been created in many other ministries and divisions. In SDGs mapping, this Ministry's role in achieving food security and responsible consumption have been downplayed. According to key informants' perception, it could not garner the community’s support in conservation initiatives. On the other hand, due to drawbacks in the legal framework, environmental justice could be ensured on an equal basis. No noticeable activities were observed that can achieve the targets 2020, agreed under the UN Convention on Biological Diversity (CBD), as part of the set of Aichi Biodiversity Targets. The Ministry could not establish any reliable database through which ecological, carbon, and green footprints can be measured. Correspondingly, Bangladesh Forest Research Institute cannot carry out need-based and world standard research activities. Institutional and legal reform is advocated to expedite the actions to achieve environmental sustainability. The study recommends enhancing the capacity of the Ministry.

Exceptional bureaucratic rivalry in mangrove forest policy: Explanations from the Sundarbans, Bangladesh

Bearing diversified natural resources, the Sundarbans mangrove forests (SMF) are, to a large extent, considered a thrust area of ecological and economic importance to which a number of public bureaucracies in Bangladesh give due attention to managing its resources. This paper analyses the extensive policy conflicts of different bureaucracies that prevail for the Sundarbans management practices on emerging issues. All the mangrove forest policies—both directives and projects pursued by multiple administrations in the Sundarbans—are scrutinized taking off in bureaucratic theory. The empirical relevance of this policy development concept is demonstrated based on data from the Government of Bangladesh. As empirical methods, first, the content analyses of various acts, rules, policy documents, missions, mandates, and development initiatives of relevant ministries and public agencies were conducted to distinguish the activities linked with actors’ interests in present practices. Subsequently, the presumed bureaucratic competition was critically analyzed deploying exchange on participating observation. The study observes that being the officially responsible bureaucracy for the Sundarbans, the Bangladesh Forest Department has the leading approach to managing the SMF while receiving guidance from the Ministry of Environment, Forest and Climate Change. The position of the Forest Department is empowered by the existing laws and rules, although the observed approach has been integrated because of multiple bureaucracies being involved in different sectors of Sundarbans for their due interests. Other bureaucracies use their institutional expertise in respective sectors, resulting in an exceptionally high degree of bureaucratic rivalry. Mangrove forest bureaucracy is currently facing challenges in technical capacities, financial resources, and institutional arrangements addressing the effective management of the Sundarbans. Administrative structures for complex landscapes, such as mangrove forests, pose substantial challenges to common bureaucratic structures, which recommends establishing integrated approach, for sharing equitable responsibilities and benefits. Still, the underlying conflicts of interests would prevail, but they can be proactively addressed through rules and procedures within the integration.

Perception Based Assessment of Ecosystem Services of Madhupur Sal Forest in Bangladesh

Madhupur Sal (Shorea robusta) forest, the largest belt of natural Sal forest in Bangladesh, is rich in ecological resources and biodiversity. In recent years, human disturbance leads to biodiversity loss from the forest, and it has a successive effect on the services that the forest provides. Thus, it is crucial to explore the present condition of the forest’s available ecosystem services with local people’s consciousness about the ecosystem. The present study investigated the available ecosystem services of Madhupur Sal forest, respondents’ perception towards those services and the socio-demographic characteristics of the respondents that influenced their perception. Data were collected by interviewing 90 respondents with a focus group discussion. Most of the respondents in the study area were ethnic people (Garo). A total of 20 ecosystem services were identified where soil erosion control, mental peace and maintenance of soil fertility were the top-ranked services. About 83% of the respondents had moderately favorable perception towards ecosystem services. The study results showed that the respondents with a higher level of education, higher family annual income, and more training received on agriculture perceived ecosystem services to a greater extent than others. So, improvement of their perception towards ecosystem services can make them aware of forest biodiversity conservation.

Towards inventory and assessment of plant resources of Bangladesh: challenges and prospects

This review is to appraise plant resources of Bangladesh. Contributions to the inventory, flora writing and establishment of National Herbarium in the country are discussed. The progress of Published Flora of Bangladesh since its independence with family name, number of genera and species including contributors‟ name is mentioned. Contributions of the botanists of the Dhaka University (DU), Chittagong University (CU), Jahangirnagar University (JU), Rajshahi University (RU), Bangladesh Forest Research Institute (BFRI), Bangladesh Council of Scientific and Industrial Research (BCSIR), Asiatic Society of Bangladesh and other institutions in botanical explorations and inventory of the flora are also mentioned. Assessment of threatened taxa, medicinal plant diversity, new discovery, new records, endemics, and production of Red Data Book are also considered as valuable entry in this study.&#x0D; J. Biodivers. Conserv. Bioresour. Manag. 2020, 6(1): 47-58

Leaf morphological plasticity in three dominant tree species in the Sundarbans mangrove forest of Bangladesh in different salinity zones

Mangrove tree species show plasticity in their leaf morphological traits in different salinity zones. However, leaf morphological plasticity and its causes in different salinity zones are incompletely understood. To understand the mechanism of plasticity, this study investigated the responses of three dominant tree species Sundri (Heritiera fomes), Gewa (Excoecaria agallocha) and Goran (Ceriops decandra) of the Sundarbans to the salinity gradients. A total of 17 leaf parameters were measured and quantified. All collected data were analyzed using univariate and multivariate statistical tools to investigate leaf morphological plasticity. A wide range of phenotypic plasticity was observed in all leaf parameters studied among the salinity zones of the Sundarbans. One-way ANOVA and Tukey’s posthoc test revealed significant differences (P < 0.05) in all leaf parameters among the salinity zones and confirming that there was a high degree of phenotypic plasticity among the salinity zones of the Sundarbans. Petiole length (PL), leaf area (LA) and leaf length/petiole length (LL/PL) showed high level of plasticity among the salinity zones of the Sundarbans for each species of Sundri, Gewa and Goran. Plasticity index (PI) was developed in this study for each species studied. High level of phenotypic plasticity in these leaf traits reflects fitness of these species to different saline environments. Our results provide clear evidence that all the leaf parameters measured for three tree species viz., Sundri, Gewa and Goran effectively utilizes a plastic strategy in different salinity zones in the Sundarbans. Morphological trait plasticity could serve as powerful biological indicators to predict the shift of leaf morphology in upcoming environmental change events like sea level rise and reduction of fresh water flow from upstream.

From vulnerability to resilience: A study of the livelihood struggles of tiger widows in Bangladesh

ABSTRACT Livelihood management is a severe challenge in the coastal area near the Sundarbans mangrove forests of Bangladesh. Human-tiger conflict in the area further complicates the situation and generates a group of women known as tiger widows who have lost their husbands because of attacks by tigers. They are therefore socially stigmatized as cursed and harbingers of bad luck. As a result, the lives of these widows in rural and geographically remote locations are full of suffering and hardships, especially with respect to their being able to manage livelihoods. This article discusses their vulnerabilities and difficult lives in this antagonistic eco-social setting. It also reveals their adoption of different livelihood strategies backed by some NGOs’ development assistance, whereby they become able to secure the survival and well-being of their families. Furthermore, our findings show how the widows have developed capacities to transform their own lives from utter misery to gain socioeconomic stability by fighting patriarchal constraints and also influencing other women to become self-reliant.

Stem and Total Above-Ground Biomass Models for the Tree Species of Freshwater Wetlands Forest, Coastal Areas and Dry Areas of Bangladesh: Using a Non-Destructive Approach

Biomass and carbon stock in a forested areas are now prime important indicators of forest management and climate change mitigation measures. But the accurate estimation of biomass and carbon in trees of forests is now a challenging issue. In most cases, pantropical and regional biomass models are used frequently to estimate biomass and carbon stock in trees, but these estimations have some uncertainty compared to the species-specific allometric biomass model. Acacia nilotica, Casuarina equisetifolia and Melia azedarach have been planted in different areas of Bangladesh considering the species-specific site requirements. While Barringtonia acutangula and Pongamia pinnata are the dominant tree species of the freshwater swamp forest of Bangladesh. This study was aimed to develop species-specific allometric biomass models for estimating stem and above ground biomass (TAGB) of these species using the non-destructive method and to compare the efficiency of the derived biomass models with the frequently used regional and pantropical biomass models. Four Ln-based models with diameter at breast height (DBH) and total height (H) were tested to derive the best fit allometric model. Among the tested models, Ln (biomass) = a + b Ln (D) + c Ln (H) was the best-fit model for A. nilotica, M. azedarach, B. acutangula and P. pinnata and Ln (biomass) = a + b Ln (D2H) was best-fit for C. equisetifolia. Finally, the derived best-fit species-specific TAGB models have shown superiority over the other frequently used pantropical and regional biomass models in relation to model efficiency and model prediction error.

Floristic Composition and Woody Species Diversity in National Park of Madhupur Tract Under Tangail North Forest Division, Bangladesh

The floristic composition, species diversity and structural characteristics of woody species in National Park range under Tangail North Forest Division, were investigated based on bit-wise classification. There were five bits in the range. We recorded 18 families, 21 genera, 21 species and 500 woody individuals from the study area (0.5 ha). Fabaceae was the most species rich family and each genus was represented by a single species. Sal (Shorea robusta C.F. Gaertn) was the most dominant species in terms of its highest and tremendously high importance values IV% in the total area and all bits, respectively. More than 40% species had very low IV%, indicating their disappearance or may not be strongly associated with Sal. These species need appropriate management to prevent their disappearance or extinction from the forest area. The values of Shannon′s index H′ and Pielou′s index J ′ (evenness) for the study area were 2.01 and 0.45, respectively. These values show low species diversity as compared to other forests in Bangladesh. Among the bits, the values of H′ and J′ were more or less similar with low index values (from 1.34 to 1.74 and from 0.44 to 0.65, respectively) which may be due to similar species composition with low similarity index values (0.24 t0 0.48). The structural characteristics of woody species diversity showed that the highest species diversity was observed at 5 cm&lt; D ≤10 cm diameter class. In addition, the mean height and basal area of woody species increased with increasing dbh. A few numbers of small trees habitat in the study sites, because the Sal forests in the study area are considered to face a severe threat to their existence due to high anthropogenic disturbances occurred inside and outside the boundary.

Determinants of forest and tree uses across households of different sites and ethnicities in Bangladesh

This study examines the determinants of forest and tree-product uses in rural households across three sites of different proximity to roads and forests in the Chittagong Hill Tracts region in Bangladesh. A structured questionnaire survey was conducted with 300 households of different ethnic groups, located in three different locations (remote, intermediate, on-road), to collect information on their forest and tree use during 2015–2016. We gathered information on household socioeconomic characteristics (family size, education level of head of household, size of farmland), location (three sites), and ethnic affiliation. By conducting a series of logistic regression modeling, we analyzed the key determinants that would explain the variations in forest use in the households. We recorded twelve different forest and tree products used in the households, primarily for subsistence purposes and cash income. Fuelwood, vegetables, and fish were recorded as the most important forest-sourced products used by people, regardless of socioeconomic condition, location context, and ethnic affiliation. Household land/farm size, location, and ethnic background explained significant variations in the use of forest and tree products (mainly timber, fodder for livestock). The greater the size of the landholding, the more likely timber was used for both subsistence and cash income, but the less the reliance on other products (fuelwood, thatch grass, vegetables). Our findings suggest that the location and ethnic characteristics of the rural households are important for understanding the diverse needs for forest and tree use, and should be factored into the site-specific management and sustainable use of forest and tree resources in Bangladesh and other tropical developing countries.

Establishment and Management of Fish Sanctuary for Conserving Indigenous Fish Diversity in the Largest Freshwater Swamp Forest of Bangladesh: A Community Based Management Approach

To restore fish biodiversity and enhance fisheries production fish sanctuary is considered as an important structural management tool. Therefore, this study was conducted in the Ratargul Swamp Forest of Bangladesh to evaluate the impact of a fish sanctuary on native fish biodiversity in and around the forest ecosystem. The investigation was carried out through focus group discussions, personal interviews, and direct catch assessments during fishing by the local fishers. After two year study 65 species of indigenous fishes were recorded as 46 genera under 23 families and covering 9 orders. Cypriniformes and Cypriniidae were recorded as dominant order and family, respectively. After establishment of the fish sanctuary, a significant increasing trend of fish population was observed in the Ratargul Swamp Forest and adjacent the Shari-Goyain and the Kapna Rivers. Fish diversity indices such as Simpson dominance index (D), Shannon-Wiener diversity index (H), Margelef richness index (d) and Pielou evenness index (J) varies 0.12-0.09, 2.77-2.98, 6.15-6.14, 0.66-0.71, respectively indicated enriched species diversity and better production which might be associated with the impact of fish sanctuary establishment. Remarkably increased average fish catch was observed in the impact year (2018-19) compared to the baseline year (2019-20). Local fishers and adjacent people perceive that sanctuary is useful for protecting biodiversity, increasing fish production and helpful for improving livelihood condition of fishers and other dependent stakeholders.

New records of three species and a variety of Angiosperms for Bangladesh

During the floristic explorations in Sundarbans mangrove forest of Bangladesh, conducted in 2016-2019, the authors collect some specimens of Angiosperms that are finally identified as Cleisostoma simondii (Gagnep.) Seidenf. of Orchidaceae and Volkameria heterophylla Vent. of Lamiaceae. Specimens of C. simondii are further identified as C. simondii var. guandongense Z.H. Tsi. The authors collect some specimens of another angiospermic plant in 2019 from Gazipur district of Bangladesh and confirm their identification as Leucas martinicensis (Jacq.) R. Br. of family Lamiaceae. All of these taxa are recorded here for the first time from Bangladesh. Detailed taxonomic description with notes on ecology, uses, distribution and distinctness from morphologically similar taxa, photographs and illustration are provided.&#x0D; Bangladesh J. Plant Taxon. 27(2): 251-260, 2020 (December)

Effectiveness of protected areas in reducing deforestation and forest fragmentation in Bangladesh

The establishment of protected areas has been considered a tool to battle deforestation in densely populated countries like Bangladesh. Since 2000, Bangladesh's Forest Department has declared about 41 protected areas. However, before more land is designated as a protected area, it is important to know how effective existing protected areas are in achieving conservation goals. Unfortunately, the determination of the conservation effectiveness of protected areas, such as their capacity to reduce deforestation and forest fragmentation over a considerable period at high temporal frequency (e.g., yearly), is still unavailable despite some known methods being available, for example, the System for the Integrated Assessment of Protected Areas. In this study, we processed and analyzed the Hansen dataset from 2000 to 2018 to produce yearly forest/non-forest maps of four protected areas in Bangladesh and used these maps, with a matching method, to estimate the effectiveness of protected area in reducing deforestation after controlling for potential hidden bias. We also analyzed the forest fragmentation scenario over the same time frame. The forest cover change results from 2010 to 2018 revealed a large-scale deforestation pattern in areas adjacent to the protected area boundary of Chunati Wildlife Sanctuary (CWS) and Baroiyadhala National Park–Hazarikhil Wildlife Sanctuary (together B-HWS). Using a propensity score matching (PSM) approach with a caliper of 0.25, we found that B-HWS was the best performing of the studied protected areas, and that 37% of forest pixels in B-HWS would have been deforested in 2018 if they had not been brought under protection in 2010. Similarly, the estimated avoided deforestation rates were approximately 21% and 4% for CWS and Dudpukuria–Dhopachari Wildlife Sanctuary, respectively. Despite an improvement in deforestation scenarios, during the period 2010–2018, for all protected areas, the forest fragmentation scenarios were exacerbated both inside their boundaries and in adjacent unprotected areas. Therefore, it remains questionable whether protected areas can ultimately maintain the integrity of conservation.

Plant diversity and local rainfall regime mediate soil ecosystem functions in tropical forests of north-east Bangladesh

The importance of local climate and biodiversity in tropical forest's ability to provide critical ecosystem services is well documented, whereas the relationship among local climatic factors and biodiversity with soil ecosystem functions largely remain unclear. We investigated the importance of local rainfall regime and indicators of plant (tree, herb, and shrub) diversity (richness and abundance) on soil ecosystem functions in two tropical forest ecosystems of north-east Bangladesh. We considered six soil parameters, i.e. soil water regulation (SWR), soil physical stability (SPS), soil microbial habitat (SMH), soil pH (pH), medium of plant growth (MPG), and soil aggregate stability (SAS) as indicators of soil ecosystem functions. Our study finds four rainfall parameters having significant (p < 0.05) positive effects on soil water regulation, soil physical stability, microbial habitat, soil pH, medium of plant growth, and soil aggregate stability. Tree species abundance had positive effects on SPS (p < 0.001) and MPG (p < 0.05), while tree species richness had negative effects on SMH (p < 0.001) and MPG (p < 0.01). Soil aggregate stability was negatively (p < 0.05) affected by tree species abundance, whereas tree species richness positively (p < 0.0001) affected SAS. We found no significant effects of tree species abundance and richness on pH and SWR. The abundance of herbaceous species had positive impacts on MPG (p <0.01) and negative impact on SAS (p < 0.001). In contrast, the richness of herbaceous species had significant negative effects on SMH (p < 0.01) and SPS (p < 0.05). Shrub abundance had no significant effects on six soil ecosystem functions in our study sites, but shrub species richness had a significant (p < 0.05) negative effect on SPS. Our study provides critical insights into the synergistic role of local climate and biodiversity on soil ecosystem functions that can guide actions to restore degraded soils in tropical forest ecosystems.