Shekhar R. Biswas

East China Normal University | ECNU · School of Ecological and Environmental Sciences

Functional trait diversity is a popular tool in modern ecology, mainly used to infer assembly processes and ecosystem functioning. Patterns of functional trait diversity are shaped by ecological processes such as environmental filtering, species interactions and dispersal that are inherently spatial, and different processes may operate at different...

The metacommunity concept provides a spatial perspective on community dynamics, and the landscape provides the physical template for a metacommunity. Several aspects of landscape heterogeneity, such as landscape diversity and composition, and characteristics of the matrix between habitat patches such as habitat connectivity, and geometry of habitat...

Understanding disturbance effects on species diversity and functional diversity is fundamental to conservation planning but remains elusive. We quantified species richness, diversity, and evenness and functional richness, diversity, and evenness of riparian and upland plants along 24 small streams subjected to a range of anthropogenic disturbances...

Plant invasion is a major threat to natural ecosystems, and mangrove forests are among the most threatened ecosystems in the world. However, since mangrove species primarily occur in the saline and intertidal environment that is inhospitable for most terrestrial and freshwater plants, it is commonly assumed that mangrove forests are resilient to pl...

Ecological processes such as environmental filtering and biotic interactions that shape species' traits and community diversity often vary with geographic distance, potentially generating spatial structures in trait variation, covariation and biodiversity data. Understanding spatial structures of trait, environment and biodiversity, or the spatial...

Since species’ traits are closely linked to ecosystem functioning, the species versus functional diversity relationship (the SD–FD relationship) is considered a valuable indicator of ecosystem health. However, the extent to which the SD–FD relationship varies among disturbed versus undisturbed subtropical forests and whether the conclusion depends...

Bangladesh government has recently pledged to restore 0.75 million hectares of degraded forest-land as part of its commitment to the Bonn challenge, however little is known about the potential challenges and opportunities towards achieving that goal. Using secondary literature complemented by expert consultation and a field survey, we examined the...

Although ecologists often emphasize the roles of environmental- versus biotic-filtering in structuring forest communities, the relative importance of these processes could vary among undisturbed versus disturbed forests. To test this assumption, we gathered leaf traits and site conditions data from intact mature forests (control), moderately distur...

The spatially autocorrelated patterns of biodiversity can be an important determinant of ecological processes, functions and delivery of services across spatial scales. Therefore, understanding disturbance effects on spatial autocorrelation in biodiversity is crucial for conservation and restoration planning but remains unclear. In a survey of dist...

Although both observational and experimental studies have shown that positive tree species diversity–productivity relationships are predominant in global forests, weak or the lack of tree species diversity and productivity relationships also exist. Growing evidence has revealed that ecosystem productivity depends more on the functional characterist...

Both inter‐ and intraspecific trait variation are critical to species distribution along environmental gradients, but our understanding of these patterns predominantly relies upon species‐level trait means and variances. Trait integration, defined as how strongly multiple traits covary with one another, is a key indicator of the dimensionality of f...

Spatial heterogeneity in site conditions and differing disturbance types are common features of natural landscapes. We asked: does the relationship between species diversity and functional trait diversity (SD-FD relationship) of plant communities vary among habitats experiencing different types of disturbance and among microhabitats (i.e., landscap...

This chapter provides an insight of the biodiversity of Bangladesh, from ecosystem to species level, genetic diversity, and major threats to the biodiversity in the country with key initiatives so far taken for biodiversity conservation. The forests of Bangladesh cover three major vegetation type occurring in three distinctly different ecosystems,...

1. Understorey vegetation accounts for the majority of plant diversity in forest ecosystems and contributes to ecosystem functioning. In restoration of degraded forested ecosystems, however, understorey vegetation is often restored passively, contrasting to clear strategies such as informed species choice and site improvement intervention for overs...

What are the projected impacts of climate change on community composition and consequentially on the distribution of functional traits? Answers to these questions are somewhat unclear but critical for designing ecological management strategies. Here we forecast potential impacts of climate change on freshwater lake fish communities of Ontario, Cana...

ContextEcological processes that shape diversity and spatial pattern of ecological communities are often altered by disturbance. Spatial patterns (spatial autocorrelation) in species diversity are thus expected to change with disturbance. Objective When examining spatial patterns, ecologists traditionally lump positive and negative spatial autocorr...

Biodiversity has become an issue of global anxiety over the past decades due to its rapid decline worldwide. Bangladesh as one of the most densely populated countries in the world is no more exception. The country, although, was once very rich in biodiversity, during the last few decades as a consequence of the rapid reduction in forest area, urban...

The impacts of climate change on forest net biomass change are poorly understood but critical for predicting forest's contribution to the global carbon cycle. Recent studies show climate change-associated net biomass declines in mature forest plots. The representativeness of these plots for regional forests, however, remains uncertain because we la...

Background and aims Belowground competition and allelopathic interference of neighbouring plants play important roles in shaping plant performance. We assessed the effect of belowground interactions involving root competition, root exudates and ectomycorrhizal (ECM) association between Kalmia and black spruce on above- and belowground biomass incre...

Identification of processes that shape the spatial structure of invasive species has important implications for understanding population regulation. In invasive Alliaria petiolata we quantified (1) spatial scale of seed dispersal under field conditions, (2) spatial structure of rosette and adult density and (3) the relative importance of environmen...

Although anthropogenic edges are an important consequence of timber harvesting, edges due to natural disturbances or landscape heterogeneity are also common. Forest edges have been well studied in temperate and tropical forests, but less so in less productive, disturbance‐adapted boreal forests. We synthesized data on forest vegetation at edges of...

In tropical developing countries, reducing emissions from deforestation and forest degradation (REDD+) is becoming an important mechanism for conserving forests and protecting biodiversity. A key prerequisite for any successful REDD+ project, however, is obtaining baseline estimates of carbon in forest ecosystems. Using available published data, we...

Non-native invasive plants often lose many of their specialist herbivores in their invaded ranges, but new enemies may be recruited from the local generalist fauna, or from enemies themselves introduced to the same region. As a result, few invaders are free of herbivore damage; however, the incidence of this herbivory and its consequences for plant...

Space and time are the two fundamental drivers of ecological dynamics. Studies exploring the Stress gradient hypothesis (SGH) – which predicts that the patterns of interspecific interactions shift from negative to positive with increasing environmental severity – conceptualize environmental severity predominantly from a spatial perspective. Here, f...

Background/Question/Methods Space and time are the two fundamental drivers of ecological dynamics. Yet, the Stress Gradient Hypothesis (SGH)—which predicts that interactions shift from competition to facilitation along a gradient from permissive to stressful environments—theorizes stresses from merely spatial perspective. We asked: do the predicti...

Aims In recent years, coastal mangroves have been frequently affected by large disturbances (cyclones, hurricanes, flooding and tsunamis) and post-disturbance vegetation is often dominated by small stature mangrove, mangrove-associate and non-mangrove species potentially affecting ecosystem functioning. Knowledge on the processes of mangrove vegeta...

The relationship between species diversity and functional diversity is a fundamental topic in conservation ecology but its direct evaluation in naturally heterogeneous systems and its relationship with disturbance intensity is limited. We examined the relationship between taxonomy-based species diversity (in terms of richness and evenness) and trai...

Forests dominated by dipterocarps are one of the few remaining terrestrial areas with high biodiversity in Bangladesh. This study was conducted in a remnant dipterocarp forest reserve to identify tree species diversity in the reserve and key regeneration traits of the dominant species. Vegetation in transects and quadrats was measured, and regenera...

As a relatively new country, the forests of Bangladesh have only been managed for 34 years under current management authority. During this period, forest management practices have been changed and revised from time to time in accordance with Government policy and legal regimes. The status of forest ecosystems has also changed. This paper reviews an...

The objective of this study was to compare the variation in the soil seed banks and the aboveground vegetation in relation to three habitats, i.e., swamp forests, grassland and sand dunes within the Sundarbans mangrove forests of Bangladesh. We collected vegetation data (species and their percentage cover) by using quadrat sampling: 10m×10m for swa...

The effect of intensive human intervention, poor socio-economic conditions and little knowledge on mangrove ecology pose enormous challenges for mangrove restoration in Southeast Asia. We present a framework for tropical mangrove restoration. Our proposed restoration framework addresses the ecology, economy and social issues simultaneously by consi...

Sundarbans mangrove forest has substantial ecological and economic importance at local, national and global scales. Over the past decades, invasive species have spread significantly in the mangrove ecosystem. We conducted a study to identify the different types of invasive species present, the rate and pattern of invasion, its intensity, associatio...

Like other developing countries, the tropical evergreen forests of Bangladesh are experiencing increasing human pressure. A study has been conducted over the last eleven years (1995-2005) to identify the types and magnitudes of anthropogenic disturbances and its impact on natural forests. 'Indirect observation method' was used for identification of...

Chittagong Hill Tracts is one of the biodiversity rich sites in Bangladesh. Unfortunately, over the last decade forest and biodiversity in this area have degraded largely because of human settlements and extensive land clearing for jhum cultivation. Aiming to restore the degraded forest ecosystem through active and efficient participation of the tr...