Raman Sukumar

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Verified

Raman verified their affiliation via an institutional email.

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• Ph.D.
• Professor Emeritus at Indian Institute of Science Bangalore

Aim Most of our current knowledge on tropical forest plant communities is based on trees, despite the substantial contribution of other lifeforms to plant diversity in these systems. In particular, there is a limited number of studies on understory herbaceous plants (herbs) in tropical forests. With their lower dispersal abilities, higher rates of...

To support their wide range of social interactions, elephants have evolved high- and low-frequency sounds for short- and long-distance communication. Our current understanding of elephant vocal communication largely comes from African elephant studies which have focused on low-frequency sounds. However, much needs to be understood about the vocal c...

The Western Ghats of India are one of the hottest biodiversity hotspots in the world, with a high level of biological diversity and endemism. It also has a very distinct seasonality brought in by the South West and North East monsoon. Our site, the Mudumalai Wildlife Sanctuary (MWS), is a seasonally dry tropical forest in the mid-elevation ranges o...

Populations of forest trees exhibit large temporal fluctuations, but little is known about the synchrony of these fluctuations across space, including their sign, magnitude, causes and characteristic scales. These have important implications for metapopulation persistence and theoretical community ecology. Using data from permanent forest plots spa...

The work is looking at the 1200-year history of vegetation change, fire, and human activity from a protected tiger Reserve in India which is occupied by by the dry deciduous forest

This work is looking athe 1200 year history of vegetation, fire and human activity change from a protected forest in India

This meeting report focuses on the potential for using long-term data to inform conservation planning and highlights key work across India on the same.

As major terrestrial carbon sinks, forests play an important role in mitigating climate change. The relationship between the seasonal uptake of carbon and its allocation to woody biomass remains poorly understood, leaving a significant gap in our capacity to predict carbon sequestration by forests. Here, we compare the intra-annual dynamics of carb...

[This corrects the article DOI: 10.1371/journal.pone.0049548.].

The Living Elephants is the authoritative resource for information on both Asian and African elephants. From the ancient origins of the proboscideans to the present-day crisis of the living elephants, this volume synthesizes the behavior, ecology and conservation of elephants, while covering also the history of human interactions with elephants, al...

Asian elephants (Elephas maximus) are the largest extant terrestrial megaherbivores native to Asia, with 60% of their wild population found in India. Despite ecological and cultural importance, their population genetic structure and diversity, demographic history, and ensuing implications for management/conservation remain understudied. We analysed...

A major fire raged through the dry tropical forests of Bandipur Tiger Reserve, a ‘biodiversity hotspot’ in southern India, in February 2019. The fire occurred in patches, burning >10,000 acres of forest, becoming one of the largest forest fires in India in recent times. Very few studies have been able to capture the dynamics of fire proxies from an...

The growth response of Himalayan pindrow fir (Abies pindrow) was investigated using tree rings at the treeline ecotone in Hirpora Wildlife Sanctuary in the northwestern Himalaya. The ring-width chronology was built based on 73 increment cores extracted from 40 healthy trees. The measurements were standardized to remove non-climatic growth trends, e...

In tropical forests, understory herbaceous angiosperms (herbs), which can comprise up to 40% of plant species richness, have received relatively little attention compared with trees, and their diversity patterns and drivers remain poorly understood. While tropical tree diversity has been shown to be driven primarily by water availability, we hypoth...

A nuclear leakage or tactical nuclear weapon use in a limited war could cause immense and long-lasting ecological consequences beyond the direct site of exposure. We call upon all scientists to communicate the importance of the environmental impacts of such an event to all life forms on Earth, including humankind. Changes to ecosystem structure and...

The field of animal movement ecology has advanced by leaps and bounds in the past few decades with the advent of sophisticated technology, advanced analytical tools, and multiple frameworks and paradigms to address key ecological problems. Unlike the longer history and faster growth of the field in North America, Europe, and Africa, movement ecolog...

The Working Group II contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) provides a comprehensive assessment of the scientific literature relevant to climate change impacts, adaptation and vulnerability. The report recognizes the interactions of climate, ecosystems and biodiversity, and human societie...

Nature-based solutions provide adaptation and mitigation benefits for climate change as well as contributing to other sustainable development goals (high confidence). Effective nature-based climate change mitigation stems from inclusive decision-making and adaptive management pathways that deliver climate-resilient systems serving multiple sustaina...

Documenting the behavioural repertoire of an animal species is important for understanding that species' natural history. Many behaviours such as mating, parturition and death may be observed only rarely in the wild due to the low frequency of occurrence, short duration and the species' elusiveness. Opportunistic documentation of rare behaviours is...

Tree size shapes forest carbon dynamics and determines how trees interact with their environment, including a changing climate. Here, we conduct the first global analysis of among‐site differences in how aboveground biomass stocks and fluxes are distributed with tree size. We analyzed repeat tree censuses from 25 large‐scale (4–52 ha) forest plots...

An impetus for growth and development in India, with the second largest human population in the world, has resulted in rapid changes in land use across the country, especially over the last two decades. While the land area under agriculture has only slightly increased, there have been significant changes in the shift from single-cropping to double-...

The growth and survival of individual trees determine the physical structure of a forest with important consequences for forest function. However, given the diversity of tree species and forest biomes, quantifying the multitude of demographic strategies within and across forests and the way that they translate into forest structure and function rem...

Over 420 million ha of forest were lost to deforestation from 1990 to 2020; more than 90% of that loss took place in tropical areas (high confidence), threatening biodiversity, environmental services, livelihoods of forest communities and resilience to climate shocks (high confidence1 ). Forty-five percent of the world’s forested areas are in the t...

Peat deposits (>50 ka) in the montane Nilgiris (Western Ghats, India), have been central to the reconstruction of late Quaternary paleoclimate using paleovegetation changes in the forest-grassland vegetation mosaic that coexist here. However, it is well-known that short-term disturbances can also cause vegetation switches when multiple stable veget...

Forests across the globe have been exploited for resouces, and over the years the demand has increased, and forests are rather exploited instead of sustainable use. Focussed research on vegetation and forerst dynamics is necessary to preserve biodiversity and functioning of forests for sustanence of human life on Earth.This article emphasis that th...

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Studies comparing the relative strengths of multiple key drivers of forest dynamics are rare, but can inform both our fundamental understanding of plant communities as well as community-ecology theory. We studied the dynamics of a woody plant community in a southern Indian seasonally-dry tropical forest (SDTF) in relation to environmental factors (...

Human migration in response to past climate change has been recorded globally. The pastoralist Todas are believed to have colonised the higher elevations (>2000 m asl) of the Nilgiris, Western Ghats, India, after ∼2000 cal. yr BP. During the late Quaternary, climate-induced vegetation shifts in tropical montane forest-grassland mosaic of the Nilgir...

When Darwin visited the Galapagos archipelago, he observed that, in spite of the islands’ physical similarity, members of species that had dispersed to them recently were beginning to diverge from each other. He postulated that these divergences must have resulted primarily from interactions with sets of other species that had also diverged across...

Mineral dust, especially from the Middle-East, has been known to affect monsoon circulation in India, a country whose economy is heavily contingent on the timely arrival of the monsoon. Reconstruction of dust circulation in the past and its relationship to the monsoon has never been attempted in India although inorganic geochemical proxies from pea...

The Himalaya is one of the major mountain ecosystems that is most likely to be impacted by climate change. The main drawback in understanding climate change in the remote Himalayan ecosystems is the lack of long-term instrumental climate records. Reconstructing past climates from tree-rings offers a useful proxy for adding data to the instrumental...

Fires determine vegetation patterns, impact human societies, and are a part of complex feedbacks into the global climate system. Empirical and process-based models differ in their scale and mechanistic assumptions, giving divergent predictions of fire drivers and extent. Although humans have historically used and managed fires, the current role of...

Background Assessment of physiological states by measuring biomarkers, such as cortisol, has significantly contributed to the monitoring of health, welfare and management of animals. Immunoreactive cortisol in hair (hC) has been used widely for deciphering ‘stressful’ past-events in various wild and captive animals. However, no such studies have be...

ForestGEO is a network of scientists and long-term forest dynamics plots (FDPs) spanning the Earth's major forest types. ForestGEO's mission is to advance understanding of the diversity and dynamics of forests and to strengthen global capacity for forest science research. ForestGEO is unique among forest plot networks in its large-scale plot dimens...

Aim Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and...

Human migration in response to climate change during the Holocene has been recorded in many regions of the world. The Todas are a pastoralist people who are believed to have colonized the higher elevations (>2000 m asl) of the Nilgiris in the Western Ghats, India, not earlier than about 2000 cal. yr BP. Vegetation shifts in response to changing cli...

Fires determine vegetation patterns, impact human societies, and provide complex feedbacks into the global climate system. Empirical and process-based models differ in their scale and mechanistic assumptions, giving divergent predictions of fire drivers and extent. Especially, the role of anthropogenic drivers remains less understood. Taking a data...

Feeding behavior of large herbivores determines the composition of their dung and together with environmental factors the intensity of decomposition processes leading to the recycling of nutrients in tropical forests. Large herbivore dung and its decomposition has so far been characterized by stoichiometric analyses of elements such as C and N. The...

Aim: Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) an...

Small-sized protected areas face increasing pressures from developmental activities and are often rendered inadequate and isolated to conserve wide-ranging species. However, in situations where wildlife persists outside protected areas, conservation goals may be met by aligning the ecological needs of wildlife with the socio-economic needs of local...

Climate change is expected to be heterogeneous across the world, with high impacts on the Himalayan ecosystems. There is a need to precisely document cambial phenology and wood formation in these regions to better understand climate-growth relationships and how trees face a warming climate. This study describes the dynamics of cambial phenology in...

When disturbed, animals use various modes of communication to alert conspecifics about the source of danger. Some species have evolved graded or continuous signals specific to the type of threats. African elephants, Loxodonta africana, are known to differentiate between threats from bees and humans by changing the energy concentrations of their ala...

Impact of dungle beetles and termites on soil properties in Mule Hole long term observatory (https://mtropics.obs-mip.fr/), Bandipur Tiger reserve, Karnataka, Southern India. Two dataset are available: (i) the physical and chemical properties of termite sheeting below elephant dung (TSDung) or below wood branches (TSBranch), the soil excavated by d...

Context Physiological stress has the potential to influence animal population persistence. The endangered Asian elephant (Elephas maximus) is involved in intense conflict with humans in many parts of its range, which likely leads to stress for individuals and groups, with consequences for population survival. Thus, it is important to understand how...

Among the local processes that determine species diversity in ecological communities, fluctuation‐dependent mechanisms that are mediated by temporal variability in the abundances of species populations have received significant attention. Higher temporal variability in the abundances of species populations can increase the strength of temporal nich...

Several studies have established that African proboscideans shifted their feeding strategies (browsing vs. grazing) in response to climatic and ecological changes. However, similar studies on their Indian relatives are rare. In this regard, we analysed the stable carbon (d 13 C) and oxygen (d 18 O) isotope composition, hypsodonty indices (HI), and...

Climate change has a signifcant impact on ecosystem dynamics and the social communities (Kahn, 2005; Webster, 2005). The Himalayan mountains are experiencing a higher warming than average global warming, which can signifcantly impact their biodiversity, vegetation distribution and ecosystem structure (Shrestha et al., 2012). Long-term records of cl...

Reactions to dying and dead conspecifics have been observed in many non-human animals. Elephants, particularly African elephants, are thought to have an awareness of the death of their conspecifics, as they show compassionate behaviour towards others in distress. However, there is a paucity of scientific documentation on thanatological responses di...

Context: Physiological stress has the potential to influence animal population persistence. The endangered Asian elephant (Elephas maximus) is involved in intense conflict with humans in many parts of its range, which likely leads to stress for individuals and groups, with consequences for population survival. Thus, it is important to understand ho...

Male Asian elephants are known to adopt a high-risk high-gain foraging strategy by venturing into agricultural areas and feeding on nutritious crops in order to improve their reproductive fitness. We hypothesised that the high risks to survival posed by increasingly urbanising and often unpredictable production landscapes may necessitate the emerge...

Symbiotic nitrogen (N)‐fixing trees can provide large quantities of new N to ecosystems, but only if they are sufficiently abundant. The overall abundance and latitudinal abundance distributions of N‐fixing trees are well characterised in the Americas, but less well outside the Americas. Here, we characterised the abundance of N‐fixing trees in a n...

Land and climate interact in complex ways through changes in forcing and multiple biophysical and biogeochemical feedbacks across different spatial and temporal scales. This chapter assesses climate impact on land and land impacts on climate, the human contributions to these changes, as well as land-based adaptation and mitigation response options...

Termites are undoubtedly amongst the most important soil macroinvertebrate decomposers in semi-arid environments in India. However, in this specific type of environment, the influence of termite foraging activity on soil functioning remains unexplored. Therefore, this study examines the link between the quality of litter and the functional impact o...

Workshop for stakeholders on reducing train-elephant accidents in northern West Bengal” on 16-17 November2018, Chalsa, Jalpaiguri, West Bengal 1. Engineering solutions to mitigate the railways-elephant deaths problem – landscaping with overpasses, underpasses, viaducts and tunnels. 2. Fencing of railway track except corridors areas to prevent s...

Overlapping habitats and sharing of resources between elephants and people has led to intense elephant‐human conflicts, especially crop depredation by elephants, across elephant‐range countries. While raiding agricultural crops, elephants face numerous threats from people through chase, injury and the risk of death which could enhance the associate...

In the tropics, termites are key litter decomposers and soil bioturbators. Termite foraging activity involves the production of sheetings and galleries that influence the physical, chemical and hydraulic properties of soils. The functional impacts of these biogenic structures and biopores have been acknowledged for a long time in soils dominated by...

In the tropics, termites are known to be key litter decomposers and soil bioturbators. Their foraging activity in the soil leads to the production of galleries with specific soil physical, chemical and biological properties. This study investigates the influence of these foraging galleries on water infiltration and soil properties in south- Indian...

Department of Forest and Park Services, Bhutan conducted National Elephant Survey. This survey spanned the whole southern districts covering almost an area of 8000 km2 of potential Asian elephant habitat in Bhutan. This survey combined multiple methods of detection using camera traps in conjunction to dung DNA sample collection in 129 of each 25km2...

Aim To examine the contribution of large‐diameter trees to biomass, stand structure, and species richness across forest biomes. Location Global. Time period Early 21st century. Major taxa studied Woody plants. Methods We examined the contribution of large trees to forest density, richness and biomass using a global network of 48 large (from 2 t...

Questions Water availability is known to be a first‐order driver of plant diversity; yet water also affects fire regimes and soil fertility which, in turn, affect plant diversity. We examined how precipitation, fire and soil properties jointly determine woody‐plant diversity. Specifically, we asked how woody‐plant diversity varies along a sharp pre...

Traditionally, people have depended on forests for their livelihood and a process of sustainable resource extraction was in place, which typically did not result in major degradation of forested landscapes. With the increase in human population, per capita consumption and commodity exports there have been substantial changes in land use patterns, a...

Conservation of any concerned taxa in altered ecosystems requires an in-depth knowledge of their ecology, including key interdependent facets such as their physiology, behaviour, and habitat. In addition, ecological and anthropogenic perturbations are known to influence the stress status of free-ranging animals. Understanding and assessing the effe...

Drought‐induced tree mortality is expected to increase globally due to climate change, with profound implications for forest composition, function and global climate feedbacks. How drought is experienced by different species is thought to depend fundamentally on where they access water vertically below‐ground, but this remains untracked so far due...

Significance Identifying and explaining regional differences in tropical forest dynamics, structure, diversity, and composition are critical for anticipating region-specific responses to global environmental change. Floristic classifications are of fundamental importance for these efforts. Here we provide a global tropical forest classification tha...

Among group-living animals, some members may derive benefit by following the decisions of other members. Free-ranging wild Asian elephants in Mudumalai National Park, southern India, must often cross roads and can be disturbed by vehicles. We assessed if measures of road and traffic characteristics serve as indicators of risk, and compared behaviou...

The phenology of figs (Ficus spp. Moraceae) is being monitored in the dry forests of Mudumalai, southern India and individuals belonging to the genus are marked with unique tag numbers and their vegetative and reproductive phenologies have been monitored since August 2000 on a monthly basis. The influence of abiotic factors on fig phenology and the...

Mangrove forest patches and plantations with known age of plantation along both western and eastern coast of India were sampled for estimation of standing biomass and C stocks. A sample plot of 0.1 ha (1000 m²) was laid in each patch depending on the contour of the patch. All woody stems >1 cm dbh were identified, measured for size and heights were...

The extensive network of the Indian Railways cuts through several forested landscapes, resulting in collisions of trains with a variety of wildlife species, including the largest land mammal–the elephant. In India, railway lines cross elephant habitats in several states, with accidents that resulted in more than 200 elephant deaths between 1987 and...