Publications by authors named "Nigel Stork"

Article Synopsis
  • Insects are declining globally, especially in tropical forests, which have high biodiversity but are also experiencing significant biodiversity loss.
  • Most predictions about insect biodiversity rely on well-studied species, leaving many undescribed species unaccounted for, particularly in hyper-diverse tropical environments.
  • A study in Borneo found that 76% of collected staphylinid beetle species were undescribed, showing that these unknown species are more negatively affected by environmental changes caused by logging.
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Article Synopsis
  • Logged and disturbed forests, often seen as degraded, actually harbor significant biodiversity and should not be dismissed in conservation efforts.
  • A study in Sabah, Malaysia examined the effects of logging intensity on 1,681 species, revealing two important conservation thresholds.
  • Lightly logged forests (less than 29% biomass removed) can recover well, while heavily degraded forests (over 68% biomass removed) may need more intensive recovery efforts, highlighting the varying conservation values of logged forests.
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Delivery of ecosystem services is strongly affected by changes in the land use/land cover (LULC) of an area. In this study, we analyze spatiotemporal changes in LULC of the rapidly changing Bagmati River Basin (BRB) of Nepal during 1988-2018 using Landsat satellite images. We also quantify carbon storage in different physiographic regions and LULC classes using the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model and assess economic valuation of carbon using the benefit transfer method.

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The amount of carbon stored in deadwood is equivalent to about 8 per cent of the global forest carbon stocks. The decomposition of deadwood is largely governed by climate with decomposer groups-such as microorganisms and insects-contributing to variations in the decomposition rates. At the global scale, the contribution of insects to the decomposition of deadwood and carbon release remains poorly understood.

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Restoring degraded forest is essential if we are to reduce human pressure on natural ecosystems and their biodiversity. Forests were nationalized in 1957 in Nepal and as a consequence, forest cover declined from 45% in 1964 to just 29% in 1994. However, as its response, sectoral plans and policies, particularly introduction of community-based forest management programs since the 1980s and conservation activities resulted in large scale forest cover restoration.

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The community-based forest management program has been successful in the conservation of forest cover in Nepal. We investigated forest cover change for the Mechinagar and Buddhashanti Landscape (MBL) area within the Jhapa district, Nepal, during 1990-2019 using Landsat images and GIS tools and valuated the major ecosystem services (ES) of Kalika Community-managed Forest (KCF) within the MBL landscape using the economic approach-market price method (revealed price). Land cover analysis of the MBL area indicated that over the study period, there were increases in urban/built-up areas, forest, and tea plantations, and declines in cultivated land, shrub, barren land, water body, and grassland areas.

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The Tarai region of Nepal is regarded as the food bowl of Nepal, and yet urban areas have increased in size at an average annual rate of 12% for the 30 years since 1988/1989, largely at the expense of prime agricultural land. Nepal is recognized internationally as highly sensitive to food security with 40% of its population undernourished. To aid future planning and reduce potential further loss of agricultural land and consequent increased food insecurity, we here investigated the previously unknown factors underlying this rapid urban expansion.

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Increased frequency and severity of drought, as a result of climate change, is expected to drive critical changes in plant-insect interactions that may elevate rates of tree mortality. The mechanisms that link water stress in plants to insect performance are not well understood. Here, we build on previous reviews and develop a framework that incorporates the severity and longevity of drought and captures the plant physiological adjustments that follow moderate and severe drought.

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Understanding the spatiotemporal dynamics of urbanization and predicting future growth is now essential for sustainable urban planning and policy making. This study explores future urban expansion in the rapidly growing region of eastern lowland Nepal. We used the hybrid cellular automata-Markov (CA-Markov) model, which utilizes historical land use and land cover (LULC) maps and several biophysical change driver variables to predict urban expansion for the years 2026 and 2036.

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Article Synopsis
  • Lianas (woody climbers) are significant in rainforests, enhancing plant diversity and potentially serving as a vital food source for herbivores, especially insect folivores.
  • Compared to trees, lianas generally have lower defenses, better nutritional profiles, and different seasonal leaf availability, leading to more specialized insect communities.
  • The increasing prevalence of lianas due to climate change raises important questions about their ecological roles, particularly in relation to insect herbivory and overall biodiversity, necessitating further research in this area.
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Clearing of dry forests globally creates edges between remnant forest and open anthropogenic habitats. We used flight intercept traps to evaluate how forest beetle communities are influenced by distance from such edges, together with vertical height, spatial location, and local vegetation structure, in an urbanising region (Brisbane, Australia). Species composition (but not total abundance or richness) differed greatly between ground and canopy.

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In the last decade, new methods of estimating global species richness have been developed and existing ones improved through the use of more appropriate statistical tools and new data. Taking the mean of most of these new estimates indicates that globally there are approximately 1.5 million, 5.

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Insects are key components of urban ecological networks and are greatly impacted by anthropogenic activities. Yet, few studies have examined how insect functional groups respond to changes to urban vegetation associated with different management actions. We investigated the response of herbivorous and predatory heteropteran bugs to differences in vegetation structure and diversity in golf courses, gardens and parks.

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It has been suggested that we do not know within an order of magnitude the number of all species on Earth [May RM (1988) Science 241(4872):1441-1449]. Roughly 1.5 million valid species of all organisms have been named and described [Costello MJ, Wilson S, Houlding B (2012) Syst Biol 61(5):871-883].

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Article Synopsis
  • Invertebrates like termites, ants, and beetles are super important in tropical rainforests because they help keep the ecosystem healthy and strong.
  • Logging (cutting down trees) has harmed more than one-third of these forests, reducing the number of invertebrates by up to half, which affects how the forest works.
  • Even though some other animals like small mammals and certain birds may increase after logging, the decline of important invertebrates shows that humans are changing how these rainforests operate.
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Mora et al. disputed that most species will be discovered before they go extinct, but not our main recommendations to accelerate species' discoveries. We show that our conclusions would be unaltered by discoveries of more microscopic species and reinforce our estimates of species description and extinction rates, that taxonomic effort has never been greater, and that there are 2 to 8 million species on Earth.

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Insect biodiversity peaks in tropical rainforest environments where a large but as yet unknown proportion of species are found in the canopy. While there has been a proliferation of insect biodiversity research undertaken in the rainforest canopy, most studies focus solely on insects that inhabit the foliage. In a recent paper, we examined the distribution of canopy insects across five microhabitats (mature leaves, new leaves, flowers, fruit and suspended dead wood) in an Australian tropical rainforest, showing that the density (per dry weight gram of microhabitat) of insects on flowers were ten to ten thousand times higher than on the leaves.

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Some people despair that most species will go extinct before they are discovered. However, such worries result from overestimates of how many species may exist, beliefs that the expertise to describe species is decreasing, and alarmist estimates of extinction rates. We argue that the number of species on Earth today is 5 ± 3 million, of which 1.

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Estimates suggest that perhaps 40% of all invertebrate species are found in tropical rainforest canopies. Extrapolations of total diversity and food web analyses have been based almost exclusively on species inhabiting the foliage, under the assumption that foliage samples are representative of the entire canopy. We examined the validity of this assumption by comparing the density of invertebrates and the species richness of beetles across three canopy microhabitats (mature leaves, new leaves and flowers) on a one hectare plot in an Australian tropical rainforest.

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A key challenge in the estimation of tropical arthropod species richness is the appropriate management of the large uncertainties associated with any model. Such uncertainties had largely been ignored until recently, when we attempted to account for uncertainty associated with model variables, using Monte Carlo analysis. This model is restricted by various assumptions.

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1. We tested the hypotheses that feeding guild structure of beetle assemblages changed with different arboreal microhabitats and that these differences were consistent across rainforest tree species. 2.

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There is a bewildering range of estimates for the number of arthropods on Earth. Several measures are based on extrapolation from species specialized to tropical rain forest, each using specific assumptions and justifications. These approaches have not provided any sound measure of uncertainty associated with richness estimates.

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We provide a cross-taxon and historical analysis of what makes tropical forest species vulnerable to extinction. Several traits have been important for species survival in the recent and distant geological past, including seed dormancy and vegetative growth in plants, small body size in mammals, and vagility in insects. For major past catastrophes, such as the five mass extinction events, large range size and vagility or dispersal were key to species survival.

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In the wake of widespread loss of old-growth forests throughout the tropics, secondary forests will likely play a growing role in the conservation of forest biodiversity. We considered a complex hierarchy of factors that interact in space and time to determine the conservation potential of tropical secondary forests. Beyond the characteristics of local forest patches, spatial and temporal landscape dynamics influence the establishment, species composition, and persistence of secondary forests.

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