Environmental Regimes Research Articles

Practitioners' perspectives on the enablers and barriers to successful Antarctic science‐policy knowledge exchange

AbstractMultilateral environmental governance regimes like the Antarctic Treaty System are pivotal in addressing today's wicked transboundary socio‐ecological problems and central to their success is the facilitation of constructive knowledge exchange (KE) between research and policymaking communities. Consequently, the literature is now ripe with studies that aim to uncover the elements that enable or hinder KE successes across diverse environmental governance settings. Yet, in the Antarctic context, the KE practices that comprise Antarctic science‐policy interfaces remain empirically under examined. Here we contribute by exploring the perspectives of 31 Antarctic practitioners to develop our understandings of successful KE practices in the policy contexts of the Antarctic Treaty Consultative Meetings and the Committee for Environmental Protection. By adopting a reflexive thematic analysis, we identify 11 enablers and 9 barriers to KE success that are overlapping, interconnected and complex. According to practitioners, in the face of pervasive barriers, such as the often overshadowing effect of politics, a deficiency of KE incentives and large‐scale wicked policy problems, certain Antarctic institutions and practitioners portray strong boundary spanning expertise, which despite the many challenges identified, serves to facilitate KE in support of evidence‐informed decision‐making. However, the extent to which boundary spanners are influential in their leadership varies, and while acknowledging that influential leadership is an important enabler for success, we raise several questions regarding the potentially unexplored assumptions that underpin current KE practices. As Antarctic practitioners share a desire to foster inclusive, iterative and multidirectional science‐policy dialogues among other identified improvements, we suggest that harnessing reflexivity and humility within these processes will be critically important for ensuring that existing asymmetries or inequities are not reinforced under the guise of improved ways of working.

The effectiveness of Ghana’s environmental impact assessment regulations to achieve green growth

ABSTRACT Achieving green growth requires that development projects with potential environmental impacts undergo a rigorous environmental impact assessment process to address negative consequences. The attainment of green growth, and consequently the Sustainable Development Goals, depends on an effective Environmental Impact Assessment regime. In Ghana, this regime must ensure that projects strictly adhere to the guidelines outlined in the Environmental Assessment Regulations, LI 1652, and LI 1703, before commencement. This research examines the effectiveness of Ghana’s environmental assessment regulation in protecting the environment to achieve green growth. Qualitative, semi-structured interviews were conducted with key stakeholders, including officials from the Environmental Protection Agency, environmental consultants, and environmental impact assessment proponents in the Eastern Region of Ghana. The findings from these engagements revealed several major challenges in Ghana’s environmental assessment regulations that hinder full compliance before projects begin. These challenges include: 1) A shortage of local experts, 2) Insufficient logistics for the EPA’s monitoring and evaluation department to conduct frequent inspections, 3) Lack of intervener funding, 4) Poor coordination among government agencies, and 5) Delays in the EIA process.

Leaf growth in third dimension: a perspective of leaf thickness from genetic regulation to ecophysiology.

Leaf thickness, the leaf growth in the third dimension as quantified by the distance between the adaxial and abaxial surface, is an indispensable aspect of leaf development. The fitness of a plant is strongly influenced by leaf thickness via modulation of major physiological processes, including photosynthesis and water use efficiency. The cellular basis of leaf thickness by alterations in either cell size or the number of cell layers is envisaged using Arabidopsis leaf thickness mutants, such as angustifolia (an) and rotundifolia (rot). Environmental factors coordinate with endogenous signaling mechanisms to exhibit leaf thickness plasticity. Plants growing in different ecological and environmental regimes show different leaf thickness attributes. However, genetic and molecular understandings of leaf thickness regulation remain largely limited. In this review, we highlight how cellular growth is transposed to fine-tune the leaf thickness via the integration of potential cues and molecular players. We further discuss the physiological significance of leaf thickness plasticity to the environmental cues that might serve as ecological adaptation enabling the plants to withstand future climatic conditions. Taken together, we seek to bridge the genetics and molecular biology of leaf thickness to its physiological significance so that leaf thickness can be systemically targeted in crop improvement programs.

Population genetics of Macrognathus siamensis (Synbranchiformes: Mastacembelidae): Implications for non-migratory fishery resources in the Mekong River basin

The spotted spiny eel, Macrognathus siamensis is an economically important freshwater fish in the Mekong River basin, which is undergoing dramatic biodiversity changes due to anthropogenic impacts. The species is non-migratory, with a moderate larval duration that facilitates downstream genetic connectivity. Restriction site-associated DNA sequence datasets that includes 3736 and 1244 single nucleotide polymorphisms representing putatively neutral loci, from all geographic sites and without the Tachileik site, indicate strong population structure in this sedentary fish, with a significant isolation-by-distance signature. This structure reflects isolation of tributary populations and downstream dispersal of these distinct populations to mix in the Mekong mainstem and contributes to increased genetic diversity in the lower reaches of the Mekong basin. Genetic data indicates that the dispersal of eggs and larvae downstream is not impeded by Khone Falls and that the falls prevent upstream dispersal of eggs and larvae. Despite this downstream connectivity, there is a strong population structure among above- and below-Khone Falls groups. An analysis of outlier loci putatively under selection provides evidence that the difference between connected metapopulations above and below the falls is due to the fundamental differences in environmental regimes. We hypothesize that instead of a physical barrier, the falls simply represents a demarcation between previously recognized upstream limited-floodplain environments and downstream extensive-floodplain environments. These findings emphasize the need to monitor genetic diversity of key sedentary fishery species to assess whether proposed dams along the river could affect genetic diversity downstream. This genetic diversity is particularly important for the resilience of downstream populations because of the many environmental impacts caused by dams, land use, and climate change. Early detection of reduced downstream genetic diversity could trigger remediation programs to ensure resilience and continued fisheries productivity of important non-migratory fish resources.

Assessing global ensemble systems’ forecasts of tropical cyclone genesis in differing environmental flow regimes in the western North Pacific

The forecast probability of tropical cyclone (TC) genesis in the western North Pacific from 2017 to 2020 was investigated using global ensembles from the Japan Meteorological Agency (JMA), the European Centre for Medium-Range Weather Forecasts (ECMWF), the U.S. National Centers for Environmental Prediction (NCEP), and the Met Office in the United Kingdom (UKMO). The time of TC genesis was defined as the time the TCs were first recorded in the best-track data (Case 1) and as the time they reached the intensity of a Tropical Storm (Case 2). The results in Case 1 showed that differences between the forecast probability based on each global ensemble were large, even for a 1-day forecast, and that mean probability were from 18 % to 74 %. The forecasts based on the NCEP had a large frequency bias and overpredicted TC genesis events. The results indicated that the representation of genesis events differed greatly between global ensembles. The effectiveness of multiple ensembles was investigated. The results from the threat score and the false alarm ratio indicated that multiple ensembles had skillful forecasts. When the forecast probability was examined for environmental patterns of synoptic low-level flow, the mean 5-day forecast probability was highest for the pattern in the confluence region. The results also showed that the forecast probability was much larger in Case 2 than in Case 1. In all global ensembles, the mean probability with a lead time of up to 1-week was below 10 % for both Case 1 and 2. This result indicates that even with today's operational forecasting systems, it is difficult to regularly predict TC genesis events with a 1-week lead time with high confidence. These results provide a better understanding of TC genesis forecast products in each global ensemble and will be useful information when multiple-ensemble products are created.

Precision Phenotyping in Crop Science: From Plant Traits to Gene Discovery for Climate‐Smart Agriculture

ABSTRACTThe global population is placing unprecedented demand on food systems, which can be met only through a complex interplay of technology, sustainable food production intensification methods and climate resilience. To address such compounded requirements, developing high‐yielding crop varieties using precise plant breeding methods bolstered with efficient and nondestructive plant trait documentation approaches is vital. High‐throughput crop phenotyping (HTCP) platforms have prominently emerged as a mainstream approach for reducing the phenotyping bottleneck in breeding programmes. HTCP has the potential to provide detailed quantitative information of large plant populations under different growth stages across diverse environmental regimes, facilitating accelerated plant breeding strategies. New imaging platforms also enable nondestructive characterization of a wide range of above and below‐ground crop parameters. The specificity in use of sensors, automation of data collection, large‐scale data handling systems and accurate analytical tools have a substantial role in dynamic crop monitoring and big data interpretation. HTCP platforms are capable of making precise measurements of a wide range of physiological, morphological, biochemical and stress responses in plants. Developments of sensors with improved precision, intervention of unmanned aerial vehicles, robotics, computed tomography and machine learning have given a dramatic developmental leap to precise and large‐scale crop phenotyping. This review provides an avenue for understanding various high‐throughput phenotyping platforms, working principles, current developments and contributions to high‐throughput phenotyping of various crops under laboratory and field conditions. A detailed comparative idea on the advantages and pitfalls of these available platforms can help researchers in choosing the right technology suiting specific practical requirements. Furthermore, the review aims to provide novel future prospects and developmental requirements that can potentially widen the application and utilization of these HTCP technologies in agriculture.

Big cities, big bodies: urbanisation correlates with large body sizes and enhanced body condition in African dwarf chameleons (Genus: Bradypodion)

Urbanisation is a major driver of habitat transformation that alters the environmental conditions and selective regimes of the habitats where it occurs. For species inhabiting urban habitats, such alterations can facilitate adaptive responses in their phenotypes, including their morphology. Quantifying potential responses could provide important information for assessing adaptation to urbanisation and may also be relevant to their conservation. Previous studies on African dwarf chameleons (Bradypodion) have shown these lizards to have remarkable adaptive capacity in response to different habitats (e.g. closed canopy habitats vs. open canopy habitats). Several of these species exploit urban habitats, but the extent to which populations are adapting to urban environments has only recently started to receive attention. In this study, we quantify differences in body size and body condition between urban and natural populations of five species of dwarf chameleons. For most comparisons, either females, males or both sexes from urban populations were longer, heavier and/or had better body condition than those from natural populations. In the remaining cases, there were no differences in these traits between populations. Our findings conform with the emerging paradigm that urbanisation positively correlates with enhanced lizard body sizes and condition, although the reasons for this may be complex. Nevertheless, our data provide an avenue for future research into investigating the potential factors (e.g. food supply, predation risk, etc.) that facilitate the trends we observed.

Species interactions drive continuous assembly of freshwater communities in stochastic environments

Understanding the factors driving the maintenance of long-term biodiversity in changing environments is essential for improving restoration and sustainability strategies in the face of global environmental change. Biodiversity is shaped by both niche and stochastic processes, however the strength of deterministic processes in unpredictable environmental regimes is highly debated. Since communities continuously change over time and space—species persist, disappear or (re)appear—understanding the drivers of species gains and losses from communities should inform us about whether niche or stochastic processes dominate community dynamics. Applying a nonparametric causal discovery approach to a 30-year time series containing annual abundances of benthic invertebrates across 66 locations in New Zealand rivers, we found a strong negative causal relationship between species gains and losses directly driven by predation indicating that niche processes dominate community dynamics. Despite the unpredictable nature of these system, environmental noise was only indirectly related to species gains and losses through altering life history trait distribution. Using a stochastic birth-death framework, we demonstrate that the negative relationship between species gains and losses can not emerge without strong niche processes. Our results showed that even in systems that are dominated by unpredictable environmental variability, species interactions drive continuous community assembly.

Global Health Management: Addressing Health Disparities And Inequalities

It is the state's responsibility to provide access to public health care management for the poor and vulnerable, as the cost of curative care is disproportionately higher among lower income groups, the majority of whom are Dalits. India's population health has significantly improved during the past 70 years. The disparity across social groupings is still rather large, though. Low health status is clearly associated with poverty, being a woman, living in a rural area, belonging to a tribal ethnic group, being a scheduled caste (SC), and belonging to particular minority groups. In order to guarantee health fairness, it is necessary to review the environment and policy implementation regime. The purpose of this article is to provide context for relevant healthcare concerns and challenges by examining a few key health, poverty, illness-related costs, and coping techniques across social groupings indicators. The conceptual foundation for the health effects of public health care management's globalisation is described in this study. An examination of the main social determinants influencing population health is known as the social determinant of health.

Fire drives major Holocene vegetation shifts between subtropical and Mediterranean‐type ecosystems: a case study from a biodiversity hotspot in South Africa

Fire plays a pivotal role in driving ecological shifts between Mediterranean‐type vegetation and subtropical ecosystems in South Africa. This study investigates long‐term environmental dynamics and ecological regime changes at the Mediterranean‐type vegetation /subtropical boundary using a 6000‐year palaeoecological sequence from the Baviaanskloof – a region of South Africa characterized by high levels of biodiversity and climate dynamism. Combining fossil pollen and microcharcoal data from a rock hyrax Procavia capensis midden, we analyse vegetation responses to environmental changes. Our findings reveal that Mediterranean‐type vegetation resilience prevailed until ca 2800 cal year BP when a major fire event triggered a transition to a subtropical thicket‐dominated environment. This abrupt ecological turnover underscores the significance of fire as a major driver of vegetation change at the Mediterranean‐type vegetation /subtropical boundary. Our study emphasizes the vulnerability of Mediterranean‐type vegetation ecosystems to global environmental change, suggesting potential implications for similar biome boundaries worldwide. By integrating multi‐proxy palaeoecological evidence, we gain insights into the resilience and vulnerability of these ecosystems, aiding in understanding future responses to climate change scenarios.

Does polymixis complicate prediction of high‐frequency dissolved oxygen in lakes and reservoirs?

AbstractAs lake and reservoir ecosystems transition across major environmental regimes (e.g., mixing regime) resulting from anthropogenic change, setting predictive expectations is imperative. We tested the hypothesis that (dissolved) oxygen is more predictable in monomictic reservoirs that thermally stratify throughout the summer (warm) season compared to polymictic reservoirs that stratify intermittently. Using two‐hourly vertical profiles of oxygen, we compared daily‐aggregated errors of oxygen predictions from random forests across and within two monomictic and two polymictic reservoirs in the south‐central (subtropical) USA. Although one monomictic reservoir was typically more predictable than the polymictic reservoirs, the hypereutrophic, small monomictic reservoir had less predictable oxygen patterns potentially related to rapid oxygen cycling and intrusions of oxygenated waters in the hypolimnion without mixing. Daily mixing did not relate strongly to model errors. Water temperature, depth, and wind were the most important predictors, but were not clearly related to season or mixing. Lastly, we compared multiple model types (regression, neural network, and process‐based) in one polymictic reservoir to test how our interpretations of oxygen predictability were sensitive to model type, finding that the models generally agreed; however, the process‐based model poorly predicted oxygen in the middle of the vertical profiles (5 m) where most models performed poorly due to a temporally unstable, vacillating metalimnion. Our results suggest predicting reservoir oxygen dynamics may be easier in stratified reservoirs, but eutrophication and complex hydrodynamics may cause forecasting surprises especially for those who use or manage water resources in mono‐ or dimictic reservoirs.

Reorganization of circadian activity and the pacemaker circuit under novel light regimes.

Many environmental features are cyclic, with predictable changes across the day, seasons and latitudes. Additionally, anthropogenic, artificial-light-induced changes in photoperiod or shiftwork-driven novel light/dark cycles also occur. Endogenous timekeepers or circadian clocks help organisms cope with such changes. The remarkable plasticity of clocks is evident in the waveforms of behavioural and molecular rhythms they govern. Despite detailed mechanistic insights into the functioning of the circadian clock, practical means to manipulate activity waveform are lacking. Previous studies using a nocturnal rodent model showed that novel light regimes caused locomotor activity to bifurcate such that mice showed two bouts of activity restricted to the dimly lit phases. Here, we explore the generalizability of these findings and leverage the genetic toolkit of Drosophila melanogaster to obtain mechanistic insights into this unique phenomenon. We find that dim scotopic illumination of specific durations induces circadian photoreceptor CRYPTOCHROME-dependent activity bifurcation in male flies. We show circadian reorganization of the pacemaker circuit, wherein the 'evening' neurons regulate the timing of both bouts of activity under novel light regimes. Our findings indicate that such environmental regimes can be exploited to design light cycles, which can ease the circadian waveform into synchronizing with challenging conditions.

Plasticity of leaf functional traits and growth responses to disturbance among cutting cultivars of Cryptomeria japonica in southern Japan

ABSTRACT Cryptomeria japonica (Thunb. ex L. f.) D. Don is the most major plantation species in Japan, and cultivars have been developed and planted under variable environmental conditions across the country. Productivity of clonal plantations is influenced by the ability of the genotype to acclimate to edaphic- and geographic-scale variation in environmental conditions and disturbance regimes. Because all individuals are genetically identical in a clonal plantation, the trait differences among individuals represent phenotypic plasticity. Here, we investigated how phenotypic plasticity and response to disturbance vary among cutting cultivars of C. japonica. We compared tree height, leaf morphology, nitrogen content, and frequency/intensity of growth-release observed in tree rings after thinning and disturbance among six cutting cultivars in 45-year-old provenance trials in south-western Japan. Nitrogen use efficiency was higher in the site where maximum tree height (H max) was taller, while shoot mass per area (SMA) was larger in the site where H max was shorter. Cultivars that grew well had high leaf nitrogen content (N G) and showed more efficient nitrogen use with high nitrogen-resorption efficiency (NRE). Yabukuguri, an intermediate-growth cultivar, was characterized by large SMA and greater plasticity in SMA and tree height in response to topographical and regional variation, as well as greater intensity of growth-release in tree-ring series indicating growth resilience following disturbance. Our results provide guidelines for selecting cultivars with high acclimation potential and resilience to environmental perturbation, which is important for sustaining plantation forests in uncertain environmental conditions expected by future climate change.

Wolbachia pipientis (Rickettsiales: Rickettsiaceae) mediated effects on the fitness and performance of Aedes aegypti (Diptera: Culicidae) under variable temperatures and initial larval densities.

Wolbachia pipientis (Hertig, 1936), also referred as Wolbachia, is a bacterium present across insect taxa, certain strains of which have been demonstrated to impact the fitness and capacity to transmit viruses in mosquitoes, particularly Aedes aegypti (Linnaeus, 1762). Most studies examine these impacts in limited sets of environmental regimes. Here we seek to understand the impacts of environmentally relevant conditions such as larval density, temperature, and their interaction on wAlbB-infected A. aegypti. Using a factorial design, we measured wAlbB stability (relative density, post-emergence in females, and in progeny), the ability for wAlbB to induce cytoplasmic incompatibility, and bacterial effects on mosquito fitness (fecundity, fertility, and body mass) and performance (adult survival and time to pupation) across 2 temperature regimes (fluctuating and constant) and 2 initial larval densities (low and high). Fluctuating daily regimes of temperature (27 to 40 °C) led to decreased post-emergence wAlbB density and increased wAlbB density in eggs compared to constant temperature (27 °C). An increased fecundity was found in wAlbB-carrying females reared at fluctuating temperatures compared to uninfected wild-type females. wAlbB-carrying adult females showed significantly increased survival than wild-type females. Contrarily, wAlbB-carrying adult males exhibited a significantly lower survival than wild-type males. We found differential effects of assessed treatments (Wolbachia infection status, temperature, and larval density) across mosquito sexes and life stages. Taken together, our results indicate that realistic conditions may not impact dramatically the stability of wAlbB infection in A. aegypti. Nonetheless, understanding the ecological consequence of A. aegypti-wAlbB interaction is complex due to life history tradeoffs under conditions faced by natural populations.

Strategy for Adapting Environmental Flow Proposals to Situations with High Agricultural Demands

Managing water in catchments with high agricultural demands, particularly during periods of low natural flows, is a challenging task. Environmental flow regimes, which are based on monthly minimum values, may not be adequate to address issues associated with rivers that have complex hydrological alteration patterns. The technical solution that provides values to create a flow regime can often be impractical for addressing large problems that planners need to solve, especially when demands are high and resources are limited. This work proposes a new approach to the problem by recognising established agricultural uses and demands that reduce river flow. The focus is on reducing the changes in the hydrological regime by proposing an alternative environmental flow regime that is compatible with agriculture. Deviation from the natural flow of these rivers has been minimized through various processes. Initially, this was achieved by reducing irrigation flows through more efficient demand calculations. The results provide solutions for various hydrological alteration problems, in three rivers, Riaza, Duratón, and Eresma; the inverted regime was corrected, in Cega, Tormes, and Adaja, whose main problem was the reduction of peak flows; controlled peak flows that are compatible with the available water and demands are proposed; and finally in the Agueda river, the reduction in monthly flows was increased on a monthly basis. A new strategy is proposed for considering environmental aspects in the management of rivers with high demands, which improves the fixed schemes for determining environmental flows used in Mediterranean basins.

A comparison of plant macrofossil-based quantitative climate reconstruction methods: A case study of the lateglacial Baltic States

The recent advancements of new quantitative tools compatible with plant macrofossil proxy data have revived its potential for paleoclimate research. Plant macrofossils are commonly used in so-called indicator-species approaches, using methodologies that are typically built on known observations linking modern plant distributions with climate. This allows complementary paleoclimate reconstructions using an approach that is not limited by the spatial availability of calibration samples obtained from surface sediments (e.g., pollen or chironomids).We aim to evaluate the impact that various methodological choices have on the plant-macrofossil based reconstructions of January and July temperature patterns for the Lateglacial (14–11 ka BP) period. We use a variety of classic and novel quantitative climate reconstruction algorithms with plant macrofossil assemblages from 13 sites of the Baltic States. We use unfiltered plant data to evaluate the ability of each method to also handle the presence of plants that might have a weak sensitivity to temperature. Additionally, we test the influence of another methodological choice – the choice of modern calibration region – on the reconstructed climate.Our findings indicate that, with no prior filtering of summer and winter-sensitive plants, temporal temperature variations can be reconstructed with methods that implement probability density functions. Although some disparities in reconstructions are seen between the tested algorithms, we note that the choice of calibration region bears a greater influence on the results. A calibration region that best represents the past environment should be chosen rather than one representing the same spatial extent as the fossil site(s). Moreover, for long-term reconstructions, a “dynamic calibration set” approach should be considered in future studies by using a range of calibration regions and mirroring the continuously changing broadscale environmental regime of the past.

ADRs and Audit Pricing: Influence of disclosure and legal environment regime

AbstractCross‐listed firms natively operate in countries where regulations are less enforced, disclosure requirements and the legal environment are laxer than in the US. Thus, cross‐listed firms typically pay lower audit fees than US peer groups. Based on reported audit data of the cross‐listed firms in the US, this study explores how their home country's regulatory environment affects audit fees when they cross‐list on US stock exchanges. The empirical results indicate that the cross‐listed firms pay lower audit fees than their US counterparts. However, other regulatory environments in the home country, like disclosure requirements or anti‐director dictatorship, may require more audit efforts. Further, the cross‐listed firms that prepare reconciliation to US GAAP pay lower audit fees than other ADR firms that are using IFRS or US GAAP. However, still most of ADR firms pay lower audit fees than US counterpart firms.

Hero or Devil: A comparison of different carbon tax policies for China

A carbon tax is a promising environmental regulation. Given its heavy industrial base and substantial reliance on coal, China is under immense pressure to transition to greener energy systems. This paper enriches Annicchiarico and Di Dio’s (2015) dynamic general equilibrium model for environmental policy analysis by integrating a Schumpeterian innovation-driven clean energy transition that endogenizes the carbon intensity of energy inputs. We analyze the environmental, energy, economic, and social impacts of various hypothetical carbon taxes – including an energy excise tax on households, an emission tax on general producers, and an energy tax on energy suppliers – across different tax rates and subsidy strategies for both short-term and long-term effects. We show that: (i) by internalizing carbon intensity, a carbon tax can achieve a “quadruple dividend”, encompassing emission reduction, energy transition, economic growth, and welfare enhancement; (ii) the optimal carbon tax strategy, integrating both an emission tax and an energy tax, directs revenue towards supporting the clean energy transition; (iii) under a single environmental regime, a composite carbon tax exceeding 250 CNY/ton is optimal, while under multiple regimes, 25 CNY/ton suffices to reduce carbon emissions per unit of output by over 90%; (iv) despite their benefits, all carbon taxes compel firms to reorganize production, inevitably risking unemployment.

Why did the Hornbill not cross the river? Upland habitats rather than a physical barrier limit the distribution of the Brown Hornbill

AbstractAimIn continuous environments, niche limits of species often determine their distribution limits. However, when these limits spatially coincide with a perceived dispersal barrier, the determinants of species' ranges may be confounded. We investigate the distribution pattern of the Brown Hornbill (Aves: Bucerotidae), which spans significant riverine barriers, but stops south of the Brahmaputra River. Considering its preference for low‐elevation evergreen forests, we posit that the lack of sufficient habitats north of the Brahmaputra prevents dispersal of the Brown Hornbill, and not the river itself.LocationThe Brahmaputra valley and the Indo‐Burma hotspot.TaxaAnorrhinus austeni, Aceros nipalensis.MethodsWe analysed citizen‐science occurrence data on hornbill presence against a suite of climatic, canopy‐specific and topographical predictors to model the environmental niche of the Brown Hornbill. We used presence‐only maximum entropy modelling in an information theoretic framework, in conjunction with constructing binary logistic regression models using presence and pseudoabsence data. We compared niche models of the Brown Hornbill and the Rufous‐necked hornbill, a close relative with a similar distribution, but which has spanned the Brahmaputra River.ResultsDespite the presence of suitable wet‐evergreen forests north of the Brahmaputra River, the hilly terrains in the region act as a biogeographic barrier for the Brown Hornbill, which prefers lowland evergreen forests. Further, highly suitable regions for the Brown and the Rufous‐necked Hornbills precisely delineate low and high‐elevation evergreen forests respectively, indicating that these birds are separated along an elevational axis.Main ConclusionsThe Brahmaputra River lies at the cusp of two subtly different environmental regimes. It may therefore serve as the niche limit for certain organisms and not as a physical obstacle to their dispersal. Our study implicitly predicts how widespread deforestation prevalent in the lowland evergreen forests of this region adversely impacts the distributions of organisms that depend on them, such as the Brown Hornbill. Further, our study proffers an approach to ascertain determinants of species distributions in a hypothesis testing framework.

Assessment of environmental impact of road construction based on results of remote sensing monitoring

Remote sensing detected the impact of road construction on important environmental properties. The digital elevation model was applied to assess the impact of road construction on environmental regimes. The study focused on the total area of the 3-km zone of influence (monitoring zone of probable impact) around the national road H-31 Dnipro-Tsarychanka-Kobeliaky-Reshetylivka from Loboikivka village to the boundary of Dnipropetrovsk Oblast. The following derivatives of the digital elevation model are considered as geomorpho­logical variables: the topographic wetness index (TWI) and erosion factor (LS). To model the effect of road construction on the moisture regime and dynamics of erosion processes, the TWI and LS indices were calculated for a digital terrain model without a road and with a road with an elevation that corresponds to the planned level. Thus, the road is considered as an anthropogenic landform that changes the direction of water redistribution along the topography and thus affects the potential moisture conditions and erosion risks. The modeling results indicate that the transformation of the water regime will be observed within the entire 3-km monitoring area. Deviations from the normal value can be up to 7 units by module, which is about one third of the landscape-wide range of topographic moisture index values. Almost no impact of construction can be predicted for 80.7% of the territory. For 10.6% of the territory, the increase in moisture regime will be moderate, and for 3.2% of the area the increase will be very significant. In turn, for 4.3% of the area the decrease in humidification will be moderate, and for 1.2% the decrease will be very significant. The greatest impact on the redistribution of moisture conditions is predicted in the immediate vicinity of the road. Changes in the moisture regime can have significant negative consequences for both soil cover and biotic components of ecosystems. Changes in vegetation as a consequence of changes in both moisture and trophic conditions can be considered as possible scenarios for the development of landscape cover dynamics.