Tracts Of Forest Research Articles

Measuring and monitoring tree cover and plant canopy height in Pune city, India

Global datasets often fall short in estimating tree cover areas outside the forest tracts, particularly in urban areas. This limitation poses a challenge for accurately estimating tree cover outside forests (ToF) and understanding their contribution to ecosystem services. In the context of increasing population pressure and unsustainable urbanization in Indian cities, regional-level tree cover and canopy height estimations are crucial for evaluating the impact of ToF on various ecosystem services, including carbon sequestration, climate change adaptation, biodiversity hotspots, groundwater recharge, soil conservation, flood control, urban heat mitigation, and psychological and emotional well-being. This technical note outlines a rapid and cost-effective methodology for assessing tree canopy cover and height, specifically tailored for ToF estimation, offering a valuable tool for addressing these socio-urban environmental challenges and enabling sustainable land use planning.

Woody invaders of a temperate forest have unique root-associated fungal communities

Non-native, invasive plants are increasingly common in Eastern North American forests, but their impact on soil fungi remains unclear. We used DNA metabarcoding to investigate the effects of nativity, plant mycorrhizal type and soil factors on root-associated fungal communities. We focused on understory woody plants in a deciduous forest tract in central New York state, and included three plant types, invasive arbuscular mycorrhizal (AM), native AM, and native ectomycorrhizal (EM), each represented by 3–5 species. We found lower fungal operational taxonomic unit (OTU) diversity in EM than AM plants, but no OTU diversity difference between native and invasive AM species. Pathogen OTU richness and relative abundance were not distinct between plant types. OTU composition was influenced by host mycorrhizal type and by AM plant nativity, with mycorrhizal fungi being important drivers in both cases. The relationships of soil characteristics (e.g., pH) with OTU composition were independent of plant nativity and mycorrhizal type. Specific root length of native AM species was lower than that of invasive AM plants, while EM plants were intermediate. Irrespective of plant type, OTU composition was distinct among plant species, particularly in fungal communities associated with the invader Rhamnus cathartica. These results suggest that invasive AM plants may shift fungal composition relative to native AM and EM plants, with potential long-term consequences for soil biodiversity.

Loss of species and functions in a deforested megadiverse tropical forest.

Tropical species richness is threatened by habitat degradation associated with land-use conversion, yet the consequences for functional diversity remain little understood. Progress has been hindered by difficulties in obtaining comprehensive species-level trait information to characterize entire assemblages and insufficient appreciation that increasing land-cover heterogeneity potentially compensates for species loss. We examined the impacts of tropical deforestation associated with land-use heterogeneity on bird species richness, functional redundancy, functional diversity, and associated components (i.e., alpha diversity, species dissimilarity, and interaction strength of the relationship between abundance and functional dissimilarity). We analyzed over 200 georeferenced bird assemblages in the Atlantic Forest of Brazil. We characterized the functional role of the species of each assemblage and modeled biodiversity metrics as a function of forest cover and land-cover heterogeneity. Replacement of native Atlantic Forest with a mosaic of land uses (e.g., agriculture, pastures, and urbanization) reduced bird species richness in a nonrandom way. Core forest species, or species considered sensitive to edges, tended to be absent in communities in heterogenous environments. Overall, functional diversity and functional redundancy of bird species were not affected by forest loss. However, birds in highly heterogenous habitats were functionally distinct from birds in forest, suggesting a shift in community composition toward mosaic-exclusive species led by land-cover heterogeneity. Threatened species of the Atlantic Forest did not seem to tolerate degraded and heterogeneous environments; they remained primarily in areas with large forest tracts. Our results shed light on the complex effects of native forest transformation to mosaics of anthropogenic landscapes and emphasize the importance of considering the effects of deforestation and land-use heterogeneity when assessing deforestation effects on Neotropical biodiversity.

Succession and seasonality of a Brazilian secondary tropical dry forest: Phenology and climate moderation

With large tracts of Tropical Dry Forests (TDF) in the Americas previously deforested, many places are currently undergoing secondary ecological succession. These processes vary in time and space, creating a landscape with forests of different ages or successional stages. These secondary forests need moreneed more understanding about how their ecosystem functionality is restored and recovering along the succession path. In particular, it is poorly understood how different successional stages moderate extremes of Essential Climatic Variables (ECV) such as temperature, relative humidity, soil moisture, and the fraction of Absorbed Photosynthetic Active Radiation (fAPAR). This paper, therefore, studies the linkages between high temporal resolution tower-based optical canopy phenology time series and seasonal changes in local ECV conditions between early (10–12 years) and late (50+ years) successional stage TDF in southeastern Brazil. We compare diurnal and seasonal patterns of understory ECVs between early/late plots and investigate the canopy’s Climate Moderating Capacity (CMC). Our data indicate at least 100 mm of precipitation within two weeks is necessary to initiate leaf flushing in this TDF. We also find that soil moisture and daytime air humidity strongly correlate (R2 > 0.75) with seasonal patterns in canopy vegetation greenness indices and fAPAR with a cross-correlation time lag peak of 12–15 days. Our results suggest that the late stage is more effective at cooling (−1.4 ± 0.6 °C vs −0.8 ± 0.6 °C) and reducing daytime evaporation (−0.41 ± 0.2 kPa vs −0.18 ± 0.12 °C) in the understory during the growing season than the early stage. Results suggest that the CMC varies with seasonal canopy leaf area dynamics and with heat and moisture scales, becoming significantly stronger when temperatures and vapour pressure deficits were highest, and correlated strongly with canopy fAPAR dynamics (R2 = 0.82). These findings demonstrate that TDFs can effectively regain microclimatic buffering capacity.

Planning cost-effective operational forest inventories.

We address a Bayesian two-stage decision problem in operational forestry where the inner stage considers scheduling the harvesting to fulfill demand targets and the outer stage considers selecting the accuracy of pre-harvest inventories that are used to estimate the timber volumes of the forest tracts. The higher accuracy of the inventory enables better scheduling decisions but also implies higher costs. We focus on the outer stage, which we formulate as a maximization of the posterior value of the inventory decision under a budget constraint. The posterior value depends on the solution to the inner stage problem and its computation is analytically intractable, featuring an NP-hard binary optimization problem within a high-dimensional integral. In particular, the binary optimization problem is a special case of a generalized quadratic assignment problem. We present a practical method that solves the outer stage problem with an approximation which combines Monte Carlo sampling with a greedy, randomized method for the binary optimization problem. We derive inventory decisions for a dataset of 100 Swedish forest tracts across a range of inventory budgets and estimate the value of the information to be obtained.

Contribution to the Botany of the Tarai Forests of the Bahraich District of Uttar Pradesh

With a view to study the vegetation and flora of the tarai forests and grasslands of the Bahraich district of Uttar Pradesh, bordering upon the tracts of forests in the Nepalese territory, three seasonal tours undertaken in this forest division in March and November, 1964 by the Senior author (G. Panigrahi) and in February, 1965 by O. P. Misra, yielded 530 species of Angiosperms and 14 species of Pteridophytes as represented by 1076 field numbers of plants. (Wherever the name of the Collector is not given between the locality and the field no. in the enumeration appended to this paper, "PANIGRAHI" may be cited).The paper presents an outline of the three classes of forest types viz. Sal, Miscellaneous and Grass and an analysis of the floristic composition in the Katarniaghat-Dharmanpur-Motipur-Doba-Chakia-Chardha and Bhinga forests which are isolated blocks separated by 8-16 km by intervening tracts of cultivation and grazing grounds, except the forests of Dhramanpur and Motipur, which adjoin.The Sal forests are divided into Moist (Gangetic) High level alluvial, dry (Gangetic) alluvial, moist (Gangetic) low level alluvial, dry (Gangetic) alluvial subtypes; the Miscellaneous forests are subdivided into North-Indian Moist Teminalia, Cane brakes, tropical valley fresh water swamp, Khair-babul, Khair-sissoo, North dry-mixed deciduous, Aegle and Gangetic saline scrub; the Grasslands belonging to the lower alluvial moist savannah type and extending over about 37,000 acres, represent the largest of the forest sub-types, discussed below.It has been established that the richness of the grass in the savannah, is not due to the large of different species in the area, but due to the distribution of some species over more stable riverain flats, which are subject to occasional floods and are locally known as PHANTAS.

Фиброцементогрунт в устройстве дорожных одежд лесовозных автомобильных дорог

The most important factor in increasing the efficiency of the development of forest tracts is the development and improvement of the transport and operational condition of the network of logging roads. Inert road construction materials, such as sand, crushed stone, crushed stone-sand mixture or gravel-sand mixture, are traditionally used for the construction of pavements for logging roads. However, in the areas with a shortage of these materials, the cost of road construction increases significantly. An alternative technology that can significantly reduce or completely eliminate the use of inert road construction materials is the stabilization of local soils for the construction of pavement structural layers. The soil stabilization technology consists in mixing them with binders and compacting them at the optimal moisture content of the mixture. In doing so, the resulting material acquires the desired strength and frost resistance. The most effective and common binder for soil stabilization is Portland cement. However, along with high strength properties and frost resistance, cement soils, due to their crystalline structure, have low crack resistance, which worsens transport and operational performance and shortens the service life of road pavements. One of the rational solutions for increasing the security of soil stabilization for the construction of road pavements is the installation of fiber cement soil layers. The object of this research is fiber cement soil for the construction of structural layers of road pavements for logging roads. The aim is to improve the physical and mechanical properties and frost resistance of soils stabilized with Portland cement with the addition of the material based on basalt fiber. Laboratory tests of compressive and tensile strength during splitting, as well as frost resistance of fiber cement soils of various compositions were carried out in accordance with GOST R 70452–2022. According to the data obtained, fiber cement soil has higher strength and frost resistance compared to cement soil. The fibers distributed throughout the cement-soil matrix effectively perceive external loads, providing high physical and mechanical indicators, and therefore crack and frost resistance of the material. The use of fiber cement soil for the construction of pavements for logging roads will increase the durability and reliability of their operation, as well as reduce the costs of construction and operation of road transport infrastructure of forest tracts.

Massive Bird Nest Losses: A Neglected Threat for Passerine Birds in Atlantic Forest Fragments from the Pernambuco Endemism Center

Understanding the mechanisms by which tropical forest fragmentation can affect the persistence of species and populations is of scientific and practical interest. However, nest survival has been one the least addressed of the potentially harmful effects associated with habitat fragmentation, and studies involving nest predator’s identification are still underdeveloped. The Pernambuco Endemism Center (PEC) is the part of the Atlantic Forest located north of the São Francisco River, in northeastern Brazil, where large forest tracts no longer exist and a wave of bird extinctions has occurred recently. Here, we investigated the nest survival of forest understory birds from three PEC fragments (690, 979, and 1036 ha), and we used infra-red camera traps for predators’ identification. Overall, the apparent nest survival was 15.5%, and nest-day-based survival probability for the four more representative species (including two endemic and threatened taxa) were 2.6, 4.4, 6.9, and 18.9%, being 2.7 to 8.5 times smaller than populations or related taxa from the Atlantic Forest of southeastern Brazil. Predators were marmosets (25%), opossums (25%), tegu (19.4%), coati (16.7%), snakes (8.3%), and hawks (5.5%). Jackknife2 model-predicted nest predator’s richness was 20.7 (SD = 1.6). We reinforce the evidence that nest predation associated with fragmentation can affect negatively the bird populations from tropical forests.

Stronger genetic differentiation among within-population genetic groups than among populations in Scots pine provides new insights into within-population genetic structuring

We investigated the presence of spatial genetic groups within forest tree populations and determined if the genetic divergence among these groups is greater than that between populations using Scots pine (Pinus sylvestris) as a model species. We genotyped 890 adult trees of Scots pine in six natural populations in Lithuania at 11 nuclear microsatellite loci. We used a Bayesian clustering approach to identify the within-population genetic groups within each of the six populations. We calculated the differentiation indexes among the genetic groups within each population and among the six populations by ignoring the genetic groups. The Bayesian clustering revealed 2 to 6 distinct genetic groups of varying size as the most likely genetic structures within populations. The genetic differentiation indexes among the genetic groups within populations were nearly tenfold greater (FST = 0.012–0.070) than those between the populations (FST = 0.003). We conclude on the existence of markedly stronger structuring of genetic variation within populations than between populations of Scots pine in large forest tracts of northern Europe. Such genetic structures serve as a contributing factor to large within population genetic diversity in northern conifers. We assume that within population mating in Scots pine is not completely random but rather is stratified into genetic clusters. Our study provides pioneering novel key insights into structuring of genetic variation within populations. Our findings have implications for examining within-population genetic diversity and genetic structure, conservation, and management of genetic resources.

Khambesvari Yatra:-a Symbol of Shakti Worship in Boudh District of Odisha

The cult of the mother Goddess is associated with the most ancient faith of human beings all over the world from time immemorial. The divine mother is considered to be a source of energy or the Shakti itself. In the ancient world from the dawn of civilization mother Goddess was worshipped in different names. Every nook and corner of Odisha is associated with the mother Goddess which is popularly known as Gramadevati. The mother Goddess enshrined almost in every village in Odisha either of a pillar or a post or an anthropomorphic representation was popularly famous as the Stambhesvari or Khambesvari. The cult of Stambhesvari alias Khambesvari is widespread and popular particularly in western Odisha and Ghumusar region of south Odisha. She is still the presiding deity in most of the villages of Ghumusar, Boudh, Sonepur, Angul, Talcher, and Dhenkanal regions which consist mostly of hill and forest tracts. Khambhesvari Yatra is one of the most popular folk tradional festival of this locality.

Transboundary Central African Protected Area Complexes Demonstrate Varied Effectiveness in Reducing Predicted Risk of Deforestation Attributed to Small-Scale Agriculture

The forests of Central Africa constitute the continent’s largest continuous tract of forest, maintained in part by over 200 protected areas across six countries with varying levels of restriction and enforcement. Despite protection, these Central African forests are subject to a multitude of overlapping proximate and underlying drivers of deforestation and degradation, such as conversion to small-scale agriculture. This pilot study explored whether transboundary protected area complexes featuring mixed resource-use restriction categories are effective in reducing the predicted disturbance risk to intact forests attributed to small-scale agriculture. At two transboundary protected area complex sites in Central Africa, we used Google Earth Engine and a suite of earth observation (EO) data, including a dataset derived using a replicable, open-source methodology stemming from a regional collaboration, to predict the increased risk of deforestation and degradation of intact forests caused by small-scale agriculture. For each complex, we then statistically compared the predicted increased risk between protected and unprotected forests for a stratified random sample of 2 km sites (n = 4000). We found varied effectiveness of protected areas for reducing the predicted risk of deforestation and degradation to intact forests attributed to agriculture by both the site and category of protected areas within the complex. Our early results have implications for sustainable agriculture development, forest conservation, and protected areas management and provide a direction for future research into spatial planning. Spatial planning could optimize the configuration of protected area types within transboundary complexes to achieve both forest conservation and sustainable agricultural production outcomes.

An intermediate level of disturbance with customary agricultural practices increases species diversity in Maya community forests in Belize

Across the planet, Indigenous societies control, use, and manage large tracts of tropical forest that are crucial for combating climate change. Here we investigate whether customary Indigenous agricultural practices can increase forest species diversity using swidden (aka, slash-and-burn) agriculture. We examine the community lands surrounding two Q’eqchi’ Maya villages in southern Belize using high-resolution multispectral imagery that we collected with drones, ground truth data related to land use and history, and a plant and tree biodiversity survey. We use computational methods including simulation and Bayesian modeling to analyze the relationship between spectral diversity, forest diversity, and landscape disturbance. Our key result, replicated in both villages, is that the highest level of spectral diversity (a proxy for forest diversity) is associated with an intermediate level of forest disturbance. In conclusion, we suggest that concepts from complex adaptive systems can provide an important conceptual framework for understanding how ecosystem enhancement can emerge from customary Indigenous land use practices.

Influence of phytocenosis on the medical potential of moss extracts: the Pleurozium schreberi (Willd. ex Brid.) Mitt. case

The question was asked “whether plant phytocenosis has an impact on the medical potential of the extracts from Pleurozium schreberi”. Moss samples were collected from four different phytocoenoses: mixed forest (oak-pine forest), a forest tract in pine forest, 5–15-year-old pine forest and 50-year-old pine forest. Chemical composition of the extracts, antioxidative capacity (FRAP and ABTS·+ assays), as well as biological activities including cytotoxicity for the mouse fibroblasts L929 line (MTT reduction assay), biostatic/biocidal effect against selected bacteria and fungi (broth microdilution method followed by culture on solid media), and regenerative properties on human fibroblasts HFF-1 line (scratch assay) were tested. The conducted research clearly proves that phytocenosis determines the quality of moss extracts. The analyses showed that in every examined aspect the IV-7 extract (obtained from a specimen collected in a Pinus sylvestris L. forest, monoculture up to 15 years old) exhibited the highest values and the strongest activity. Other extracts of the same species but growing in other phytocenoses—in a mixed forest (IV-5), a forest tract in a Pinus sylvestris monoculture forest (IV-6) and in a P. sylvestris forest of pine monoculture about 50 years old (IV-8) showed much weaker activity and lower values of the above-mentioned parameters. At the same time, none of the tested extracts exerted a pro-regenerative effect. The P. schreberi extracts were characterized by a varied total content of phenolic compounds in the range from 0.63 ± 0.02 to 14.01 ± 0.25 mg/g of plant material. UPLC/MS analysis showed a varied phenolic profile of the extracts, with caffeoylquinic acid and quercetin triglucoside predominating in all of them.

Small scale agriculture continues to drive deforestation and degradation in fragmented forests in the Congo Basin (2015–2020)

The Central African region hosts the largest continuous tract of forest in Africa, regulating global climate while providing essential resources and livelihoods for millions of people and harbouring extensive biodiversity. Extractive industries, infrastructure development and industrial agriculture have often been cited as major threats to these forests and are expected to increase. A regional collaborative effort has produced the first systematically validated remote sensing assessment of deforestation and degradation drivers in six central African countries for the 2015–2020 time period. Multiple, overlapping drivers are assessed through visual interpretation and show that the rural complex, a combination of small-scale agriculture, villages, and roads contributes to the majority of observed deforestation and degradation. Industrial drivers such as mining and forestry are less common, although their impacts on carbon and biodiversity could be more permanent and significant than informal activities. Artisanal forestry is the only driver that is observed to be consistently increasing over the study period. Our assessment produces information relevant for climate change mitigation and land use planning which requires detailed information on multiple direct drivers to target specific activities and investments.

Park conservation or degradation? iCLUE modelling of land use change projections in the upper Manafwa watershed on Mount Elgon, Uganda

Land use changes result from interactions between different factors over time. Land use models support natural resource conservation by helping stakeholders to understand and predict these changes. Through such model-based projections, governments and conservationists can identify hotspots of encroachment and formulate informed decisions for sustainable conservation. Land use on Mount Elgon has undergone rapid changes in the conservation area and community land since the 1970s. Park encroachment has threatened natural cover due to population pressure and increasing demand for agricultural land. To support conservation efforts, this study conducted near-future potential land use change projections using historical land use change and iCLUE model simulations. This study established hotspots of land use conversion, locations of park encroachment and the extent of land use intensification in the upper Manafwa watershed of Mount Elgon. The study applied remote sensing, a geographic information system, and a land use change model (iCLUE), while considering nine land use classes to project land use change for 2030, 2040 and 2050 using a “business-as-usual” scenario. Stakeholder verification of the model output was conducted in a dedicated workshop. The results showed that in 2050, agriculture (44.24%) and low-stocked tropical high forest (22.56%) will be the largest land cover classes with bushland and shrubs as the smallest land cover classes (∼0.5%). Most of the land use conversion in the park is projected to occur along the boundary of the conservation area by agriculture and built-up areas. This study will guide stakeholders and decision makers in planning future sustainable management strategies to conserve and enhance remaining forest tracts in Mount Elgon.

Spatiotemporal dynamics reveals forest rejuvenation, fragmentation, and edge effects in an Atlantic Forest hotspot, the Pernambuco Endemism Center, northeastern Brazil.

Large forested tracts are increasingly rare in the tropics, where conservation managers are often presented with the challenge of preserving biodiversity in small and isolated fragments. The Atlantic Forest is one of the world's most important biodiversity hotspots, jeopardized by habitat loss and fragmentation. The Pernambuco Endemism Center (PEC) is the most degraded of the Atlantic Forest regions and because of the dramatic levels of deforestation, fragmentation, and ongoing species losses, studies on the distribution and configuration of the PEC's forest cover are necessary. However, across dynamic tropical landscapes, investigating changes over time is essential because it may reveal trends in forest quality attributes. Here, we used Google Earth Engine to assess land use and land cover data from MapBiomas ranging from 1985 to 2020 to calculate current landscape metrics and to reveal for the first time the spatiotemporal dynamics of the PEC's forests. We identified a forest cover area that ranged from 571,661 ha in 1985 to 539,877 ha in 2020, and about 90% of the fragments were smaller than 10 ha. The average fragment size was about 11 ha, and only four fragments had more than 5,000 ha. Deforestation was mostly concentrated in northern Alagoas, southern Pernambuco, and non-coastal Paraíba and Rio Grande do Norte. On average, borders represented 53.6% of the forests from 1985 to 2020, and younger forests covered 52.3% of the area in 2017, revealing a vegetation rejuvenation process 2.5 times higher than in total Atlantic Forest. In 2017, older forest cores in fragments larger than 1000 ha (i.e., higher-quality habitats) represented only 12% of the remaining forests. We recommend that the amount of forest cover alone may poorly assist conservation managers, and our results indicate that ensuring legal protection and increasing surveillance of the PEC's few last higher-quality habitats is urgently needed.

Criminalizing reprisals against the natural environment

AbstractThroughout history, armed conflicts have frequently seen serious harm committed against the natural environment. From the early 1960s to 1971, the United States used Agent Orange to defoliate large tracts of Vietnamese forests. In the 1990s, Saddam Hussein vengefully ordered the burning of Kuwaiti oil wells, resulting in massive pollution to the air, land and surrounding seas. More recently, ecocentric harm has been documented in the Colombian civil war, by the so-called Islamic State group, and in the Ukraine conflict, among others. Whilst international humanitarian law (IHL) contains several prohibitions against environmental harm, the most striking is Article 55(2) of Additional Protocol I, whereby “[a]ttacks against the natural environment by way of reprisals are prohibited”. Although this provision appears absolute and unconditional, critical questions persist regarding its status under customary international law and its applicability in non-international armed conflicts. Moreover, its criminalization has not been explored in the jurisprudence of international courts or in the relevant scholarly literature, despite the fact that penal sanctions against individuals are an important factor for enforcement of environmental protections.To fill the lacuna, the following analysis examines the prohibition and criminalization of reprisals against the natural environment. It reviews conventional and customary international law to determine the current status of a putative criminal prohibition and its potential as lex ferenda. Importantly, it also assesses the relevance of reprisals against the natural environment for prosecutions under existing war crimes, such as attacks on civilian objects and destruction of enemy property. It generates novel insights for the application of international law to ecocentric harm, including that (1) reprisals against the natural environment are not criminal per se, but (2) conceptualizing the environment as a civilian object opens up clear paths for prosecuting attacks, including reprisals, against it; (3) the inherently intentional nature of reprisals has far-reaching implications for their prosecution; (4) reprisals can significantly impact the pivotal test of military necessity which arises in criminal prohibitions such as that found in Article 8(2)(b)(iv) of the Rome Statute; and (5) situations of reprisals could impact the application of the proposed definition of ecocide.Traversing IHL and international criminal law (ICL), the article identifies ways in which these traditionally anthropocentric bodies of law can be reoriented to accommodate ecocentric values. This reconceptualization is significant, as the prospect of criminal sanctions is critical for deterring potential perpetrators and potentially adds a basis for reparations designed to remediate damage to the environment. The assessment redresses the fact that the natural environment has been seen as a peripheral matter under both IHL and ICL and has remained under-explored despite the ongoing destruction wrought on nature including during armed conflict. It seeks to elevate the environment to a core protected value under these legal regimes, as a reflection of our increasing awareness that the natural environment is critical for the well-being of current and future generations and our growing appreciation of the intrinsic importance of protecting nature.

Factors determining the seasonal habitat use of Asian elephants in the Western Ghats of India

AbstractAsian elephants (Elephas maximus) are globally endangered, and their populations persist in several meta‐populations within fragmented landscapes across their distribution. Developing landscape‐level management plans for elephants requires reliable information on the pattern and determinants of their distribution across relevant spatial and temporal scales. The Brahmagiri‐Nilgiri‐Eastern Ghats Landscape (Nilgiri landscape) of peninsular India supports the largest breeding population of Asian elephants globally. The Wayanad Plateau, a wet forest tract in the dry forest‐dominated Nilgiri landscape, witnessed extensive forest fragmentation recently and evolved as a forest‐agriculture matrix. We predicted that habitat use by elephants in the Wayanad Plateau would be high during summer because of the availability of numerous perennial streams and associated swamps that retain water and soil moisture for plant growth over the dry season. We also hypothesized that elephants would use areas with greater forest cover that are removed from human settlements. We used an occupancy‐based approach that accounts for detection probability to understand factors influencing habitat use by elephants in summer (low rainfall, high temperature) and post‐monsoon (largely rainless winter conditions but with abundant forage and water) in 2019 and 2020. As expected, the intensity of habitat use was higher during the summer than during the post‐monsoon season. Elephants used habitats near perennial water sources and with greater forest cover, avoiding areas with high human disturbances. We emphasize the importance of areas that provide key resources for elephants during resource scarcity and the need to prevent habitat degradation for long‐term persistence of elephants and mitigation of human–elephant conflict.

Changes in Coleopteran assemblages over a successional chronosequence in a Mexican tropical dry forest.

Coleopterans are the most diverse animal group on Earth and constitute good indicators of environmental change. However, little information is available about Coleopteran communities' responses to disturbance and land-use change. Tropical dry forests have undergone especially extensive anthropogenic impacts in the past decades. This has led to mosaic landscapes consisting of areas of primary forest surrounded by pastures, agricultural fields and secondary forests, which negatively impacts many taxonomic groups. However, such impacts have not been assessed for most arthropod groups. In this work, we compared the abundance, richness and diversity of Coleopteran morphospecies in four different successional stages in a tropical dry forest in western Mexico, to answer the question: How do Coleopteran assemblages associate with vegetation change over the course of forest succession? In addition, we assessed the family composition and trophic guilds for the four successional stages. We found 971 Coleopterans belonging to 107 morphospecies distributed in 28 families. Coleopteran abundance and richness were greatest for pastures than for latter successional stages, and the most abundant family was Chrysomelidae, with 29% of the individuals. Herbivores were the most abundant guild, accounting for 57% of the individuals, followed by predators (22%) and saprophages (21%) beetles. Given the high diversity and richness found throughout the successional chronosequence of the studied tropical dry forest, in order to have the maximum number of species associated with tropical dry forests, large tracts of forest should be preserved so that successional dynamics are able to occur naturally.

An embarrassingly simple approach for visual navigation of forest environments.

Navigation in forest environments is a challenging and open problem in the area of field robotics. Rovers in forest environments are required to infer the traversability of a priori unknown terrains, comprising a number of different types of compliant and rigid obstacles, under varying lighting and weather conditions. The challenges are further compounded for inexpensive small-sized (portable) rovers. While such rovers may be useful for collaboratively monitoring large tracts of forests as a swarm, with low environmental impact, their small-size affords them only a low viewpoint of their proximal terrain. Moreover, their limited view may frequently be partially occluded by compliant obstacles in close proximity such as shrubs and tall grass. Perhaps, consequently, most studies on off-road navigation typically use large-sized rovers equipped with expensive exteroceptive navigation sensors. We design a low-cost navigation system tailored for small-sized forest rovers. For navigation, a light-weight convolution neural network is used to predict depth images from RGB input images from a low-viewpoint monocular camera. Subsequently, a simple coarse-grained navigation algorithm aggregates the predicted depth information to steer our mobile platform towards open traversable areas in the forest while avoiding obstacles. In this study, the steering commands output from our navigation algorithm direct an operator pushing the mobile platform. Our navigation algorithm has been extensively tested in high-fidelity forest simulations and in field trials. Using no more than a 16 × 16 pixel depth prediction image from a 32 × 32 pixel RGB image, our algorithm running on a Raspberry Pi was able to successfully navigate a total of over 750 m of real-world forest terrain comprising shrubs, dense bushes, tall grass, fallen branches, fallen tree trunks, small ditches and mounds, and standing trees, under five different weather conditions and four different times of day. Furthermore, our algorithm exhibits robustness to changes in the mobile platform's camera pitch angle, motion blur, low lighting at dusk, and high-contrast lighting conditions.