Large Tracts Research Articles

Nuclear power and environmental injustice

AbstractPolicy makers around the world have been advocating for an expansion of nuclear energy as a way to mitigate climate change, putting in place financial and political incentives for building new reactors and associated facilities. At the same time, policy makers have also been emphasizing the importance of incorporating justice considerations while decarbonizing. The two are not compatible because of the environmental injustices inflicted by the chain of processes required to generate electricity at nuclear power plants. These injustices are a result of the radioactive nature of the waste materials produced at each step of the nuclear fuel chain. Some of these materials remain hazardous for tens of thousands of years. In addition, nuclear facilities face the ever present risk of catastrophic accidents which can contaminate large tracts of land, rendering them uninhabitable for decades if not centuries. These consequences disproportionately fall on Indigenous Peoples and other disempowered communities, as well as non‐human entities. Such impacts are overlooked in our current socio‐political system committed to growth and a techno‐economic approach to dealing with any challenges to its continued existence.This article is categorized under: Human and Social Dimensions > Energy and Climate Justice Energy and Power Systems > Energy Infrastructure

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.

(Invited) Green Hydrogen R&D in South Africa

For decades, proton-exchange membrane (PEM) water electrolysis (WE) has been used mainly for oxygen generation in anaerobic environments. Over the past two decades, however, it has been increasingly used for hydrogen generation in the industrial sector at various and increasing scale. The PEMWE technology is also considered as a key one in the frame of the ongoing energy transition if the process of hydrogen generation by means of WE is linked to renewable energy sources, such as wind, solar, etc.Among other existing water electrolysis technologies, such as alkaline, solid oxide, the technology based on proton-exchange membranes has received a great deal of interest in South Africa. One of the reasons is endowment of South Africa with its PGM resources, such as platinum (Pt) and iridium (Ir) that are used in PEM water electrolysis (WE) catalytic components. As it is known, PEMWE technology is very well suited to accommodate intermittency of energy supply associated with renewables. PEMWE technology can also deliver relatively high-pressure hydrogen gas of high purity. South Africa has also superior endowment of both onshore wind and solar. It is known thar renewable energy (RE) is one of the largest operational cost components in the production of green hydrogen. Other factors contributing to the interest in green hydrogen water electrolysis technology in South Africa that are not obvious, but important, include large tracts of sparsely populated land with little alternative use, which can be dedicated for RE production. South Africa also has a suitable geographical position with deep water ports for the potential export of large quantity of hydrogen and its derivatives such as ammonia.Approximately 15 years ago South African Government approved national program HySA: Hydrogen South Africa that resulted in developing expertise and capacity to conduct research, development, and earlier commercial activities around green hydrogen production by means of water electrolysis. These activities include development of local IP at the components, stack and system levels. Recently, a number of “catalytic” projects have been identified in order to increase a demand in green hydrogen and stimulate investments.Recently, an international R&D project between South Africa and Japan was launched to develop further expertise in both green hydrogen and ammonia technologies [1]. Most recently, large companies, such as SASOL, made commitments to lead green hydrogen production at a large scale for the variety of applications, aiming at decarbonisation of mining and petrochemical sectors [2]. On the Governmental level, South Africa recently has approved its national hydrogen road map [3].This talk will provide a comprehensive update on the research, technology, and commercialisation activities in South Africa in the area of green hydrogen production.

Negligible Impact on Precipitation From a Permanent Inland Lake in Central Australia

AbstractFor over a century, numerous proposals for increasing available water in central Australia have been raised, inspired in part by the natural occurrence of the ephemeral lake, Kati Thanda‐Lake Eyre. It has also been proposed that additional rainfall generated by the lake would spread beyond the lake itself, potentially opening up large tracts of uncultivated land to dryland agriculture. Here we use a climate model to examine how adding a permanent lake to Australia's arid center might influence local and regional precipitation. Locally, evaporative cooling from the lake increases low‐level divergence, suppressing precipitation. Regionally, additional moisture from the lake is spread thinly over the Australian continent, resulting in little change to total precipitation. Overall, our results do not support the assertion that maintaining a large inland lake like Kati Thanda‐Lake Eyre in central Australia would significantly increase precipitation, either locally or regionally.

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.

Wide field block face imaging using deep ultraviolet induced autofluorescence of the human brain

BackgroundImaging large volume human brains at cellular resolution involve histological methods that cause structural changes. A reference point prior to sectioning is needed to quantify these changes and is achieved by serial block face imaging (BFI) methods that have been applied to small volume tissue (∼1 cm3). New methodWe have developed a BFI uniquely designed for large volume tissues (∼1300 cm3) with a very large field of view (20 × 20 cm) at a resolution of 70 µm/pixel under deep ultraviolet (UV-C) illumination which highlights key features. ResultsThe UV-C imaging ensures high contrast imaging of the brain tissue and highlights salient features of the brain. The system is designed to provide uniform and stable illumination across the entire surface area of the tissue and to work at low temperatures, which are required during cryosectioning. Most importantly, it has been designed to maintain its optical focus over the large depth of tissue and over long periods of time, without readjustments. The BFI was installed within a cryomacrotome, and was used to image a large cryoblock of an adult human cerebellum and brainstem (∼6 cm depth resulting in 2995 serial images) with precise optical focus and no loss during continuous serial acquisition. Comparison with existing method(s)The deep UV-C induced BFI highlights several large fibre tracts within the brain including the cerebellar peduncles, and the corticospinal tract providing important advantage over white light BFI. ConclusionsThe 3D reconstructed serial BFI images can assist in the registration and alignment of the microscopic high-resolution histological tissue sections.

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.

Wildfire immediately reduces nest and adult survival of greater sage-grouse

Wildfire events are becoming more frequent and severe on a global scale. Rising temperatures, prolonged drought, and the presence of pyrophytic invasive grasses are contributing to the degradation of native vegetation communities. Within the Great Basin region of the western U.S., increasing wildfire frequency is transforming the ecosystem toward a higher degree of homogeneity, one dominated by invasive annual grasses and declining landscape productivity. Greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) are a species of conservation concern that rely on large tracts of structurally and functionally diverse sagebrush (Artemisia spp.) communities. Using a 12-year (2008–2019) telemetry dataset, we documented immediate impacts of wildfire on demographic rates of a population of sage-grouse that were exposed to two large wildfire events (Virginia Mountains Fire Complex—2016; Long Valley Fire—2017) near the border of California and Nevada. Spatiotemporal heterogeneity in demographic rates were accounted for using a Before-After Control-Impact Paired Series (BACIPS) study design. Results revealed a 40% reduction in adult survival and a 79% reduction in nest survival within areas impacted by wildfires. Our results indicate that wildfire has strong and immediate impacts to two key life stages of a sagebrush indicator species and underscores the importance of fire suppression and immediate restoration following wildfire events.

Origins of green turtle fishery bycatch in the central pacific revealed by mixed genetic markers

Longline fishing vessels, such as those that target tuna or billfish, also unintentionally catch endangered marine turtle species on the high seas. The stock composition of this bycatch is often unknown but potentially complex, with individuals coming from many possible origins on an ocean-basin scale. To better understand the stock composition of green turtle (Chelonia mydas) bycatch we obtained 46 turtles, 27-91 cm in curved carapace length, caught by Hawaii- and American Samoa-based pelagic longline fishing vessels across large areas of the North- and South-central Pacific. We genotyped these at nine microsatellite loci and one mitochondrial DNA marker, and used a baseline of 1,043 nesting female green turtles from beaches across the Pacific for population assignment and mixed-stock analysis. By analyzing both marker types jointly we were able to increase power and genetically resolve ten baseline stocks of nesting females with mean self-assignment and simulated accuracies of 75-97%. Above the Equator, green turtle bycatch was composed mostly of individuals from Hawaiian and Eastern Pacific stocks, with a small number from the Western Pacific. Below the Equator, the most common stocks in the bycatch were from Australia and the Coral Sea, American Samoa and French Polynesia, and the Galápagos Islands. Overall, turtles originating from East, West, and Central Pacific breeding populations were major components of the bycatch, suggesting that the geographic ranges of these populations overlap across large tracts of ocean during the pelagic life history stages.

Essential planetary health workers: Positioning rangers within global policy

AbstractOur planet is facing increasing challenges: climate change, biodiversity loss, pandemics, poverty, and many other problems closely linked to a deteriorating environment. Meanwhile, one of our most important assets, rangers working in protected and conserved areas responsible for managing large tracts of the planet's lands and waters, are often underutilized, underrecognized and underequipped. They are generally left out of the debate about conservation and sustainable development policy, despite being central to the success of those policies. This paper outlines the need for global leaders across multiple sectors to recognize the profession of rangers as essential planetary health workers and to position rangers more effectively within global conservation and environmental policy mechanisms. It introduces the challenges facing rangers, the emerging diversity of roles within the ranger profession and the important contribution of rangers to conservation and sustainable development. It presents policy and implementation avenues to improve recognition and professionalization of rangers as key executors of conservation and development policy, particularly considering the recent Global Biodiversity Framework ambitions.

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.

Identification of Brush Species and Herbicide Effect Assessment in Southern Texas Using an Unoccupied Aerial System (UAS)

Cultivation and grazing since the mid-nineteenth century in Texas has caused dramatic changes in grassland vegetation. Among these changes is the encroachment of native and introduced brush species. The distribution and quantity of brush can affect livestock production and water holding capacity of soil. Still, at the same time, brush can improve carbon sequestration and enhance agritourism and real estate value. The accurate identification of brush species and their distribution over large land tracts are important in developing brush management plans which may include herbicide application decisions. Near-real-time imaging and analyses of brush using an Unoccupied Aerial System (UAS) is a powerful tool to achieve such tasks. The use of multispectral imagery collected by a UAS to estimate the efficacy of herbicide treatment on noxious brush has not been evaluated previously. There has been no previous comparison of band combinations and pixel- and object-based methods to determine the best methodology for discrimination and classification of noxious brush species with Random Forest (RF) classification. In this study, two rangelands in southern Texas with encroachment of huisache (Vachellia farnesianna [L.] Wight & Arn.) and honey mesquite (Prosopis glandulosa Torr. var. glandulosa) were studied. Two study sites were flown with an eBee X fixed-wing to collect UAS images with four bands (Green, Red, Red-Edge, and Near-infrared) and ground truth data points pre- and post-herbicide application to study the herbicide effect on brush. Post-herbicide data were collected one year after herbicide application. Pixel-based and object-based RF classifications were used to identify brush in orthomosaic images generated from UAS images. The classification had an overall accuracy in the range 83–96%, and object-based classification had better results than pixel-based classification since object-based classification had the highest overall accuracy in both sites at 96%. The UAS image was useful for assessing herbicide efficacy by calculating canopy change after herbicide treatment. Different effects of herbicides and application rates on brush defoliation were measured by comparing canopy change in herbicide treatment zones. UAS-derived multispectral imagery can be used to identify brush species in rangelands and aid in objectively assessing the herbicide effect on brush encroachment.

Preserving large tracts of natural grassland promotes mammal species richness and occurrence in afforested areas

The global loss of biodiversity paired with the shortcomings of protected areas highlights the need to improve the conservation potential of human-modified lands. Although often referred to as “ecological deserts”, large spatial scales and long rotation periods make tree plantations a relatively stable and permeable environment that could provide an important link between fragmented natural habitats. Different intensities of afforestation within the same geographic grassland region provide an opportunity to test how transformation by commercial plantations affects local biodiversity. We conducted camera trap surveys at two sites characterised by different degrees of afforestation. We demonstrate a higher mammalian diversity and a higher probability of habitat use in less transformed areas, suggesting that preserving large tracts of native vegetation is vital when offsetting biodiversity loss from timber plantations, especially regarding grassland-specialist species. Community-level habitat use increased in more rugged areas, while in the highly transformed site, habitat use increased closer to indigenous patches and roads. Our research highlights the importance of maintaining comprehensive networks of protected units as part of a broader landscape management approach and identifies a major challenge for the forestry industry moving forward, with plantation stands being dominated by species that threaten the long-term sustainability of the crop itself.

Contract farming as an alternative to large‐scale land acquisition and promoting inclusive and responsible agricultural investment: Evidences from Ethiopia

AbstractThe acquisition of large tracts of land for agricultural investment from developing countries, including Ethiopia, by commercial firms has been aggravated after global food crisis in 2007–2008. Given the current attention to large‐scale land acquisition or land grabbing phenomenon, contract farming has been identified as a participatory and inclusive farming model which does not require agricultural firms to purchase or lease land in order to operate agricultural investments. Contract farming enables local smallholder farmers to produce agricultural products on their own land and ensure the benefits of land‐based agricultural investments remain with them. Unfortunately, the understanding and practice of contract farming as an alternative to large‐scale land acquisition to protect the land rights of the local people is underexplored in Ethiopia. This study, therefore, is aimed to examine the practice and conceptual understanding of contract farming in the context of agricultural investment in Ethiopia. To achieve this objective, mixed research approach was employed. Intensive document reviews, questionnaire, key informant interview and FGD were used as data collection tools. The results show that the practice of contract farming in Ethiopia is very insignificant and commercial farming is almost entirely relied on land acquisition. Moreover, gaps in policy and legal framework to guide contract farming has made difficult to effectively implement contract framing at national level. Finally, this study advised to introduce contract framing as a viable alternative to land acquisition for agricultural investment that fosters local smallholder farmers' participation in agricultural production and contributes to sustainable development.

Mapping forest ecosystem service supply in two case studies in Latvia

Forest ecosystems provide a wide range of goods and benefits for human survival and well-being. This includes materials, food and fiber and other goods and benefits. Ecosystem services (ES) paradigm is increasingly used in socio-ecological studies. ES generally include provisioning services, regulation & maintenance services and cultural services. Identifying and mapping areas important for ES supply in peri-urban forested landscapes is crucial for comprehensive spatial planning process which takes into account the needs and preferences of local inhabitants. This is in contrast to planning approaches which have focused on which have been focused on mapping and valuing ES supply but ignoring ES demand. The aim of this study was to identify and assess the benefits provided by peri-urban forest ecosystems in two case study regions in Latvia. For this study, we chose two case study areas in Latvia: the city of Daugavpils and its surrounding district. Daugavpils district is located in South-eastern part of Latvia and covers 1876.1 km2. Population in Daugavpils district is 19,553, city of Daugavpils – 80,627. We used 238 structured interviews to collect data on local inhabitants’ preferences and views. Interviewer asked to rank 21 types of forest landscapes using printed photographs of which were linked to particular ES. Later we mapped co-occurrences of desirable types of forest landscapes (selected by >20% of respondents) using 1 × 1 km grid and identified Hot- and Cold-spots of ES supply using Getis-Ord GI* analysis in ArcGIS Pro. We found that more than 70% of respondents, both urban and rural, saw thinned deciduous forest and middle-aged pine forest landscape as important for their well-being. Respondents also did not rank highly regulation & maintenace ES but focused on cultural and provisioning ES. Hot-spot analysis indicated multiple, statistically significant (α = 0.01) clusters of ES supply which were located in large tracts of mainly production forests and few in protected forest areas with significant restrictions. Overall, our approach demonstrated that our approach for identifying and mapping co-occurrences of desirable forest landscapes can be useful for spatial planning at local and regional levels. This approach is based on needs and preferences of local inhabitants and provide the perspective more relevant to local communities compared to imposed top-down planning approaches.

Effect of microhabitat characteristics for predicting habitat suitability for a stalking large carnivore—the Eurasian lynx in middle Europe

AbstractLarge European carnivores are generally considered forest animals. However, there are a number of interacting factors that may have different impact on the availability and suitability of habitat for individual species. Felids, because of their stalking hunting mode, are habitat specialists requiring a heterogeneous environment, making them specifically vulnerable to habitat disturbance. The Eurasian lynx (Lynx lynx), despite protection in many European countries, has a surprisingly limited range. To explain environmental factors that affect its distribution, we undertook habitat selection and habitat suitability analyses at the macrohabitat and microhabitat scales, based on lynx occurrence and environmental data in Poland. Since the species occurs in two populations, one of which inhabits lowland and the other mountainous area, we modelled habitat suitability separately in both areas and then extrapolated it for the whole country scale. The lynx selected forests with medium undergrowth density in the lowlands and highly rugged terrain in the mountain areas—a proxy of stalking cover. Habitat suitability modelling performed at the macrohabitat scale identified around 110 000 km2 of habitat available from which 55 700 km2 was classified as high quality including large tracts of forests in western Poland that are beyond the natural range of the lynx. However, the microhabitat model built by including stalking cover variables, decreased high‐quality habitats to only 33% of the area designated at the macrohabitat scale. This model is largely consistent with the current distribution of lynx in Poland. This suggests that the simplified internal structure of forests (lacking understory cover) may act as a hindrance to increasing the distribution of lynx populations and helps to explain its limited range in the Central European lowlands. This research suggests that the microhabitat structure may play the crucial role in the effective conservation of the Eurasian lynx.

Native and Dryland Pasture Seed Mixes Impact Revegetation 12 Years after Pipeline Construction in Southern Alberta

Activities associated with agriculture, grazing, and the energy industry have altered large tracts of native rangeland in North America. Pipelining causes intense local disturbance by removal of vegetation and alterations to soil horizons. Following a disturbance, reclamation is required to return the land to equivalent land capability. Revegetation is usually by seeding native and/or agronomic (non-native, dominant) species. This study investigated the long-term effects of native and dryland pasture (91% non-native species) seed mixes, grazing, and right-of-way (RoW) treatments on revegetation of native rangeland in southeastern Alberta. Native seed mixes were more successful at enhancing seeded vegetation cover than dryland pasture seed mixes. Grazing had a significant impact only on the survival of non-native grasses. The seed mix did not significantly affect total, native, non-native, annual, or perennial forb cover. Total forb cover was significantly higher on the trench with the dryland pasture seed mix than all other RoW treatments (storage, work). This long-term study suggests that native seed mixes can result in successful revegetation of reclamation following pipeline construction.

Adivasi migrant labour and agrarian capitalism in southern India

AbstractThis paper looks at a case of rural‐to‐rural movement of agrarian capital in southern India and the ways in which capital–labour relations are reworked to maintain oppressive forms of exploitation. Faced with an agrarian crisis, capitalist farmers from affluent communities of Wayanad, Kerala, take large tracts of land for lease in the neighbouring state of Karnataka and grow ginger based on price speculation. Landless Adivasis from Wayanad have served as labourers on these ginger farmlands for the past three decades. Recently, farmers have shifted to employing labourers from a Scheduled Caste (SC) from Karnataka. The change happened not just because of the lower wages the SC labourers were willing to work for but also because of the farmers' inclination to move away from Adivasis who have been resisting the poor working conditions on the farm. The story resonates with the broader dynamics of agrarian–labour relations amidst capitalist expansion and highlights the centrality of socio‐political factors at play.

Land-use and land cover change dynamics in urban Ghana: implications for peri-urban livelihoods

ABSTRACTThis paper examined the dynamics of urban land use and land cover change, and their implications for livelihoods in peri-urban Tamale, Ghana. The study employed household data and Landsat Thematic Mapper (TM) for 1986, Enhanced Thematic Mapper Plus (ETM +) for 2004 and Landsat 8 Operationalised Landsat Imager/Thermal Infrared Sensor (OLIS/TIRS) for 2019. The findings show that the urban expansion process witnessed a transition from agricultural livelihood to a more complex and monetised urban economy, which presented mixed impacts on the livelihoods of the peri-urban households. We argued that the horizontal expansion of urban areas into prime agricultural lands could be halted by promoting vertical development in the form of multi-storey buildings rather than the horizontal multiplication of individual housing units. Supporting the peri-urban households to diversify their livelihood portfolios by venturing into beekeeping, poultry farming, and livestock keeping, which do not require large tracts of land is recommended.

Adaptive convolution kernel network for change detection in hyperspectral images.

Feature extraction is a key step in hyperspectral image change detection. However, many targets with great various sizes, such as narrow paths, wide rivers, and large tracts of cultivated land, can appear in a satellite remote sensing image at the same time, which will increase the difficulty of feature extraction. In addition, the phenomenon that the number of changed pixels is much less than unchanged pixels will lead to class imbalance and affect the accuracy of change detection. To address the above issues, based on the U-Net model, we propose an adaptive convolution kernel structure to replace the original convolution operations and design a weight loss function in the training stage. The adaptive convolution kernel contains two various kernel sizes and can automatically generate their corresponding weight feature map during training. Each output pixel obtains the corresponding convolution kernel combination according to the weight. This structure of automatically selecting the size of the convolution kernel can effectively adapt to different sizes of targets and extract multi-scale spatial features. The modified cross-entropy loss function solves the problem of class imbalance by increasing the weight of changed pixels. Study results on four datasets indicate that the proposed method performs better than most existing methods.