Land Conversion Research Articles

Habitat characteristics and threats of little-known endemic dragonfly, Neurothemis feralis (Burmeister, 1839) (Odonata: Libellulidae) in East Java, Indonesia

Abstract. Susanto MAD, Gama ZP, Leksono AS. 2024. Habitat characteristics and threats of little-known endemic dragonfly, Neurothemis feralis (Burmeister, 1839) (Odonata: Libellulidae) in East Java, Indonesia. Biodiversitas 25: 2907-2920. Neurothemis feralis is a dragonfly with limited distribution and is found only in the lowlands of Java, Sumatra, Krakatau, and Bangka. Its habitats that traverse anthropogenic area face various threats from human activities. Despite the imminent of its depopulation, many essential information regarding the biology of N. feralis remain scarce, deem it with data deficient conservation status according to the International Union for Conservation of Nature (IUCN) Red List. This study aims to study habitat characteristics of N. feralis for future conservation purposes. This study was conducted in Surabaya, Sidoarjo, and Gresik, East Java Province, with a five-month study period of July-November 2023. The results showed that N. feralis prefers locations with 36-64% air humidity, 29.2-35.8°C air temperature, and 16970-36400 lux light intensity. Air humidity positively correlated with the abundance of N. feralis, while high temperatures and light intensity tend to have negative impact. The coverage of vegetation with 20-100 cm height was found as another habitat component that positively affects its abundance, while the loss of this coverage understandably negate the dragonfly abundance. Vegetation provides habitat for N. feralis, as well as its prey, competitors and even predators. Despite N. feralis population can still be observed from urban areas with up to 82.40% residential allotment (within 500 m radius of the study site), the disappearance of its population is likely if believably impending if anthropogenic activities (e.g., land conversion and vegetation burning) continue to occur.

Mapping global land conversion pressure to support conservation planning

Proactively identifying where land conversion might occur is critical to targeted and effective conservation planning. Previous efforts to map future habitat loss have largely focused on forested systems and have been limited in their consideration of drivers of loss. We developed a 1-km resolution, global map of land conversion pressure from multiple drivers, referred to as the conversion pressure index (CPI). The CPI combines past rates of anthropogenic change, as measured by temporal human modification maps, with suitability maps for potential future expansion by large-scale development. The CPI thus offers a new way to measure a cumulative gradient of anthropogenic pressure as opposed to categorical land cover change. We find that nearly 23% of land across 200 countries have relatively high conversion pressure, potentially impacting over 460 million ha of intact natural lands. We illustrate how this information can be used to identify areas for proactive conservation to avoid future loss and ensure that national commitments under the Kunming-Montreal Global Biodiversity and Paris Agreement Climate Frameworks are upheld.

LEGAL CERTAINTY ON BUILDING DISTRIBUTION AND CONFORMITY WITH THE DETAILED SPATING PLAN IN THE WILDLAND OF MENGWI SPECIFICALLY IN THE GREEN OPEN SPACE ZONE AND THE AGRICULTURAL ZONE (ANALYSIS OF LEGAL CERTAINTY FOR BUILDINGS THAT VIOLATE SPATIAL PLANNING)

This study aims to identify and understand in depth the factors that cause development in the green open space zone and agricultural zone in Mengwi District, Badung Regency, as well as analyze the legal certainty for building owners in these zones. The research was carried out in a qualitative descriptive manner with legal interpretation and legal communication methods, which systematically prepared legal materials to be presented in the thesis entitled "Legal Certainty Against the Distribution of Buildings and Conformity with Detailed Spatial Plans in the Mengwan District Area (RDTR WP), Especially in the Green Open Space Zone and Agricultural Zone." The results show that social factors such as population growth, inheritance rights distribution system, and low interest of the younger generation in agriculture are the most important factors that affect the development and conversion of green open spaces (RTH) in this area. However, there are challenges in law enforcement such as the effectiveness of long-standing regulations and the lack of public awareness of the importance of preserving green lanes. The government and related agencies need to be more decisive in sanctioning buildings in the area to maintain green areas and agriculture as a mitigation effort in preventing land conversion. This research is expected to be a guideline for the community in using land in accordance with spatial planning, providing input for the government on the legal impact of land use transitions, and providing guidance for all stakeholders related to land use.

Blue carbon habitats in Aotearoa New Zealand—opportunities for conservation, restoration, and carbon sequestration

Coastal marine habitats (i.e. mangroves, saltmarshes, and seagrasses) have a high capacity for carbon sequestration (termed “blue carbon”) and the potential to reduce the effects of greenhouse gas emissions. However, blue carbon habitats have historically decreased as a consequence of land conversion, coastal development, and pollution and are under threat in many locations. Restoration of these habitats can reverse historic losses and generate carbon credits through increased carbon sequestration. With a long coastline, we hypothesized that there would be significant opportunities for coastal blue carbon in Aotearoa New Zealand. Results revealed Aotearoa estuaries and coastal areas contain approximately 20,932 ha of saltmarsh, 30,533 ha of mangrove, and 61,340 ha of seagrass, estimated to sequester a total of approximately 57,800 tC/year. A further 87,861 ha of land was estimated to be potentially suitable for blue carbon projects via tidal restoration, of which 56,482 ha was suitable for saltmarsh restoration (equivalent to 60,435 tC yr if restored), 17,291 ha was suitable for mangroves (26,455 tC/year), and 14,087 ha was suitable for seagrass (4790 tC/year). Both existing extent and restoration opportunity varied throughout the country, with greater opportunity in some regions than others. Nationwide, the total sequestration potential for blue carbon restoration was estimated at 91,680 tC yr−1 if all potential areas were restored. Carbon credits generated by blue carbon projects could be traded on a carbon market in Aotearoa, generate revenue for landowners, provide an additional pathway to meet domestic and international climate change targets, and result in a diversity of other ecological, social, and cultural co‐benefits from coastal restoration.

Impacts of Land Use on Runoff and Sediment Dynamics in Tropical Watersheds: A Case Study in Bogowonto Upper Watershed

Land use changes in tropical regions have increased, leading to rising environmental stress in Java, Indonesia. Food shortages have driven land conversion and expansion, which increases peak flows during the rainy season and reduces water storage in the dry season, heightening flood risks. Research on integrated catchment hydrology is crucial. This study examines the relationship between land use, runoff, and sediment in the Bogowonto Upper Watershed using SWAT hydrological modeling. The SWAT model helps understand hydrological processes at the watershed scale and the impact of land use changes on runoff and sediment dynamics. The sensitivity of SWAT model parameters varies in the Bogowonto Upper Watershed. Runoff sensitivity analysis indicates a +62% increase with a 50% change in CN value, showing high sensitivity. A 50% change in vegetation cover results in a +50% model output, indicating moderate sensitivity. Slope, Ksat (saturated hydraulic conductivity), and bulk density are fairly sensitive, while AWC is slightly sensitive. For sediment, a 50% increase in CN value results in a +47% change, and a 50% increase in vegetation cover leads to a +58% model output, showing moderate sensitivity. The model, run from 2014-2019, shows excellent accuracy with NSE of 0.82, RRMSE of 0.43, R² of 0.83, and PBIAS of 9.8%.

Analisis Daya Dukung Lahan untuk Permukiman di Kota Bukittinggi

Bukittinggi City, with the land conversion to built-up land continues to increase and the availability of land that does not increase, faces difficulties in utilizing land for settlements along with increasing population growth. The purpose of this study is to analyze the suitability of land for settlements and the carrying capacity of Bukittinggi City's residential land for the next 30 years. The quantitative descriptive research method with data presented through tables and maps, calculations refer to the Ministry of Environment's 2014 carrying capacity guidelines and RP3KP. The results of the study indicate that the area of land suitable for settlements is Suitable (S2) covering 710 ha, less suitable (S3) covering 1,147 ha, and not suitable covering 430 ha. For the carrying capacity of Bukittinggi City settlements, in Guguk Panjang District it is in the deficit class, with a DDPm value of 0.24, while 2 other districts are in the surplus class, with Mandiangin Koto Selayan District valued at 2.42, and Aur Birugo Tigobaleh District of 4.09. And for a period of 30 years, 2032, 2042, and 2052, Mandiangin Koto Selayan sub-district and Aur Birugo Tigobaleh sub district still have a surplus while Guguk Panjang sub-district is still in deficit.

Analisis Hasil Tanaman Perkebunan (Kopi Dan Teh) Menggunakan Regresi Linear

Plantation crops are an agricultural sub-sector which also plays an important role in boosting the country's economy, one of which is coffee and tea. However, it is known from the Statistics Indonesia that data shows that the production of plantation crops has decreased, this is caused by one of the factors, namely due to the reduced area of plantation land caused by changes in the conversion of plantation land. The purpose of this study was to determine the influence of land area on the production of plantation crops with linear regression. The results of the study with linear regression analysis show that the variable area of land simultaneously or partially can affect the production of plantation crops, especially coffee and tea plant.

Quantification of Ecosystem Services of the Melghat Tiger Reserve, Maharashtra, India

The present study was an attempt to quantify the direct as well as indirect ecosystem services from forest ecosystems in the Melghat area, which were undervalued in economic terms as compared to other developmental projects. The valuation of growing stock in the Melghat Tiger Reserve (MTR) was estimated to be IRs 80221 crores (equal to 9600 million US $). While the carbon sequestration potential of the system was estimated to be IRs 9291 crores, the value of non-timber forest products (NTFP), a part of the provisioning service, was IRs 3.92 crore. The Forest land itself is valued at IRs 66874 crores using the current land costs in the region for non-forest uses. Recreation benefits are estimated to be IRs 30.94 crores which is more than the user fee collections at entry points. The contribution value of biodiversity and other ecosystem services for the entire Melghat landscape was IRs 2156 crore. Timber and carbon sequestration loss due to land distributed under forest rights was IRs 447.23 crore, while gains from agricultural use of that land by farmers was merely IRs 7.07 crore. Thus, the land conversion resulted in 63 times higher loss in the total ecosystem services than the gains from the subsistence-level farming practice for provisioning service alone. The total economic value of the Melghat landscape was estimated at IRs 1,69,853 crore, equalling to IRs 57.20 lakh per ha. The Net Present Value (NPV) of IRs 7.5 lakh per ha for protected areas such as the MTR prescribed by the Ministry of Environment, Forests and Climate Change, Government of India is much lower than the estimated value, emphasizing the need to revise NPV using appropriate valuation methodology.

The Role Of Civil Society In Sustainable Agrarian Policy Advocacy

Agrarian problems in Indonesia are still complex and have not been resolved completely. Inequality of land tenure, agrarian conflicts, environmental degradation, and land conversion are some examples of problems that continue to occur. In the midst of this situation, the role of civil society becomes important in fighting for sustainable agrarian policies. This research aims to analyze the role of civil society in agrarian policy advocacy in Indonesia. This research adopts a qualitative research method. Data collection is done through literature study. After the data is collected, the analysis is carried out in three stages, namely reducing data, presenting data, and drawing conclusions. The results show that the role of civil society in sustainable agrarian policy advocacy is very important in ensuring social justice, environmental protection, and strengthening the rights of farmers or indigenous peoples related to land. Civil society, through non-governmental organizations (NGOs) and activist networks, acts as a watchdog and critic of agrarian policies issued by the government. In addition, civil society also plays a role in providing education and understanding to local communities about their rights related to land, as well as mobilizing public support to strengthen their demands for equitable agrarian policies.

Perjuangan Perempuan pada Novel Teruslah Bodoh Jangan Pintar Karya Tere Liye (Kajian Ekofeminisme)

This research aims to know and find the form of oppression experienced by female characters and nature as well as how women's struggle for nature and environmental preservation in the novel Teruslah Bodoh Jangan Pintar by Tere Liye. The method used in this research is descriptive qualitative. The results of this study are the forms of oppression against nature and women in the novel Teruslah Bodoh Jangan Pintar by Tere Liye can be seen from the many forms of oppression in the novel, based on De'Eaubonne's ecofeminism theory divided into two, namely the first exploitation of nature and women such as indiscriminate land conversion, illegal logging. The second is environmental and human degradation such as poor soil quality due to mining waste and degrading human dignity. The form of women's struggle against nature and women in the novel Teruslah Bodoh Jangan Pintar by Tere Liye can be in three aspects, namely the first liberation from the patriarchal system. Second, the protection of the environment and natural resources. Third, criticism of exploitation and capitalism.

Transformation of coastal wetlands in the Sundarban Delta (1999–2020)

Spanning across Bangladesh and India, the Sundarban Delta consists of over a thousand islands, the majority of which are protected. These islands are important for the rich biodiversity and unique species found here. However, these islands are also at the forefront of climate change due to the impact of rising sea levels and extreme weather events. Therefore, we analyzed the long-term transformations in the land use land cover (LULC) between 1999 and 2020. We used a variety of geostatistical methods, including optimized hot spots cold spots and join count statistics, to examine the spatial patterns of changes in LULC across the study area. The results of our analysis revealed substantial changes in the spatial patterns of mangroves and pond aquaculture. The changes revealed a distinct north–south demarcation in spatial patterns, in the form of clustering of mangroves in the uninhabited islands located in the south and pond aquaculture clustered in the northern inhabited islands. The loss of area under mangroves was concentrated in the southern edges of the islands, which were most exposed to erosion in the open ocean. Nevertheless, we observed an increase in the area under mangroves in some of the northern riverine islands (17 km2). In the case of pond aquaculture, it was mostly concentrated in inhabited islands in the north. Most of the expansions were concentrated in the Indian part of the delta (631 km2). It is noteworthy that because of effective conservation measures, there was very limited overlap between mangroves and pond aquaculture, denoting the conversion of agricultural land to pond aquaculture instead of mangroves. Thus, the results of our study revealed the importance of local level conservation policies and anthropogenic activities, such as deforestation and local level disturbance like over-extraction of water and pollution, on the changing patterns of LULC across this unique, fragile ecosystem. Future studies may incorporate a finer resolution time series of LULC changes over time and space to enable more detailed analysis.

The role of "The Power of Mama" in addressing fires and forest degradation in Ketapang, Indonesia

In recent years, the destruction of forests, which can take many forms including deforestation and forest fires, has emerged as a major concern worldwide, and Indonesia is no exception. The deforestation rate in Indonesia is rising annually due to a number of factors, including decentralization and illegal land conversion. Kalimantan, known as the "lungs of the world," is the most impacted area, accounting for 51% of total tree cover loss between 2001 and 2022. This situation is alarming as it undermines the sustainability of the flora and fauna ecosystem and directly affects global warming. The government has intensified its efforts to prevent and manage forest fires, working in collaboration with businesses and non-governmental organizations (NGOs) like Greenpeace to reduce the risk of forest damage. In addition to these efforts, a protection initiative by a group of women in Ketapang, West Kalimantan, has gained public attention. Known as The Power of Mama, this group, as the one most affected by forest fires, undertakes heroic effortsto stop forest destruction. This research aims to examine the impact of The Power of Mama on forest degradation and fire management in Ketapang, West Kalimantan. Using a nonviolence approach that emphasizes alternative strategies and tactics leading away from violence, this study demonstrates the long-term positive impact of The Power of Mama through patrols, outreach, counselling, and third-party intervention in managing forest damage and fires. Furthermore,using qualitative methods and focusing on secondary data collection, this research reveals several challenges encountered by The Power of Mama in implementing its actions. Despite these challenges, The Power of Mama's nonviolent strategies and efforts have achieved widespread recognition and have positively impacted sustainability. This is particularly evident in the recognition that women are not only victims of environmental degradation but also play a significant role in environmental protection. Keywords: Non-violence; The Power of Mama; forest destruction; forest fires; women community

Effect of Soil Tillage Systems and Crop Seasonality on the Sediment Geochemical Properties Transferred into a Headwater: A Case of Study in Tobacco Plantation

ABSTRACT The global impacts of agricultural land conversion on soil erosion and pollution, particularly in tobacco cultivation areas, are well-recognized as significant contributors to soil degradation. These areas are identified as hotspots for environmental concerns due to practices that lead to increased erosion and pollution. From this perspective, this case of study explores fine sediment samples from two areas with tobacco cultivation under different tillage systems and seasonal variations, transport into a headwater, and evaluates, on a local scale: (1) the impact of tillage systems on the geochemical signature of sediments; (2) if whether crop seasonality affects these sediment geochemical signatures. The Conventional Ridge Tillage (CRT) system involves extensive soil exposure and machinery for soil management, while the Mulch Ridge Tillage (MRT) system prioritizes soil conservation and relies on herbicides for weed control. The analytical methodology used to assess the sample element characteristics was Energy Dispersive X-ray Fluorescence (EDXRF). It was applied on the twenty fine sediments (ten of harvest and ten of inter-harvest season of tobacco) to quantitatively assess their inorganic composition. Additionally, Pearson correlation analysis, Hierarchical Cluster Analysis (HCA), and Principal Component Analysis (PCA) were applied on the EDXRF data to highlight the similarities and, thus, providing information to assess the complex data clustering patterns. As a result, the sediment compositions from the two studied soil systems are not similar. The PCA showed that the CRT sediments are characterized by the P, S, K, Ca, and Mn content, presenting a geochemical signature related to manure and fertilizer compared to the MRT, which is correlated with Al, Ti, Fe, Cu, and Zn contents, exhibiting a geochemical signature characterized by the natural soil composition. Therefore, the sediment geochemical signatures might be affected by two phases in the study area: a) tillage system characteristics and b) seasonal soil erosion. These findings underscore the importance of managing soil nutrients to mitigate soil pollution and nutrient exportation to aquatic systems. Moreover, the results emphasize the recommendations for sustainable agricultural practices in tobacco-growing areas to protect environmental quality.

Quantifying forest degradation rates and their drivers in Alle district, southwestern Ethiopia: Implications for sustainable forest management practices

Forest ecosystems contribute significantly to global climate regulation. Nonetheless, vulnerability has emerged as a multifaceted topic in the scientific world. Despite the importance of forest ecosystem services, there has been little quantification of worldwide forest change. The main objective of this study was to quantify forest degradation rates and drivers in the Alle district in Southwest Ethiopia. A mixed-research design was used to collect data on forest degradation rates and drivers in Alle district, incorporating both quantitative and qualitative method. The Land Use/Cover (LULC) for 1990, 2010, and 2022 derived from Landsat Thematic Mapper (TM) and Landsat Operational Land Imager (OLI) were used to detect changes and rates of forest degradation. Using a simple random sampling technique, 284 respondents were selected and questionnaires, interviews, and field observations were used to collect survey data. The results indicated that the forest cover of Abidibor per hectare was 2467.5 ha (97.2 %), 2268.3 ha (89.4 %) and 2203.9 ha (86.8 %) during 1990, 2010, and 2022, respectively. The forest coverage of Aba Gamta was 8296.7 ha (96.7 %), 6796.9 ha (79.2 %), and 6654.5 ha (77.6 %) in 1990, 2010, and 2022, respectively. Agricultural and grazing land increased, whereas forests and wetlands decreased during the respective years. The majority (39.36 %) of the sampled respondents reported that the conversion of forest land to agriculture by a rapidly growing population resulted in the expansion of agricultural land and rural settlements, resulting in forest degradation manifested by deforestation, overgrazing, and overexploitation. Thus, the forest coverage of the area decreased rapidly with time. As a solution to the devastating problems of diminishing forests, the local government and other stakeholders should consider conserving and managing depreciating forests by controlling direct drivers and determinants through participatory and institutionalized mechanisms.

Accounting for deep soil carbon in tropical forest conservation payments

Secondary tropical forests are at the forefront of deforestation pressures. They store large amounts of carbon, which, if compensated for to avoid net emissions associated with conversion to non-forest uses, may help advance tropical forest conservation. We measured above- and below-ground carbon stocks down to 1 m soil depth across a secondary forest and in oil palm plantations in Malaysia. We calculated net carbon losses when converting secondary forests to oil palm plantations and estimated payments to avoid net emissions arising from land conversion to a 22-year oil palm rotation, based on land opportunity costs per hectare. We explored how estimates would vary between forests by also extracting carbon stock data for primary forest from the literature. When tree and soil carbon was accounted for, payments of US$18–51 tCO2–1 for secondary forests and US$14–40 tCO2–1 for primary forest would equal opportunity costs associated with oil palm plantations per hectare. If detailed assessments of soil carbon were not accounted for, payments to offset opportunity costs would need to be considerably higher for secondary forests (US$28–80 tCO2–1). These results show that assessment of carbon stocks down to 1 m soil depth in tropical forests can substantially influence the estimated value of avoided-emission payments.

Modelling reveals the effect of climate and land use change on Madagascar’s chameleons fauna

The global biodiversity crisis is generated by the combined effects of human-induced climate change and land conversion. Madagascar is one of the World’s most renewed hotspots of biodiversity. Yet, its rich variety of plant and animal species is threatened by deforestation and climate change. Predicting the future of Madagascar’s chameleons, in particular, is complicated by their ecological rarity, making it hard to tell which factor is the most menacing to their survival. By applying an extension of the ENphylo species distribution model algorithm to work with extremely rare species, we find that Madagascar chameleons will face intense species loss in the north-western sector of the island. Land conversion by humans will drive most of the loss, and will intersect in a complex, nonlinear manner with climate change. We find that some 30% of the Madagascar’s chameleons may lose in the future nearly all their habitats, critically jeopardizing their chance for survival.

Cross-boundary effects of human impacts on animal assemblages in the coastal zone

Human impacts on ecosystems often transcend ecosystem boundaries and environmental realms, complicating ecosystem assessment, conservation, and management. Whether and how different impacts affect ecosystems in distinct but adjacent domains remains untested in many settings, and is rarely tested concurrently at the same spatial scales. In this study, we quantified the effects of coastal urbanisation on the structure of terrestrial coastal vertebrate assemblages (including birds, reptiles and mammals using baited trail cameras) and marine surf zone fish assemblages (using baited underwater videography) at 100 sites along 50 km of beach in eastern Australia. Sites occurred along a gradient of intensities of urban land conversion in the hind dunes. While the effects of urbanisation on the species sampled were pervasive across both ecosystems, the area of urbanised land mattered more for the coastal vertebrates observed, while proximity to urbanised land was more important for the surf zone fish observed. Here, fewer individuals and species of coastal vertebrates were found at sites with a greater extent of urbanised land within 5 km. Conversely, fish assemblages were more diverse in the surf zones abutting urban areas and more abundant at sites approximately 150 m from urbanised land. The spatial properties of these landscapes, including proximity to headlands for coastal vertebrates and reefs for fish, modified the effects of urbanisation. Our findings suggest that urbanisation can have ecologically nuanced effects that are detectable across the land-sea boundary, and stress the importance of landscape context when assessing and conserving animal assemblages in and around coastal cities.

Community trust and decisions in the conversion of agricultural land (Case study: Mulyoagung Village, Indonesia)

<p dir="ltr"><span>Urbanization is caused by a drastic increase in population in an area, thus spurring high demand for space or land, leading to land conversion. The phenomenon of land conversion in rural areas is a reciprocal relationship between urban and rural areas influencing the spread of urbanization to rural areas. Mulyoagung Village, one of the villages in Malang, experiencing significant agricultural land conversion. This research aims to identify the classification of area based on the land conversion. Discussion also made on the beliefs and the demographics that played a role in influencing decisions regarding land conversion. The result revealed that Mulyoagung Village is a secondary rural peri-urban classification located between Malang City and Batu City, experienced a conversion of 24.01% of non-built-up land to built-up land within a period of 20 years (2002-2022). The conversion led to a change from initially rural fringe to urban-rural fringe. This results also supported by SEM-PLS analysis which showed that community demographics are the central construct influencing the decision of farming communities to convert their agricultural land.</span></p>

Spatial variations of runoff thresholds associated with changes in land use over the period 1990-2018 in the Mediterranean side of Andalusia

The runoff threshold is the amount of precipitation that exceeds the infiltration capacity of the soil and from which water begins to flow over the land surface. Its spatial variation will determine the appearance of a series of processes and risks such as soil erosion, sediment transport, water pollution or flooding, all of which are of great interest in the field of land planning and management. This article provides an update of the runoff threshold in the territorial scope of the Demarcación Hidrográfica de las Cuencas Mediterráneas Andaluzas and evaluates the spatial changes occurred between 1990 and 2018 because of land use dynamics. For this purpose, the methodology described in Regulation 5.2-IC related to surface drainage, of the Instrucción de Carreteras (Ministerio de Obras Públicas y Urbanismo [MOPU], 1990; Ministerio de Fomento, 2016, 2019) was used. The results obtained show very contrasting runoff threshold values, with maximums in the western sector and minimums in the eastern sector. On the other hand, the dynamics of land use changes have led to a significant increase in impermeable surfaces and sclerophyllous vegetation, which has generated a clear reduction in runoff threshold values in different areas, mainly in the eastern region. Specifically, the former forest areas, currently occupied by sclerophyllous vegetation, stand out, with a reduction of 17 mm over an area of approximately 229.1 km2. The conversion of agricultural lands into urban areas is also noteworthy, with a decrease in their retention capacity by up to 14 mm of precipitation, covering a total area of 97.1 km2.

Spatially-explicit land use change emissions and carbon payback times of biofuels under the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA)

The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) requires airlines to offset their greenhouse gas (GHG) emissions above 2019 levels by either buying carbon offsets or using Sustainable Aviation Fuels (SAFs). These are drop-in jet fuels made from biomass or other renewable resources that reduce GHG emissions by at least 10 % compared to kerosene and meet certain sustainability criteria. This study assesses the direct land use change (DLUC) emissions of SAF, i.e., GHG emissions from on-site land conversion from previous uses (excluding primary forests, peatlands, wetlands, and protected and biodiversity-rich areas) into alternative feedstocks, considering spatial variability in global yields and land carbon stocks. The results provide DLUC values and carbon payback times at 0.5-degree resolution for six SAF pathways, with and without irrigation and a medium-input intensity, according to CORSIA sustainability criteria. When excluding CORSIA non-compliant areas, soybean SAF shows the highest mean DLUC factor (31.9 ± 20.7 gCO2/MJ), followed by reed canary grass and maize. Jatropha SAF shows the lowest mean DLUC factor (3.6 ± 31.4 gCO2/MJ), followed by miscanthus and switchgrass. The latter feedstocks show potential for reducing GHG emissions over large areas but with relatively greater variability. Country-average DLUC values are higher than accepted ILUC ones for all pathways except for maize. To ensure the GHG benefits of CORSIA, feedstocks must be produced in areas where not only carbon stocks are relatively low but also where attainable yields are sufficiently high. The results help identify locations where the combination of these two factors may be favourable for low-DLUC SAF production. Irrigated miscanthus offers the highest SAF production potential (2.75 EJ globally) if grown on CORSIA-compliant cropland and grassland areas, accounting for ∼1/5 of the total kerosene used in 2019. Quantifying other environmental impacts of SAFs is desirable to understand sustainability trade-offs and financial constraints that may further limit production potentials.