Asian Ecosystems Research Articles

Seeking a multi‐dimensional approach to understand agricultural commodity expansion in Asian tropics

AbstractAgricultural commodity expansion into natural and semi‐natural ecosystems in Asia is a multi‐dimensional sustainability challenge posing a threat to natural and human capital. At the symposium pertaining to agricultural commodity landscapes organized at the 59th meeting of the Association for Tropical Biology and Conservation, we aimed to identify key aspects that require further attention to address the negative impacts of commodity‐driven agricultural expansion in the Asian tropics. Using a combination of insights obtained both from participants' research and those that developed organically in the symposium, we identified five key themes: (1) Robust land use suitability assessments to determine the viability of agricultural expansion or other competing demands on productive land in given landscapes; (2) the need for plot‐level studies of soil biodiversity and ecological functions for commodity crops; (3) Irrigation for commodity crops with blue and green water and evaluating co‐dependent drivers and outcomes; (4) an improved understanding of local producer motivations and supply chains and (5) the analysis of co‐benefits, trade‐offs and synergies in agro‐commodity systems. These themes include the various steps involved in agricultural commodity expansion, right from land selection and crop patterns to aspects pertaining to the post‐harvest value chain. These themes are inter‐connected and span across multiple local and regional spatial scales in tropical Asia but hold relevance to agricultural landscapes elsewhere too. Immediate and sustained attention on these themes would secure multiple goals of sustainable land use, biodiversity conservation, climate change mitigation and human well‐being.

Remote Sensing of the Interaction between Human and Natural Ecosystems in Asia

Remote Sensing of the Interaction between Human and Natural Ecosystems in Asia

Mangrove ecosystem in Asia: review and synthesis of ecosystem services and economic valuation methods

Mangroves provide multiple ecological and socioeconomic benefits in both terrestrial and aquatic ecosystems; however, little is known about their benefits to humans. This study presents a systematic synthesis of the ecosystem services (ESs) and economic valuation methods (EVMs) of mangrove ecosystems in Asia. A total of 28 studies published from 12 countries encompassing 194 observations were reviewed and included in the analysis using Publish or Perish Software. Results revealed that the majority of the mangrove forests in Asia host the genera Rhizophora and Avicennia spp. in the largest proportion, indicating that these genera contribute significantly to mangrove ESs. Market price and factor income methods were the most frequently used EVMs with 96 and 66 value estimates, respectively. Provisioning ecosystem services were valued the most often among ESs types. Moreover, regarding the values of specific ESs, the median values of those that belong to regulating ecosystem services were the highest, specifically erosion prevention (5833.22 $ ha–1 year–1) and moderation of extreme events (3633.69 $ ha–1 year ). Considering contemporary protection and conservation measures, research studies on mangrove ESs and EVMs can be further improved through broader geographic area coverage and improved economic assessment of the rarely studied ESs. Overall, the findings recommend focusing on these gaps, particularly encouraging institutions and policymakers to acknowledge the undervalued ecological and socioeconomic values of mangrove ecosystem services.

Vegetation cover is a crucial key to the success of ecological restoration in the desertified steppe of Inner Mongolia

In this study, we analyzed the environmental factors influencing the restoration process of the degraded ecosystem in the Inner Mongolian steppe, the largest steppe ecosystem in Asia, which is experiencing rapid desertification, and evaluated the effects of restoration on the damaged ecosystem in China. For this purpose, we selected degraded steppe areas left to desertification in the Hulunbuir region, four restored sites where vegetation was artificially introduced for restoration, and reference ecosystems, including a non-desertified area with the dominant Pinus sylvestris var. mongolica community and a meadow steppe area. We conducted analyses and monitoring of plant community characteristics and soil environmental factors to assess the progress of restoration. The results showed that the introduction of indigenous woody plants in the degraded areas led to a proportional increase in vegetation cover, plant biodiversity, and species abundance over time. The primary external forces driving the succession of vegetation in the restored sites were soil factors including organic matter content, temperature and total nitrogen levels, which were associated with an increase in vegetation cover. These results can be interpreted as an increase in vegetation cover leading to an increase in litter production. This in turn reduces soil temperature and evaporation, subsequently enhancing the activity of soil microorganisms. Over time, the species composition, structural diversity of communities, and ecosystem functions in the restored sites gradually became more similar to those of the reference ecosystems. This indicates that vegetation restoration in this area has been very successful. In particular, the positive change in local residents’ awareness regarding the necessity of restoration has been considered a crucial contribution to the success of restoration in the degraded areas. It has led to a decrease in perceived anthropogenic threats to the restored sites. These results indicate that the introduction of native woody plants is crucial and can increase vegetation cover and species composition complexity and local residents’ positive perception of restoration for the successful restoration of desertified drylands.

A survey of attitudes, behaviors and experiences of Nigerian investors in cryptocurrencies

Purpose Given the many activities of Nigerian investors in the crypto ecosystem, this paper investigates the level of their awareness, attitudes, risk tolerance, experience, reasons for investing and level of financial literacy.Design/methodology/approach The research approach is based on a self-administered questionnaire. The Organization for Economic Cooperation and Development (OECD) permitted the use of its reliable and validated survey instrument, administered in Malaysia, the Philippines and Vietnam in 2019. The results are tabulated and analyzed.Findings The key results include the participation of respondents, who are generally young males, not fully financially literate but risk-averse. Many held the false view that investing in global markets is a higher risk than in national markets. Their reasons for investing in crypto include the fear of missing out on good opportunities and the desire to have fun. The results also revealed that social media, conversations with non-experts and online articles are among the most used investment information sources, highlighting the role of digital platforms and informal discussions in shaping perceptions and knowledge about cryptocurrencies. Investments in cryptos are financed through savings, regular monthly budgets or borrowed from friends or family. As for specific attitudes to risk, the results suggest that for most respondents, preserving their invested capital is of paramount importance.Originality/value The importance of this research also resides in the possibility of comparing the crypto ecosystem in Asia with Nigeria because the same OECD data instrument is employed in data collection. Moreover, this study is the most comprehensive research about Nigerian investors in cryptocurrencies.

Tropical ocean teleconnections with gross primary productivity of monsoon-Asia

The intricate oceanic climate interactions with terrestrial primary production of Asian ecosystems exert crucial social-economical-environmental repercussions. Yet, a holistic understanding of tropical sea surface temperature (SST) anomalies associated with the gross primary productivity (GPP) variations of monsoon-Asia remains constrained. This study provides a statistical framework demonstrating how SST perturbations in the tropics influence GPP fluctuations in monsoon-Asia by modulating hydrothermal conditions of different climate system components. Observation evidence explicitly illustrated the characteristic anomalous SST signatures of positive and negative GPP anomalies in South and Southeast Asia during June–August. The SST anomalies of the central-eastern tropical Pacific showed a robust negative impact on the GPP variability of South-Asia. The GPP alterations in maritime-Southeast-Asia exhibited strong connections with SST anomalies of the western Pacific (positive) and eastern equatorial Pacific (negative). The oceanic signals in the GPP variability of South-Asia and maritime-Southeast-Asia mirrored canonical El Niño and La Niña patterns. The detected SST–GPP link is feasible through large-scale atmospheric circulation variability and the consequent regional modulation of heat and moisture fluxes. The anomalous strengthening (weakening) of Walker cell enhances (reduces) water availability to plants for photosynthesis during the La Niña (El Niño) phase of the ENSO cycle and thus elevates (lowers) GPP in South-Asia and Maritime-southeast-Asia. In contrast, the enhanced GPP anomaly in mainland-Southeast-Asia depicts signs of canonical La Niña and Indian Ocean subtropical dipole (IOSD) teleconnections. The positive impact of IOSD was through the modulation of the Mascarene High and the consequent impact on the monsoon. Meanwhile, decreased GPP bears the imprint of El Niño Modoki and warm tropical Indian Ocean SSTs. The atmospheric teleconnections demonstrated the delayed impact of El Niño Modoki on GPP variability through the Indian Ocean capacitor effect. Our findings could be instrumental in forecasting the probable effects on vegetation growth in monsoon-Asia associated with high-frequency tropical oceanic changes.

KF‐metaweb: A trophic metaweb of freshwater ecosystems of South Korea

AbstractMotivationThe metaweb is a dictionary of nodes and their potential interactions developed for a particular region, focusing on a particular type of ecosystem. Based on the local biodiversity information at different spatial and temporal scales, the regional metaweb can be easily decomposed into local webs. The generated local webs are useful for understanding spatiotemporal variations in ecological interactions in a particular region. In this study, an attempt was made to develop a trophic metaweb for freshwater ecosystems in South Korea, called the KF‐metaweb. The metaweb contains 23,074 interactions between 446 taxa collected from 730 studies. This metaweb can be used to understand the spatiotemporal variability of different local food webs and the effects of the environment on food web properties. Furthermore, this is the first metaweb developed for any Asian ecosystem that contains information about many interactions that are unavailable in any other existing database. In addition, this metaweb study enriches our global understanding of ecological interactions.Main Types of Variables ContainedThe data contained trophic interactions between resources (prey) and consumers (predators).Spatial Location and GrainThe mainland of South Korea and Jeju Island.Time Period and Grain2008–2021.Major TaxaMicroalgae (belonging to the phyla Cyanobacteria, Bygra, Cryophyta, Myozoa, Ochrophyta, Charophyta, Chlorophyta, Euglenozoa and Mycetozoa), zooplankton (belonging to the phyla Arthropoda and Rotifera), benthic macroinvertebrates (Platyhelmenthes, Annelida, Arthropoda and Mollusca) and fish.Level of MeasurementMinimum taxonomic resolution was at the genus level for fish and benthic macroinvertebrates and order level for zooplankton and microalgae.Software FormatExcel (*.xlsx).

Enhancing physiological metrics, yield, zinc bioavailability, and economic viability of Basmati rice through nano zinc fertilization and summer green manuring in semi-arid South Asian ecosystem.

During the summer and rainy seasons (April-October) of 2020 and 2021, two consecutive field experiments were conducted at the research farm of the ICAR-Indian Agricultural Research Institute, New Delhi, India. In this study, we examined the effects of summer green manuring crops (GM) and a variety of zinc fertilizers (ZnF) on Basmati rice (Oryza sativa L.) growth, physiological development, yield response, zinc nutrition and economic returns. A combination of GM residues and nano zinc fertilization helped significantly enhancing Basmati rice's growth and its physiological development. Following the incorporation of Sesbania aculeata (Sesbania), successive Basmati rice physiological parameters were significantly improved, as well as grain, straw, biological yields, harvest index and economic returns. The highest Zn content of 15.1 mg kg -1 and the lowest of 11.8 mg kg -1 in milled rice grain were recorded in Sesbania green manuring (G2) and control i.e., in the fallow (G1), respectively. Coating onto urea with 0.2% nano zinc oxide (NZnCU) was observed to be more effective than other zinc sources in terms of growth parameters, yield attributes, zinc nutrition, grain and straw yields for succeeding Basmati rice crop; however, the effects were comparable to those of bulk zinc oxide-coated urea (BZnCU) of 1%. The highest Zn content of 15.1 mg kg -1 was recorded with the application of 1% BZnCU and the lowest of 11.96 mg kg -1 with the soil application of 5 kg Zn ha -1 through bulk ZnO in the milled rice grain. Application of 1% BZnCU led to a 26.25% increase in Zn content of milled rice grain compared to soil application of 5 kg Zn ha -1 through bulk ZnO. As a result, the combination of inclusion of Sesbania aculeata (Sesbania) residue and 0.2% NZnCU was identified as the most effective treatment, for Basmati rice growth and physiological development. A combination of nano Zn fertilization in conjunction with the incorporation of green manure can be advocated for better growth, physiological performance, zinc dense grains, and higher profitability of Basmati rice for farmers and consumers.

Towards the Assessment of Ecosystem Health of Ecosystems in Asia and Promoting Nature-Based Solutions

Towards the Assessment of Ecosystem Health of Ecosystems in Asia and Promoting Nature-Based Solutions

Alternative tree-cover states of dryland ecosystems: Inconsistencies between global and continental scales

Dryland ecosystems are complex systems that can exhibit alternative tree-cover states, making conservation and restoration efforts challenging. However, our understanding of these states is still limited, particularly at the global level. In this study, we utilized remote sensing data to analyze the distribution of tree cover in drylands and assess the impacts of factors such as the aridity index, temperature, fire frequency, and grazing on tree cover at both the global and continental scales. The results showed that dryland ecosystems in Asia, Australia, and South America exhibited alternative tree-cover states, while dryland ecosystems at the global scale and in Africa, Europe, and North America did not. Livestock density and the aridity index appeared to be the primary drivers of these states in the regions where they occurred. This study highlights the importance of considering the variability in dryland vegetation states across different scales and regions, as small-scale processes may not always accurately predict large-scale dynamics. By examining dryland woody vegetation at both global and continental scales, our work contributes to a more comprehensive understanding of the factors that affect the tree-cover states in these ecosystems.

Land-use change is associated with multi-century loss of elephant ecosystems in Asia

Understanding historic patterns of land use and land cover change across large temporal and spatial scales is critical for developing effective biodiversity conservation management and policy. We quantify the extent and fragmentation of suitable habitat across the continental range of Asian elephants (Elephas maximus) based on present-day occurrence data and land-use variables between 850 and 2015 A.D. We found that following centuries of relative stability, over 64% (3.36 million km2) of suitable elephant habitat across Asia was lost since the year 1700, coincident with colonial-era land-use practices in South Asia and subsequent agricultural intensification in Southeast Asia. Average patch size dropped 83% from approximately 99,000–16,000 km2 and the area occupied by the largest patch decreased 83% from ~ 4 million km2 (45% of area) to 54,000 km2 (~ 7.5% of area). Whereas 100% of the area within 100 km of the current elephant range could have been considered suitable habitat in the year 1700, over half was unsuitable by 2015, driving potential conflict with people. These losses reflect long-term decline of non-forested ecosystems, exceeding estimates of deforestation within this century. Societies must consider ecological histories in addition to proximate threats to develop more just and sustainable land-use and conservation strategies.

Perspective: Improving the accuracy of plant phenology observations and land-cover and land-use detection by optical satellite remote-sensing in the Asian tropics

Recent advances in satellite-borne optical sensors led to important developments in the monitoring of tropical ecosystems in Asia, which have been strongly affected by recent anthropogenic activities and climate change. Based on our feasibility analyses conducted in Indonesia in Sumatra and Sarawak, Malaysia in Borneo, we discuss the current situation, problems, recent improvements, and future tasks regarding plant phenology observations and land-cover and land-use detection. We found that the Multispectral Instrument (MSI) on board the Sentinel-2A/2B satellites with a 10-m spatial resolution and 5-day observational intervals could be used to monitor phenology among tree species. For the Advanced Himawari Imager (AHI) on board the Himawari-8 geostationary satellite with a 1,000-m spatial resolution and 10-min observational intervals, we found that the time-series in vegetation indices without gaps due to cloud contamination may be used to accurately detect the timing and patterns of phenology among tree species, although the spatial resolution of the sensor requires further improvement. We also found and validated that text and pictures with geolocation information published on the Internet, and historical field notes could be used for ground-truthing land cover and land use in the past and present time. The future development of both high frequency (≤ 10 min) and high spatial resolution (≤ 10 m) optical sensors aboard satellites is expected to dramatically improve our understanding of ecosystems in the tropical Asia.

Dental topography and dietary specialization in Papionini primates

Our understanding of primate adaptive evolution depends on appreciating the way in which dental functional morphology affects food processing. The Papionini tribe ofCercopithecoideaprimates shows great dietary versatility and ecological adaptations to resource seasonality across the African and Asian ecosystems, however, there are few studies focusing on the occlusal topography of the bilophodont teeth and the effect of tooth wear in the crown shape. Here, we explore the relationship between wear-related dental functional morphology and dietary ecological constraints within the Papionini. Three-dimensional (3D) polygonal meshes of the upper permanent molar row (M1-3) were obtained in a large papionine sample (838 specimens) of known dietary preferences including species from six genera (Cercocebus,Lophocebus,Macaca,Mandrillus,Papio, andTheropithecus). All the sample was classified in four diet categories and four topographic metrics (orientation patch count rotated, OPCR; Dirichlet normal energy, DNE; occlusal relief, OR; and ambient occlusion, portion de ciel visible, PCV) were measured for each tooth-type according to wear stage (lightly and moderately worn) to determine diet-related interspecific morphological changes with long-term functionality. The results indicate that hard-object feeders (CercocebusandLophocebus) and grass eaters (Theropithecus gelada) exhibit a pattern of occlusal complexity (OPCR), surface curvature (DNE), relief (OR), and morphological wear resistance (PCV) that is significantly different from the omnivores and folivore-frugivore species (MandrillusandMacaca) despite the overall homogeneity of the bilophodont dentition. A multifactorial ANOVA showed that the topographic metrics were sensitive to tooth wear as expected. The results also indicate that the interspecific variability of dental topography of the upper molars reflects dietary specializations rather than phylogenetic proximity. These findings support the hypothesis that evolutionary convergence processes could have affected the Papionini, clustering the hard-object feeders (LophocebusandCercocebus)together in the morphospace, and clearly discriminating this group from the graminivorous and frugivores-folivores.

Projected changes of ecosystem productivity and their responses to extreme heat events in northern asia

Change of ecosystem productivity and its response to climate extremes in the context of global warming are of great interest and particular concern for ecosystem management and adaptation. Using the simulations with and without the CO2 fertilization effect from the Yale Interactive Biosphere (YIBs) model driven by seven CMIP5 climate models, this article investigates the future change in the gross primary productivity (GPP) of the Northern Asian ecosystem as well as the impacts from extreme heat events under the RCP2.6 and RCP8.5 scenarios, respectively. The results show an overall increase of GPP in Northern Asia during the growing season (May-September) under both scenarios, in which the CO2 fertilization effect plays a dominant role. The increases in GPP under RCP8.5 are larger than that under RCP2.6, and the greatest projected increases occur in western Siberia and Northeast China. The extreme heat events are also projected to increase generally and their influences on the Northern Asian ecosystem GPP exhibit spatiotemporal heterogeneity. Under the RCP2.6 scenario, the positive and adverse effects from the extreme heat events coexist in Northern Asia during the middle of the 21st century. During the end of the 21st century, the areas dominated by positive effects are expected to expand particularly in Northeast China and central-western Siberia. For the RCP8.5 scenario, the facilitation effects of the extreme heat events are widely distributed in Northern Asia during the middle of the 21st century, which tends to decline in both intensity and extent during the end of the 21st century. The case is similar after the CO2 fertilization effect is excluded.

Optimizing the capture of neophobic rice field rats in lowland Asian rice ecosystems

BACKGROUNDTrapping is a key method for monitoring small mammals and is also one of a number of methods recommended under an ecologically‐based rodent management program to control rodent pest populations. Live‐traps are widely used globally for studying small mammal populations. In Asia where rodents are major pests of rice, single capture traps typically provide low trap success. We compared the trap success between two types of live‐traps in rice fields in Indonesia and the Philippines.RESULTSMultiple‐capture traps (MCTs) in conjunction with a linear trap barrier were significantly more effective in catching rodent pest species than single‐capture traps (SCTs) in Indonesia and the Philippines. In Indonesia, MCTs captured more individuals with a mean (±SE) percent trap success rate of (15.54 ± 4.29) compared to SCTs (3.88 ± 1.58). In the Philippines, MCTs captured more species of rodents and had a significantly higher recapture rate (1.96 ± 0.79), than SCTs (0.58 ± 0.32).CONCLUSIONMultiple‐capture traps with a linear trap‐barrier were more effective for capturing Rattus argentiventer and Rattus tanezumi in rice field ecosystems compared to single‐capture traps. MCTs captured more species of rodent pests in the Philippines and recaptured more individuals of each species. These results indicate that rodent populations can be more effectively monitored and controlled by using a multi‐capture trap with barrier system than the use of single capture traps on their own. This is the first time these two trap types have been compared for use in rice ecosystems in Asia. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Water Deficit May Cause Vegetation Browning in Central Asia

There is consistent evidence of vegetation greening in Central Asia over the past four decades. However, in the early 1990s, the greening temporarily stagnated and even for a time reversed. In this study, we evaluate changes in the normalized difference vegetation index (NDVI) based on the long-term satellite-derived remote sensing data systems of the Global Inventory Modelling and Mapping Studies (GIMMS) NDVI from 1981 to 2013 and MODIS NDVI from 2000 to 2020 to determine whether the vegetation in Central Asia has browned. Our findings indicate that the seasonal sequence of NDVI is summer > spring > autumn > winter, and the spatial distribution pattern is a semicircular distribution, with the Aral Sea Basin as its core and an upward tendency from inside to outside. Around the mid-1990s, the region’s vegetation experienced two climatic environments with opposing trends (cold and wet; dry and hot). Prior to 1994, NDVI increased substantially throughout the growth phase (April–October), but this trend reversed after 1994, when vegetation began to brown. Our findings suggest that changes in vegetation NDVI are linked to climate change induced by increased CO2. The state of water deficit caused by temperature changes is a major cause of the browning turning point across the study area. At the same time, changes in vegetation NDVI were consistent with changes in drought degree (PDSI). This research is relevant for monitoring vegetation NDVI and carbon neutralization in Central Asian ecosystems.

Composting Strategy Instead of Waste-to-Energy in the Urban Context—A Case Study from Ho Chi Minh City, Vietnam

The waste-to-energy programs that have taken place in recent years present a daunting picture in terms of sustainable material management. The incineration of much organic and unorganized waste in metropolitan waste treatment facilities is not meet with sustainable development. The solution to this problem may be to increase urban composting programs in the future, which is a sustainable treatment option but also a serious technical challenge. Our research question is whether composting programs can play a key role in rapidly evolving urban ecosystems in Asia, due to the specificities associated with the waste rates outlined and developmental differences outlined. Instead of the waste-to-energy or waste-to-landfill strategies often used today, can central composting focusing on high organic matter content be a suitable alternative? Using the AHP method (Analytical Hierarchy Process), the following alternatives were examined to clarify the issue: Wastes are commingled and processed at the treatment facilities; Classification of organic and non-organic waste at source for composting; Totally separating waste at source before processing at the treatment facilities. We have found that the use of central composting (separation of organic and non-organic waste at source) strategies to support circular development is one of the most innovative development strategies in the fast-growing cities of Asia, in line with E.U. targets.

Climate Change Decreased Net Ecosystem Productivity in the Arid Region of Central Asia

Numerous studies have confirmed that climate change leads to a decrease in the net ecosystem productivity (NEP) of terrestrial ecosystems and alters regional carbon source/sink patterns. However, the response mechanism of NEP to climate change in the arid regions of Central Asia remains unclear. Therefore, this study combined the Carnegie–Ames–Stanford approach (CASA) and empirical models to estimate the NEP in Central Asia and quantitatively evaluate the sensitivity of the NEP to climate factors. The results show that although the net primary productivity (NPP) in Central Asia exhibits an increasing trend, it is not significant. Soil heterotrophic respiration (RH) has increased significantly, while the NEP has decreased at a rate of 6.1 g C·m−2·10 a−1. Spatially, the regional distribution of the significant increase in RH is consistent with that of the significant decrease in the NEP, which is concentrated in western and southern Central Asia. Specifically, the NPP is more sensitive to precipitation than temperature, whereas RH and NEP are more sensitive to temperature than precipitation. The annual contribution rates of temperature and precipitation to the NEP are 28.79% and 23.23%, respectively. Additionally, drought has an important impact on the carbon source/sink in Central Asia. Drought intensified from 2001 to 2008, leading to a significant expansion of the carbon source area in Central Asia. Therefore, since the start of the 21st century, climate change has damaged the NEP of the Central Asian ecosystem. Varying degrees of warming under different climate scenarios will further aggravate the expansion of carbon source areas in Central Asia. An improved understanding of climate change impacts in Central Asia is critically required for sustainable development of the regional economy and protection of its natural environment. Our results provide a scientific reference for the construction of the Silk Road Economic Belt and global emissions reduction.

Spatio-Temporal Characteristics and Trend Analysis of Grassland Ecosystem Drought in Asia From 2010 to 2018

Under the background of global climate change, the impact from drought on the ecosystem exhibits the characteristics of complexity and multi-process, especially for the main component, which is the grassland ecosystem of the overall ecosystem. Identifying past droughts and predicting future ones is vital in limiting their effects. However, the random and non-linear nature of drought variables makes accurate drought prediction still a challenging scientific problem. In this study, the boundaries, Land Surface Temperature (LST) and Enhanced Vegetation Index (EVI) of Asian Grassland Ecosystem (AGE) were obtained by Google Earth Engine (GEE), which were used to construct LST-EVI feature spaces to calculate the dry-wet edge fitting equations and Temperature Vegetation Drought Index (TVDI). Mann–Kendall test and Sen trend degrees were further used to analyze the drought trend of AGE. The results showed that there were obvious spatial differences in the wet and dry conditions of AGE, which showed that the TVDI increased from east to west and from north to south, with humid areas mainly concentrated in northern Asia and severe drought areas concentrated in southern Asia. From 2010 to 2018, the area of humid areas and severe drought areas of AGE decreased, and some humid areas changed to normal areas or even drought areas, while the drought in severe drought areas was alleviated. The results of the Sen trend test further show that the aggravating trend of drought in severe drought areas of South Asia is relatively low, and some areas show a trend of changing to humidity. However, there is an obvious aggravating trend of drought in humid areas or low drought areas of South Asia, these areas should also be the focus areas for drought prevention in the future. This study identified the spatio-temporal distribution characteristics and evaluated the evolution trend of the drought of AGE, which is of great significance to the management and prevention of drought of AGE.

A partial oviraptorosaur skeleton suggests low caenagnathid diversity in the Late Cretaceous Nemegt Formation of Mongolia.

The Nemegt Formation of the Gobi Desert of Mongolia has produced one of the most abundant and diverse oviraptorosaur records globally. However, the caenagnathid component of this fauna remains poorly known. Two caenagnathid taxa are currently recognized from the Nemegt Formation: Elmisaurus rarus and Nomingia gobiensis. Because these taxa are known from mostly non-overlapping material, there are concerns that they could represent the same animal. A partial, weathered caenagnathid skeleton discovered adjacent to the holotype quarry of Nomingia gobiensis is referable to Elmisaurus rarus, revealing more of the morphology of the cranium, mandible, pectoral girdle, and pubis. Despite metatarsals clearly exhibiting autapomorphies of Elmisaurus rarus, overlapping elements are identical to those of Nomingia gobiensis, and add to a growing body of evidence that these taxa represent a single morphotype. In the absence of any positive evidence for two caenagnathid taxa in the Nemegt Formation, Nomingia gobiensis is best regarded as a junior synonym of Elmisaurus rarus. Low caenagnathid diversity in the Nemegt Formation may reflect broader coexistence patterns with other oviraptorosaur families, particularly oviraptorids. In contrast to North America, competition with the exceptionally diverse oviraptorids may have restricted caenagnathids to marginal roles in Late Cretaceous Asian ecosystems.