Change In Central Asia Research Articles

Societal Shifts in Central Asia: Figures and Trends

Central Asia has been undergoing considerable transformations by becoming mature independent states in international arena and experiencing socio-demographic shifts. It clearly resembles the dynamics described in Moises Naím’s “The End of power” where he argues that “the more, mobility, and mentality” revolutions challenge political leaders with fluid and unpredictable environment. This article aims to do an empirical analysis of the socio-demographic changes in Central Asia to test the assumption in the regional context.

Extreme precipitation and temperature indices under future climate change in central Asia based on CORDEX-CORE

The present study analyzes the projected changes of extreme climate indices over Central Asia using regional climate model (RCM) simulations from the Coordinated Regional Climate Downscaling Experiment (CORDEX) - Coordinated Output for Regional Evaluations (CORE). The extreme indices are based on precipitation and temperature and are inspected for present (1981–2005) and future periods - near- (2031–2055) and far-future (2071–2095) - to assess the long-term climate change under the representative concentration pathway RCP8.5. Projected changes are analyzed for three different model ensembles. These ensembles are based on CORDEX-Central Asia (ENS_CAS, four ensemble members) and CORDEX-East Asia (ENS_EAS, six ensemble members), and a combination of both (ENS, ten ensemble members) for our study area centered over high mountain Asia, called Central East Asia (CEAS). For precipitation indices, an increase of consecutive dry days (CDD) in ENS_EAS and a slight to moderate decrease in northern parts in ENS_CAS during near-future is observed. Consecutive wet days (CWD), very heavy precipitation events (R20mm), maximum one-day precipitation (RX1day), and very wet days (R95p) are projected to increase in most areas. All indices show a further intensification towards the end of the century over large parts of the domain, e.g., + 7.8% / +5.6 days for CDD, + 96.6% / +0.26 days for R20mm, and + 19.7% for RX1day as median of ENS over CEAS. For temperature indices, the ensembles project a strong increase over the high mountain regions and southern parts for consecutive summer days (CSU, + 108.5% / +38.3 days), heat wave duration index (HWDI, + 1379.1% / +91.37 days), and the percentage of very hot days (TX90p, + 391.1% / +34.54 days). Accordingly, the number of consecutive frost days (CFD, -43.7% / -25.2 days) and the percentage of very cold days (TX10p, -83.4% / -8.13 days) are projected to decrease. The first-time usage of CORDEX-CORE and the larger ensemble size by considering simulations from overlapping domains increase the robustness of the findings from earlier studies. However, some discrepancies in the projected changes prevail among the different RCMs being part of the two CORDEX-domains and in specific landscapes like complex mountainous or lake areas. These uncertainties may be tackled by further model development with improved land-surface processes and potentially higher spatial resolution.

First Pediastrum–temperature transfer function and its application to mid-to-late Holocene reconstruction in Central Asia

The green alga Pediastrum is an ecologically significant component of freshwater ecosystems, but its potential as an independent proxy for quantitative paleoenvironmental reconstruction is relatively unexplored. Here we use multivariate statistical analysis to explore the relationship between the Pediastrum composition of lake surface sediments and environmental variables. The findings highlight the mean growing season air temperature between March and October (TMar-Oct) as the most important factor determining the Pediastrum composition. We then establish the first transfer function between the Pediastrum taxa and TMar-Oct, which enables us to provide a quantitative temperature reconstruction for the past ∼8.2 kyr based on sedimentary subfossil Pediastrum records from Bosten Lake in Xinjiang, China. Our findings reveal an exceptionally warm climate during ∼4.8–3.6 kyr, with temperatures ∼4 °C higher compared to those during ∼8.2–4.8 kyr. This unusually warm climate is verified by the carbonate clumped isotopes record of the same core and other paleoclimate records. These findings contribute to our understanding of past temperature changes in Central Asia and provide a basis for future research on long-term lake ecosystem dynamics under past climatic warming.

The Interdecadal Pacific Oscillation is responsible for the linkage of decadal changes in precipitation and moisture in arid central Asia and the humid Asian monsoon region during the last millennium

Abstract. Reconstruction and observational studies imply a potential linkage of moisture and precipitation change in arid central Asia and monsoonal East Asia, in which the evolution of moisture and precipitation in central Asia is out of phase with that in northern China but in phase with that in southern China. In order to ascertain whether there is a robust linkage between the changes in climate in Asian arid regions and monsoon regions and to elucidate the underlying dynamic mechanisms, we analyzed the Last Millennium Reanalysis dataset and outputs from the Community Earth System Model Last Millennium Ensemble (CESM-LME). The results indicate a significant decadal linkage between precipitation changes in central Asia's arid region and the Asian monsoon region during the last millennium, which is primarily driven by the Interdecadal Pacific Oscillation (IPO). In spring, the positive IPO could enhance westerlies over the Mediterranean Sea and to its east, which could transport more water vapor and cause increased precipitation over central Asia. In summer, the positive IPO is accompanied by a weakened Asian monsoon and southward Asian subtropical westerly jet, which can lead to increased (decreased) summer precipitation over southern China (over northern China and South Asia). The IPO plays a dominant role in connecting the decadal variations in precipitation between arid central Asia and monsoonal Asia by modulating the precipitation of their respective major rainy seasons. Model results suggest that this decadal linkage stems entirely from the internal variability present in the CESM-LME control and all single-forcing simulations. Changes in external forcing factors do not alter this inherent linkage caused by the IPO. Moreover, based on analyses of the aridity index and soil moisture content, this relationship of precipitation variation also causes a similar decadal linkage of moisture changes in central Asia and monsoonal Asia. The differences in the multi-centennial-scale moisture and precipitation variations in the Asian arid region and the monsoon region between the Medieval Climate Anomaly and Little Ice Age are also likely caused by IPO-like sea surface temperature anomalies.

НЕКОТОРЫЕ ОСОБЕННОСТИ ГЕОСТРАТЕГИЧЕСКИХ ИНТЕРЕСОВ ЭКОНОМИЧЕСКОЙ ПОЛИТИКИ ЯПОНИИ В ЦЕНТРАЛЬНОЙ АЗИИ В НАЧАЛЕ ХХI ВЕКА

The article presents the features of Japan's economic policy in the five Central Asian republics in 2000-2024 on the basis of materials from authoritative sources in Russian, English and Japanese. On the basis of authoritative sources, the specifics of the geostrategic importance of Kazakhstan, Uzbekistan, Kyrgyzstan, Turkmenistan and Tajikistan for Japan in a developing multipolar world and Tokyo's vital need for stable partnerships in order to increase its influence are reflected. The main specific trends of economic relations between Japan and Central Asia are revealed. The period 2000-2024 of the study is a logical period of time defining Tokyo's policy in the five republics, as a successor to the previous 1993-1999. This shows the predictability and logic of building schemes for stable economic relations of Tokyo in the region. The specific trends of Japan's policy changes in Central Asia are revealed, taking into account the competitive advantages of the great powers in the region. Seoul's strategies have been taken into account, which are similar to Tokyo's course in the five republics. The main regions in Kazakhstan, Turkmenistan, Tajikistan, Uzbekistan and Kyrgyzstan have been identified, where Japanese companies conduct main and contract economic activities at the beginning of the XX1 century, taking into account the dynamics of the previous period 1993-1999. The forecast of the prospects for the development of the dialogue between Japan and Central Asian countries in the 2030s is given.

Book Review: Climate Change in Central Asia: Decarbonization, Energy Transition, and Climate Policy

Book Review: Climate Change in Central Asia: Decarbonization, Energy Transition, and Climate Policy

Спутниковые оценки вариаций увлажненности внутреннего Тянь-Шаня в период 1982–2022 гг. на примере хребта Ат-Баши (Киргизия)

Introduction. Western atmospheric jet streams carry moisture over the Northern Tian Shan ridges into the Inner Tian Shan. Long-term weather changes in the Inner Tian Shan diagnose climatic fluctuations in atmospheric moisture transport. This is of considerable interest for understanding the direction of modern climate change in Central Asia. Materials. The area of the At-Bashi Ridge (2700 км2) in Inner Tian Shan, including a large high-altitude Lake Chatyr-Kul (170 km2, 3530 m), were considered. The ridge, with a peak of 4786 m, has a length of 135 km and is characterized by an Alpine type of relief. The initial information related to the period 1982-2022. The list of data used included: FLDASSnowDepth_inst; JRC Monthly Water History, v1.4; ECMWF/ERA5_LAND/MONTHLY (precipitation); NOAA/NCEP_DOE_RE2 (cloud fraction). Also, to diagnose the mountain glaciation state of the At-Bashi Ridge, three satellite images of sub meter resolution dated 09/21/2002, 07/27/2013 and 09/13/2021 were used. The purpose of the work. The aim of the research was to study the humidity regime of the At-Bashi Ridge area during 1982-2022. Research methodology. The change in the average annual snow depth in the test area in the period 1982-2022 was analyzed, as well as the degree of correlation of this parameter with other weather characteristics.Fischer’s criterion acted as a quantitative basis for estimates. Satellite images of sub meter resolution were used to analyze long–term changes in the area of rock outcrops from ice on the slopes of glacial chambers, which diagnoses the glacier state (degradation – stability – growth). Satellite data recorded the process of mountain glaciation growth above the height of 4000 m in the period between 2002–2013. Research results. In order of increasing correlation (F-criterion), with the snowiness of the cold period (October-May) of the At-Bashi Ridge area, the parameters considered were arranged as follows (F=2.11; α=0.01): cloud fraction, F= 3.02; precipitation, F=12.42; the Lake Chatyr-Kul area, F= 12.53; the balance of snow deposits between the windward (north-western) and leeward (south-eastern) At-Bashi Ridge slopes, F= 22.01. According to satellite data, the growth of mountain glaciation in the zone with an altitude above 4000 m in the period 2002-2013 was recorded. Discussion. The At-Bashi Ridge area has three different periods in terms of humidity: dry in 1982-1999 with an average annual snow depth of 0.099± 0.051 m; wet in 2000-2012; 0.192± 0.074 m; and moderately humid in 2013-2022; 0.133± 0.058 m. Ultra-high-resolution satellite images recorded the growth of the mountain glaciation of the At-Bashi Ridge at altitudes of more than 4000 m in the period from 2002 to 2013. This confirms the actual existence of the wet period of 2001-2012. Conclusion. Thus, the current trend of humidity changes of the At-Bashi Ridge does not have an unambiguous direction, but in general, for the period 1982-2022, it is aimed at a certain increase in the snow content in mountains and the area of the Lake Chatyr-Kul. Apparently, the current climate change is accompanied by an increase in the ability of western atmospheric jet fluxes to transfer moisture over the front Northern Tian Shan ranges into the Inner and Central Tian Shan ridges, which may even be accompanied by an increase in the mountain glaciation of these territories in certain periods of time.

Central Asia revealed as a key area in evolution of Eremurus (Asphodelaceae)

Eremurus was described at the beginning of the 19th century. However, due to limited sampling and the small number of gene markers to date, its phylogeny and evolution are largely unknown. In this study, we analyzed plastomes from 27 species belonging to 2 subgenera and 3 sections of Eremurus, which are found in Central Asia (its center of diversity) and China. We also analyzed nuclear DNA ITS of 33 species, encompassing all subgenera and sections of the genus in Central Asia, southwest Asia and China. Our findings revealed that the genus was monophyletic, although both subgenera Eremurus and Henningia were found to be paraphyletic. Both plastome and nrDNA-based phylogenetic trees had three clades that did not reflect the current taxonomy of the genus. Our biogeographical and time-calibrated trees suggest that Eremurus originated in the ancient Tethyan area in the second half of the Eocene. Diversification of Eremurus occurred from the early Oligocene to the late Miocene. Paratethys Sea retreat and several orogenetic events, such as the progressive uplift of the Qinghai-Tibet Plateau and surrounding mountain belts (Altai, Pamir, Tian Shan), caused serious topographic and climate (aridification) changes in Central Asia that may have triggered a split of clades and speciation. In this transformed Central Asia, speciation proceeded rapidly driven mainly by vicariance caused by numerous mountain chains and specialization to a variety of climatic, topographic and soil conditions that exist in this region.

Measuring the Capacity for Adaptation to Climate Change in Central Asia

Climate change poses a formidable threat to the Central Asian region, exacerbating preexisting vulnerabilities and necessitating enhanced adaptation efforts. The economic and environmental costs of these changing climatic conditions are substantial, compelling governments to bolster their adaptive capacity. In this study, we employ the United Nations Framework Convention on Climate Change (UNFCCC) adaptation framework and high-quality data to quantitatively measure the capacities of the Central Asian countries to adapt to the impacts of climate change. Our primary objective is to compare the adaptation progress in the Central Asian countries with that of countries outside the region. The results of our analysis indicate that, despite announced adaptation strategies, Central Asia lags behind in this critical area. Several factors contribute to the low scores for adaptation in the region, including heavy reliance on fossil fuels, resource-intensive economies, and limited innovation capacity. This deficiency in adaptive readiness leaves the Central Asian countries ill-prepared for the impending consequences of climate change. Urgent action is imperative for policymakers to address this disparity, formulate effective adaptation strategies, and safeguard the region’s future resilience.

Plants alter their aboveground and belowground biomass allocation and affect community-level resistance in response to snow cover change in Central Asia, Northwest China

It is important to elucidate the changing distribution pattern of net primary productivity (NPP) to mechanistically understand the changes in aboveground and belowground ecosystem functions. In water-scarce desert environments, snow provides a crucial supply of water for plant development and the spread of herbaceous species. Yet uncertainty persists regarding how herbaceous plants' NPP allocation responds to variation in snow cover. The goal of this study was to investigate how variation in snow cover in a temperate desert influenced the NPP allocation dynamics of herbaceous species and their resistance to environmental change in terms aboveground and belowground productivity. In the Gurbantunggut Desert, wintertime snow cover depth was adjusted in plots by applying four treatments: snow removal (−S), ambient snow, double snow (+S), and triple snow (+2S). We examined their species richness, aboveground NPP (ANPP), belowground NPP (BNPP), and the resistance of ANPP and BNPP. We found that species diversity of the aboveground community increased significantly with increasing snow cover and decreased significantly Pielou evenness in plots. This resulted in greater ANPP with increasing snow cover; meanwhile, BNPP first increased and then decreased with increasing snow cover. However, this productivity in different soil layers responded differently to changed snow cover. In the 0–10 cm soil layer, productivity first rose and then declined, while it declined linearly in both the 10–20 cm and 20–30 cm soil layers, whereas in the 30–40 cm soil layer it showed an increasing trend. Belowground resistance would increase given that greater snow cover improved the BNPP in deeper soil and maintained the resource provisioning for plant growth, thus improving overall belowground stability. These results can serve as a promising research foundation for future work on how the functioning of desert ecosystems becomes altered due to changes in plant community expansion and, in particular, changes in snow cover driven by global climate change.

Gradually increasing precipitation since 20 ka as evidenced by loess dolomite abundance in the Ili Basin, Central Asia

The mechanisms and processes of precipitation change during warm climatic periods, such as the Holocene, may provide critical insights into future regional precipitation trends in the arid and semiarid Central Asian core in the context of potential global warming. Previous studies have reconstructed different effective moisture changes during the warm Holocene epoch, i.e., a long-term wetting trend vs. a long-term drying trend. A potential reason for these conflicting results is that the reconstructed effective moisture proxies may involve effects from both temperature and precipitation, which can differ in different contexts. A pure precipitation proxy, which could be used to disentangle the interference of temperature, is important to solving this conflict. Here, we present two precipitation records based on the dolomite abundance in loess sections, which is nearly independent of temperature change, in the Ili Basin. These records span the past 20 ka and are constrained by high-resolution chronologies based on quartz optically stimulated luminescence. Our records indicate gradually increasing precipitation since 20 ka. This precipitation change is then assessed in the context of the Northern Hemisphere high-latitude ice volume, migration of the mid-latitude westerlies, and penetration of the Asian monsoon. We conclude that (1) the precipitation change is generally consistent with the reported effective moisture change since 20 ka in the study area; (2) increasing precipitation from the Last Glacial Maximum to the early Holocene was mainly controlled by the decreasing Northern Hemisphere high-latitude ice volume; and (3) further increases in precipitation during the Holocene were possibly related to the southward migration of the mid-latitude westerlies and penetration of the Asian monsoon. Our precipitation records also reconcile the common disconnection using the driving mechanism of precipitation to interpret the geological effective moisture changes in Central Asia.

Divergent trends in grassland degradation and desertification under land use and climate change in Central Asia from 2000 to 2020

Grassland degradation (within-state change) and desertification (state conversion from grasslands to deserts) are different states in the complex dynamic process of grassland deterioration. However, the dynamics and associated drivers of the two states have been rarely examined separately, which is critical for early warning and conservation policy making. Here, the grassland degradation and desertification in Central Asia (CA) were studied due to their evident vulnerability to climate extremes and human activities. We performed a two-step approach to identify the critical state zones first (i.e., grasslands, deserts, and the desertification zones) and then assess the vegetation dynamics within each zone. Finally, we quantified the roles of CO2 fertilization effect, climate change, climate variability, land use (LU), and anthropogenic climate change (ACC) on the vegetation dynamics in different state zones. The results showed that the areas of grasslands and sparse vegetation regions (including deserts and desertification zones) were stable from 2000 to 2020, but the trends of vegetation greenness were divergent with a reduction in grasslands and an increase in sparse vegetation regions. Furthermore, climate change and climate variability were the main driving force affecting grassland degradation in CA. Yet the vegetation greening in the desertification and desert zones was mainly driven by the rising CO2 and LU. Moreover, ACC degraded 20.63% of grasslands and sparsely vegetated lands in CA on the baseline of 2000. The results highlighted the risks of grassland degradation in CA. This study proposed a methodology to examine grassland degradation and desertification in detail and quantify the associated driving factors (especially ACC) at the pixel scale, which provided some insights on developing region-precise strategies for grassland conservation in CA and other drylands.

Using Open Foris Collect Earth in Kyrgyzstan to support greenhouse gas inventory in the land use, land use change, and forestry sector.

The Kyrgyz Republic (Kyrgyzstan) is one of the countries most vulnerable to the adverse effects of climate change in Central Asia. The land use, land use change, and forestry (LULUCF) sector is critical in climate change mitigation in Kyrgyzstan and is integral to national greenhouse gas (GHG) inventories. However, consistent, complete, and updated activity data is required for the LULUCF sector to develop a transparent GHG inventory. Collect Earth (CE), developed by the Food and Agriculture Organization of the United Nations (FAO), is a free, user-friendly, and open-source tool for collecting activity data for the LULUCF sector. CE assists countries in developing GHG inventories by providing consistent and complete land representation. This article reports an estimate of land use and land-use change dynamics in Kyrgyzstan, based on analyzing 13,414 1-hectare (ha) sampling units through an augmented visual interpretation approach using satellite imagery at the very high spatial and temporal resolution available through the Google Earth platform. The results show that in 2019, forests covered 1.36 million ha or 6.83% of the total land with a 6.23% uncertainty. This estimate was 5 to 16% higher than previous estimates, detecting an additional 63,024 to 188,164ha of forestland that had not been reported previously. The new estimates suggest an average increase of 10.4% in the current forestlands of Kyrgyzstan.

Tree-ring perspective on past and future mass balance of the glaciers in Tien Shan (Central Asia): An example from the accumulation area of Tuyuksu Glacier, Kazakhstan

The Tien Shan glaciers, known as “Central Asia's Water Tower,” have a direct influence on water resource management in downstream parched areas. The limited time periods of currently available observational climate datasets hamper an accurate examination of glacial changes in Central Asia in terms of long-term climate change implications. In this work, we analysed this change by combining tree-ring-based reconstructions of the accumulation area of the Tuyuksu Glacier during the last 382 years with models of the future mass balance of this glacier until the year 2100 CE. The results show that mountain precipitation is an important force driving the cycles of the cryosphere, biosphere and hydrosphere in arid Central Asia. This driving force has broad coherence in spatiotemporal variation, with periodic cycles and decadal shifts caused by the North Atlantic Oscillation and the El Niño-Southern Oscillation. The multi-model mean in CMIP6 suggests a downward trend in glacier mass balance until 2100, but this trend will be moderated by increased precipitation. The findings of the study could help to explain how the glacial mass balance has evolved in the Tien Shan Mountains of Central Asia throughout time and its relationship to biosphere and hydrosphere.

Two Millennia of Climate History for the Russian Altai: Integrated Reconstruction from Lake Sediment Data

Abstract—A continuous history of annual air temperatures in the Russian Altai for the past 2000 years has been reconstructed for the first time by integrating climate archives stored in the bottom sediments of four lakes in Gorny Altai (Teletskoye, Kucherla, Lower Multa, and Middle Multa). The integrated chronology comprises all known climate events of the two millennia time span: Roman warm epoch (~200 to 500 AD), Dark Age cold epoch (~500 to 750 AD), medieval warming (~750 to 1300 AD), and Little Ice Age (~1300 to 1850 AD). The events distinguished in the integrated climate reconstruction agree perfectly in number and time with the events reconstructed from other climate proxies for the Altai and adjacent areas of West Siberia, Tyva, and West Mongolia. Therefore, the temperature patterns represent a common course of the 2000-year climate evolution over a large part of Central Asia. Similar synchronicity is observed with the available quantitative climate reconstructions for the Northern Hemisphere and its different regions. It means that the climate change in Central Asia over the past two millennia has followed the general global scenario.

Revised magnetostratigraphy of the Linxia Basin in the northeast Tibetan Plateau, constrained by micromammalian fossils

The Linxia Basin along the northeastern margin of the Tibetan Plateau has drawn enormous attention due to its rich mammalian fossils and great potential for exploring regional tectonics, paleoenvironmental history, and bio-evolution. However, the geochronology of the sedimentary sequences is in great dispute owing to uncertain lithostratigraphic correlation and poorly calibrated magnetostratigraphy. From 2017 to 2021, we carried out lithostratigraphic correlation of the strata from the southern part of the basin, which is rich in fossils, to the Maogou section in the central basin, and established a solid intra-basinal lithostratigraphic framework with accurate fossil locations. Then, high-resolution magnetostratigraphic investigations were performed on the Maogou section, which comprises, from oldest to youngest, the Jiaozigou, Shangzhuang, Dongxiang, Liushu/Hujialiang, and “Liushu” formations. Magnetostratigraphic results show that the Maogou sedimentary sequence (from Jiaozigou to Liushu/Hujialiang formations) spans from chron C10r to chron C5r.2n, yielding an age of 29–11.6 Ma, with constraints from four mammalian assemblage levels. The revised magnetostratigraphy indicates that the Jiaozigou Formation corresponds to chrons C6Cn.3n–C10r (∼23–29 Ma), with Paraceratherium fauna from the lower Jiaozigou Formation being determined as ∼29 Ma, and that the Hujialiang Formation, containing Platybelodon fauna, corresponds to chrons C5r.2n–C5Ar.2r (∼11.6–12.8 Ma). The revised magnetostratigraphy of the Maogou section has significantly refined the chronology of the Linxia Basin sedimentary sequences and its associated mammalian evolution, tectonism, and climate change in Central Asia.

CLIMATE CHANGE: THE ROLE OF SOCIOLOGY

This review article aims to comprehend which themes sociologists should focus on when discussing climate change. To conduct the study, the systematic review method was adopted. By scanning the sources, six major themes were identified based on the codes extracted from the documents that establish a relationship between sociology and climate change. This is followed by a discussion of reflections on these themes among Central Asian countries. The final part of the paper presents various academic and action-oriented suggestions to Central Asian academicians about the sociological context of climate change. It seems necessary to increase sociological studies and academic activities on climate change in Central Asia, given the current inequalities and potential dangers.

Eocene paleoelevation of the Tuoyun Basin, northeastern Pamirs: Evidence from a lava-vesicle-based paleoaltimeter

The arc-shape Pamir tectonic belt is located on the northwestern margin of the Tibetian plateau. At present, there are many different understandings on the history of the Pamir Plateau uplift, mainly on the time of uplift, which seriously affects the understanding of the global paleo-environmental changes since the Cenozoic. The method of reconstructing paleoelevation based on lava vesicles has improved in recent years, providing the means for establishing reliable constraints on the uplift time of the Pamir plateau. We studied Cenozoic vesicular basalt from the Tuoyun Basin in the northeastern margin of the Pamir tectonic belt. We used a lava-vesicle paleoaltimeter that measured vesicle volume at the tops and bottoms of two basalt layers, allowing the elevation of the Tuoyun Basin during the Eocene to be reconstructed according to the relationship between atmospheric pressure and altitude. Results show that the Tuoyun Basin had reached the elevation of > 2000 m at ca. 48 Ma, indicating that the influence of the Pamir tectonic belt on the Tianshan Mountains began during the Eocene. This new finding offers our contribution to better understand the impact the uplift of the Tibetian plateau on the Tianshan region and the environmental changes in central Asia during the Cenozoic.

Gene Profiling of the Ascorbate Oxidase Family Genes under Osmotic and Cold Stress Reveals the Role of AnAO5 in Cold Adaptation in Ammopiptanthus nanus.

The uplift of the Qinghai Tibet Plateau has led to a drastic change in the climate in Central Asia, from warm and rainy, to dry and less rainfall. Ammopiptanthus nanus, a rare evergreen broad-leaved shrub distributed in the temperate desert region of Central Asia, has survived the drastic climate change in Central Asia caused by the uplift of the Qinghai-Tibet Plateau. Ascorbate oxidase (AO) regulates the redox status of the apoplast by catalyzing the oxidation of ascorbate acid to dehydroascorbic acid, and plays a key role in the adaptation of plants to environmental changes. Analyzing the evolution, environmental response, and biological functions of the AO family of A. nanus is helpful for understanding how plant genome evolution responds to climate change in Central Asia. A total of 16 AOs were identified in A. nanus, all of which contained the ascorbate oxidase domain, most of which contained transmembrane domain, and many were predicted to be localized in the apoplast. Segmental duplication and tandem duplication are the main factors driving the gene amplification of the AO gene family in A. nanus. Gene expression analysis based on transcriptome data and fluorescence quantitative PCR, as well as enzyme activity measurements, showed that the expression levels of AO genes and total enzyme activity decreased under short-term osmotic stress and low-temperature stress, but the expression of some AO genes (AnAO5, AnAO13, and AnAO16) and total enzyme activity increased under 7 days of cold stress. AnAO5 and AnAO11 are targeted by miR4415. Further functional studies on AnAO5 showed that AnAO5 protein was localized in the apoplast. The expression of AnAO5 in yeast cells and the transient expression in tobacco enhanced the tolerance of yeast and tobacco to low-temperature stress, and the overexpression of AnAO5 enhanced the tolerance of Arabidopsis seedlings to cold stress. Our research provides important data for understanding the role of AOs in plant adaptation to environmental change.

Recent Response of Vegetation Water Use Efficiency to Climate Change in Central Asia

Quantifying the coupled cycles of carbon and water is essential for exploring the response mechanisms of arid zone terrestrial ecosystems and for formulating a sustainable and practical solution to issues caused by climate change. Water use efficiency (WUE), one of the comprehensive indicators for assessing plant growth suitability, can accurately reflect vegetation’s dynamic response to changing climate patterns. This study assesses the spatio-temporal changes in WUE (ecosystem water use efficiency, soil water use efficiency, and precipitation water use efficiency) from 2000 to 2018 and quantifies their relationship with meteorological elements (precipitation, temperature, drought) and the vegetation index (NDVI). The study finds that the sensitivity of NDVI to WUE is highly consistent with the spatial law of precipitation. The εPre threshold range of different types of WUE is about 200 mm or 1600 mm (low-value valley point) and 300 mm or 1500 mm (high-value peak point), and the εTem threshold value is 3~6 °C (high-value peak point) and 9~12 °C (low-value valley point). The degree to which vegetation WUE is influenced by precipitation is positively correlated with its time lag, whereas the degree to which temperature influences vegetation is negatively correlated. The WUE time lag is very long in hilly regions and is less impacted by drought; it is quite short in plains and deserts, where it is substantially affected by drought. These findings may be of great significance in responding to the severe situation of increasingly scarce water resources and the deterioration of the ecological environment across Central Asia.