Soil moisture threshold in controlling above- and belowground community stability in a temperate desert of Central Asia

2020 ◽  
Vol 703 ◽  
pp. 134650 ◽  
Author(s):  
Yangyang Jia ◽  
Zhaoyong Shi ◽  
Zhichao Chen ◽  
Florian Walder ◽  
Changyan Tian ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Central Asia ◽  
Community Stability ◽  
Temperate Desert

scholarly journals Spatiotemporal Variation of the Burned Area and Its Relationship with Climatic Factors in Central Kazakhstan

2021 ◽  
Vol 13 (2) ◽  
pp. 313
Author(s):  
Yongfang Xu ◽  
Zhaohui Lin ◽  
Chenglai Wu
Keyword(s):  
Soil Moisture ◽  
Relative Humidity ◽  
Central Asia ◽  
Climatic Factors ◽  
Spatiotemporal Variation ◽  
Lower Atmosphere ◽  
Burned Area ◽  
Circulation Index ◽  
Precipitation Anomalies ◽  
The Relationship

Central Asia is prone to wildfires, but the relationship between wildfires and climatic factors in this area is still not clear. In this study, the spatiotemporal variation in wildfire activities across Central Asia during 1997–2016 in terms of the burned area (BA) was investigated with Global Fire Emission Database version 4s (GFED4s). The relationship between BA and climatic factors in the region was also analyzed. The results reveal that more than 90% of the BA across Central Asia is located in Kazakhstan. The peak BA occurs from June to September, and remarkable interannual variation in wildfire activities occurs in western central Kazakhstan (WCKZ). At the interannual scale, the BA is negatively correlated with precipitation (correlation coefficient r = −0.66), soil moisture (r = −0.68), and relative humidity (r = −0.65), while it is positively correlated with the frequency of hot days (r = 0.37) during the burning season (from June to September). Composite analysis suggests that the years in which the BA is higher are generally associated with positive geopotential height anomalies at 500 hPa over the WCKZ region, which lead to the strengthening of the downdraft at 500 hPa and the weakening of westerlies at 850 hPa over the region. The weakened westerlies suppress the transport of water vapor from the Atlantic Ocean to the WCKZ region, resulting in decreased precipitation, soil moisture, and relative humidity in the lower atmosphere over the WCKZ region; these conditions promote an increase in BA throughout the region. Moreover, the westerly circulation index is positively correlated (r = 0.53) with precipitation anomalies and negatively correlated (r = −0.37) with BA anomalies in the WCKZ region during the burning season, which further underscores that wildfires associated with atmospheric circulation systems are becoming an increasingly important component of the relationship between climate and wildfire.

scholarly journals Impact of elevated precipitation, nitrogen deposition and warming on soil respiration in a temperate desert

2018 ◽  
Vol 15 (7) ◽  
pp. 2007-2019 ◽  
Author(s):  
Ping Yue ◽  
Xiaoqing Cui ◽  
Yanming Gong ◽  
Kaihui Li ◽  
Keith Goulding ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Respiration ◽  
Soil Temperature ◽  
Carbon Dioxide Emissions ◽  
Environmental Changes ◽  
N Deposition ◽  
Climate Feedback ◽  
Single Factor ◽  
Extreme Precipitation Events ◽  
Temperate Desert

Abstract. Soil respiration (Rs) is the most important source of carbon dioxide emissions from soil to atmosphere. However, it is unclear what the interactive response of Rs would be to environmental changes such as elevated precipitation, nitrogen (N) deposition and warming, especially in unique temperate desert ecosystems. To investigate this an in situ field experiment was conducted in the Gurbantunggut Desert, northwest China, from September 2014 to October 2016. The results showed that precipitation and N deposition significantly increased Rs, but warming decreased Rs, except in extreme precipitation events, which was mainly through its impact on the variation of soil moisture at 5 cm depth. In addition, the interactive response of Rs to combinations of the factors was much less than that of any single-factor, and the main response was a positive effect, except for the response from the interaction of increased precipitation and high N deposition (60 kg N ha−1 yr−1). Although Rs was found to show a unimodal change pattern with the variation of soil moisture, soil temperature and soil NH4+-N content, and it was significantly positively correlated to soil dissolved organic carbon (DOC) and pH, a structural equation model found that soil temperature was the most important controlling factor. Those results indicated that Rs was mainly interactively controlled by the soil multi-environmental factors and soil nutrients, and was very sensitive to elevated precipitation, N deposition and warming. However, the interactions of multiple factors largely reduced between-year variation of Rs more than any single-factor, suggesting that the carbon cycle in temperate deserts could be profoundly influenced by positive carbon–climate feedback.

Different responses of Central Asian precipitation to strong and weak El Niño events

2021 ◽  
pp. 1-60
Keyword(s):  
Soil Moisture ◽  
Central Asia ◽  
El Niño ◽  
El Nino ◽  
Moisture Flux ◽  
The Arctic ◽  
Central Asian ◽  
El Niño Events ◽  
Sst Anomalies ◽  
El Nino Events

Abstract The present study investigated impacts of strong and weak El Niño events on Central Asian precipitation variability from El Niño developing years to decaying years. It is found that strong El Niño events persistently enhance Central Asian precipitation from the mature winter to decaying summer. Large warm sea surface temperature (SST) anomalies in the tropical central-eastern Pacific induce anomalous upper-level divergence and updraft over Central Asia through large-scale convergence and divergence in the mature winter and decaying spring. Meanwhile, the associated wind anomalies induce anomalous eastward and northeastward moisture flux from the North Atlantic and Arabian Sea to Central Asia. Both anomalous ascent and moisture flux convergence favor above-normal precipitation over Central Asia in the mature winter and decaying spring. The El Niño events induced Central Asian precipitation anomalies are extended to the decaying summer due to the role of soil moisture. Increased rainfall in winter and spring enhances soil moisture in the following summer, which in turn, contributes to more precipitation in summer through modulating regional evaporation. During weak El Niño events, significant wet anomalies are only seen in the developing autumn, which result from anomalous southeastward moisture flux from the Arctic Ocean, and the abnormal signals are weak in the other seasons. The different responses of Central Asian precipitation to strong and weak El Niño events may be attributed to the difference in intensity of tropical SST anomalies between the two types of events.

Soil nutrient stoichiometry on linear sand dunes from a temperate desert in Central Asia

CATENA ◽  
2020 ◽  
Vol 195 ◽  
pp. 104847
Author(s):  
Ye Tao ◽  
Xiao-Bing Zhou ◽  
Shi-Hang Zhang ◽  
Hai-Ying Lu ◽  
Hongbo Shao
Keyword(s):  
Central Asia ◽  
Sand Dunes ◽  
Soil Nutrient ◽  
Nutrient Stoichiometry ◽  
Temperate Desert

Moss patch size and microhabitats influence stoichiometry of moss crusts in a temperate desert, Central Asia

2019 ◽  
Vol 443 (1-2) ◽  
pp. 55-72 ◽  
Author(s):  
Yong-Gang Li ◽  
Xiao-Bing Zhou ◽  
Yuan-Ming Zhang
Keyword(s):  
Central Asia ◽  
Patch Size ◽  
Moss Crusts ◽  
Temperate Desert

scholarly journals Assessment of Climate Change in Central Asia from 1980 to 2100 Using the Köppen-Geiger Climate Classification

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 123
Author(s):  
Huili He ◽  
Geping Luo ◽  
Peng Cai ◽  
Rafiq Hamdi ◽  
Piet Termonia ◽  
...  
Keyword(s):  
Climate Change ◽  
High Risk ◽  
Central Asia ◽  
Climatic Zone ◽  
Climate Classification ◽  
Spatial Shift ◽  
Temperate Desert ◽  
The Stability ◽  
Social Economic Development ◽  
Impacts Of Climate Change

The accelerated global warming and heterogeneous change in precipitation have been resulting in climate system shifts, which plays a key role in the stability of ecosystem and social economic development. Central Asia is account 80% of the temperate desert, characterized by fragile ecosystem; however, it has experienced the fastest warming in recent decades and projected warming in future. The Köppen-Geiger climate classification is a useful tool to assess the potential impacts of climate change on regional ecosystem. The spatial shift and temporal evolution of each climatic zone based on Köppen-Geiger climate classification are analyzed in historical and future period under different scenarios (RCP2.6, RCP4.5 and RCP8.5), high risk regions that might experience more frequent climatic zone shifts are delimited in this study, which could provide the useful information for developing mitigate strategies in coping with the warming threat. The hotter and dryer subtypes of arid climatic zone and warmer subtypes of temperate climatic zone expanded their coverage in Central Asia, corresponding to the tundra climatic, cooler subtype of arid and temperate climatic zone contracted. Based on a method defining the climate-sensitivity, high risk regions are mainly distributed in northern Kazakhstan and Tianshan Mountains region.

scholarly journals Spatial Scale-Depended Characteristic Of Moss and Soil C, N, P and K Stoichiometry and Their Relationships In A Temperate Desert of Central Asia

2021 ◽  
Author(s):  
Yonggang Li ◽  
Xiao-Bing Zhou ◽  
Yongxing Lu ◽  
Yuanming Zhang
Keyword(s):  
Central Asia ◽  
Global Climate ◽  
Spatial Scales ◽  
Desert Ecosystem ◽  
Spatial Distance ◽  
Scaling Exponents ◽  
Available Nutrients ◽  
Below Ground ◽  
Temperate Desert ◽  
Soil Available Nutrients

Abstract Background and aims: Previous studies showed that moss stoichiometric characteristics were influenced by moss patch size and shrubs in desert. Study of moss stoichiometry in different spatial scales is crucial for understanding of growth and adaptation strategy of the mosses in temperate desert. Methods: In this study, the dominant moss (Syntrichia caninervis Mitt.) of biological soil crusts, and soil under the moss patches in the Gurbantunggut Desert were selected to determine their stoichiometry in different dunes and sites. Carbon (C), nitrogen (N), phosphorus (P) and potassium (K) contents of the moss and soil, and soil available nutrients were measured. Results: Moss stoichiometry and soil available nutrients were significantly influenced by changes in spatial distance scales except for moss C. The scaling exponents of moss N, P and K elements between above-ground and below-ground parts were 0.251, 0.389, 0.442, which were less than 1. The N vs. P scaling exponents were 0.71, 0.84 in above-ground and below-ground parts of moss. Moss C, P and K elements content in above-ground parts higher than that in below-ground parts. Moreover, moss N, P and K elements were influenced by MAP, longitude and soil nutrients. Conclusion: This study provided the C, N, P and K stoichiometric characteristics of desert moss and explored their relationships with environmental variables, which can help understand nutrient stoichiometry patterns and utilization strategy of N, P and K and their potential responses to global climate changes in the desert ecosystem of central Asia.

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