Climate Sensitivity of the Arid Scrublands on the Tibetan Plateau Mediated by Plant Nutrient Traits and Soil Nutrient Availability

Abstract

Climate models predict the further intensification of global warming in the future. Drylands, as one of the most fragile ecosystems, are vulnerable to changes in temperature, precipitation, and drought extremes. However, it is still unclear how plant traits interact with soil properties to regulate drylands’ responses to seasonal and interannual climate change. The vegetation sensitivity index (VSI) of desert scrubs in the Qaidam Basin (NE Tibetan Plateau) was assessed by summarizing the relative contributions of temperature (SGST), precipitation (SGSP), and drought (temperature vegetation dryness index, STVDI) to the dynamics of the normalized difference vegetation index (NDVI) during plant growing months yearly from 2000 to 2015. Nutrient contents, including carbon, nitrogen, phosphorus, and potassium in topsoils and leaves of plants, were measured for seven types of desert scrub communities at 22 sites in the summer of 2016. Multiple linear and structural equation models were used to reveal how leaf and soil nutrient regimes affect desert scrubs’ sensitivity to climate variability. The results showed that total soil nitrogen (STN) and leaf carbon content (LC), respectively, explained 25.9% and 17.0% of the VSI variance across different scrub communities. Structural equation modeling (SEM) revealed that STN and total soil potassium (STK) mediated desert scrub’s VSI indirectly via SGST (with standardized path strength of −0.35 and +0.32, respectively) while LC indirectly via SGST and SGSP (with standardized path strength of −0.31 and −0.19, respectively). Neither soil nor leave nutrient contents alone could explain the VSI variance across different sites, except for the indirect influences of STN and STK via STVDI (−0.18 and 0.16, respectively). Overall, this study disentangled the relative importance of plant nutrient traits and soil nutrient availability in mediating the climatic sensitivity of desert scrubs in the Tibetan Plateau. Integrating soil nutrient availability with plant functional traits together is recommended to better understand the mechanisms behind dryland dynamics under global climate change.

Serratia plymuthicaHK9‐3 enhances tomato resistance against Phytophthora capsici by modulating antioxidant defense systems and rhizosphere micro‐ecological condition

“…As previously reported (Chen et al, 2022), the content of nitrogen, phosphorus and potassium in the tomato rhizosphere soil under normal and P. capsici-infected conditions were determined. The soil samples were collected two weeks after P. capsici inoculation.…”

Study on the Spatial and Temporal Evolution of NDVI and Its Driving Mechanism Based on Geodetector and Hurst Indexes: A Case Study of the Tibet Autonomous Region

“…From 1998 to 2019, the TAR experienced higher air temperature changes than China [38] and lower precipitation than China [39]. The rapid increase in air temperature [40] and the relatively stable precipitation [41] in the TAR have led to regional warming and drought [42]. Some studies have shown that alpine meadows and grasslands strongly respond to precipitation [18].…”

Spatiotemporal Variations in the Sensitivity of Vegetation Growth to Typical Climate Factors on the Qinghai–Tibet Plateau

“…Overall, current studies on vegetation sensitivity mainly focus on the spatial domain while generally ignoring its temporal variability, i.e., assuming vegetation sensitivity to be constant over time. Previous studies generally found that temperature is the climatic factor that regulates vegetation growth in the southeastern QTP, while precipitation is the dominant climatic factor driving vegetation growth in the northwestern QTP [20][21][22]. The study of Wang et al [23] pointed out that alpine grasslands exhibited divergent responses to precipitation, and Li et al [21] further reported a widespread increasing vegetation sensitivity to soil moisture on a global scale.…”