Hydrological response of biological soil crusts to global warming: A ten‐year simulative study

Abstract

Biological soil crusts across the desert regions play a key role in regional ecological security and ecological health. They are vital biotic components of desert ecosystems that maintain soil stability, fix carbon and nitrogen, influence the establishment of vascular plants, and serve as habitats for a large number of arthropods and microorganisms, as well as influencing soil hydrological processes. Changes in temperature and precipitation are expected to influence the functioning of desert ecosystems by altering biotic components such as the species composition of biological soil crusts. However, it remains unclear how these important components will respond to the prolonged warming and reduced precipitation that is predicted to occur with climate change. To evaluate how the hydrological properties of these biological soil crusts respond to these alterations, we used open-top chambers over a 10-year period to simulate warming and reduced precipitation. Infiltration, dew entrapment, and evaporation were measured as surrogates of the hydrological functioning of biological soil crusts. It was found that the ongoing warming coupled with reduced precipitation will more strongly affect moss in crustal communities than lichens and cyanobacteria, which will lead to a direct alteration of the hydrological performance of biological soil crusts. Reductions in moss abundance, surface cover, and biomass resulted in a change in structure and function of crustal communities, decreased dew entrapment, and increased infiltration and evaporation of biological soil crusts in desert ecosystems, which further impacted on the desert soil water balance.

A Combination Forecasting Strategy for Precipitation, Temperature and Wind Speed in the Southeastern Margin of the Tengger Desert

“…It is widely spread in arid and semiarid regions as one of the major components of desert ecosystems because BSC has developed strong adaptability to resistant the drought, extreme temperatures, and UV-B radiation [7,8] to adapt the extreme environment. Its existence and development is an important indicator of the reversal of the ecological environment [9], as well as an important indicator for the evaluation of the health of desert ecosystems [10].…”

“…Studies have shown that the main a-biological factors affecting BSC are water, temperature, wind speed, light, etc., among which water is considered to be the most important a-biological factor affecting the ecological and physiological functions of BSC [2,8,11]. Almost all studies on the ecological and physiological functions of BSC involve the influence of water [10]. The scarcity of rain and high temperature are two major constraint factors during the growing season in the desert [3].…”

“…Wind speed is an important abiotic factor which affects the physiological, biochemical, material metabolism and ecological adaptability of BSC, studies show that the higher the wind speed often acompanied by the lower the development degree of BSC [2,5,8,12]. Carbon dioxide and other meteorological factors, such as temperature, water and light, jointly affect the photosynthesis of BSC, and light is only second to water which has an important impact on the ecological and physiological characteristics of BSC [10,12]. However, studies have shown that BSC photosynthesis does not require much light, and the response of photosynthesis to light is affected by water [3,13].…”

“…At present, the research on the response of BSC to meteorological factors such as precipitation, temperature and wind speed focuses on the physiological and biochemical effects of different kinds of plants [14]. The change of community species richness, abundance, coverage and biomass of BSC caused by climate change are important to measure the evolution of ecological structure in arid and semiarid regions [2,10,15], therefore, it is particularly important to forecast the precipitation, temperature, wind speed respectively under background of global climate warming [16][17][18].Due to the chaotic and intrinsic complexity of weather parameters, no single method or model can perform well in the forecasting process [19][20][21][22] In order to improve prediction accuracy, hybrid models based on data pre-processing technique [23], parameter selection and optimization technique combined with artificial intelligent models or conventional statistical models being proposed [24][25][26]. The results proved that the preprocessing of the original data could effectively decrease the forecasting errors [27].…”

“…At present, the research on the response of BSC to meteorological factors such as precipitation, temperature and wind speed focuses on the physiological and biochemical effects of different kinds of plants [14]. The change of community species richness, abundance, coverage and biomass of BSC caused by climate change are important to measure the evolution of ecological structure in arid and semiarid regions [2,10,15], therefore, it is particularly important to forecast the precipitation, temperature, wind speed respectively under background of global climate warming [16][17][18].…”