Halomorphic Soils of Coastal Designs of Endorous Pulsating Chloride Lakes During the Regressive (Arid) Climatic Phase

Abstract

Over the past half century, global warming has become one of humanity’s serious problems, which is accompanied by ecosystem reactions, that is, climate aridization and subsequent desertification of landscapes. In southeastern Transbaikalia (Dauria) and the bordering regions of Mongolia and China, the problem is intensified by regionally occurring cyclical (approximately 30-year) humid (transgressive) and arid (regressive) climate phases. In these territories there are more than 500 drainless salt and brackish lakes of various chemical compositions and varying degrees of mineralization. Naturally, all the ongoing climate changes are clearly reflected in the hydrology and chemical composition of these reservoirs and in the landscapes of lake depressions, including the soil cover. During the regressive climate phase, we conducted studies of the main types of soils in the lakeside depression of the pulsating chloride Lake Bab’e. Their morphology, particle size distribution, physicochemical and other properties, composition, and salinity chemistry were studied for the first time. It has been established that these soils form a genetically related series of saline soils: quasi-gley solonchaks of the chloride type of salinity–humus-quasi-gley saline soils–light humus saline soils. It was revealed that the formation of salt marshes is directly influenced by highly mineralized lake waters. Humus-quasi-gley saline soils formed in superaquatic positions are periodically affected by lake waters and are active only in the humid climate phase. Also, the research results indicated that in humus-quasi-gley and light humus soils, chloride–soda and soda-chloride salinization of the lower horizons was noted. The obtained materials will be necessary for monitoring saline soils and ecosystems of lakeside depressions of cyclically pulsating highly mineralized drainless reservoirs in the transboundary territories of Transbaikalia (Russia), Mongolia, and China during global and regional climate changes.