Seasonal changes in the soil moisture distribution around bare rock outcrops within a karst rocky desertification area (Fuyuan County, Yunnan Province, China)

Abstract

The spatial and temporal soil moisture distribution is an important control on surface ecological processes in areas with rock outcrops resulting from karst rocky desertification (KRD). To explore the local effects of bare rocks within different seasons, soil moisture was measured in a KRD region (Fuyuan County, Yunnan Province, southwest China) at different depths and in different directions and distances from rock outcrops in both the dry and the wet seasons. The soil moisture north and east of the rocks was higher compared to the other directions and to the control plot. This effect is attributed to the shading by the rocks. The shading effect is evident in all seasons but more pronounced in the dry season. In the wet season, the directional dependency is restricted to the surface layer and the increase in soil moisture with depth is more pronounced around the rocks than at the control plot. This is attributed to precipitation-induced runoff from the rock outcrops infiltrating into the deeper layers at the rock-soil interface. These findings suggest the redistribution of water in the wet season and the spatial variation of evapotranspiration in the dry season are factors controlling the local soil moisture pattern around the rock outcrops.

Soil Bacterial Community Structure and Co-occurrence Pattern during Vegetation Restoration in Karst Rocky Desertification Area

“…The main type of soil is red limestone. The KRD area covers 601.018 km 2 , accounting for 29.33% of the Karst region ( Li et al, 2016 ). The five typical types of vegetation in the area are grassland, shrubbery, secondary forest, pure plantation, and mixed plantation.…”

Characteristics of climate change and its relationship with land use/cover change in Yunnan Province, China

“…the rainy (from May to October, including summer and autumn) and dry (from November to April of the next year, including winter and spring) seasons, are divided according to the precipitation amount (e.g. Huang, 2011;Fan et al, 2013;Yang et al, 2015;Li et al, 2016). Because of the summer monsoons, precipitation in this region mainly occurs in the rainy season, which can take up more than 80% of the annual total precipitation.…”

Impacts of warming winters on recharge in a seasonally frozen bedrock aquifer

“…Despite this, a continuous layer of ice (~2. Lateral flow along a low permeability boundary, particularly along a soil-bedrock interface, has previously been reported in the literature (e.g., Appels et al, 2015;Kormos et al, 2015;Li et al, 2016;Peters et al, 1995;Spence and Woo, 2003;Tromp-van Meerveld and McDonnell, 2006). However, to the best of the author's knowledge, this mechanism of recharge near outcrops has yet to be observed in detail during midwinter warming or ROS events in this type of setting.…”