Vegetation dynamics during different abandoned year spans in the land of the Loess Plateau of China

Abstract

In this semi-arid area, many studies focused on the two-phase vegetation pattern were carried out to explore a changing vegetation trajectory on degraded land. However, this study conducted an analysis of a two-phase vegetation pattern and explored the successional vegetation trajectories in a positive succession without disturbance. In this work, 60 randomly distributed plots (1×1 m) were invested on four abandoned land areas (4-, 12-, 22-, and 50-year abandoned land) to determine attributes of vegetation, and soil physical and nutritional properties. It was found that vegetation distribution development went from homogeneous on 4-year abandoned land to heterogeneous on 50-year abandoned land, with a positive succession. Meanwhile, there was a significant difference in soil physical and nutritional properties for the inside and outside of vegetation patches. Vegetation patches can supply better soil physical and nutritional properties for vegetation than bare patches along the abandoned time. Vegetation diversity changes without a regular trend which may be due to the effect of environment and interspecies competition. This work picked up the slack for vegetation patterns succession research and provided a quantitative analysis approach.

Dynamics of Community Biomass and Soil Nutrients in the Process of Vegetation Succession of Abandoned Farmland in the Loess Plateau

“…During the process of community succession, the change of community biomass is closely related to the community structure and dominant community. AGB distribution mainly relates to the competition for light resources, while BGB distribution mainly relates to the competition for soil nutrients (Du et al, 2008;An et al, 2011;Jia et al, 2011;Hou and Fu, 2014;Mu et al, 2016;Zhang et al, 2018). In this study, there were many vacant niches during the early stage of succession, and the competition was not fierce.…”

“…Vegetation is an important soil-forming factor and also the basis of sustainable utilization of soil. In the process of growth, plants gradually improve the physical and chemical properties of soil by absorption and utilization of soil nutrients (Jiang, 2007;Chang et al, 2008;Jia et al, 2011;Hou and Fu, 2014;Kämpf et al, 2016;Yang et al, 2018;Li et al, 2019;Shang et al, 2019;Hou et al, 2020). Community biomass, as an important measure of ecosystem productivity, reflects the growth and development of plants and changes in their morphological characteristics and is also one of the important indicators to describe the community structure and function, which is a comprehensive reflection of the mutual competition between species and the mutual adaptation between species and the environment (Yan et al, 2006;Wang et al, 2009;Costa et al, 2014;Hou et al, 2020).…”

“…Abandonment succession is the process of vegetation succession recovering to the top community after farmland abandonment. Many studies had shown that, during the vegetation succession after farmland abandonment, the species diversity and community productivity increased gradually, and the community structure tended to be complicated, which better improved the regional ecological environment (Jiang, 2007;Hou and Fu, 2014;Hülber et al, 2017;Du et al, 2020). There is a close relationship between vegetation restoration and soil nutrients.…”

Quantifying the effect of ecological restoration on runoff and sediment yields

“…Compared to loess regions in Western and Central Europe, the Loess Plateau had the highest soil loss across all land use types, with bare land always having the highest soil loss rate. Although abandoned land (similar to fallows) was an important land use type for rewilding and for conserving biodiversity, retaining soil, and restoring the ecological function by natural succession (Corlett, 2016; Hou and Fu, 2014b; Queiroz et al, 2014), unmanaged abandoned land in the early stage of ecological restoration has been found to have relatively high annual sediment yields, even exceeding the annual mean soil loss rate of cropland (Lasanta et al, 2000; Maetens et al, 2012; Mutema et al, 2015; Prosdocimi et al, 2016). In our study, the annual reduction sediment effectiveness of shrubland, natural grassland, forest, and artificial grassland was found to be higher than that of cropland and abandoned land, and overall, the effectiveness of ecological restoration land types were approximately two times that of LDTs.…”