Effects of habitat types on the dynamic changes in allocation in carbon and nitrogen storage of vegetation–soil system in sandy grasslands: How habitat types affect C and N allocation?

Abstract

The progressively restoration of degraded vegetation in semiarid and arid desertified areas undoubtedly formed different habitat types. The most plants regulate their growth by fixing carbon with their energy deriving from photosynthesis; carbon (C) and nitrogen (N) play the crucial role in regulating plant growth, community structure, and function in the vegetation restoration progress. However, it is still unclear how habitat types affect the dynamic changes in allocation in C and N storage of vegetation–soil system in sandy grasslands. Here, we investigated plant community characteristics and soil properties across three successional stages of habitat types: semi‐fixed dunes (SFD), fixed dunes (FD), and grasslands (G) in 2011, 2013, and 2015. We also examined the C and N concentrations of vegetation–soil system and estimated their C and N storage. The C and N storage of vegetation system, soil, and vegetation–soil system remarkably increased from SFD to G. The litter C and N storage in SFD, N storage of vegetation system in SFD, and N storage of soil and vegetation–soil system in FD increased from 2011 to 2015, while aboveground plant C and N storage of FD were higher in 2011 than in 2013 and 2015. Most of C and N were sequestered in soil in the vegetation restoration progress. These results suggest that the dynamic changes in allocation in C and N storage in vegetation–soil systems varied with habitat types. Our study highlights that SFD has higher N sequestration rate in vegetation, while FD has the considerably N sequestration rate in the soil.

Effect of Root and Mycelia on Fine Root Decomposition and Release of Carbon and Nitrogen Under Artemisia halodendron in a Semi-arid Sandy Grassland in China

“…In addition, the mass loss after 1 year of decomposition in the current study ranged from 65.5 to 72%, which is also higher than the former studies (Luo et al, 2016a , 2020b ). The relatively higher decomposition rate for the fine roots of A. halodendron would result from the patterns of precipitation over years (Luo et al, 2016a , 2020b ).…”

“…In this study, the mass loss of the fine roots of A. halodendron was as high as 41.7-45.3% at the initial stage of decomposition (33 days), which was higher than the previous study (Luo et al, 2016a). In addition, the mass loss after 1 year of decomposition in the current study ranged from 65.5 to 72%, which is also higher than the former studies (Luo et al, 2016a(Luo et al, , 2020b. The relatively higher decomposition rate for the fine roots of A. halodendron would result from the patterns of precipitation over years (Luo et al, 2016a(Luo et al, , 2020b.…”

“…This is a typical AMF infestation species (Te, 2007) and is one of the dominant shrubs in Horqin sandy land and plays an important role during the process of dune stabilization (Huang et al, 2012;Luo et al, 2020a). Meanwhile, the decomposition rate of the fine root of A. halodendron under natural conditions also differed significantly compared with another study in the same region (Li et al, 2016;Luo et al, 2020b). Therefore, we preliminarily hypothesized that the difference of water and temperature in the initial decomposition stage (caused by the difference in the starting date) would be the main factor for these differences.…”

“…Therefore, we preliminarily hypothesized that the difference of water and temperature in the initial decomposition stage (caused by the difference in the starting date) would be the main factor for these differences. Thus, we carried out an experiment focusing on the effect of starting time on root decomposition of A. halodendron (Luo et al, 2020b). It was found that the fine root decomposition rate of A. halodendron at different starting times differed significantly; however, the difference was small, and the root decomposition is likely to be affected by other factors such as the variance of soil moisture and its interaction with soil temperature (Luo et al, 2016a(Luo et al, , 2020b.…”

“…Thus, we carried out an experiment focusing on the effect of starting time on root decomposition of A. halodendron (Luo et al, 2020b ). It was found that the fine root decomposition rate of A. halodendron at different starting times differed significantly; however, the difference was small, and the root decomposition is likely to be affected by other factors such as the variance of soil moisture and its interaction with soil temperature (Luo et al, 2016a , 2020b ). Given that the plant community in this area is dominated by short-lived annual species, and the composition and structure of plant community varied greatly in both spatial and temporal scales (Wang, 1989 ; Zuo et al, 2009 ; Duan et al, 2014 ; Wang et al, 2018 ), we then hypothesized that the existence of the living roots and their related processes such as mycorrhizal fungal mycelia and root exudates in the vicinity of litterbags might affect the process of root decomposition and element transformations in the litter-soil system.…”