Natural vegetation restoration is more beneficial to soil surface organic and inorganic carbon sequestration than tree plantation on the Loess Plateau of China

Abstract

Natural vegetation restoration and tree plantation are the two most important measures for ecosystem restoration on the Loess Plateau of China. However, few studies have compared the effects of the two contrasting measures on soil organic and inorganic carbon (SOC and SIC) sequestration or have further used SOC and SIC isotopes to analyze the inherent sequestration mechanism. This study examined a pair of neighboring small watersheds with similar topographical and geological backgrounds. Since 1954, natural vegetation restoration has been conducted in one of these watersheds, and tree plantation has been conducted in the other. The two watersheds have now formed completely different landscapes (naturally restored grassland and artificial forestland). Differences in soil bulk density, SOC and SIC content and storage, and SOC and SIC δ(13)C values were investigated in the two ecosystems in the upper 1m of the soil. We found that SOC storage was higher in the grassland than in the forestland, with a difference of 14.90 Mg ha(-1). The vertical changes in the δ(13)CSOC value demonstrated that the two ecosystems have different mechanisms of soil surface organic carbon accumulation. The SIC storage in the grassland was lower than that in the forestland, with a difference of 38.99 Mg ha(-1). The δ(13)CSIC values indicated that the grassland generates more secondary carbonate than the forestland and that SIC was most likely transported to the rivers from the grassland as dissolved inorganic carbon (DIC). The biogeochemical characteristics of the grassland were favorable for the formation of bicarbonate. Thus, more DIC derived from the dissolution of root and microbial respired CO2 into soil water could have been transported to the rivers through flood runoff. It is necessary to study further the transportation of DIC from the grassland because this process can produce a large potential carbon sink.

Carbon sequestration and Jerusalem artichoke biomass under nitrogen applications in coastal saline zone in the northern region of Jiangsu, China

“…Soil is an important carbon sink in the biosphere (Jin et al, 2014). It is estimated that the reserves of soil C are approximately 2.5 to 3.0 times of the vegetation carbon reserve in terrestrial ecosystems and 2 to 3 times that of carbon pools in the atmosphere (Yang et al, 2010).…”

Ecosystem Services and Ecological Restoration in the Northern Shaanxi Loess Plateau, China, in Relation to Climate Fluctuation and Investments in Natural Capital

“…Sustainability 2017, 9,199 7 of 20 correlation coefficient between y and z. The calculation of the correlation coefficient Rxy (or Rxz or Rxz) is detailed in Xu [60].…”

“…Vegetation coverage of the NSLP has gradually improved since the implementation of GFG [6][7][8]. This improvement in vegetation cover has realized huge ecological effects, including the potential in sequestrating greenhouse gases [9,10] or regulating climate, which is a hot issue in the background of climate change. However, because some regions of GFG (e.g., NSLP) belong to the semi-arid area, some research has raised concerns about the problems of food security and water scarcity caused by GFG [11,12].…”

Soil CO2 Uptake in Deserts and Its Implications to the Groundwater Environment

“…Although soil CO2 uptake in deserts has been investigated in many previous studies, its potential influences on the groundwater environment remain unaddressed [25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]. This is partially due to the lack of a simple method for the separation and quantification of such CO2 uptake.…”

“…Most studies assumed that these absorbed CO2 are partially dissolved in the soil-groundwater system. However, the magnitude of the beneath CO2 dissolution remains undetermined [25][26][27][28][29][30].…”