Increased precipitation and nitrogen addition accelerate the temporal increase in soil respiration during 8‐year old‐field grassland succession

Abstract

Ecological succession after disturbance plays a vital role in influencing ecosystem structure and functioning. However, how global change factors regulate ecosystem carbon (C) cycling in successional plant communities remains largely elusive. As part of an 8‐year (2012–2019) manipulative experiment, this study was designed to examine the responses of soil respiration and its heterotrophic component to simulated increases in precipitation and atmospheric nitrogen (N) deposition in an old‐field grassland undergoing secondary succession. Over the 8‐year experimental period, increased precipitation stimulated soil respiration by 11.6%, but did not affect soil heterotrophic respiration. Nitrogen addition increased both soil respiration (5.1%) and heterotrophic respiration (6.2%). Soil respiration and heterotrophic respiration linearly increased with time in the control plots, resulting from changes in soil moisture and shifts of plant community composition from grass–forb codominance to grass dominance in this old‐field grassland. Compared to the control, increased precipitation significantly strengthened the temporal increase in soil respiration through stimulating belowground net primary productivity. By contrast, N addition accelerated temporal increases in both soil respiration and its heterotrophic component by driving plant community shifts and thus stimulating soil organic C. Our findings indicate that increases in water and N availabilities may accelerate soil C release during old‐field grassland succession and reduce their potential positive impacts on soil C accumulation under future climate change scenarios.

Changes in soil fungal community composition and functional groups during the succession of Alpine grassland

“…During ecological succession, vegetation communities change over time, which could shift primary productivity, litter quantity, and quality, with subsequent effects on carbon and nitrogen cycle processes (Shao et al 2017;Smith et al 2015;Zhang et al 2022). Previous studies have reported that Alpine grassland succession in Qinghai-Tibet Plateau toward degradation, it is not only reduced plant biomass, soil organic carbon (C), and total nitrogen (N), but also changed the ratio of roots to shoots, soil water content, and these may weaken the C sink effect of vegetation and in turn aggravate the climate warming (Alhassan et al 2018;Jiang et al 2020;Liu et al 2018).…”

Dryland nitrogen deposition induces microbiome‐driven increases in biocrust respiration and losses of soil carbon

“…More importantly, although the stimulating function of short-term N addition on biocrust R s was supported by several past investigations (Gao et al, 2014), it is notable that the influence of N input on R s is a prolonged and complicated process (Zhang et al, 2022). With longer T A B L E 2 Impacts of N addition on soil respiration in different regions and ecosystems around the world.…”

Divergent Response of Carbon Sink to Climate Change Along Topographical Gradient in China Based on EEMD Detrending

“…As slope increases, the importance of PRE and VPD for NEP variation gradually diminishes, because of the exacerbates soil erosion caused by PRE (Berger et al., 2010), and the reduced respiration due to water loss (L. Liu et al., 2016), respectively. It is noteworthy that VPD is always more important than SM in all slopes despite the growing importance of SM, possibly because increased SM also enhances soil respiration (J. Zhang et al., 2022), offsetting some of the positive effects, while VPD has essentially only negative effects on vegetation (Yuan et al., 2019).…”