Long-Term Phosphorus Addition Strongly Weakens the Carbon Sink Function of a Temperate Peatland

Complexity of nutrient enrichment on subarctic peatland soil CO2 and CH4 production under increasing wildfire and permafrost thaw

“…The microbial CUE was estimated for the bog soil by fumigation extraction method at the end of the incubation (Table 3). The The mere amount of OC substrates is likely not at all limiting in peatland soils, and microbial strategies to overcome relative nutrient imbalances may fall into three broad categories: (1) increase the production of extracellular enzymes to acquire necessary nutrient elements from enzyme-facilitated organic matter degradation, (2) recycle the nutrient elements assimilated in dead microbial cells (i.e., necromass recycling), and (3) release extra substrate C via respiration without biomass assimilation (i.e., overflow respiration) (Giesler et al, 2011;Manzoni et al, 2012;Lin et al, 2014;Hoyos-Santillan et al, 2018;Schillereff et al, 2021;Lu et al, 2022). The quality or degradability of C substrates may have a determining effect on which strategy to be activated by soil microbes, which in turn accelerates or decelerates the overall decomposition rate of soil organic matter (SOM).…”

The Effect of Warming-Amplified Phosphorus Addition on a Peatland’s N2O Emissions

“…The warming was passively achieved by the open top chamber (OTC, 0.8 m × 0.8 m at the top and 1.2 m × 1.2 m at the bottom), which increased the air temperature by about 0.6 • C during the growing season (Figure S1). For more information, see Bu, et al [37]; Yi, et al [30]; and Lu, et al [6].…”

“…Phenol oxidase (POX) can partially oxidize phenolic substances into simple organic compounds, and the activity of POX is crucial for the accumulation of organic matter in peatlands [42,43]. The microporous plate fluorescence method was used to determine the activities of the above three hydrolases and one oxidase in peat soil [6,44].…”

“…The litter of vascular plants was rich in lignin, which need a high level of POX activity to break down [66]. According to the "enzyme latch" hypothesis, high POX activity may reduce phenolics to promote the activities of hydrolases, leading to increased peat decomposition and hence increased DOC concentration, providing an energy source for nitrification and denitrification [6,7,43]. The SEM demonstrates the process through which P addition affects N 2 O fluxes by affecting vegetation succession, enzyme activity response, and then organic matter decomposition.…”

“…Nitrous oxide (N 2 O) is an important greenhouse gas with a warming potential 273 times that of carbon dioxide (CO 2 ) [1]. Montane peatlands are huge nitrogen (N) pools, but not a significant source of N 2 O emissions due to phosphorus (P) limitations and low temperature [2][3][4][5][6][7]. However, the increase in P deposition and continuous warming caused by global changes will change the current status of peatlands, which may increase the possibility of peatlands being a hotspot of N 2 O emissions [8][9][10].…”