Soil Enzyme Activities and Their Relationships With Soil C, N, and P in Peatlands From Different Types of Permafrost Regions, Northeast China

Abstract

Peatland is a key component of terrestrial ecosystems in permafrost regions and have important effects on climate warming. Soil enzymes are involved in biogeochemical cycle of soil carbon (C), nitrogen (N) and phosphorus (P), which can be used as early sensitive indicators of soil nutrient changes caused by climate change. To predict the possible effects of permafrost degradation on soil enzymes in peatlands, ten peatlands from three types of permafrost regions along the permafrost degradation sequence (predominantly continuous permafrost region-predominantly continuous and island permafrost region-sparsely island permafrost region) in northeast China were selected to examine the activities of soil invertase, β-glucosidase, urease and acid phosphatase and their relationships with soil physicochemical properties. The results demonstrated that permafrost type had significant effect on soil enzyme activities. Soil enzyme activities in predominantly continuous and island permafrost region were significantly higher than those in sparsely island permafrost region and predominantly continuous permafrost region. The activities of four soil enzymes were higher in 0–15 cm than 15–30 cm soil layer. Soil enzymes activities were positively correlated with soil ammonia nitrogen (NH4+-N), soil moisture content (SMC), total phosphorus (TP) and total nitrogen (TN), but negatively correlated with soil nitrate nitrogen (NO3−-N). Soil inorganic nitrogen and moisture contents were the main factors affecting soil enzyme activities, with NH4+-N accounted for 41.6% of the variance, SMC 29.6%, and NO3−-N 11.0%. These results suggested that permafrost degradation may change soil enzyme activities by changing soil physicochemical properties. In this study, only 0–30 cm peat soil in permafrost regions was collected during the complete thawing period of permafrost active layer, further studies should be placed on the change of soil enzyme activities in active layer and permafrost layer during freezing and thawing process in the southernmost location of northeast China in the Eurasia permafrost body and boreal forest belt.

Residue‐ and nitrogen‐induced carbon mineralization varies with soil fertility status

“…Treatment effects on β‐glucosidase are reported in Figure 8, which shows that activities for this enzyme were invariably greater for the HNS than the LNS and increased significantly in the presence of residue, and that further increases occurred when residue was applied with AS but not PN. The stimulatory effect of mineral N on β‐glucosidase activity has been reported previously (e.g., Keeler et al., 2009; Liu et al., 2021) and can be attributed to enhanced microbial activities that promote the production of C‐degrading enzymes by supplying an essential elemental constituent of all enzymes. The finding that NH 4 + had a greater effect than NO 3 − (Figure 8) is consistent with microbial preferences for a source of mineral N that can be readily assimilated without the need for reduction.…”

Influence of Organic Amendments Based on Garden Waste for Microbial Community Growth in Coastal Saline Soil

“…They participate in the circulation of almost all organic matter and nutrient elements in the soil, and they are important indicators of soil biological characteristics [46]. Among them, sucrase is the key enzyme of soil carbon cycle transformation, while urease is used to characterize the soil nitrogen supply [47]. The results of our study show that the addition of organic amendments can significantly promote the activities of soil urease, sucrase and dehydrogenase.…”

Organic Carbon Mineralization and Bacterial Community of Active Layer Soils Response to Short-Term Warming in the Great Hing’an Mountains of Northeast China

“…In addition, Yergeau et al (2009) pointed out the response of microorganisms to environmental change are closely related to enzymes. And our previous studies showed that upper layers exhibited higher β-glucosidase and phosphatase activity (Liu et al, 2021). The presence of these enzymes suggested rich environment of C sources (Coolen et al, 2011).…”