Soil C:N:P stoichiometry and its influencing factors in forest ecosystems in southern China

Abstract

IntroductionSoil carbon and nutrient contents and their stoichiometric characteristics play a vital role in indicating plant growth and element balance, which can be used to indicate nutrient limitation. However, it has been less studied about their driving factors within forest soils at the regional scale in southern China.MethodsIn this study, soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) were analyzed in the topsoil (0–10 cm) at 345 sampling plots representing different forest types in Guangxi Province.ResultsThe results showed that the mean contents of C, N, and P were 29.80, 2.46, and 0.51 g/kg, respectively, and soil C:N, C:P, and N:P were 13.95, 69.60, and 5.53 respectively. The ratios also showed remarkable correlations with each other. C, N, and P contents and their ratios presented significant differences among different soil and vegetation types. C, N, and P concentrations increased with the increase of elevation and latitude, and decrease with the increase of average annual temperature (MAT). Conversely, C:N showed an opposite trend. C, N, and N:P were also increased with increasing average annual precipitation (MAP). Collectively, soil type, vegetation type, geographical, and climatic factors explained 43.46, 64.02, 68.61, 32.93, 39.64, and 37.87% of the variance in C, N, P, C:N, C:P, and N:P, respectively. For Soil C, both latitude and MAP had strong influences. Soil type was the largest explanation for soil N and P contents. Latitude and longitude were the key factors determining the soil stoichiometric ratios.DiscussionOverall, soil type, geographical and climatic factors were the most vital explanation variables for soil nutrients and their stoichiometric ratios. These results could help improve our understanding of soil stoichiometry within forest ecosystems in southern China.

The patterns of soil nitrogen stocks and C : N stoichiometry under impervious surfaces in China

“…It has been observed that the soil stoichiometric characteristics in China are influenced by geographical parameters such as altitude and latitude (Sheng et al, 2022). Lu et al (2023) found a lower C : N ratio at higher latitudes in China, suggesting a positive correlation between C : N and temperature in natural ecosystem soils. Our study, however, found that the C : N ISA ratio increased with latitude and that there was a significant negative correlation between the C : N ISA ratio and temperature.…”

“…However, the content of soil inorganic C under impervious surfaces is likely altered by anthropogenic C from construction materials, and black C (the soot or carbonaceous products formed during the incomplete combustion of biomass and fossil fuels) (He and Zhang, 2009;Zhao et al, 2017;Zhu et al, 2019;O'Riordan et al, 2021). In this study, we used the ratio between SOC and N to investigate the soil C : N stoichiometry, just like most soil studies in both ISA (Wei et al, 2014a;Raciti et al, 2012;Piotrowska-Długosz and Charzyński, 2015) and PSA (Lu et al, 2023;Schroeder et al, 2022;Yang et al, 2021).…”

Variations in soil carbon, nitrogen, and phosphorus concentrations and stoichiometry with stand age in Acacia hybrid plantations in Southern Vietnam

“…Nitrogen and phosphorous are vital determinants of plant growth and development (Lu et al 2023). The soil N/P ratio is often used to diagnose soil nutrient-limiting indicators and assess nutrient restriction thresholds (Batjes 1996;Jiang et al 2021).…”