Hu Gang, Zhang Zhonghua, Li Lei
Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Sciences, Hainan Normal University, Haikou, China.
Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, School of Environmental and Life Sciences, Nanning Normal University, Nanning, China.
Front Plant Sci. 2023 May 9;14:1181365. doi: 10.3389/fpls.2023.1181365. eCollection 2023.
The stoichiometry of key elements such as C, N, and P is an important indicator of ecosystem nutrient status and biogeochemical cycling. Nevertheless, the responses of soil and plant C:N:P stoichiometric characteristics to natural vegetation restoration remain poorly understood. In this study, we investigated C, N, and P contents and stoichiometry in soil and fine roots along vegetation restoration stages (grassland, shrubland, secondary forest, and primary forest) in a tropical mountainous area in southern China. We found that soil organic carbon, total N, C:P ratio, and N:P ratio significantly increased with vegetation restoration and significantly decreased with increasing soil depth, whereas there was no significant effect on soil total P and C:N ratio. Furthermore, vegetation restoration significantly increased the fine root N and P content and N:P ratio, whereas soil depth significantly decreased the fine root N content and increased the C:N ratio. The increasing average N:P ratio in fine roots from 17.59 to 21.45 suggested that P limitation increased with vegetation restoration. There were many significant correlations between C, N, and P contents and their ratios in soil and fine roots, indicating a reciprocal control of nutrient stoichiometric characteristics between them. These results contribute to our understanding of changes in soil and plant nutrient status and biogeochemical cycling during vegetation restoration and provide valuable information for restoration and management of tropical ecosystems.
碳、氮、磷等关键元素的化学计量比是生态系统养分状况和生物地球化学循环的重要指标。然而，土壤和植物碳氮磷化学计量特征对天然植被恢复的响应仍知之甚少。在本研究中，我们调查了中国南方热带山区沿植被恢复阶段（草地、灌丛、次生林和原始林）的土壤和细根中的碳、氮、磷含量及化学计量比。我们发现，土壤有机碳、全氮、碳磷比和氮磷比随植被恢复显著增加，随土壤深度增加显著降低，而对土壤全磷和碳氮比没有显著影响。此外，植被恢复显著增加了细根氮和磷含量以及氮磷比，而土壤深度显著降低了细根氮含量并增加了碳氮比。细根平均氮磷比从17.59增加到21.45，表明随着植被恢复磷限制加剧。土壤和细根中碳、氮、磷含量及其比例之间存在许多显著相关性，表明它们之间对养分化学计量特征存在相互控制。这些结果有助于我们理解植被恢复过程中土壤和植物养分状况及生物地球化学循环的变化，并为热带生态系统的恢复和管理提供有价值的信息。
