Wang Wancai, Peng Yuanying, Chen Yazhen, Lei Shilong, Wang Xiaojun, Farooq Taimoor Hassan, Liang Xiaocui, Zhang Chao, Yan Wende, Chen Xiaoyong
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Xianyang 712100, China.
College of Arts and Sciences, Lewis University, Romeoville, IL 60446, USA.
Plants (Basel). 2023 Jun 30;12(13):2503. doi: 10.3390/plants12132503.
Ecological stoichiometry plays important roles in understanding the nutrient constraints on tree growth and development, as well in maintaining ecosystem services in forests, yet the characteristics of carbon:nitrogen:phosphorous (C:N:P) stoichiometry in forests under karst environment have not been sufficiently evaluated. In this study, concentration, distribution, stocks of Nitrogen (N) and Phosphorous (P), and ecological stoichiometry were studied in three common forest types: Masson pine natural forests (MPNF), Masson pine plantation forests (MPPF), and Slash pine plantation forests (SPPF) in a karst region of southwestern China. Results showed that N concentrations were higher in overstory than in understory and litter in the studied forests. However, P concentration was relatively low in overstory component of the forested ecosystems. Meanwhile, the N and P concentrations were higher in SPPF in the stem and litter, while these contents were higher in MPPF and MPNP in the overstory and understory. The N and P stocks ranged from 5.7-6.2 t ha, and 0.5-0.6 t ha in the examined forests. The ecological stoichiometry of C:N:P in the three forest types was similar in litter (46-49:2:1), and relatively steady in soil (250-320:13-16:1) and tree leaf (100-200:14-20:1). Soil P status was the primary limiting factor in affecting tree growth in MPPF and SPPF (N:P ratio > 16), while both N and P conditions were the main restrictive factors in MPNP (N:P ratio = 15) in the study area. Our study provides scientific references and useful datasets of C:N:P stoichiometry for sustainable management of forest ecosystems in karst regions.
生态化学计量学在理解树木生长发育的养分限制以及维持森林生态系统服务方面发挥着重要作用，然而喀斯特环境下森林中碳：氮：磷（C：N：P）化学计量学的特征尚未得到充分评估。在本研究中，对中国西南部喀斯特地区三种常见森林类型：马尾松天然林（MPNF）、马尾松人工林（MPPF）和湿地松人工林（SPPF）中的氮（N）和磷（P）的浓度、分布、储量以及生态化学计量学进行了研究。结果表明，在所研究的森林中，上层林分的N浓度高于下层林分和凋落物。然而，森林生态系统上层林分中的P浓度相对较低。同时，湿地松人工林茎和凋落物中的N和P浓度较高，而马尾松人工林和马尾松天然林上层林分和下层林分中的这些含量较高。在所研究的森林中，N和P储量范围分别为5.7 - 6.2吨/公顷和0.5 - 0.6吨/公顷。三种森林类型凋落物中C：N：P的生态化学计量学相似（46 - 49：2：1），土壤（250 - 320：13 - 16：1）和树叶（100 - 200：14 - 20：1）中相对稳定。在研究区域，土壤P状况是影响马尾松人工林和湿地松人工林树木生长的主要限制因素（N：P比率> 16），而氮和磷状况都是马尾松天然林树木生长的主要限制因素（N：P比率 = 15）。我们的研究为喀斯特地区森林生态系统的可持续管理提供了C：N：P化学计量学的科学参考和有用数据集。
