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萌生更新是森林更新的重要方式,是硬叶栎林受到干扰后植被恢复的主要机制。以位于青藏高原东南缘的川西折多山东坡川滇高山栎(Quercus aquifoliodes)灌丛为研究对象,调查分析了砍伐后灌丛萌生过程中基株根系和萌株生物量动态、营养元素含量,以及基株根系和土壤对萌株生长过程中的营养元素供应动态。结果表明,川滇高山栎灌丛平均地上和地下生物量分别为(11.25±0.92)t·hm-2和(34.85±2.02)t·hm-2,具有较大的根冠比(3.10:1);萌生过程中,萌株生物量呈线性增加趋势,以灌丛活细根生物量变化为最大,其次是活中根和活粗根,树桩和根蔸生物量变化最小;萌生过程中,灌丛细根和中根N、P含量表现为先增加、后降低的变化趋势,萌生初期树桩、粗根和根蔸中N和K的含量明显下降,根蔸中Ca含量略有下降,而P没有明显下降,根系Mg含量变化幅度较大,灌丛地下根系储存了较多的营养元素;土壤、树桩、粗根和根蔸是川滇高山栎灌丛砍伐后0-120天萌生生长的主要营养来源,砍伐后60天,萌株生长所需的营养除K元素主要来源于根系外,其余营养元素主要来源于土壤;在砍伐后60-120天,基株根系对萌株生长所需的N、K和Ca贡献较大,而对P和Mg的贡献较小;在砍伐后120-180天,根系除K元素对萌生生长还保持较大的贡献外,对其余营养元素的贡献均较小。高山栎林管理要注重加强地下根系的保护。
Initiation renewal is an important way of forest renewal and the main mechanism of vegetation recovery after disturbed Quercus variabilis forest. Taking Quercus aquifoliodes shrubs located in the southeast slope of the Chuladu Mountains in the southeastern part of the Qinghai-Tibet Plateau as research objects, the dynamic changes of biomass and nutrient elements in roots and adventitious roots of screened shrubs after deforestation were investigated. As well as the root system and soil on the growth of vegetative elements in the supply of nutrients. The results showed that the average aboveground biomass and underground biomass of Quercus shrub and oak shrubs were (11.25 ± 0.92) t · hm-2 and (34.85 ± 2.02) t · hm-2, respectively, ). During the process of germination, the biomass of the adventitious buds increased linearly. The fine root biomass of shrubs was the largest, followed by the live root and the live coarse root, and the smallest change of the stump and root. The content of N and P in the fine roots and middle roots showed the trend of first increasing and then decreasing, and the contents of N and K in stumps, coarse roots and rhizomes decreased significantly at the early stage of sprouting, while the content of Ca decreased slightly in roots, while P did not Significantly decreased, the content of Mg in roots varied a lot, and the underground root system of shrubs stored more nutrients; soil, stumps, coarse roots and rhizomes were the main nutrition for 0-120 days after cutting in Quercus aliena shrubs Source, 60 days after harvesting, the nutrients required for the growth of the adventitious buds were mainly derived from the root system and the rest of the nutrients were mainly from the soil. After 60-120 days of harvesting, , K and Ca contribute more, but less contribution to P and Mg; 120-180 days after harvesting, except for K element root growth also To maintain a larger contribution, the contribution of the remaining nutrients are small. Management of alpine oak forests should focus on strengthening the protection of underground roots.