不同生态修复边坡凋落物分解与养分动态变化特征

    Characteristics of litter decomposition and nutrient dynamics on slopes resotred with different ecological restoration techniques

    • 摘要: 为了探究生态修复边坡土壤养分平衡,对不同生态修复边坡凋落物分解过程中养分归还的动态特征进行研究。以宜昌市5处不同生态修复技术边坡(植被混凝土生态防护技术边坡、高次团粒植被恢复技术边坡、仿植被混凝土生态修复技术边坡、植生水泥生境构筑技术边坡+植被混凝土生态防护技术边坡及客土喷播技术边坡)为研究对象,采用样方法收集凋落物,测定凋落物的初始养分含量,结合分解袋法进行原位分解实验,测定其分解特征与养分动态变化。结果表明: ①在相同分解条件下,植被混凝土边坡凋落物分解速率最快,客土喷播边坡分解速率最慢。② 5处边坡凋落物TOC含量存在显著差异,初始凋落物木质素、N、P元素含量差异显著,其凋落物C: N在同一分解时间内差异显著。③相关性分析结果显示,凋落物分解系数K与TOC、N、C: N呈显著负相关,表明不同生态修复边坡凋落物分解速率主要受到凋落物TOC含量与凋落物C: N的影响,在分解过程中受到N限制,即凋落物初始TOC、N含量与C: N越高,分解速率越慢,越不利于分解。

       

      Abstract: By studying the dynamic characteristics of nutrient return during the decomposition of litter on slopes restored with different ecological restoration techniques, we can explore the soil nutrient balance of these slopes, providing foundational data and theoretical support for research on nutrient return in slope ecological restoration.Five slopes restored with different ecological restoration techniques in Yichang City were selected as study subjects, namely slopes with vegetation-concrete ecological protection technology, slope with high-aggregate vegetation restoration technology, slope with imitation vegetation-concrete ecological restoration technology, slope with plantable cement habitat construction technology + vegetation-concrete ecological protection technology, and slope with native species hydro-seeding technology.The litter was collected using the quadrat method, and its initial nutrient content was measured.An in-situ decomposition experiment was conducted using the litterbag method to determine decomposition characteristics and dynamic nutrient changes.The results showed that under the same decomposition conditions, the litter on vegetation-concrete slopes decomposed the fastest, while that on soil-sprayed slopes decomposed the slowest.There were significant differences in the TOC content of litter among the five slopes, as well as in the initial lignin, N, and P content of the litter.The C: N ratio of the litters also varied significantly over the same decomposition period.Correlation analysis revealed that the decomposition coefficient K was significantly negatively correlated with TOC, N, and C: N, indicating that the decomposition rate of litter on slopes restored with different ecological techniques was primarily influenced by the TOC content and C: N ratio of the litter.The decomposition process was constrained by N availability, meaning that the higher initial TOC, N content, and C: N ratio in the litter were, the slower decomposition rates were, which were less favorable for decomposition.

       

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