?陳旗退化喀斯特森林群落常見植物葉片氮磷元素含量變異特征

摘 要：以陳旗退化喀斯特森林群落4種典型植物為研究對象，測定植物葉片N、P元素含量，分析元素含量間的變異特征。結果表明：流域內常見植物葉片的N、P元素含量分別為11.71～30.51、0.37～0.83 mg/g，平均值分別為18.48 和0.66 mg/g；流域內小葉鼠李、火棘、竹葉花椒、小果薔薇植物葉片N/P值均大于16，生長主要受P限制，均屬P制約型植物；植物葉片N、P元素含量在流域內不同種間的差異均顯著（P＜0.05）；植物葉片N元素含量在不同演替階段植物群落不同種間的差異均顯著，P元素含量在喬灌過渡林和喬木林的不同種間差異顯著，但在稀灌草叢、藤刺灌叢、灌木林的不同種間差異不顯著；植物葉片N元素含量在不同演替階段植物群落間均有顯著差異，P元素含量在不同演替階段植物群落間均無顯著差異； N元素含量受植物種和群落類型的交互影響顯著，P元素含量受植物種和群落類型的交互影響不顯著。該研究結果有助于理解植物養分限制狀況，為退化生態系統修復提供數據支持。

關鍵詞：退化喀斯特森林群落;植物葉片; N、P元素含量;變異特征

中圖分類號：S718.54" 文獻標識碼：A 文章編號： 1006-060X（2023）03-0055-06

Abstract： This paper， taking four typical plant species of degraded karst forest community in Chenqi catchment as the research objects， measured the contents of N and P elements in plant leaves， and analyzed the variation characteristics of the elements among different plant species and communities. The results showed that： （1） the contents of N and P in the leaves of common plants in the catchment was 11.71-30.51 mg/g and 0.37-0.83 mg/g， respectively with an average of 18.48 mg/g and 0.66 mg/g; （2） Rhamnus parvifolia， Pyracantha fortuneana， Zanthoxylum armatum and Rosa cymosa were all over 16 in the leaf N / P ratio， and their growth was mainly restricted by P， belonging to p-restricted plants; （3） there were significant differences in leaf N and P contents between species within the catchment （P＜0.05）; （4） there were significant differences in leaf N element content between species of the plant communities in different succession stages （P＜0.05）; there were significant differences in P element content between species of the arbor and shrub transitional forest and the arbor forest （P＜0.05）， but no significant differences between species of the thin shrub-grassland， the vine-shrubberry， and the shrubberry （P＞0.05）; （5） between plant communities in different succession stages， there were significant differences in leaf N element content （P＜0.05）， while P element content had no significant differences （P＞0.05）; （6） N element content was significantly affected by the interaction between plant species and community types （P＜0.05）， but P element content was not （P＞0.05）. The research results help to understand the nutrient limitation status of plants， and provide data support for the restoration of degraded ecosystems.

Key words： degraded karst forest community; plant leaves; N and P element contents; variation characteristics

喀斯特森林是由可溶性碳酸鹽形成的喀斯特地貌上發育而來的一種脆弱的森林生態系統，在改善生態環境、防止石漠化方面具有十分重要的作用[1-2]。但人為活動的干擾導致喀斯特森林大面積退化。喀斯特森林退化是群落的逆向演替，是其森林生態系統失去平衡并導致結構和功能退化的過程[3-4]。

貴州省是我國喀斯特地貌分布面積最大的省，由于其生態系統的脆弱性和人類的不合理開發利用，植被退化較為嚴重，已成為當地最嚴重的生態環境問題[5]。……