元江干热河谷稀树灌丛养分元素储量及其分配格局

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中图分类号：Q948 文献标识码：A 文章编号：1000-3142（2026）02-0332-11

Abstract：Nutrientstorageandallcation patterns inplantcommunitiesare critical forunderstanding nutrientutilization andcycling withinecosystems.Thedry-hotvaleys ofSouthwest China，characterized bytheirextreme climatic conditions of high temperatures and low precipitation，support a unique savanna vegetation type.To investigate nutrient element storageand alocationpatterns inthis region，this studytookthesavannaecosystemintheYuanjiang dry-hotvalleyof Yunan Provinceas the research object and systematically analyzed the storage and alocation paterns offive nutrient elements： nitrogen（N），phosphorus（P），potassium （K）： ，calcium （Ca），and magnesium （ Mg ）. The results were as follows：：（1）The total nutrient storage of nitrogen（N），phosphorus（P），potassium（K），calcium（Ca），and magnesium （ Mg ）was 8.3377t⋅hm-2 ， with Ca having the highest storage （ 2.5878t⋅hm-2 ）and P having the lowest storage （ ⋅0.297 3t⋅hm-2 ）.Compared to other forest ecosystems，nutrient storage in this savanna system was relatively low.（2）Verticall，nutrient distribution showed a clear hierarchy：the tree layer contributed the most （ 84.29% ）， followed by the grass layer（ 9.65% ）and shrub layer （5.69%） ，withminimal contribution from the litter layer （0.37 % ）.（3）Notably，belowground nutrient storage accounted for 47.81% of the total，indicating a significant allocation of nutrients torootsandother subterraneancomponents.（4）Teregion’slowannualrainfalland prolonged seasonal droughts imposed severeconstraints onplant growth，leading totheobserved low nutrientstorage inthissavanna ecosystem.（5）As an adaptive strategy to long-term drought stress，the savanna plants in this region alocate a greater proportion of nutrients to belowground structures such as roots tomaintain ecological adaptability.This studyreveals the characteristicsof nutrient storage and spatial alocation inthedry-hotvalleyecosystem，providing animportant basis for understanding material cyclingpaternsin thisregion，scientific guidance fortherestorationand reconstructionof degradedecosystems，and valuablereference forin-depth explorationof plantadaptation strategiesand ecosystem management practices in arid and semi-arid regions.

Key words：nutrient storage，distribution pattern，dry-hot valley，drought，savanna

生态系统中的养分积累与循环是维系生态系统的稳定与健康、促进生产力持久稳定的关键功能（Xu&He，2000）。（剩余21323字）