滇南喀斯特典型草本植物化学计量性状对水分变化的响应特点

Leaf stoichiometric response of two typical herbaceous plants to water additions in degraded Karst areas in southern Yunnan,China

基于水分添加方法,研究水分胁迫对滇南喀斯特地区典型草本植物芸香草(Cymbopogon distans)和刺芒野古草(Arundinella setosa)叶片营养元素积累和化学计量性状的影响.研究发现,两种草本植物的元素质量比有较强的相似性,其中K、Ca、Mg和Na质量比均较高.在旱季,水分添加提高了刺芒野古草叶N、Ca、Al和Mn质量比,特别是显著促进N质量比增加.在雨季,水分添加促进刺芒野古草N和K富集;与旱季相比,刺芒野古草叶K含量显著下降.随着土壤水分变化,芸香草叶中大量元素内稳性高于刺芒野古草.研究结果对气候变化形势下喀斯特断陷盆地植物生态系统的经营具有重要指导意义.

Based on the method of water addition,the effects of water stress on nutrient accumulation and stoichiometric characters of Cymbopogon distans and Arundinella setosa were studied in Karst area of southern Yunnan.It was found that the content of elements of the two herbs were similar,among which the content of K,Ca,Mg and Na was relatively higher than other elements.In dry season,the accumulation of N,Ca,Al and Mn was affected by water addition,in particular,it significantly promoted the increase of N content.In wet season,N and K were enriched in A.setosa under water addition conditions.Moreover,compared with dry season,the content of K in the leaves of A.setosa decreased significantly in wet season.With the changes of soil moistures,the stability of macroelements in C.distans leaves was higher than that of A.setosa.The results of this study are important in guiding the management of plant ecosystems in degraded Karst basin under climate change.