贵州北盘江喀斯特地区兰科植物叶片生态化学计量学特征及影响因素

Ecological Stoichiometric Characteristics and Influencing Factors of Leaves of Orchids in Beipan River Karst Area,Guizhou Province

植物叶片生态化学计量特征及其差异可以反映植物对生态环境变化的响应,是探究植物与环境相互作用的关键。为揭示喀斯特地区不同生活型兰科植物叶片生态化学计量学特征及其与环境因子间的关系,对贵州北盘江喀斯特地区16种兰科植物叶片碳(C)、氮(N)和磷(P)含量进行测定,分析附生兰和地生兰之间化学计量学特征及其影响因素。结果显示:(1)植物叶片生态化学计量学特征在生活型上表现为地生兰叶片C/N和C/P含量显著低于附生兰(P<0.05),N、P含量显著高于附生兰,两者之间的C、N/P含量无显著差异。(2)不同生活型植物叶片元素含量间的关系相似,C与N、P呈负相关,N、P之间呈显著正相关(P<0.05),C/N、C/P和N/P三者之间呈正相关关系,C/P与N/P和C/N与C/P正相关关系达极显著水平(P<0.01)。(3)气温年较差等气候因子对附生兰叶片元素含量的差异变化具有更强的解释性,海拔等地形因子是影响地生兰化学计量学特征的关键因素。

The ecological stoichiometric characteristics and differences of plant leaves can reflect the responses of plants to environmental changes,which is the key to exploring the interactions between plants and environment.In order to reveal the ecological stoichiometric characteristics of different life forms of orchids in karst areas and their relationship with environmental factors,we measured the leaf carbon(C),nitrogen(N)and phosphorus(P)contents of 16 species of orchids in the karst area of Beipan River in Guizhou province,and analyzed the stoichiometric characteristics and influencing factors between epiphytic and terrestrial orchids.The results showed that:(1)The ecological stoichiometry of plant leaves showed that the C/N and C/P contents of terrestrial orchids were significantly lower than those of epiphytic orchids(P<0.05),and the N and P contents of terrestrial orchids were significantly higher than those of epiphytic orchids,and there was no significant difference in the C and N/P contents between them.(2)Leaf element contents of plants with different life forms were similar to each other,C was negatively correlated with N and P,and significantly positively correlated with N and P(P<0.05).C/N,C/P and N/P were positively correlated,and the positive correlations between C/P and N/P and C/N and C/P were extremely significant(P<0.01).(3)the temperature in the poor climate factor on attached-living orchid blade element content difference changes have stronger explanatory,terrain factors such as altitude is ground-living orchid chemometrics characteristics of the key factors.