云南文山3种苏铁属极小种群资源现状及土壤和植物叶片养分分析

Current Resource Status,Nutrients of Soil and Leaf of Three Cycas Specieswith Extremely Small Population Distributed in Wenshan of Yunnan

为有效保护极小种群苏铁属植物资源,对云南文山地区3种苏铁植物种群分布状况及生境土壤与植物叶片养分特征进行分析。结果显示:(1)德保苏铁主要分布于富宁县,有6个居群1 454株;叉孢苏铁主要分布于广南县和富宁县,有4个居群775株;长叶苏铁主要分布于马关县和麻栗坡县,有5个居群425株。(2)3种苏铁植物种群较小,个体数量少而分散,年龄结构不合理,亟待拯救保护。(3)3种苏铁原生境土壤养分含量存在差异,长叶苏铁分布点土壤养分含量相对较高,叉孢苏铁分布点养分含量处于中等水平,德保苏铁分布点养分含量相对较低;3种苏铁土壤中有效Fe、Ca和Mn含量较丰富,而全P含量整体较缺乏。(4)3种苏铁叶片养分利用效率存在差异,长叶苏铁对N、K和Ca元素的吸收利用效率较高,德保苏铁对有机C、P和Mg元素的利用效率较高,叉孢苏铁对Fe元素的利用效率较高;3种苏铁叶片中除有机C和Mg元素含量相对缺乏外,其它元素处于适量或高量水平。

In order to protect the resources of 3 Extremely Small Population of Cysas distributed in Wenshan of Yunnan province,soil and leaf nutrients were analyzed.The results showed that C.debaoensis was mainly distributed in Funing,with 6 populations and 1454 individuals,C.segmentifida was mainly distributed in Guangnan and Funing,with 4 populations and 775 individuals,C.dolichophylla was mainly distributed in Maguan and Malipo,with 5 populations and 425 individuals.It was found that the populations of three Cysas were small,the numbers of individuals were low,and the distribution were scattered,the age structures were irrational,rescue and conservation were urgently needed.The soil nutrient contents of the habitats varied among the three Cysas species.The soil nutrient content of C.dolichophylla was relatively high,that of C.segmentifida was moderate,and that of C.debaoensis was relatively low.The contents of available Fe,Ca and Mn in soils of three Cycas species were relatively rich,whereas the content of P was deficient.The nutrient contents of three Cycas species were varied,the N,K and Ca in leaves of C.dolichophylla were high,the C,P and Mg in leaves of C.debaoensis were high,the Fe content in leaves of C.segmentifida was high.The C and Mg contents in leaves of three Cycas species were relatively deficient,the contents of other nutrients were moderate and high.