粤北岩溶峰林植物钙吸收、转运、返还能力及适应性分析

Analysis on the absorbing,transfer,restoration and adaptation mechanism of calcium in different peak forest plants in northern Guangdong Province,China

选择粤北岩溶峰林30种典型植物种,系统测定了不同植物的根际土、根、茎干、叶片、枯落物全钙含量,采用吸收系数、转运率、返还率指标分析了不同植物对钙利用、储存及返还土壤的特征,并以各样本全钙含量为指标进行不同植物钙适应性的聚类分析,结果表明:(1)峰林植物对岩溶土壤富钙环境具有良好的适应性,其全钙含量与土壤根际全钙含量之间呈显著的正相关关系,但不同植物的钙吸收系数差异较大,攀援灌木的钙吸收系数分别是乔木、小灌木和草本植物的1.21倍、1.22倍和1.30倍;(2)不同生活型植物的叶片、茎干、根系全钙含量差异较大,各类灌木的叶片、茎干、根系全钙含量平均值分别是乔木全钙含量的1.08倍、1.07倍、1.17倍,是草本植物叶片和根系全钙含量的1.39倍、1.82倍,全钙含量总体上呈现:根系>叶片>茎干的趋势;(3)30种峰林植物的钙返还率在22.06%~103.84%之间,草本植物钙返还率最大,为67.18%,其次为乔木的58.72%,灌木最小,为55.90%,但3种生活型类型之间无显著性差异;(4)根据聚类分析结果可以将30种峰林植物对富钙环境的适应性分为富钙高吸收低返还型、少钙低吸收高返还型、多钙高吸收中返还型、多钙中吸收中返还型4种类型,30种植物中有26种属于多钙中吸收中返还型,这证明岩溶峰林植物对土壤富钙环境有良好适应性。

Thirty kinds of karst peak forest plants in the Shijiao village,Jiulong town,Yingde City,Guangdong Province（N24°08.113′,E112°51.855′,altitude,121 m,height of hill 80m）were selected as the object of quantitative analysis to reveal their adaptation to the karst soil environment rich in calcium.The measured variable included the total calcium content of rhizosphere soil,and root,stem,leaf and litter in different plants.The characteristics of utilization,store,and returning soil of calcium in different plants were analyzed based on the absorption coefficient,transfer rate,and return rates.In addition,adaptation mechanism for karst soil in different plants was classified based on the result of cluster analysis.The results show that,（1）The significant positive correlation between the total calcium content in plants and in rhizosphere soil shows the plants in karst peak forest have a good adaptation to karst soil.But the absorption coefficients have large differences among the different plants.The total calcium absorption coefficient of climbing plants is 1.21 times,1.22 times,and 1.30 times of trees,small shrubs and herbs,respectively.It means the climbing plants have a better adaptability to the karst environment.（2）There are large differences of total calcium in different living types of plants in the leaf,stem,and root,of which the average total calcium content are 1.08 times,1.07 times 1.17 times of trees,respectively,and 1.39 times and 1.82 times of herbs in leaf and root,respectively.The total calcium content has a tendency of rootleafstem.（3）The litter is the main way through which calcium in plants returns to the soil.The rates of 30 kinds of karst peak forest plants are between 22.06%-103.84%,among which herbs has the biggest rate,and tree has the second,and shrubs has the smallest,which are 67.18%,58.72%,55.90%,respectively.（4）The results of cluster analysis based on the total calcium content of rhizosphere soil,root,stem,leaf,and litter show different adaptation ways of plants to karst soil,which are classified into four categories,abundant calcium-high absorption-low restoration,few calcium-low absorption-high restoration,more calcium-high absorption-medium restoration,and more calcium-medium absorption-medium restoration.There are 26 kinds of plants belong to the last one,implying that the most of plants in karst peak forests have a good adaptation to the karst high-calcium environment through continual absorption,steady accumulation and high-rate restoration.