引种针叶树种矿质元素浓度及季节变化的比较研究

A COMPARISON STUDY ON NUTRIENT CONCENTRATIONS AND SEASONAL DYNAMICS IN NEEDLES OF 15 INTRODUCED CONIFERS

以８～１０年生的引种试验林为取材对象，分别在１９９２年４月３０日、７月３０日、１０月３０日及１９９３年１月３０日，同时采１５个树种当年和１年生针叶，测定Ｎ、Ｐ、Ｋ、Ｃａ和Ｍｇ浓度。结果表明，矿质元素浓度种间存在极显著差异。各元素浓度高低总趋势为Ｎ＞Ｋ＞Ｃａ＞Ｐ＞Ｍｇ。松属中单维管束亚属和双维管束亚属分别表现为富Ｎ、Ｍｇ和Ｋ、Ｐ两种元素含量型。树种间Ｍｇ元素季节动态存在显著多样性，Ｎ、Ｐ、Ｋ、Ｃａ动态模式松类树种具有极大的相似性。

This paper deals with the results of a comparison study on mineral element (N、P、K、Ca and Mg) concentrations and their seasonal dynamics in needles collected from 15 introduced conifers. During a year at spring(30,April), summer (30,July), autumn (30,October ) and winter (30,January), the current-year and one-year-old needles were collected from ten trees of each species. The needles from all ten trees were bulked into two composite samples according their foliar age for chemical determination. The results show that,there are significant differences in foliar nutrient concentration among 15 woody species planted at same site. The element concentration for all 15 species was following:N>K>Ca>P>Mg. The P,K,and Ca seasonal dynamic patterns in foliar concentration showed extremely similar for all species but the N and Mg exhibited higher differentiation among species. The results also indicated that the element concentrations and seasonal dynamics of each element had remarkable differences between two subgenus in Pinus.