环境因子对海岛植物茎、叶功能性状的影响

植物功能性状与环境之间的关系是功能性状研究的重点,海岛作为独特的生态系统,其植物功能性状必然和大陆存在差异。为了明确海岛植被的生态适应机制,该文以平潭岛森林群落为研究对象,通过测定茎、叶10个功能性状,以及地形和土壤9个环境因子,探讨了植物功能性状之间的权衡关系,分析了环境因子对海岛植物功能性状的影响。结果表明:(1)比叶面积(SLA)与叶氮含量(LNC)、叶磷含量(LPC)呈正相关,与叶厚度(LT)、叶干物质含量(LDMC)、茎组织密度(STD)、叶碳含量(LCC)呈负相关; LDMC与LNC、茎氮含量(SNC)呈负相关; LT与STD呈正相关,与LNC和LPC呈负相关; LPC与LNC、SNC呈正相关;茎和叶C、N含量均呈正相关。(2)土壤有机质和TN是海岛植物功能性状的主要土壤影响因子。然而,由于土壤中磷含量的缺乏,LNC、茎磷含量(SPC)、SNC均与土壤全磷呈正相关; LDMC与土壤全氮呈正相关;STD与土壤有机质呈正相关; SLA随着土壤pH的增加而增加。(3)坡位和坡度是海岛植物功能性状的主要地形影响因子。SLA、SPC随着海拔上升而下降; STD、LDMC随着海拔和坡度增大而增大; LNC、LPC阴坡大于阳坡。该研究为海岛植被修复和重建提供了参考依据。

Effects of environmental factors on stem and leaf functional traits of island plants

The relationship between plant functional traits and environments is the focus of research on functional traits. As a unique ecosystem, the plant function traits of the island must be different from that of mainland. In order to definite the adaptability mechanism of forest communities in Pingtan Island, we explored the trade-off relations between the plant functional traits, and analyzed the impact of environmental factor on the functional traits of island plants, by measuring ten functional traits of stems and leaves as well as nine environmental factors of topography and soil. The results were as follows:(1)The specific leaf area(SLA)was positively correlated with leaf nitrogen content(LNC)and leaf phosphorus content(LPC), and negatively correlated with leaf thickness(LT), leaf dry matter(LDMC), stem tissue density(STD)and leaf carbon content(LCC). Furthermore, LDMC was negatively correlated with LNC and stem nitrogen content(SNC). There was a positive correlation between LT and STD, while LT had a negative correlation with LNC and LPC, as well as LPC had a positive correlation with LNC and SNC. In a word, carbon(C)and nitrogen(N)contents in stems and leaves had a positive correlation.(2)The main influencing factors of soil on plant functional traits were soil organic matter and TN in Pingtan Island. However, because of the lack of phosphorus content in the soil, LNC, stem phosphorus content(SPC), SNC were positively correlated with soil total phosphorus, while LDMC positively correlated with soil total nitrogen; STD was positively correlated with soil organic matter; and SLA increased with the increase of soil pH.(3)In Pingtan Island, slope position and slope were the two most influential topographical factors, on plant functional traits. SLA and SPC decreased with the elevation increase. STD and LDMC increased with the increases of elevation and slope, and LNC and LPC in the shady slope were greater than those in the sunny slope. This study provides a reference for the restoration and reconstruction of island vegetation.