喀斯特高原峡谷优势种叶片功能性状分析

Leaf functional traits of dominant species in karst plateau-canyon areas

关键词:  优势种, 叶片功能性状, 土壤养分, 喀斯特高原峡谷

Key words:  dominant species,leaf functional traits,soil nutrient,karst plateau-canyon area

摘要:

该研究对喀斯特石漠化高原峡谷地区优势种的叶片功能性状进行了分析,调查了17种植物的叶片厚度、叶面积、叶片鲜重、叶片干重、叶干物质含量、比叶面积、叶组织密度等能反映植物生存策略且易于测量的叶片功能性状,并采用逐步回归的方法探究了叶片功能性状与土壤养分之间的关系。结果表明:(1)不同优势种叶片功能性状差异明显,叶片的厚度为0.18～0.78 mm、鲜重为0.07～6.51 g、干重为0.04～3.19 g、叶面积为3.07～325.64 cm²、叶干物质含量为318.61～573.22 mg·g^-1、比叶面积为60.98～236.90 cm²·g^-1、叶组织密度为0.022 1～ 0.036 g·cm^-3。(2)植物通过较小的比叶面积与较大的叶干物质含量来减少水分散失、增加养分储存,以适应高温、缺水少土的环境。(3)叶片功能性状之间存在广泛的相关关系,且均达到极显著水平。叶片厚度对鲜重、干重均表现为促进效应,比叶面积与叶干物质含量及叶组织密度之间均存在极显著的抑制效应。(4)叶片功能性状随土壤养分的变化产生规律性变化。土壤全氮、全钾和有机碳对叶片功能性状产生显著影响,尤以土壤有机碳的影响更为显著。进一步分析发现,喀斯特高原峡谷地区植被恢复及重建的优势种或建群种为翅荚香槐、清香木、枇杷等; 施用有机肥能够提高花椒、金银花等经济林树种的适应能力。

Abstract:

Illuminating the leaf functional traits of different dominant species and discussing the correlation between leaf functional traits and rhizospheric soil nutrients in the karst plateau-canyon areas, that contribute to reveal the dominant plants' survival strategies in specific region. In the study reported here analyzed the leaf functional traits of dominant species in the karst plateau-canyon, the following leaf functional traits were measured at each sample, leaf thickness, leaf area, leaf fresh weight, leaf dry weight, leaf dry matter content, specific leaf area, leaf tissue density. These indices were chosen because they were adequately reflected plant survival strategies and easily measurable, then explored the relationship between leaf functional traits and 4 soil nutrients by stepwise regression. The results were as follows:(1)In this area, the leaf functional traits of different dominant species were obviously different. Leaf thickness was 0.18-0.78 mm, leaf fresh weight was 0.07-6.51 g, leaf dry weight was 0.04-3.19 g, leaf area was 3.07-325.64 cm², leaf dry matter content was 318.61-573.22 mg·g^-1, specific leaf area was 60.98-236.90 cm²·g^-1, leaf tissue density was 0.022 1-0.036 g·cm^-3.(2)Compared to other areas, the dominant species in this area had smaller specific leaf area and bigger leaf dry matter content, which can reduce water loss and increase nutrient storage, that to adapt to high temperature and lacking of water and soil.(3)Almost all correlations significantly differed among the leaf functional traits. Leaf thickness had a promotional effect on fresh and dry weight, and specific leaf area had a significant inhibiting effect on leaf dry matter content and leaf tissue density.(4)The leaf functional traits changed regularly with the change of soil nutrients. Soil total nitrogen, total kalium and organic carbon had significant effects on leaf functional traits, especially there was very significant in organic carbon. Further analyses indicated that the most appropriate dominant species or constructive species for vegetation restoration and reconstruction in karst plateau-canyon was selected, they were Cladrastis platycarpa, Pistacia weinmannifolia, Eriobotrya japonica. In addition, applying organic fertilizer to Zanthoxylum bungeanum and Lonicera japonica, etc. could improve their adaptability. The research results above have deepened the understanding of vegetation in karst plateau-canyon areas, which provided theoretical and practical bases for vegetation restoration and reconstruction.