竞争对马尾松和木荷觅取异质分布养分行为的影响  

EFFECTS OF COMPETITION ON FORAGING BEHAVIOR OF PINUS MASSONIANA AND SCHIMA SUPERBA IN A HETEROGENEOUS NUTRIENT ENVIRONMENT

作　　者：马雪红[1] 周志春[1] 金国庆[1] 张一[1] 

机构地区：[1]中国林业科学研究院亚热带林业研究所,浙江富阳311400

出　　处：《植物生态学报》2009年第1期81-88,共8页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(30571482);国家林业局948项目(2006-4-59)

摘　　要：为了研究邻株竞争对马尾松(Pinus massoniana)和木荷(Schima superba)觅取异质分布养分机理和行为的影响,我们设计单植、双株纯栽和两株混植3种栽植方式,构建了同质和异质养分环境开展盆栽实验。结果表明:单植时,马尾松和木荷苗木生长对斑块养分反应敏感,与同质养分环境相比,两树种在异质养分环境中具有苗高生长量大、干物质积累量高、根系在富养斑块中大量增生,根系N、P含量和吸收效率高等特点。在异质养分环境中,木荷与马尾松邻株竞争时的生长表现优于双株纯栽模式而与单植处理相近,根系形态可塑性和生理可塑性在其觅取斑块养分中的作用显著增强;与木荷邻株竞争时,马尾松苗高生长也表现出较单植和双株纯栽模式一定的优势,这与其根系的广布性、觅养精确性和反应敏感度变化较小及富养斑块中根系P素含量和吸收效率较高等有关。相反,同种邻株竞争则使得异质养分环境中马尾松和木荷的根系广布性减小,反应敏感度减弱,富养斑块中根系N、P含量降低,苗高生长量和干物质积累量减小。与马尾松相比,同种邻株竞争对异质养分环境中木荷生长的负向影响更为强烈。建议在生产中采用混交造林的方式促进马尾松和木荷生长。若要营造人工纯林,可通过适当降低初植密度或及时调控林分密度促进林木生长。Aims Pinus massoniana and Schima superba are important coniferous and broad-leaved species, respectively, in timber plantations in the subtropical mountain area of China. Our aim was to elucidate the effects of competition on foraging behavior of these two species in a heterogeneous nutrient environment to provide scientifically based guidelines for mixed afforestation establishment in South China. Methods We designed a pot experiment consisting of three treatments to evaluate effects of competion on seedling growth and foraging behavior of P. massoniana and S. superba. The treatments were single-, pure- and mixed-plantings under heterogeneous and homogeneous environments. Important findings Compared with the homogeneous nutrient envionment, seedlings in the heterogeneous nutrient environment were taller, had greater dry matter accumulation and had more effective nutrient absorption with increased root proliferation in the nutrient-rich patches. In the heterogeneous environment, S. superba had better growth in mixed- than in single- and pure-plantings, and exhibited enhancement of root morphological and physiological plasticity in foraging patchy nutrients. Pinus massoniana in the mixed-planting also was taller, not only because of little change of root scale, sensitivity and precision but also increased nutrient absorption efficiency. However, intraspecific competition reduced root scale, sensitivity and root N, and P content and resulted in significantly decreased seedling height and dry matter accumulation. Schima superba was affected more markedly by intraspecific competition than P. massoniana in the heterogeneous environment. It is suggested that mixed-plantings can improve the growth of P. massoniana and S. superba and appropriate decrease of initial density or timely control of stand density can increase the productivity of pure plantations of the two species.

关 键 词：马尾松 木荷 异质养分环境 竞争 觅养行为 

分 类 号：S718[农业科学—林学]