油茶-鼠茅草复合系统细根空间分布及地下竞争  

Spatial distribution of fine roots and underground competition in Camellia oleifera-Vulpia myuros intercropping system

作　　者：丁怡飞 曹永庆[1] 姚小华[1] 吴鹏飞 龚洪恩[1] 傅松玲[2] 张平安 DING Yi-fei1,2, CAO Yong-qing1 , YAO Xiao-hua1, WU Peng- fei1, GONG Hong-en1, FU Song-ling2, ZHANG Ping-an3(1Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Fuyang 311400, Zhejiang, China; 2College of Forestry and Gardening, Anhui Agricultural University, Hefei 230036, China ; 3 Qingtian County Forestry Bureau, Qingtian 323900, Zhejiang, China)

机构地区：[1]中国林科院亚热带林业研究所,浙江富阳311400 [2]安徽农业大学林学与园林学院,合肥230036 [3]青田县林业局,浙江青田323900

出　　处：《生态学杂志》2018年第4期981-986,共6页Chinese Journal of Ecology

基　　金：浙江省省院合作林业科技项目"浙江省油茶林地高效复合经营技术研究与示范"(2014SY03)资助

摘　　要：采用田间分层挖掘法和图像扫描分析法,研究油茶-鼠茅草复合系统中油茶与鼠茅草细根生物量及形态空间分布,并用Levins提出的生态位重叠公式计算了油茶与鼠茅草种间的地下竞争指数。结果表明:油茶和鼠茅草细根(≤1 mm)的平均生物量分别是0.52和0.38 mg·cm-3,油茶细根生物量是鼠茅草的1.37倍;在水平方向上,油茶细根生物量整体趋势随着距树干距离增加而下降,而油茶细根的根长密度与比根长随着距树干距离的增加而升高;鼠茅草的细根生物量整体趋势随着距树干距离增加先升高后下降,根长密度及比根长都分布比较均匀;不同水平距离鼠茅草的根长密度均大于油茶,除距树干90 cm外,油茶细根生物量与竞争指数均大于鼠茅草;在垂直方向上,油茶细根生物量是随着土层加深先升高再下降,根长密度随着土层的加深而升高,比根长分布均匀;鼠茅草的细根生物量及根长密度均随着土层的加深而下降,而比根长则随着土层深度增加而上升;除0~10 cm土层外,油茶细根生物量与竞争指数均大于鼠茅草。在油茶-鼠茅草复合系统中,油茶根系遭遇鼠茅草根系的竞争,作为生存策略,为了避开这种竞争,最大限度地获取土壤中的资源,其根系产生了各种可塑性反应。Using methods of field stratified excavation and image scanning, the spatial distribution of biomass and morphology of fine root （≤1 mm） ofCamellia oleiferaand Vulpia myuros in Camellia oleifera-Vulpia myuros intercropping system was examined. The underground competition between those two specieswas quantified by the niche overlap formula proposed by Levins. The results showed that the fine root biomass ofC. oleiferawas 1.37 times as high as that of V. myuros, with average fine root biomass ofC. oleifera andV. myuros being 0.52 and 0.38 mg·cm-3,respectively. In the horizontal direction, fine root biomass of C. oleifera decreased with increasing distance from trees, while the root length density and specific root length of C. oleifera increased with theincreases of distance from trees. Fine root biomass ofV. myuros decreased with the increases of distance from trees, and the root length density and specific root length showed an even distribution. The root length density ofV. myuros was greater than that ofC. oleifera at different distances from trees, whereas fine root biomass and competition index of C. oleifera were greater than that ofV. myuros except for the distance 90 cm. In the vertical direction, fine root biomass ofC. oleifera first increased and then decreased with the deepening of soil layer, and the root length density increased with the soil layer, while the specific root length was evenly distributed. The fine root biomass and root length density ofV. myuros decreased with the deepening of the soil layer, while the specific root length increased with the soil layer. Except for the 0-10 cm layer, the fine root biomass and competition index of C. oleifera was greater than that ofV. myuros. Our results indicated that fine roots ofC. oleifera had higher plasticity to avoid competition and maximize uptake of soil resources in the intercropping system.

关 键 词：油茶 鼠茅草 细根 种间竞争 

分 类 号：S718.5[农业科学—林学]