祁连山北坡混播草地密度制约下燕麦和毛苕子比根长分布格局  

Spatial distribution patterns of specific root lengths of Avena sativa L. and Vicia villosa Roth in mixed-sowing grassland under density dependence in northern slope of Qilian Mountains

作　　者：宋清华[1] 赵成章[1] 史元春[1] 杜晶[1] 

机构地区：[1]西北师范大学地理与环境科学学院,甘肃省湿地资源保护与产业发展工程研究中心,兰州730070

出　　处：《生态学杂志》2015年第2期497-503,共7页Chinese Journal of Ecology

基　　金：国家林业局林业科技推广项目([2012]5号);国家自然科学基金项目(40971039和91125014);甘肃省科技支撑计划项目(1011FKCA157);甘肃省生态学重点学科项目资助

摘　　要：比根长反映了植物对不同生境的适应特征,密度制约下比根长的变化可能是植物对地上和地下资源投资权衡的结果。在祁连山建立禾本科牧草燕麦(Avena sativa L.)与豆科毛苕子(Vicia villosa Roth)混播草地,按燕麦与毛苕子的密度比例设置CK1(1∶0)、A1(8∶2)、A2(6∶4)、A3(5∶5)、A4(4∶6)、A5(2∶8)和CK2(0∶1)7个密度组,研究了混播草地密度制约下燕麦与毛苕子根系比根长的空间分布格局。结果表明:各混播组燕麦根长和比根长均大于毛苕子(P<0.05),二者地下生物量无明显差异;随着混播草地中燕麦密度的减小和毛苕子密度的增大,燕麦和毛苕子的根长逐渐增加(P<0.05),根系生物量先减小后增大(P<0.05),比根长先增加后减小(P<0.05);5个混播组中燕麦和毛苕子比根长随土层加深持续减小,且燕麦细根表层化程度大于毛苕子。1年生牧草根系在空间上的分层分布改变了混播草地的资源分配策略,逐渐优化了资源利用格局,实现了土壤资源利用的最大化。The specific root length （SRL） reflects the feature of plants＇adaptation to different en-vironments. In this study, the mixed-sowing grassland of gramineous grass Avena sativa and legu-minous grass Vicia vilosa with the density ratio of CK1 （ 1 ： 0）, A1 （ 8 ： 2 ）, As （ 6 ： 4 ）, A3（5 ： 5）, A4（4 ： 6） , A5（2 ： 8） and CK2（0 ： 1） was established in the upper reaches of QilianMountains, Gansu Province, Northwest China in 2013, aimed to study the spatial distributionpatterns of SRLs of the two mixed-sowing grasses. The results showed that the total root length andSRL of all mixed sowing groups of A. sativa were greater than those of V. villosa （P〈O.05）, butboth species had no significant difference in underground biomass. With the decrease of A. sativadensity and the increase of V. vilosa density in mixed-sowing grassland, the root lengths of bothgrasses increased gradually （P〈0.05）, the root biomass decreased first and then increased （P〈0.05）, the SRLs increased first and then decreased （P〈0.05）. The SRLs of both species in thefive mixed sowing groups gradually decreased with soil layers, and the superficial degree in fineroots of A. sativa was higher than that of V. villosa. The layering distribution of roots of current-year grass changed the resource allocation strategy, gradually optimized the utilization structure ofresources, and maximized the utilization of soil resources.

关 键 词：祁连山北坡 混播草地 燕麦 毛苕子 比根长 取代试验 

分 类 号：S54[农业科学—作物学]