岷江干旱河谷灌木幼苗的土壤养分适应性研究  

Study on nutrition limitation type of Bauhinia faberi var. microphylla seedlings

作　　者：孔红梅[1] 刘天星[1] 段靖[1] 马克明[1] 

机构地区：[1]中国科学院生态环境研究中心城市与区域生态国家重点实验室,北京100085

出　　处：《生态环境学报》2012年第6期1016-1023,共8页Ecology and Environmental Sciences

摘　　要：岷江上游干旱河谷地区的植被恢复是目前急需解决的问题,小马鞍羊蹄甲(Bauhinia faberi var. microphylla)是干旱河谷地区的优势乡土灌木,并作为当地植被恢复过程中的重要备选物种,因而进行小马鞍羊蹄甲种群在土壤贫瘠的干旱河谷的养分限制研究十分必要。针对性地进行施肥将影响到小马鞍羊蹄甲幼苗存活、生长和定殖,而如何有效提高该物种的存活和生长速率对于干旱河谷植被恢复将具有重要的意义。采用野外调查与模拟实验相结合的方法,分别研究了干旱河谷地区3个典型群落(干旱河谷的核心区——飞虹,干旱河谷灌丛与亚高山森林的过渡区——北部的石大关、干旱河谷灌丛与温性森林的过渡区——南部的蓝新镇)中小马鞍羊蹄甲幼苗叶片的化学计量特征,和施肥试验[w(有效氮)分别为100、280、460 mg·kg–1、w(有效磷)分别为12、24、48 mg·kg–1、w(氮)分别为40、70、100 mg·kg–1、w(磷)分别为12和24 mg·kg–1]中叶片化学计量特征及幼苗生长参数(叶片数、基径和株高)和各器官(根茎叶)生物量。结果表明:在野外各演替阶段的小马鞍羊蹄甲幼苗生物量和营养元素质量分数都随着磷肥的增加而增加,表明磷素是植物生长的限制因子,同时N∶P比均大于16,也暗示其受到P养分的限制;在室内施肥试验中,施加N肥没有促进小马鞍羊蹄甲生物量的积累,反而抑制了幼苗生长;施加P肥促进了幼苗生物量的积累,表明幼苗缺乏P元素,养分限制类型为P限制。Aims Bauhinia faberi var. microphylla is an important candidate shrub for vegetation restoration in the arid valley,SW China.Fertilization may facilitate the survival and establishment of B.faberi seedlings.Therefore,research on the nutrition limitation type of this species is necessary.It is very significant for revegetation in the arid valley to fertilize the Bauhinia faberi seedlings,which could influence the survival growth and settlement.Methods Field investigation was carried out on N：P stoichiometry of Bauhinia faberi seedlings in Feihong,the core district of dry valley,Shidaguan in north（the transition region between arid valley shrub and subalpine forest） and Lanxin in south（the transition region between arid valley shrub and temperate forest）;two greenhouse experiments which investigated N：P stoichiometry,the growth parameters（basal diameter,leaf number and seedling length） and biomass of each components（root,stem and leaf） were carried out,one fertilizing N at rates of 100,280,460 mg·kg–1 and P fertilization at rates of 12,24,48 mg·kg–1,while the other fertilizing N at rates of 40,70,100 mg·kg–1and P fertilization at rates of 12,24 mg·kg–1..Important Findings The results showed that,the biomass and nutrient concentration was increased with the addition of P fertilizer,and the leaf N∶P ratio of B.faberi seedlings in different communities in field was higher than 16,which both implied that the growth of B.faberi was mainly limited by P nutrient.In the greenhouse experiments,N application did not enhance the biomass accumulation,but restrain the growth of B.faberi.P application increased the accumulation of biomass,which suggested the nutrient limitation type is P limitation.

关 键 词：岷江干旱河谷 小马鞍羊蹄甲 养分限制类型 N∶P比 植被恢复 

分 类 号：Q948.118[生物学—植物学]