摘要
生物量在地上与地下的分配是植物生长策略的反映,对于研究生态系统碳储量和碳循环有着重要的意义.在青藏高原东部地区布设了83个样点,包括15种高寒杜鹃群落,采用收获法对灌木层和草本层2个不同层片地上和地下生物量进行测定,并分析温度和降雨量等气候因素对灌丛群落地上和地下生物量及构成的影响.结果表明:(1)该地区高寒杜鹃灌丛灌木层平均生物量为21.16 t/hm^(2),地上、地下分别为14.90、6.26 t/hm^(2),草本层平均生物量为9.79 t/hm^(2),地上、地下分别为2.40、7.39 t/hm^(2);灌木层、草本层根冠比分别为0.6、7.89,表明该地区内灌木层植物将更多的生物量分配到地上部分的光合器官,草本层植物将更多的生物量分配到地下吸收养分和水分的根系.(2)比较5种主要高寒杜鹃灌丛后发现,不同灌丛间灌木层地上、地下生物量存在显著性差异,地上生物量大小依次是腺房杜鹃灌丛>腋花杜鹃灌丛>头花杜鹃+千里香杜鹃灌丛>草原杜鹃灌丛>雪层杜鹃灌丛,地下生物量大小依次是腋花杜鹃灌丛>腺房杜鹃灌丛>雪层杜鹃灌丛>头花杜鹃+千里香杜鹃灌丛>草原杜鹃灌丛;草本层地上生物量无显著性差异,地下生物量之间存在显著性差异,大小依次为雪层杜鹃灌丛>头花杜鹃+千里香杜鹃灌丛>草原杜鹃灌丛>腺房杜鹃灌丛>腋花杜鹃灌丛.(3)该地区高寒杜鹃灌丛灌木层地上、地下生物量之间遵循等速生长关系,与草原、森林一致;草本层地上、地下生物量之间遵循异速生长关系.其中5种主要高寒杜鹃灌丛群落2个层片的地上、地下生物量之间的异速生长关系不同.雪层杜鹃灌丛灌木层和头花杜鹃+千里香杜鹃灌丛草本层地上、地下生物量为异速生长关系,其余3种灌丛的各层片都为等速生长关系.(4)灌木层生物量主要受干旱、年均温度、年均降雨量的影响,随着年均温和年均降雨量增加而增加
Above-and below-ground biomass allocation not only reflects plant growth adaptations to environmental variations but also impacts carbon input to the soil and thus terrestrial carbon cycling.In this study,83 samples were collected from the eastern part of the Qinghai–Tibet Plateau,including 15 species of alpine Rhododendron communities.The aboveground and underground biomass of two different layers of shrub and herb layers were measured using the harvesting method,and we explored the effects of climate factors (such as mean annual temperature,MAT and mean annual precipitation,MAP) on the biomass partitioning pattern.Our results indicated that:(1) The average biomass of the shrub layer was 21.16 t/hm^(2);above-and belowground biomass of the shrub layer were 14.90 and 6.26 t/hm^(2),respectively;the average biomass of the herb layer was 9.79–2.40 t/hm^(2) above ground and 7.39 t/hm^(2) below ground,respectively.The root–shoot ratios (R/S) of the shrub and herb layers were 0.6 and 7.89,respectively,indicating that the shrub layer allocated more biomass to the photosynthetic organs of the above-ground part,and the herb layer allocated more biomass to the roots that absorbed nutrients and water below the ground in the area.(2) After comparing the?ve major alpine Rhododendron shrubs,signi?cant differences were found in the above-and below-ground biomass in the shrub layer of the different scrubs.The above-ground biomass of the scrubs was in the order Rhododendron adenogynum>R.racemosum>R.capitatum+R.telmateium>R.thymifolium>R.nivale.The belowground biomass of the scrubs was in the order of R.racemosum>R.adenogynum>R.nivale>R.capitatum+R.telmateium>R.thymifolium.No fundamental difference was found in the above-ground biomass in the herbaceous layer.However,a fundamental difference was observed in the below-ground biomass,and the order of scrub size was as follows:R.nivale>R.capitatum+R.telmateium>R.thymifolium>R.adenogynum>R.racemosum.(3) The above-and below-ground biomass of the shrub layer of Rhododendron alpines
作者
刘秋蓉
李丽
胡君
刘美
周国英
阳小成
张林
巩合德
刘庆
LIU Qiurong;LI Li;HU Jun;LIU Mei;ZHOU Guoying;YANG Xiaocheng;ZHANG Lin;GONG Hede;LIU Qing(CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization&Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province,Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China;Northwest Institute of Plateau Biology,Chinese Academy of Sciences,Xining 810008,China;College of Ecology and Environment,Chengdu University of Technology,Chengdu 610059,China;Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China;College of Ecotourism,Southwest Forestry University,Kunming 650224,China)
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2022年第5期1120-1128,共9页
Chinese Journal of Applied and Environmental Biology
基金
中国科学院战略性先导科技专项(XDA05050303)
科技部科技基础性工作专项(2015FY110300)
第二次青藏高原综合考察研究项目(2019QZKK0301)资助。
关键词
高寒灌丛
杜鹃
生物量分配
气候因素
alpine scrub
Rhododendron
biomass allocation
climatic factor
