降水变化对高寒草甸两种植物不同器官生物量和养分分配的影响  

Effects of precipitation change on biomass and nutrient allocations in different organs of two plants in an alpine meadow

作　　者：王一静 王长庭 刘丹 胡雷 WANG Yijing;WANG Changting;LIU Dan;HU Lei(Institute of Qinghai-Tibetan Plateau,Southwest Minzu University,Chengdu 610041,China)

机构地区：[1]西南民族大学青藏高原研究院,成都610041

出　　处：《应用与环境生物学报》2024年第1期65-74,共10页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(U20A2008,31870407);第二次青藏高原综合科学考察研究项目(2019QZKK0302-02);西南民族大学研究生“创新型科研项目”重点项目(CX2021SZ29)资助。

摘　　要：植物生物量和养分分配反映了其对外界资源利用最大化的生长对策,探究降水变化对高寒草甸植物不同器官生物量和养分分配的影响,有助于预测植物对未来气候变化的响应策略.以高寒草甸多年生菊科植物乳白香青(Anaphalis lactea)和钝苞雪莲(Saussurea nigrescens)为研究对象,设置5个降水梯度(0.1P:降水减少90%;0.5P:降水减少50%;0.7P:降水减少30%;CK:自然降水;1.5P:降水增加50%),比较两种植物花苞、茎及叶片的生物量和养分分配特征的差异,探索模拟降水下植物生物量和养分分配格局变化的影响因素.结果表明:(1)0.1P和0.7P提高了两种植物各器官生物量,乳白香青茎、叶和花生物量均在1.5P最低,而钝苞雪莲茎、叶和花生物量在0.5P最低.(2)乳白香青各器官生物量分配比例为茎(42.95%±7.66%)>花(35.05%±7.42%)>叶(22.01%±6.57%),而钝苞雪莲为叶(37.44%±9.29%)>茎(31.75%±6.83%)>花(30.75%±7.58%).(3)0.5P和0.7P处理下乳白香青繁殖器官生物量生长速度较CK快,但其营养和繁殖器官整体呈等速生长;钝苞雪莲在0.1P和1.5P下营养器官生物量生长速度显著快于繁殖器官,呈异速生长关系.(4)降水变化没有显著改变两种植物花苞碳(FC)和叶片碳(LC)含量,但1.5P显著提高了植物花苞氮(FN)和花苞磷(FP)含量.(5)结构方程模型(SEM)表明降水通过改变土壤全氮(STN)影响乳白香青不同器官生物量分配,还通过土壤含水量(SWC)影响其养分分配;而SWC和土壤速效磷(AP)则分别是影响钝苞雪莲器官生物量和养分分配的关键因子.综上,降水没有显著改变两种植物不同器官结构性物质(C)的含量,但能通过改变土壤因子进而影响植物不同器官生物量和养分分配;在本研究区适当减少降水有利于乳白香青的繁殖生长,而降水增加下钝苞雪莲的营养生长更有优势.(图4表4参66)Plant biomass and nutrient allocation reflect growth strategies that maximize the utilization of external resources.Understanding the effects of precipitation on biomass and nutrient allocation in different plant organs can help predict future plant responses to climate change.Five simulated precipitation treatments were set up in an alpine meadow:decreasing water by 90%(0.1P),50%(0.5P),and 30%(0.7P);natural water(CK);and increasing water by 50%(1.5P).Moreover,we compared the biomass and nutrient content in the flowers,stems,and leaves of Anaphalis lactea and Saussurea nigrescens and the factors influencing the biomass and nutrient allocation of these two plants were explored.The results showed that:(1)Compared to the CK,0.1P and 0.7P increased t he b iomass i n e ach o rgan o f t he t wo p lants.T he b iomasses o f s tems,l eaves,a nd f lowers o f A.lactea were the lowest in the 1.5P treatment,whereas those of stems,leaves,and flowers of S.nigrescens was the lowest in the 0.5P treatment.(2)The biomass allocation of A.lactea was in the order:stems(42.95%±7.66%)>flowers(35.05%±7.42%)>leaves(22.01%±6.57%).Meanwhile,the biomass allocation of S.nigrescens was in the order:leaves(37.44%±9.29%)>stems(31.75%±6.83%)>flowers(30.75%±7.58%).(3)Although the growth rates of the reproductive organ biomasses of A.lactea in the 0.5P and 0.7P treatments were marginally higher than those in the CK,the vegetative and reproductive biomasses of A.lactea grew at the same speed.Conversely,the vegetative biomass of S.nigrescens grew significantly faster than the reproductive biomass in the 0.1P and 1.5P treatments,indicating an allometric growth relationship.(4)The flower carbon and leaf carbon contents of the two plants varied insignificantly between the five precipitation treatments;however,1.5P significantly enhanced the flower nitrogen and flower phosphorus contents of the two plants.(5)The structural equation model showed that precipitation mainly influenced biomass allocation in different organs of A.lactea through soil tota

关 键 词：植物生物量 养分 降水模拟 资源分配 高寒草甸 

分 类 号：S812[农业科学—草业科学]