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草业学报 ›› 2025, Vol. 34 ›› Issue (2): 67-80.DOI: 10.11686/cyxb2024101

• 研究论文 • 上一篇    下一篇

季节性雪被厚度对高山草甸4种优势晚花植物生物量分配的影响

张宁1,2,3(), 王金牛1,2(), 罗栋梁4, 张林5, 徐波6, 吴彦1   

  1. 1.中国科学院成都生物研究所,四川 成都 610041
    2.西藏生态安全屏障监测站网芒康生物多样性与生态站,西藏 昌都 854000
    3.甘肃农业大学资源与环境学院,甘肃 兰州 730070
    4.中国科学院西北生态环境与资源研究院,甘肃 兰州 730000
    5.中国科学院青藏高原研究所,北京 100101
    6.阿坝师范学院教师教育学院,四川 汶川 623002
  • 收稿日期:2024-03-26 修回日期:2024-05-16 出版日期:2025-02-20 发布日期:2024-11-27
  • 通讯作者: 王金牛
  • 作者简介:E-mail: wangjn@cib.ac.cn
    张宁(1997-),女,山西晋城人,在读硕士。E-mail: 1344253699@qq.com
  • 基金资助:
    西北生态环境与资源研究院冰冻圈科学国家重点实验室(SKLCS-OP-2021-06);中国国家自然科学基金项目(31400389);中国科学院西部之光西部青年学者项目(2021XBZG_XBQNXZ_A_007)

Effects of seasonal snow cover thickness on biomass allocation of four dominant late flowering plants in an alpine meadow

Ning ZHANG1,2,3(), Jin-niu WANG1,2(), Dong-liang LUO4, Lin ZHANG5, Bo XU6, Yan WU1   

  1. 1.Chengdu Institute of Biology,Chinese Academy of Science,Chengdu 610041,China
    2.Mangkang Biodiversity and Ecological Station,Tibet Ecological Safety Monitor Network,Changdu 854000,China
    3.College of Resources and Environmental Sciences,Gansu Agricultural University,Lanzhou 730070,China
    4.Northwest Institute of Eco-Environment and Resource,Chinese Academy of Science,Lanzhou 730000,China
    5.Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China
    6.College of Teacher Education,Aba Teachers University,Wenchuan 623002,China
  • Received:2024-03-26 Revised:2024-05-16 Online:2025-02-20 Published:2024-11-27
  • Contact: Jin-niu WANG

摘要:

植物生物量在个体器官的分配表征了同化产物的形成及驱动机制,且不同器官间的协同生长受外界环境及植株内部因素的共同调控。季节性雪被在生长季较短的高寒生态系统中作为调控植物生长的关键环境因子之一。本研究通过分析青藏高原东缘岷江源区高寒草甸4种优势晚花植物(线叶龙胆、条叶垂头菊、高山韭和六叶龙胆)不同器官(根、茎、叶和花)生物量分配随雪被厚度的变化,探讨了不同物种在异质性雪被下的生物量权衡及生长策略。结果表明:1)雪被厚度显著影响物种株高及各器官生物量分配,条叶垂头菊在不同雪被厚度下均生长受限,偏向于地下生物量的积累(α=0.286,α=0.216,P<0.05),中雪厚度下生物量积累未能完全达到繁殖阈值,造成种群数量减少;较厚的雪被使得高山韭的花生物量、株高和总生物量增加(P<0.05),而地上-地下生物量积累均为异速生长关系(α=0.208,α=0.262,P<0.05)。随着雪被厚度的增加,繁殖器官绝对投资增大,繁殖分配减小,具有大小依赖性。2)基于性状响应模型分析得出,不同雪被厚度下生态位的变化主要体现在茎叶的资源获取能力与花的繁殖作用。条叶垂头菊、高山韭和六叶龙胆的生态位主要与地上生物量分配、地下生物量分配及地下-地上生物量分配比显著相关;雪被厚度提高了可利用资源,高山韭繁殖阈值增加,线叶龙胆繁殖阈值降低,而六叶龙胆繁殖阈值则较稳定,说明繁殖阈值的变化受多因素调控,具有物种特异性。3)高山韭深雪部位面临种子成熟风险性,繁殖阈值的提高促进了对繁殖器官的绝对投入,是典型高山晚花自交植物生长策略的代表;而线叶龙胆为异交植物,在资源丰富的中雪部位降低繁殖阈值,属于花粉风险型策略。

关键词: 岷江源区, 气候变化, 繁殖分配, 异速生长, 生长策略

Abstract:

The distribution of plant biomass among individual organs indicates the allocation of assimilation products, and is a driving mechanism of the differential growth of different organs, regulated by both external environment and internal factors. In alpine ecosystems the growing season is short and seasonal snow cover is a critical environmental factor with wide ranging implications for regulation of plant growth. This study was conducted in the Minjiang River headwaters on the eastern edge of the Qinghai-Tibet Plateau, to elucidate the growth strategies under different patterns of seasonal snow cover and their biomass trade-offs. For this purpose, data were collected on the biomass allocation to different organs (roots, stems leaves and flowers) of four dominant late flowering herb species (Gentiana farreriCremanthodium lineareAllium sikkimense and Gentiana hexaphylla). The findings revealed that: 1) The biomass of different components of the four plant species responded differently to different snow cover thicknesses. For C. lineare, biomass of all plant organs tended to be reduced in medium snow compared to shallow snow, with the reductions significant (P<0.05) for stem and leaf biomass. Moreover, under medium snow cover, C. lineare biomass accumulation failed to meet the threshold for seed set, leading to a decrease in population size. By contrast, biomass of all plant organs of G. farreri tended to be higher in medium snow than in shallow snow, with root and leaf biomass values significantly (P<0.05) increased. Similarly, A. sikkimense plant biomass was increased in deep snow compared to medium snow with the increases significant (P<0.05) for all plant organs-roots, stems, leaves and flowers, and for plant height. In addition, A. sikkimense consistently exhibited allometric growth relationships between the above- and belowground biomass [α=0.208, α=0.262, P<0.05, where α denotes lg (above ground biomass)∶lg (below ground biomass)]. Meanwhile, G. hexaphylla plant biomass and allocation to plant parts was not significantly different in deep snow from that in shallow snow. With increase in depth of snow cover, investment in reproductive organs increased, but reproductive allocation decreased, indicating size-dependency. 2) Based on the response-effect trait model, the variations in plant form with different snow thickness mainly reflected different resource acquisition roles of stems and leaves, as well as the reproductive function of flowers. The niches of C. lineareA. sikkimense, and G. hexaphylla were significantly correlated with their aboveground biomass allocation, belowground biomass allocation, and the ratio of belowground to aboveground biomass. Thicker snow cover enhanced resource availability, leading to an increased reproductive performance for A. sikkimense and a decreased one for G. farreri, whereas G. hexaphylla maintained a constant reproductive performance with change in snow cover. This demonstrates that changes in reproductive performance are governed by various factors and exhibit species-specific responses. 3) When A. sikkimense is in locations with deep snow, it faces a ‘seed-risk’ scenario. By raising the reproductive investment, it boosts its absolute investment in reproductive organs, exemplifying the traits of a classic late-flowering alpine self-pollinating plant. Conversely, G. farreri, a cross-pollinating species, reduces its reproductive investment in moderately snowy areas rich in resources, following a strategy known as pollen-risking.

Key words: Minjiang headwater region, climate change, reproductive allocation, allometric growth, growth strategies