Effects of Summer Nocturnal Warming on Biomass Production of Leymus chinensis in the Songnen Grassland of China: From Bud Bank and Photosynthetic Compensation
Effects of Summer Nocturnal Warming on Biomass Production of Leymus chinensis in the Songnen Grassland of China: From Bud Bank and Photosynthetic Compensation
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DOI：
10.1111/jac.12041
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发表时间：
2014-02
影响因子：
3.5
通讯作者：
Zhuolin Li;Jixiang Lin;T. Zhang;N. Zhang;C. Mu;Junfeng Wang
中科院分区：
文献类型：
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作者：
Zhuolin Li;Jixiang Lin;T. Zhang;N. Zhang;C. Mu;Junfeng Wang
夜间增温对植物生物量产生多种影响。为了了解东温带欧亚草原优势草地物种羊草（Leymus chinensis）的生物量生产对夏季夜间增温的响应，我们基于过去12年的昼夜温度变化，利用植物tron系统模拟了100天的夏季夜间增温（+4°C）。结果表明：夏季夜间增温显著提高了亲本和子芽地上生物量产量，显著提高了地下根和根茎生物量产量；根茎生物量增加快于根系生物量，导致根茎生物量与根系生物量之比增加。夜间增温使单株子芽数略有增加，地下芽库芽数、根状茎数和根状茎长均显著增加。夜间增温条件下，暗呼吸速率和净光合速率、Jmax、三磷酸利用率和叶绿素荧光参数（ΦPSII和qP）均显著高于夜间增温条件。上述结果表明，夜间增温通过光合补偿促进了羊草的生物量积累，并可能通过增加羊草生态演替早期地下芽库中的芽数来提高羊草的种群密度和生产力。
Nocturnal warming has various effects on plant biomass production. To understand how biomass production of the dominant grassland species Leymus chinensis responds to summer nocturnal warming in the eastern temperate Eurasian steppes, we simulated summer nocturnal warming (+4 °C) using a phytotron system for 100 days operated based on the variation of diurnal temperatures over the past 12 years in the Songnen Grasslands. Our results show summer nocturnal warming significantly increased above-ground biomass production of parent and daughter shoots as well as increased below-ground root and rhizome biomass production; rhizome biomass increased faster than root biomass leading to an increase in the rhizome biomass to root biomass ratio. Nocturnal warming slightly increased the number of daughter shoots per plant, and significantly increased the number of buds in the below-ground bud bank and the number and length of rhizomes per plant. Also, the dark respiratory and net photosynthetic rates, Jmax, the rate of triosephosphate utilization and chlorophyll fluorescence parameters (ΦPSII and qP) were significantly higher under nocturnal warming conditions. These findings show that nocturnal warming in this ecosystem improves individual biomass accumulation due to photosynthetic compensation, and may enhance the population density and productivity of L. chinensis by increasing bud number in the below-ground bud bank during the early stage of ecological succession for grasslands dominated by L. chinensis.