Jing Panpan, Wang Dan, Zhu Chunwu, Chen Jiquan
International Center for Ecology, Meteorology, and Environment, School of Applied Meteorology, Nanjing University of Information Science and Technology Nanjing, China.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences Nanjing, China.
Front Plant Sci. 2016 Nov 24;7:1774. doi: 10.3389/fpls.2016.01774. eCollection 2016.
Land surface temperature over the past decades has shown a faster warming trend during the night than during the day. Extremely low night temperatures have occurred frequently due to the influence of land-sea thermal difference, topography and climate change. This asymmetric night temperature change is expected to affect plant ecophysiology and growth, as the plant carbon consumption processes could be affected more than the assimilation processes because photosynthesis in most plants occurs during the daytime whereas plant respiration occurs throughout the day. The effects of high night temperature (HNT) and low night temperature (LNT) on plant ecophysiological and growing processes and how the effects vary among different plant functional types (PFTs) have not been analyzed extensively. In this meta-analysis, we examined the effect of HNT and LNT on plant physiology and growth across different PFTs and experimental settings. Plant species were grouped according to their photosynthetic pathways (C, C, and CAM), growth forms (herbaceous, woody), and economic purposes (crop, non-crop). We found that HNT and LNT both had a negative effect on plant yield, but the effect of HNT on plant yield was primarily related to a reduction in biomass allocation to reproduction organs and the effect of LNT on plant yield was more related to a negative effect on total biomass. Leaf growth was stimulated at HNT and suppressed at LNT. HNT accelerated plants ecophysiological processes, including photosynthesis and dark respiration, while LNT slowed these processes. Overall, the results showed that the effects of night temperature on plant physiology and growth varied between HNT and LNT, among the response variables and PFTs, and depended on the magnitude of temperature change and experimental design. These findings suggest complexities and challenges in seeking general patterns of terrestrial plant growth in HNT and LNT. The PFT specific responses of plants are critical for obtaining credible predictions of the changes in crop production, plant community structure, vegetation dynamics, biodiversity, and ecosystem functioning of terrestrial biomes when asymmetric night temperature change continues.
在过去几十年中，陆地表面温度夜间的变暖趋势比白天更快。由于海陆热力差异、地形和气候变化的影响，极低的夜间温度频繁出现。这种不对称的夜间温度变化预计会影响植物的生态生理学和生长，因为植物的碳消耗过程可能比同化过程受到更大影响，这是由于大多数植物的光合作用发生在白天，而植物呼吸作用全天都在进行。高温夜间温度（HNT）和低温夜间温度（LNT）对植物生态生理和生长过程的影响以及这些影响在不同植物功能类型（PFTs）之间如何变化，尚未得到广泛分析。在这项荟萃分析中，我们研究了HNT和LNT对不同PFTs和实验设置下植物生理和生长的影响。植物物种根据其光合途径（C3、C4和景天酸代谢）、生长形式（草本、木本）和经济用途（作物、非作物）进行分组。我们发现，HNT和LNT都对植物产量有负面影响，但HNT对植物产量的影响主要与分配给繁殖器官的生物量减少有关，而LNT对植物产量的影响更多地与对总生物量的负面影响有关。叶片生长在HNT时受到刺激，在LNT时受到抑制。HNT加速了植物的生态生理过程，包括光合作用和暗呼吸，而LNT减缓了这些过程。总体而言，结果表明夜间温度对植物生理和生长的影响在HNT和LNT之间、响应变量和PFTs之间存在差异，并取决于温度变化的幅度和实验设计。这些发现表明，在寻找高温夜间温度和低温夜间温度下陆地植物生长的一般模式时存在复杂性和挑战。当不对称夜间温度变化持续时，植物的PFT特定反应对于获得作物产量、植物群落结构、植被动态、生物多样性和陆地生物群落生态系统功能变化的可靠预测至关重要。
