用微信扫码二维码

分享至好友和朋友圈

WE ARE COMMITTED TO REPORTING THE LATEST FORESTRY ACADEMIC ACHIEVEMENTS

元江干热河谷两种优势植物光合色素对不同降水变化的响应

Response of Photosynthetic Pigments in Two Dominant Plant Species to Precipitation Changes in the Yuanjiang Dry-Hot Valley

  • 摘要: 在气候变化加剧干旱的背景下,木本植物叶片光合色素对干旱的适应策略仍缺乏系统认知。本研究在元江干热河谷设置稀树灌草丛原位降水控制实验平台,设置对照、减水30%、减水50%、减水70%、增水30%、增水50%和增水70%共7个处理,系统研究了降水变化下厚皮树(Lannea coromandelica)和老人皮(Polyalthia cerasoides)两种优势植物叶片光合色素的变化规律。相比增水处理,两种植物在极端干旱(70%减水处理)下显著提高叶绿素与类胡萝卜素含量。不同的是,厚皮树保持叶绿素a/b稳定,但在30%减水处理下降低类胡萝卜素占比,而老人皮则在极端干旱下通过升高叶绿素a/b比值,并维持稳定的类胡萝卜素占比以优化光能分配。此外,老人皮的光合色素水平高于厚皮树。以上结果表明,两种植物通过不同的光合色素调节策略适应干旱胁迫:厚皮树积极向光合机构投资,而老人皮则展现出维持光合机构稳定的适应特征。研究结果不仅揭示了自然干旱生境中木本植物生理适应的多样性,也为该地区植被恢复与适应性树种的筛选提供了关键科学依据。

     

    Abstract: Against the context of intensifying drought due to climate change, the adaptive strategies of leaf photosynthetic pigments in woody species to combined drought stress remain unclear. This study was conducted at a savanna in-situ precipitation manipulation platform established in the Yuanjiang dry-hot valley. The platform comprised seven treatments: a control, precipitation exclusion of 30%, 50%, and 70%, and precipitation addition of 30%, 50%, and 70%. We systematically investigated the responses of leaf photosynthetic pigments in two dominant species, Lannea coromandelica and Polyalthia cerasoides, to these precipitation gradients. Compared to precipitation addition treatments, both species significantly increased chlorophyll and carotenoids contents under extreme drought condition (70% precipitation exclusion). However, they exhibited distinct regulatory patterns. L. coromandelica maintained a stable chlorophyll a/b but reduced the proportion of carotenoids under 30% precipitation exclusion. In contrast, chlorophyll a/b of P. cerasoides increased under extreme drought while maintaining a stable carotenoids proportion, suggesting an optimized allocation of light energy. Furthermore, P. cerasoides consistently exhibited higher photosynthetic pigment levels than L. coromandelica across all treatments. These findings reveal that the two species employ different photosynthetic adjustment pathways to cope with drought stress: L. coromandelica adopts an active photosynthetic investment strategy, whereas P. cerasoides exhibits a more conservative adaptive trait. The results not only elucidate the diversity of physiological adaptations in woody plants within natural drought habitats, but also provide a crucial scientific basis for vegetation restoration and the selection of stress-adapted tree species in this region.

     

/

返回文章
返回