大气增温对滇西北高原典型湿地湖滨带优势植物的光和CO2利用能力的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 大气增温对滇西北高原典型湿地湖滨带优势植物的光和CO2利用能力的影响 DOI: 10.5846/stxb201610021989 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（31370497，31500409）；云南省高原湿地创新团队（2012HC007） Influence of simulated warming on light and CO2 utilization capacities of lakeside dominant plants in a typical plateau wetland in northwestern Yunnan Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:大气增温对湿地植物光合作用的影响及其作用机制是近年来生态学界关注的热点。采用开顶式生长室（Open-top chambers，OTCs）模拟大气增温（（2.0±0.5）℃，（3.5±0.5）℃），研究增温对滇西北高原典型湿地纳帕海湖滨带2种优势植物（茭草Zizania caduciflora，黑三棱Sparganium stoloniferum）的光和CO2利用以及光合碳同化速率的影响。结果表明，（1）增温对不同植物的光和CO2利用能力以及碳同化速率的影响存在种间差异。增温显著降低了茭草的光饱和点（LSP）、光补偿点（LCP）、光能利用幅（LSP-LCP）、CO2饱和点（CSP）、CO2利用幅（CSP-CCP）以及最大净光合速率（Pmax），却显著增加了其CO2补偿点（CCP）；相反，增温显著提高了黑三棱的LSP、（LSP-LCP）以及最大净光合速率（Pnmax），而显著降低了其LCP，但对其CO2利用参数无显著影响。（2）2种植物的光和CO2利用能力对增温的响应存在季节性差异。不同温度处理下，茭草在6、8月的LSP和（LSP-LCP）均显著高于10月的对应值，其Pnmax也随生长期的增加而降低；黑三棱的光响应参数在不同生长季间无显著差异，其Pnmax在8月最高，而在6月和10月相对较低。（3）温度因子与茭草的光能利用参数均呈负相关，而与黑三棱的光能利用参数均呈正相关。本研究的温度因子中，日间积温对Pnmax和（LSP-LCP），年均温和最低温对（CSP-CCP）值的影响最为显著。本研究进一步表明，气候变暖对滇西北高原湿地湖滨带优势植物光合作用存在影响，但不同物种间存在差异响应，这种差异响应可能导致湿地生态系统植被结构的改变，其有关生态过程有待于进一步研究。 Abstract:The influence of air warming on the photosynthesis of wetland plants and the underlying mechanisms has recently been one of the important topics in ecological research. Using the open-top chambers (OTC), we studied the influence of experimental air warming on the light and CO2 utilization capacities and photosynthetic rate of two dominant species (Zizania caduciflora and Sparganium stoloniferum) on the lakeside of Napahai plateau wetland in northwestern Yunnan. The results showed that (1) the effects of warming on light and CO2 utilization capacities were species-specific. For Z. caduciflora, air warming significantly decreased the light saturation point, light compensation point, light utilization range, CO2 saturation point, CO2 utilization range, and maximum net photosynthetic rate, but it increased the CO2 compensation point. In contrast, in S. stoloniferum, air warming significantly increased the light saturation point, light utilization range, and maximum net photosynthetic rate, but it decreased the light compensation point and weakly influenced the CO2 utilization parameters. (2) The effect of air warming on the light and CO2 utilization capacities of the two plant species showed seasonal variation. In Z. caduciflora, under the three temperature treatments, the light saturation point and light utilization range in October were significantly lower than those in June and August, and a seasonal decrease was observed in its maximum net photosynthetic rate. Contrarily, in S. stoloniferum, both the light and CO2 utilization parameters were not influenced by air warming, but its maximum net photosynthetic rate was higher in August than that in June and October. (3) All temperature parameters were negatively correlated with photosynthetic parameters in Z. caduciflora, whereas they were positively correlated in S. stoloniferum. The diurnal temperature was the major factor influencing the maximum net photosynthetic rate and light utilization range, while the mean and minimum temperatures mainly affected the CO2 utilization range. This study indicates that the lakeside dominant plants in northwestern Yunnan plateau show different adaptive strategies to air warming. In the context of continuous climate warming in northwestern Yunnan, the dominate status of Z. caduciflora might get weakened, while that of S. stoloniferum might get strengthened, and these changes, in turn, can induce alterations in vegetative components, structures, and functions of the whole ecosystem. 参考文献 相似文献 引证文献