State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China; Beijing Urban Ecosystem Research Station, Chinese Academy of Sciences, Beijing 100085, China.
Sci Total Environ. 2019 Feb 25;653:120-130. doi: 10.1016/j.scitotenv.2018.10.281. Epub 2018 Oct 22.
Investigations into the photosynthetic response of urban trees on paved land under drought stress would help to improve the management of trees under rapid urbanization and climate change. An experiment was designed to grow two common greening tree saplings, ash (Fraxinus chinensis Roxb.) and ginkgo (Ginkgo biloba L.), in environments of both land pavement and drought. The results showed that (1) land pavement increased surface and air temperatures and decreased air humidity as well as net photosynthetic rate (P) and photosynthetic capacity (A) of ginkgo significantly; (2) drought significantly decreased P, A and maximum net photosynthetic rate (P) as well as other photosynthetic parameters of both ash and ginkgo; (3) the negative effects of the combination of land pavement and drought on photosynthetic parameters were more significant than the effects of drought treatment for both ash and ginkgo. This implies that urban trees, especially those growing on land pavements, will confront harsher environments and a greater decline of photosynthesis under the severe and more frequent droughts predicted in the future. Overall, ash showed more tolerance to land pavement and drought than ginkgo, indicating that the selection of tolerant tree species is important for urban planting.
研究城市树木在干旱胁迫下对铺面土地的光合响应，有助于改善快速城市化和气候变化下树木的管理。本研究设计了一个实验，在铺面土地和干旱两种环境下种植两种常见的绿化树种，即白蜡（Fraxinus chinensis Roxb.）和银杏（Ginkgo biloba L.）。结果表明：（1）铺面土地显著提高了银杏的地表和空气温度，降低了空气湿度以及净光合速率（P）和光合能力（A）；（2）干旱显著降低了白蜡和银杏的 P、A 和最大净光合速率（P）以及其他光合参数；（3）铺面土地和干旱对光合参数的综合影响大于干旱处理对白蜡和银杏的影响。这意味着城市树木，尤其是生长在铺面土地上的树木，将面临未来更严重和更频繁的干旱条件下更恶劣的环境和光合作用更大幅度的下降。总体而言，白蜡对白蜡和干旱的耐受性均高于银杏，这表明选择耐胁迫的树种对于城市种植非常重要。
