基于时间生态位在城市绿地中再引入濒危植物明党参

Reintroduction of an endangered species,Changium smyrnioides,into urban green spaces based on temporal niche

城市绿地作为珍稀濒危物种的保护和保存地日益受到关注，然而对其保护潜力缺少定量研究。本文通过调查亚热带城市杭州市和宁波市明党参（Changium smyrnioides）的野外生境和测定明党参的生理生态参数，确定了该种的时间生态位；进而在城市绿地中开展调查，寻找与该种野外相似的生境，分析将明党参再引入到城市绿地中的潜力和方式。结果表明，明党参分布于亚热带东部森林的落叶树下，落叶树无叶期为11月到次年4月，此时林下的光照和热量条件适宜于明党参生长。明党参12月至次年1月萌发，光热条件最适宜的3月进入快速光合和生长期，5月开花、光合变弱，6月种子成熟后休眠；在杭州市和宁波市绿地中，落叶树种分别占乔木树种总数的62%和60%，这些落叶树的林下都具有栽培明党参的潜力；由展叶物候期在4月的重要落叶树以及与野外相同或相近的落叶树提供的林下生境最适合引入明党参；目前杭州市和宁波市的城市绿地分别具有18.97和18.42 km^2的潜在可引种生境。若将这些生境充分利用，分别可引种1.01×10^8和0.98×10^8株明党参。

Urban green spaces have received more and more attention for rare and endangered species conservation. However, the conservation potential in urban green spaces has been less studied. Based on the habitat survey of Changium smyrnioides in cities Hangzhou and Ningbo and the eco-physiological experiment, we determined the temporal niche of this species. Then we investigated the urban green spaces to search the habitats that are similar to that in the field and analyzed the potential and the way for reintroducing C. smyrnioides into urban green spaces. Results show that C. smyrnioides mainly occurs under the deciduous trees in eastern subtropical forest. When the deciduous trees are with no leaves from November to next April, the understory light and temperature conditions are suitable for the growth of C. smyrnioides. In Hangzhou and Ningbo,C. smyrnioides begins to germinate during December and January, and enter a period of high photosynthesis and rapid growth with optimal temperature and light in March; it blooms and the photosynthesis becomes weak in May; it enters dormancy after seed maturation in June. In urban green spaces of Hangzhou and Ningbo, the deciduous tree species account for 62% and 60% of the total number of tree species, respectively. The spaces under these deciduous trees have the potential for C. smyrnioidescultivation. Moreover, the understory habitats of the important deciduous species that similar to the wild species are most suitable forC. smyrnioidesreintroduction. At present, there are 18.97 and 18.42 km^2of potential habitats for C. smyrnioidesin urban green spaces of Hangzhou and Ningbo respectively, and if the potential habitats are taken full use of, 1.01×10^8 and 0.98×10^8 individuals of C. smyrnioides can be cultivated, respectively.