中文摘要：

2008年初，我国南方19个省经历了50年一遇的持续低温雨雪冰冻天气。极端气候对华南沿海各省的红树林区造成不同程度的危害。2008年3月，在我国南方各省红树林区的10个代表性地点，对这次寒害造成的红树植物伤害程度进行了系统的调查。结果表明：冬季低温对红树林的影响极为显著，特别是在低纬度的海南、广西和广东湛江，由于极端低温正值夜间退潮，对红树林的影响更为显著；在纬度较高的福建，本地红树种类秋茄（Kandelia obovam）、桐花树（Aegiceras corniculatum）和白骨壤（Avicenniamarina）及引种的木榄（Bruguiera gymnorrhiza）等，由于长期适应于冬季较低的气温或在种植前经过抗寒锻炼，具有较强的抗寒能力。各地主要红树植物中，广布种秋茄、桐花树和白骨壤最为耐寒，其耐寒性均大于红树科的木榄、海莲（Bruguiera sexangula）和红海榄（Rhizophora stylosa）。海桑（Sonneratia caseolaris）对温度的敏感性最强，抗寒能力最低，因此，即使在其原产地海南也受到较为严重的寒害，在纬度更高的引种地出现大面积受害甚至全部死亡，而从孟加拉国引种的无瓣海桑（Sonneratia apetala）却显示出一定的抗寒能力。同一地点的红树植物幼苗的抗寒能力低于大树。此次寒害也造成了苗圃场的种苗大量死亡，成熟的植株提前落花落果，这势必会影响后继一两年内红树林的自然更新和人工造林。因此，在未来红树林造林或人工引种中，一定要考虑到红树植物的抗寒能力。

英文摘要：

Aims Unusually low temperatures associated with heavy rain, snow and frost occurred in 19 provinces in southem China in January-February 2008. Our objectives were to evaluate the impact of the cold weather event on mangroves and to compare differences in cold tolerance Methods In March 2008, we conducted an intensive between exotic and native mangrove species survey of cold damage in ten mangrove nature reserves along the coastal areas of mainland China. Parameters such as scorch percentage, defoliation percentage and leaf Fv/Fm values （an indicator of leaf physiological health） were determined on selected seedlings and trees of the mangrove species at each site.Important findings With low latitudes in Hainan, Guangxi and Zhanjiang of Guangdong, low air temperature coupled with the ebb tide at night, which caused serious damage to several mangrove species. However, native mangrove species in Fujian, such as Kandelia obovata, Aegiceras corniculatum, Avicennia marina and transplanted Bruguiera gymnorrhiza, which were adapted to low temperature events in winters, had higher cold resistance. Among all mangrove species surveyed, K. obovata, Aegiceras corniculatum and Avicennia marina were the most cold-resistant, followed by B. gymnorrhiza, B. sexangula and Rhizophora stylosa, which belong to the family Rhizophoraceae. Sonneratia caseolaris was the least cold-resistent mangrove species, having suffered serious damage or even complete loss in some locations. S. apetala introduced from Bangladesh showed much less damage than its counterpart S. caseolaris, indicating higher resistance to low temperature. Furthermore, mangrove seedlings were more sensitive than mature trees. The extreme cold event killed many mangrove seedlings in the nurseries and caused immature flowers and fruits to drop from trees, which would have an adverse effect on mangrove natural reproduction and reforestation projects. Thus, it is essential to consider cold resistance in future mangrove afforestration and restoration projects.