| 摘要: | Apiaceae is a monophyletic group of plants which is mostly composed of herbaceous taxa. According to the literature, ancestors of the families have originated in the mesic tropics of southern hemisphere, and were woody species. However, the current diversity of family is extensively distributed in the northern hemisphere, where almost all northern hemispheric species being herbaceous. This evolutionary success of the family in the northern hemisphere was accounted by literature, to the adaptation of a lineage/s of advanced Apiaceae which originated in tropical East Asia, in to arid temperate conditions as a result of climatic cooling in tertiary. During the tertiary climatic cooling, most flowering plants have forced to be moved in to tropical refugia, where Apiaceae seem to have overcome the climatic barrier. This scenario hypothesized by biogeographic reconstruction of the family deserves further investigation. Therefore, the current study attempts to resolve the interrelationships of distributional patterns, contemporary ecology, geographic factors and phylogeny of the family. Current study hypothesizes Apiaceae occupy a variety of environmental conditions ranging from tropical to temperate, where ancestral taxa occupy humid tropical habitats and advanced taxa occupy arid temperate habitats. Following the hypothesis, the study ascertain following points 1) species richness of Apiaceae is limited by high summer temperatures strongly while the family prefer cold and dry climatic conditions, 2) extreme aridity and cold (xeric climatic conditions) adversely influence the distribution of the family, thereby making the mid-latitude regions species rich, 3) distribution patterns of ancestral and advanced Apiaceae is different in East Asia, 4) climatic niche space of advanced taxa is colder and drier than that of ancestral taxa in East Asia, 5) thus phylogeny of taxa coincides with the climatic niche of Apiaceae taxa, 6) south western China is the diversity center of the family in Eastern Asiatic region, and 7) high elevated regions coincide with species rich regions of Apiaceae. Therefore, it is possible that the adaptation of an Apioid ancestor/s with Eastern Asiatic origin from warm wet to cold dry conditions in their biogeographic history caused extensive diversification of the family in northern hemisphere, leading the evolutionary success of this group of flowering plants. |
