Comparative studies on the ecological strategies of an endangered species Changium smyrnioides and a non-endangered species Anthriscus sylvestris

Changium smyrnioides Wolff, a monotypic species of family Umbellaceae, has a narrow distribution area and can found only in Yangtze River basin in China; the widespread Anthriscus sylvestris (L.) Hoffm can be found from temperate to subtropical zone in Asia, Europe and North America. Both species have fleshy roots, which are prized in Chinese medicine. Because of the land use, C. smyrnioides has now become an endangered species, while A. sylvestris do not endangered. Comparative studies on the ecological strategies based on the biological and ecological traits of the two species in present paper, aimed to find out the endangered mechanism of C. smyrnioides. Research was conducted at Hangzhou, Ningbo, Nanjing, Chuzhou and Anqing. The shoot of C. smyrnioides has only the basal leaf, which ensures it can capture light efficiently at ground level. The aboveground leaf area ratio (LAR_a) of C. smyrnioides was found to be higher than A. sylvestris, suggesting it can capture more light per unit of biomass. After spring time, C. smyrnioides loses its survival competitiveness as other herbaceous species can grow rapidly and impedes sunlight. C. smyrnioides is not a shade-tolerant species, that may explain why C. smyrnioides are typically found in small population under defoliated trees. Conversely, A. sylvestris can increase light absorption and out-compete other herbaceous by its distinct ability to expand densely and occupies extra horizontal and vertical space. In a word, C. smyrnioides is more effective in light capture and water acquisition than A. sylvestris, but the ecological strategy it with cause it specialized or overspecialized to the narrow environment, which were limited under the deciduous trees in subtropical evergreen broad-leaved forest zone in winter. As the human disturbance (digging for medicinal use and deforestation) becoming serious, C. smyrnioides becoming rare and an endangered plant.