Studies On Ecological Adaptability Of The Invasive Plant Solidago Canadensis

Solidago canadensis L., a perennial composite plant originating from North America, was introduced into China as a horticultural plant in 1935. S. canadensis is the most devastating invasive plant in China. With high reproductive capacity and fast spread speed, this exotic plant has changed the constitution of ecosystem, destroyed the biodiversity and soil utility in the places it invaded and caused serious damage to agricultural production and ecosystems in several provinces of China. The former research about S. canadensis mainly focused on spread model, biological characteristics, allelopathic effects, control and use, et al. This paper focuses on some aspects related to the issues about the ecological adaptability of the weed, such as the relationship between ecologically influencing factors and invasiveness, comparison of photosynthetic characteristics between S. canadensis and its companion weed species, the genetic diversity and invasive mechanism with molecular knowledge, the energy distribution in different reproduction investment strategy and how to control the weed in its inflorescence differentiation period.The main results were concluded as follows:1. Under natural conditions, S. canadensis allocates large amounts of energy to sexual reproduction and produces many seeds. In addition, naturalized populations have a great capacity to grow clonally with rhizome. Under natural conditions, the germination period of S. canadensis lasts from March to October, with a germination peak in April and May. Vegetative growth and asexual reproduction are especially vigorous during the summer season. Most S. canadensis blossom between September and January, and fruit in late October. The mean weight of 1000-seeds ranges from 0.045g to 0.050g, and mean seed moisture content ranges from 60% to 80%. S. canadensis seeds have a wide tolerance for different values of pH, salinity and soil moisture. The mean percent germination of seeds is 30% under suitable conditions. The results of seed germination under various environmental stresses and the investigation of soil...