The Ecological Responses And Enrichment Characteristics Of Solidago Canadensis L.under Arsenic Pressure In Soil

Solidago canadensis L.is an invasive herb species with strong adaptability and large biomass.Even under adverse environment it can still demonstrate a strong ability to grow and spread.According to field observations,S.canadensis is usually distributed in the residential area and roadside.Such locations usually have different degrees of pollution,which is not suitable for general plant growth and reproduction.To further investigate S.canadensis's ability to resist adverse environments,especially the ability to grow and reproduce in soil contaminated areas,we conducted pot-planting experiment of S.canadensis with different concentration of arsenic soil.This paper studied the ecological response and enrichment characteristics of S.canadensis.Main results are as follows:?1?The observed data of height,stem diameter and biomass showed that S.canadensis grows normally when the arsenic concentration is 0-100mgkg^-1,but the growth is greatly suppressed when the arsenic concentration is 100mgkg^-1-500mg^-1.The plants cannot grow and the biomass is less than 60%of the reference group when the arsenic concentration exceeds 500mgkg^-1.In summary,the tolerance concentration of S.canadensis in the arsenic soil is 0-100mgkg^-1.?2?When the concentration of arsenic is 0-100mgkg^-1,the content of nitrate and vitamin C in the S.canadensis did not change significantly.When the concentration of arsenic is 200-500mgkg^-1,the content of nitrate and vitamin C in the Scanadensis significantly increased.When the arsenic concentration is 0-100mgkg^-1 the catalase and MDA did not increase.When the arsenic concentration is 200-500mgkg^-1,S,canadensis began to produce toxic substances and both catalase and the amount of MDA increased.When the arsenic concentration is 0-100mgkg^-1,the proline and the soluble sugar didnot change.When the arsenic concentration is 200-500mgkg^-1,S canadensis can generate a lot of proline and soluble sugar as a spontaneous response,which increase simultaneously for the maintenance of the plant cell osmotic potential.When the concentration of arsenic is in tolerance range of S.canadensis,the content of chlorophyll b is small and the content of chlorophyll have big ups and downs,the ratio of chlorophyll a and chlorophyll b declines as the amount of arsenic increases.?3?The order of arsenic concentration in S.canadensis is root>leaf>stem.The enrichment index increases as the arsenic concentration increases.The index is less than 0.5 in all cases.Therefore,S.canadensis does not belong to the hyperaccumulator,for which the enrichment index should be greater than 1.The total amount of arsenic in S.Canadensis underground is less than that aboveground,which means the transfer coefficient is more than 1.Among all plant parts examined,the abovegroud accumulate arsenic the most.?4?The concentrations of N,P,K in S.canadensis's root,stem and leave were significantly different.Overall,the order is:leaf N>Root N>stem N,leaf P>root P>stems P,leaf K>root K>K stems(only arsenic concentrations more than 200mg^-1,leaf K>stem K>K root).The correlation analysis show that the concentration of arsenic in leaves is significant correlated with the concentration of leaf N and leaf K.The concentration of arsenic in stem is significant correlated with the concentration of stem N and stem K.This study gave quantitative results about the tolerance and enrichment capabilities of S.canadensis in arsenic contaminated soil.The results showed that S.canadensis in arsenic-contaminated soil had a strong ability to grow in adverse environment and a certain capacity of absorbing metal contaminants in soil.The results will be helpful for better understanding the resilience of S.Canadensis.Results will also be helpful for exploring new ideas and scientific approaches to the control of this invasive species and a comprehensive management of heavy metal pollution in soil.