Warming And Nitrogen Deposition Affect The Growth And Morphological Characteristics Of An Invasive Herb Solidago Canadensis

Global climate change has become a hotspot in research of ecology, and as itstwo most important part, climate warming and nitrogen deposition are directlychanging the ecological environment that human live on, of which are attracting moreand more attention. As two most important limiting factors on plant growth,temperature and nitrogen are closely related to the plasticity of the invasive plants.Therefore, carrying out researches on the effects of warming, nitrogen deposition andtheir interaction on invasive plant morphological plasticity or invasiveness are quiteneeded. For this reason, the mechanisms that invasive plants differently adopt toclimate warming and N deposition were determined as the center focus of this article.In a particular ecosystem, discussing the role of global warming and N deposition onplant growth and morphological plasticity in the course of invasion in a particularecosystem helps to fulfill the climate change disturbance theory and provides reliablebasis for analyzing the growth and invasiveness of invasive plants under thebackground of global warming and N deposition. This article chose Solidagocanadensis both from China (SCN) and North America (SNA) as objectives andseparately conducted three experiments by using simulated warming treatment, Naddition treatment, and warming plus N addition treatment to discuss the impact ofwarming and N decomposition on Solidago Canadensis. Results are as follows:SCN out-performed SNA across all the three treatment on the traits of plantheight, leaf number, tillers number and leaf quality, demonstrating that SolidagoCanadensis behaved stronger growth ability in the invasion area than its originalsource, of which may be attributed to the reason that the environment in invasion area(Zhe Jiang, China) are superior to that of original source (Montana, American) forSolidago Canadensis, thus leading to its adaptive differentiation.In the warming treatment, compared to control group, plant height, leaf numberand tiller number of SCN in warming group tend to increase across all its differentgrowth period, and this increase of leaf number became significant in November. Plant height of SNA slightly decreased, while its leaf number and tiller numberslightly increased. Warming significantly added the dry weight and specific leafweight of SNA, while it tend to reduce the leaf area, dry weight and specific leafweight of SCN. In a word, warming affect the growth and development of SolidagoCanadensis to some extent, and this impact may be different in its invasion area andoriginal place.Both of SCN and SNA responded similarly to N addition treatment that plantheight of them slightly increased (not significant) while leaf number and tiller numberbecome much greater. Thus, N addition at such level may greatly enhance the growthof Solidago Canadensis.Both of these two sources of Solidago Canadensis showed strong response ofplasticity in the treatment of warming plus N addition treatment. Leaf number andtiller number were significant higher in N addition treatment than those in warmingplus N addition treatment. On the contrary, leaf number and tiller number were lowerin warming treatment than those in warming plus N addition treatment. Moreover,leaf area, leaf fresh weight and dry weight were lower in N addition treatment orwarming treatment than those in warming plus N addition treatment. Thosecharacteristics demonstrated that the interaction of Solidago Canadensis showeddifferent complementary and antagonistic action on different life history traits, thusaffecting its morphological characteristics.