Search

Predicting the potential range of invasive alien plants and their adaptabilities to different environments could give early warning and prevention measures. The diverse bioclimatic types in Yunnan province would provide rich potential habitats for alien invasive plants. Tithonia diversifolia, an alien plant invading in tropical and sub-tropical regions of Yunnan, has quickly dispersed in recent years. In order to evaluate the risk of its invasion in different geographical environments, we investigated the invasion situation of T. diversifolia in Yunnan Province, and collected the distribution samples in the world. Using this species' distribution coordinates and 12 main environmental variables, we analyzed the suitability of T. diversifolia to different environments and the dominating environmental factors by MaxEnt model. The results were as follows: Yunnan had not high-suitability area in the worldwide pattern of T. diversifolia's distribution, meanwhile sub-, medium-, low-, un-suitability area accounted for 3.58%, 32.90%, 42.80% and 20.72% of the provincial area, respectively; Medium-suitability area was the main risk region, which widely interspersed in the south of 26° N in Yunnan; Field investigation showed T. diversifolia mainly distributed at the altitude of 1 000-1 500 m and its upper altitudinal limit was 2 200 m, while the model predicted that the altitude region below 2 000 m was suitable, especially between 500-2 000 m; The most important environmental factors affecting distribution of T. diversifolia were annual precipitation, human footprint, annual average temperature and altitude. In conclusion, although T. diversifolia has reached sporadically its suitable geographical limiting boundary at present, the invaded area is far less than the potential suitable area. It is necessary to keep monitoring T. diversifolia's dispersal dynamic in the future, so that hazard caused by T. diversifolia could be controlled in time. [ABSTRACT FROM AUTHOR]

Tagetes minuta, as a newly invasive species in Tibet of China, its damage is beginning to appear. However, there are few studies on its invasion mechanism in China. In order to explore the biomass and its allocation characteristics of population modules of T. minuta in heterogeneous habitats, and to further understand its survival strategies and invasive habitats, we determined and analyzed the biomass characteristics and calculated the index values of phenotypic plasticity of the population modules in the flowering and fruiting stages of the T. minuta in five typical invasive habitats, including vegetable garden, orchard, roadside, wasteland and riverside. The results were as follows:(1)The basic law of biomass of module in T. minuta population was stem > flower and fruit > leaf > root. The biomass of each module was the largest in the roadside and the smallest in the vegetable garden, and there were significant differences between these two habitats(P<0.05).(2)The total coefficient of variation(CV)and phenotypic plasticity index(PI), based on maximum and minimum means of each module were 46.93% and 61.44%, respectively.(3)The relationship between biomass ratio of reproductive module and nutrient module of T. minuta was wasteland > roadside > orchard > riverside > vegetable garden, and the root-shoot ratio was vegetable garden > wasteland > riverside > roadside > orchard.(4)There were significantly positive correlation between biomass of different modules, between biomass of different modules and total biomass, which showed its ensemble and consistent strategy of survival. The above results indicate that T. minuta can adapt to heterogeneous habitats by adjusting the biomass of each module, and thus has a strong phenotypic plasticity. High reproductive output and adaptability to heterogeneous environments may be the important reasons for its successful invasion. [ABSTRACT FROM AUTHOR]

Biological invasions seriously threat the global biodiversity and ecosystem health, causing great losses to global environment and economy. However, rapid climate change could significantly affect the diffusion and invasion of alien species. To explore the development situation of biological invasions under climate change could be helpful for better understanding the status and hot spots in this field, and also the benefitial for understanding the invasion mechanism and making effective management measures. In our study, we studied the Web of Science(WOS)database for publications pertaining to the biological invasions under climate change between the years 1990-2016, we then used the Thomson Data Analyzer(TDA)to operate the systematic analysis. We found that there were total 1 736 published papers in recent 27 years. The number of publications increased annually, while it rapidly increased since 2009. This research area related to several subjects such as environmental science and ecology, biodiversity protection, botany, etc. Prof. Chown SL form Monash University had the largest amounts of publications. USA had the maximum total papers, highly cited and high impact factor papers. California University published the most papers among international research institutes, while the Chinese Academy of Science(CAS)ranked the 10th. Biological Invasions was the academic journal which had the largest publications. Recent studies focused primarily on topics related to species distribution models, biodiversity, global warming and risk assessment. China totally published 52 articles, Chinese Academy of Science had the largest amounts of papers, while Institute of Zoology, Wuhan Botanical Garden, Institute of Botany ranking Top 3 among the branch organizations of CAS. In the future, China should give more attentions on the high level research papers and international cooperation of biological invasions under climate change. In addition, we need to focus on prediction and risk assessment of alien species, relationships between biological invasions and biodiversity, system evolution of invaders, relationships among multiple trophic levels of invaded ecosystem, marine biological invasion, influence of invasion on human health, etc under a rapid global climate change. [ABSTRACT FROM AUTHOR]