| With the development of world economic integration, international exchange and international trade, the invasion of alien plants become more and more evident, the Phenomenon becomes a hot topic of the world in the plants research. China with a vast territory, possesses of abundant ecosystem diversity country, there are different invasive alien plants among different ecosystems, as well as the adaptive features. At present, the research field is mostly about the invasive alien plants in administrative regions. There are very few of cases studies about invasive alien plants in Scenic Areas. Based on the investigation, analysis, screening to the naturalized plants of Mount Huang scenic area, we establish the alien plants invasion risk assessment index and establish risk assessment system, we purpose is to make a scientific and reasonable management plan to prevent the invasion of alien plants in Mount Huang Scenic Area.The main results are:1. Based on our investigation, there were101naturalized plants, belonging to81genera and42families. A further research showed that naturalized plants comprised31invasive alien plants, belonging to25genera and14families.2. The significant difference between invasive alien plants and native plants were: breeding frequency, the crested or winged seeds; The extremely significant difference between invasive alien plants and native plants were:The origin, asteraceae, the average seed yield, positive, neutral,life history, stress tolerance, allelopathy, predators and other factors. By compared the average value of the indexes,the data showed that invasive alien plants were mostly asteraceae, florescence is longer, bisexual flowers, many seeds, positive plants, few neutral and negative plants, life history is one or two yearsl, stress tolerant, the seeds were mostly crested or wings, allelopathy, predators and other factors obviously do not exist.3. The significant difference between invasive alien plants and cultivated plants were:The origin, breeding system, aquatic; The extremely significant difference between invasive alien plants and cultivated plants were:asteraceae, seed size, seed yield, xeric, stress tolerance, mode of reproduction, the crested or winged seeds, allelopathy, predators and other factors. By compared the average value of the indexes,the data showed that invasive alien plants’origins were mostly American, florescence was longer, smaller and more seeds, xeric, the crested or winged seeds, their allelopathy were more obvious, few predators and other limiting factors; cultivated plants mostly from the other areas, bisexual flowers, inclined to vegetative reproduction.4. We analyzed the correlations between indexes and invasion capability, the results showed:asteraceae, many seeds, small seeds, positive, drought tolerance, shorter life history, stress tolerance, sexual reproduction, seed with hook or pappus or wings, allelopathy, from the Americas(especially from the North America), lack of predators and other limiting factors could enhance the invasive ability in the Mount Huang scenic area. Contrary, breeding system, shade, wetland, aquatic plants, poisonous or barbs, upright growth, creeping growth, climbing growth, breeding times of one year could not enhance the invasive ability.5. We constructed the alien plants invasion risk assessment system of Mount Huang scenic area from5levels:introduction, establishing a population, diffusion, hazard. The system consisted of6first grade indexes:the introduction of risk, environmental adaptability, spreading possibility, distribution of invaded/invasion history, harmfulness and control probability. We count and analyzed indexes of invasive alien plants in this region, the asteraceae, origin, positive, xeric, stress resistance, allelopathy, life history were into environmental adaptability as two grade indexes, flowering duration, mode of reproduction, the crested or winged seeds, seeds size, seeds yield, lack of predators and other limiting factors were into diffusion potential as two grade indexes. We set the results after investigations into the two grade indexes which local attractions distribution and the range of harm.6. We selected3groups of alien plants to inspect the risk assessment system, the result was:in the existing invasive alien plants group, Erigeron annuus to be got the highest score(3.11), Opuntia stricta (Haw.) Haw. var. dillenii to be got the lowest score(2.03). In the unexisting invasive alien plants group, Ambrosia artemisiifolia to be got the highest score(3.27), Eichhornia crassipes to be got the lowest score(2.59). In the cultivated plants group, Canna indica to be got the highest score(0.76), these results proved the effectiveness of the system.7.We used200g.L-1Starane,77.7%Ammonium glyphosate,56%MCPA to control Bidens frondosa. The fatality rates were82.03%、92.44%and85.33%, The plant death rate is extremely significant difference for3concentrations. The death rates between high concentration and medium concentration were not obvious. The death rates between moderate concentrations and low concentrations were not obvious.The death rates between high concentration and low concentration were significant difference. The3kinds of high concentration herbicides were effects to control Bidens frondosa. We used each type of herbicides in seedling stage, blooming and florescence to find death rates were significantly, but the death rates of early stage and middle stage were not significantly, the death rates of early stage and late stage/middle stage and late stage were different, are significantly above the level of the period, the earlier plants resistant to low, control the effect is more ideal. The effects were better when used them in early stage.8. Based on our country has not issued comprehensive legal which to control invasive alien plants. We put forward the countermeasures and suggestions from the angle oflandscape and ecological protection for Mount Huang scenic area. |
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