| Summary: | 碩士 === 國立中興大學 === 水土保持學系所 === 104 === This study intends to discuss the vegetation succession mechanism on landslide areas following the vegetation engineering. Surrounding environment, soil, and vegetation are investigation respectively, and pteridophyte quotient, importance value index, tree diameter structure, and degree of succession are utilized for a series of succession analyses. It is found in the research that the crown density in the succession series does not appear stable increase. The crown density decreases in the beginning of vegetation succession because of the succession among tree species. A stable trend would appear after the succession enters the understory reproduction interval. Pioneer trees enters the succession in the stand initiation stage and withdraw the succession in the stem exclusion stage. Rhus semialata, the most obvious species, the most rapidly achieves the highest overstory importance value index, but the decline rate is also fast. The same succession of Villebrunea pedunculata and Debregeasia edulis, which are the tree species in the early time of succession, in different sampling areas is observed. Debregeasia edulis appears more early than Villebrunea pedunculata, but the importance value index of Villebrunea pedunculata, after the appearance, would rapidly exceed it of Debregeasia edulis Meanwhile, the importance value of Debregeasia edulis presents decline trend. Such two tree species enter the succession in the stem exclusion and withdraw in the understory reproduction interval. Tree species like Machilus thunbergii in the late succession could be observed the survival in the understory reproduction interval. In the degree of succession equation proposed by Numata, the number of species n is regarded as a negative factor that the degree of succession would decline in the actual calculation. The calculation result better conforms to the field observation after removing the number of species n. This study could provide reference for the successive revegetation of vegetation engineering on landslide. It is also suggested to continuously modify Numata’s degree of succession equation in order to accurately respond to the degree of succession.
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