| Cerasus clarofolia, Rosaceae, is a deciduous shrubs or trees, and C. clarofolia has advantages of high ornamental value and suitability. Based on the sample plot survey, this paper studied the population and community characteristics of C. clarofolia community in Huangshan Mountain scenic area, including particularly community structure and composition, species diversity, niche breadth and niche overlapping of dominant population and regeneration trait. In addition, establishment of regeneration system of C. clarofolia also were studied. The main results were as follows:(1) Based on the field investigation into the typical sample plots of Cerasus clarofolia, the floristic composition, structure, physiognomy and species diversity were analyzed. The results showed that 120 species in 98 genera and 57 families of vascular plants were recorded in a 3600 m2 plot. The temperate elements were the dominant (83.5%) in which N. temperate and E.Asia taked an important part. The community was dominated by the phaenerophyte of deciduous, microphyll or mesophyll, single, herbaceous leaf. Although the community structure seemed to be simple, it could be divided into four stories, i.e., first, the tree layer with dominant species of C. clarofolia, Symplocos paniculata, Castanea seguinii, Dendrobenthamia japonica var. chinensis, and Acer mono whose important values (IV) were 20.24,9.24,8.34,7.91 and 5.19 respectively; second, the shrub layer that was dominated by Hydrangea angustipetala, Rubus trianthus, Weigela japonica var.sinica and the sapling of S. paniculata whose IV were 14.70,9.08,7.07, 4.42 respectively; third, the herb layer was mainly composed of the species preferred (or resisted) cold and dankness entironment, and the interlayer species were principally lianas. Generally, the order of the magnitude of species diversity was:shrub layer>tree layer>herb layer. The variation of indices order was herb layer>shrub layer>tree layer. C.clarofolia responds to natural and anthropogenic disturbance by sprouting, which may have helped conserve this species.(2) The niche breadths and overlaps of 13 dominant populations in tree layer and 16 dominant populations in shrub layer of Cerasus clarofolia community in Huangshan Mountain scenic areas were measured using the formulas described by Levins, Hurlbert and Hom. The results showed that in the tree layer, niche breadths of C.clarofolia and Symplocos paniculata were broader than other species, with Levins(Bi) and Hurlbert's (Ba) values being 0.9418, 0.8835 and 0.9386,0.7301, respectively, but that of Quercus stewardii, Pinus taiwanensis and Pterostyrax corymbosus were narrower.47 species counterparts, accounting for 60.3% of the total, had niche overlap values smaller than 0.5; 28 species counterparts, accounting for 35.9%, had niche overlap values larger than 0.5, and 3 species counterparts had no niche overlap. In shrub layer, young tree of S. paniculata, Hydrangea angustipetala and Stephanandra chinensis had broder niche breadths, and their Bt and Ba values were 0.8724,0.8618,0.7985 and 0.7422, 0.6889,0.5873, respectively, while Morus australis, Maddenia incisoserrata and Kerria japonica had narrower niche breadths.67 species counterparts, accounting for 55.8% of the total, had niche overlap values smaller than 0.5; 48 species counterparts, accounting for 40.0%, had niche overlap values larger than 0.5, and 5 species counterparts had no niche overlap. Those species with broader niche breadths were dominant or accompanying species, and had high adaptability to community microclimate characteristics. The niche overlaps among the species with the same or similar environment requirements and similar biological properties were greater, and it is possible for the species with narrower niche breadths to overlap more.(3) Sprouting is an important life history strategy of woody species in response to natural and anthropogenic disturbance. The results of the field investigation reveal that Cerasus clarofolia had poor seedling and sapling recruitment from seed, and vegetative reproduction was the main approach of regeneration of the species in Huangshan Mountain scenic areas. Based on the life table of population and the theory of survival ananlysis, a static life table of C. clarofolia sprout population was worked out, the survival rate curve, mortality rate curve, killing power curve, and survival function curve were drawn, and the population's quantitative dynamics was analyzed. The results showed: 1) the number of young individuals was larger than that of middle-aged and old individuals, and the size-class structure showed positive pyramidal type; the Vpi index indicated that the sprout population of C. clarofolia was stable one.2) The mortality rate curve and killing power curve in the lifespan had similar variation trend, all with the peaks in 1th and 9th age class periods; the survival curve of the populations was Deevey typeⅡ.3) The cumulative mortality rate increased monotonically, whereas the survival rate was in adverse, and the mortality density remain low-level status in the middle and later period; the hazard rate had the same variation trend as the mortality rate.4) There was a regularity of periodic fluctuation in the process of quantitative dynamics of C.clarofolia population, which was related to the characteristic of the sprout regeneration.(4) Using Cerasus clarofolia of explants, the effects of different plant growth regulators on adventitious bud's induction, multiplication and rooting of explants were studied. The result indicated that the medium of MS+6-BA1.0 mg·L-1+NAA0.05 mg·L-1 was optimum for induction of adventitious bud, with 87.5% buds induced; the best medium for the multiplication of clustering buds was MS+6-BA0.5 mg·L-1+NAA0.02 mg·L-1, and the propagation rate was 4.7; the best medium for the multiplication of single bud was MS+6-BA0.5 mg·L-1+NAA0.05 mg·L-1, and the propagation rate was 2.5; the optimum medium for rooting was 1/2MS+IBA0.5 mg·L-1 or 1/2MS+IBA0.2 mg·L-1+NAA0.2 mg·L-1, with the rooting rate of 100% and 88% respectively. |
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