Study On Plant Diversity And Conservation In ShangFang Mountain, Beijing

Shangfang Mountain is one of few areas in Beijing where reserves natural secondary forest and lives a number of special plants. In order to deeply understand the characteristics and threats of plant diversity in ShangFang Mountain, this paper analysised them from five aspects which included flora, population characteristic of rara species, pattern of plants diversity along an altitudinal gradient, classification and ordination of vegetation , formation mechanisms of the biodiversity and protection countermeasure.(1)There are 303 wild vascular plants which belong to 213 genera and 81 families. Among of them, the single-species families and single-species genera are predominant. At the family level, the cosmopolitan type and pantropic type own absolute superiority. At the genera level, the temperate and pantropic types are predominant.By compared with the flora of three vicinities, Shang Fang has 29 particular species and the Pantropical elements is obviously higher than that in the three vicinities. In addition, there are 6 rare specieses in Beijing with different existing crisises and some of them grow only in ShangFang Mountain.(2)Staphylea bumalda is one of rare specieses in Beijing.In order to reveal the factors limiting the dispersal of it, the population and community characteristic of it were analysised. Moreover, the Spatial distribution regularities of it was analyzed using geostatistical methods. The results indicat that low seed germination percentage and special requirements for light and understory space are key factors to limite the dispersal of the population.The results of geostatistical analysis show that the variograms of crown width of the population in four different directions could all be fitted by exponential model and the population exhibited an aggregation pattern. The different sills and ranges in four different directions showed that the spatial structure of the population were typical zonal anisotropy. By analysis, the slope, tourism disturbance, random factors and the biological characteristics of the population were main causes for this kind of spatial distribution.(3) With the variations of altitude,αandβdiversity of plants have different change trend.αdiversity of various life forms have different change trend.αdiversity of tree layer is negative correlation with increasing altitude. The shrub layer is positive correlation. The herb layer and total increase first and decrease afterwards. In contrast,βdiversity of various life forms all raise with increasing altitude.The result shows that environment change range of high altitude is higher than low altitude. The analysis also implies that humidity is the decisive factor of the diversity distribution pattern. In addition, there are 6 areas have higher biodiversity, so they should be protected as key areas.(4) In accordance with classification system of"Chinese Vegetation", the vegetation of ShangFang Mountain could be divided into 3 vegetation type groups, 3 vegetation types, 12 formations, 18 associations. DCA sorting results are consistent with the classification results.The results also show that the vegetation distribution patterns are correlates with humidity and altitude gradient. The results also indicate that the special vegetation has high protection and research value, so it should be included in the Beijing Nature Reserve system.(5) Special geographical position, terrain, geological conditions as well as human protection since 1,000 years ago may be the main reasons for the forming of the special biodiversity. Moreover, the protection of ShangFang Mountain plant diversity face a number of problems, such as difficulty of community renewing, destroy of tourism development etc. Therefore, it is suggested that the following measures should be taken: establishing nature conservation spot; taking artificialy renewing for communit; taking special survey for rare specieses etc.