湖南大围山和八面山香果树种群的年龄结构和演替动态比较

选取湖南大围山和八面山3处典型的香果树(Emmenopterys henryi)群落,通过分析香果树种群的重要值、物种多样性、年龄结构,绘制生命表和生存曲线图,并与其他不同地区3处香果树群落进行比较,探讨不同纬度、不同立地生境对香果树种群的年龄结构和演替动态的影响。结果表明:(1)大围山上游香果树群落的优势种群为多脉榆(Ulmus castaneifolia)、香果树和青钱柳(Cyclocaryapaliuru);大围山下游香果树群落的优势种群为黄檀(Dalbergia hupeana)、香果树和油茶(Camellia oleifera);八面山香果树群落的优势种群为野核桃(Juglans cathayensis)、香果树和小叶青冈(Cyclobalanopsis myrsinifolia)。(2)大围山上游香果树群落共有维管植物60科96属118种,大围山下游香果树群落共有维管植物76科120属163种,大围山上游和下游香果树群落地理成分均表现为温带成分高于热带成分;八面山香果树群落共有维管植物61科95属108种,地理成分表明热带成分高于温带成分。(3)根据年龄结构和生存分析,香果树种群在不同的群落中所处演替阶段不同,大围山上游为衰退型种群,大围山下游为稳定型种群,八面山为增长型种群,均具有代表性。(4)经分析对比,纬度位置、岩石裸露度、郁闭度、群落内优势种群的生长状况和人为破坏程度等是影响香果树种群生长趋势的因素,建议对大围山的2个香果树群落应加强后续监测,并参照八面山的香果树种群生存状况针对岩石裸露度、郁闭度等进行适当人工干扰和管理,以保障香果树种群的健康生长。

Age Structure and Succession Dynamic Comparison of Emmenopteris henryi Populations in Dawei Mountain and Bamian Mountain, Hunan Province

Three typical Emmenopterys henryi communities were selected from Dawei Mountain and Bamian Mountain in Hunan Province. According to the analysis of the important values, species diversity, age structure, life table and survival curve of E. henryi populations, and the comparison of other three E. henryi communities in different regions, we discussed the effect of different latitude and site habitat to the age structure and succession dynamic of E. henryi populations. The results are as follows: (1) the dominant populations of the E. henryi community in Bamian Mountain upstream are Ulmus castaneifolia, E. henryi, Cyclocarya paliuru; and in Dawei Mountain downstream are Dalbergia hupeana, E. henryi, Camellia oleiferawy while the dominant populations of the E. henryi community in Bamian Mountain are Juglans cathayensis, E. henryi, Cyclobalanopsis myrsinifolia. (2) One hundred and eighteen species in 96 genera of 60 families compose the E. henryi community of Dawei Mountain upstream and the E. henryi community of Dawei Mountain contains 76 families 120 genera with 163 species. Their proportions of temperate genera of seed plants are higher than that of tropical genera, which shows the subtropical montane proportion of geographical elements. One hundred and eight species in 95 genera of 61 families compose the E. henryi community of Bamian Mountain. (3) According to the age frequency distribution and the survival analysis, the succession stages of E. henryi population are different in those communities, the E. henryi is a decaying population in the upstream of Dawei Mountain, while it is a stable population in the downstream of Dawei Mountain. It is representative of the growth population in the E. henryi community of Bamian Mountain. (4) Through the comparative analysis, latitude, bareness degree of rock, canopy density, growth conditions of dominant populations in the community, artificial destructiveness are the factors that affect the growth tendency of E. henryi population. In conclusion, we suggest that it should strengthen the further monitoring to the two E. henryi communities in Dawei Mountain. Through the reference to the growth conditions of E. henryi population in Bamian Mountain, proper human intervention and administration to the bareness degree of rock and canopy density are necessary for the two communities to guarantee healthy growth of E. henryi population.