安徽黄山风景区微毛樱桃萌枝种群动态研究

为探明安徽黄山风景区微毛樱桃〔Cerasus clarofolia(Schneid.)Yu et Li〕萌枝种群的生长规律和更新特点,在野外调查基础上,分别对该种群的萌枝类型、龄级结构〔由径级结构代替,根据胸径(DBH)和树高(H)划分径级〕、静态生命表、存活曲线和生存函数进行了分析.结果表明:该种群萌枝主要以根颈萌枝为主,根蘖萌枝较少,且多与根颈萌枝同时出现;幼龄萌枝数量较多、中龄萌枝数量较少、老龄萌枝数量更少,说明该种群的幼苗和幼树众多,而中龄和老龄植株却很少.该种群的萌枝数量变化动态指数在自然状态下为56.39%,而在考虑干扰时为5.64%.总体上看,Ⅰ级(DBH<3 cm,H<130 cm)至Ⅲ级(3 cm≤DBH<8 cm)萌枝的存活数和标准化存活数均较多,而Ⅷ级(28 cm≤DBH<33 cm)至Ⅹ级(DBH≥38 cm)萌枝的存活数和标准化存活数均较少;Ⅱ级(DBH<3 cm,H≥130 cm)萌枝的期望寿命最高(2.980),而Ⅹ级萌枝的期望寿命最低(0.500);各龄级萌枝的死亡率和损失度变化趋势基本一致,均有2个峰值,分别出现在Ⅰ级和Ⅸ级萌枝.该种群的存活曲线介于DeeveyⅡ型和DeeveyⅢ型之间,但更趋向DeeveyⅡ型.Ⅰ级萌枝的死亡密度函数和危险率函数均最大,Ⅱ级萌枝的死亡密度函数和危险率函数均为0.000,其余龄级萌枝的死亡密度函数和危险率函数则趋于平缓;随龄级增大,萌枝的积累死亡率函数持续上升,而生存率函数却持续下降.上述结果表明:黄山风景区微毛樱桃萌枝种群总体上处于动态的稳定状态;从种群发展角度考虑,建议对该种群进行适当的小尺度的人为干扰,以改善幼苗的生存环境,促进种群更新.

Study on dynamics of sprouting population of Cerasus clarofolia in Huangshan Mountain Scenic Area of Anhui

In order to explore the growth rule and regeneration characteristics of sprouting population of Cerasus clarofolia (Schneid.) Yu et Li in Huangshan Mountain Scenic Area of Anhui, sprouting branch type, age class structure 〔replaced by diameter class structure, according to diameter at breast height ( DBH) and height ( H ) for dividing diameter class〕, static life table, survival curve and survival function of this population were analyzed respectively on the basis of field survey. The results show that the main sprouting branch in this population is root collar sprouting branch, root sucker sprouting branch is fewer and mostly appears simultaneously with root collar sprouting branch. Number of young sprouting branches is more, that of middle age sprouting branches is less, while that of old age sprouting branches is even less, indicating that there are many seedlings and young trees but a few middle age and old plants in this population. Dynamic index of variation of sprouting branch number of this population is 56. 39% in natural state, while that is 5. 64% when considering disturbance. On the whole, survival number and standardized survival number of sprouting branches are more fromⅠclass ( DBH<3 cm, H<130 cm) toⅢ class ( 3 cm≤DBH<8 cm ) , and those are less from Ⅷ class ( 28 cm≤DBH<33 cm ) to Ⅹ class (DBH≥38 cm). Life expectancy of sprouting branch at Ⅱ class (DBH<3 cm, H≥130 cm) is the highest (2. 980), while that atⅩclass is the lowest (0. 500). Variation tendencies of mortality rate and loss degree of sprouting branch at each class are basically consistent with two peak values appearing in sprouting branches at Ⅰ and Ⅸ class, respectively. Survival curve of this population is between DeeveyⅡtype and Deevey Ⅲ type, but is closer to Deevey Ⅱ type. Mortality density function and hazard rate function of sprouting branch at Ⅰ class are the largest, those at Ⅱ class are 0. 000, and those at other age classes tend to flatten. With increasing of age class, cumulative mortality function of sprouting branch elevates continually, while survival rate function decreases continually. It is suggested that in general, sprouting population of C. clarofolia in Huangshan Mountain Scenic Area is in a dynamic stable state. From the view of population development, appropriate minor artificial disturbance is recommended to improve living environment of seedlings and promote regeneration of the population.