江苏溧阳山区银缕梅种群结构、分布格局与更新

Structure,spatial pattern and regeneration of Parrotia subaequalis population in Liyang mountainous area of Jiangsu Province

银缕梅为国家I级珍稀濒危树种。以新近发现的江苏溧阳山区银缕梅种群为研究对象,采用时空互代法、方差/均值比的t检验法和Magini更新指数法分析银缕梅的种群结构、分布格局和更新特点。结果表明:该区银缕梅种群结构呈倒J形,属增长型;总体上,种群分布格局呈现明显的集群分布,但随着高度级的增加,其集群强度逐渐减弱。银缕梅更新方式有4种,即实生苗(23.26%)、残桩萌枝(54.26%)、根蘖萌枝(14.73%)和机会萌枝(7.75%),这表明萌枝对种群更新发挥了重要作用。因此,建议通过建立自然保护小区对该区分布的银缕梅种群进行就地保护,同时辅以一定的人工管护措施以促进种群更新。

Parrotia subaequalis, a rare and endangered species, is ranked as the first class on the List of the Important WildPlants for Conservation in China （first passel）. In this paper, the structure, spatial pattern and regeneration of P. subaequalis population recently discovered in Liyang, Jiangsu Province were analyzed by applying the method of spatial sere substituting for time sere, t-test of variance / mean value ratio and Magini index. The results showed that the population presented an inverted-J pattern in height classes, indicating an increasing type in terms of population structure. This speciesshowed aggregation distribution, but its aggregation intensity decreased with the time going from seedlings to trees. The species had four categories of regeneration modes, including seedlings （ 23. 26%）, crown sprouts （ 54. 26%）, root suckers（14.73%） and opportunistic sprouts （7.75%）, suggesting that sprouting plays a key role in population regeneration of P.subaequalis. Therefore, it is recommended carrying out in situ conservation by establishing nature mini-reserve in this area,in tandem with certain artificial management measures to promote its population regeneration.