新疆野苹果居群年龄结构及郁闭度研究

Study on the age structure and density of the wild apple forest of Malus sieversii

对新疆巩留与新源2地的新疆野苹果居群年龄结构及郁闭度进行测定和分析,旨在为新疆野苹果资源的保护保存提供依据。结果表明,在随机选取的200个单株中,巩留居群Ⅰ级幼树为0,而且Ⅱ级小树数量也极少,仅2株,只占1%,年龄级构成有下降性特征,存活曲线呈断点凸型,故年龄结构应属老衰类型,郁闭度为0.47;新源居群有Ⅰ级幼树,10株占5%,Ⅱ级小树达26株占13%,年龄级构成有稳定中略有上升的特征,存活曲线呈弧形凸型,故年龄结构应属稳定类型,郁闭度为0.80。上述结果显示,巩留新疆野苹果居群破坏严重,亟待加强保护,而新源新疆野苹果居群保存较完好。

The age structure and crown density of the wild apple forest of Malus sieversii （lAb.） Roem., endemic to Gongliu and Xinyuan counties, Xinjiang, were studied. The aim is to provide information for its protection and conservation. Results showed that there were no younglings and only 2 arborets of second class （1%）among the randomly selected 200 trees in the wild apple forest of Gongliu county, appearing a declining trend of it. However, there were 10 arborets of the first class （5%） and 26 arborets of the second class （13%） in Xinyuan wild apple forest, showing a slight ascending feature of it. Crown density of Gongliu wild apple forest was 0.47 and 0.80 of Xinyuan wild apple forest. The survival curves of the two apple forests presented a breakpoint projection profile and an arc projection profile, respectively. So, it is believed that the Gongliu wild apple forest was destructed badly while the Xinyuan wild apple forest was conserved much better.