新疆野核桃自然保护区不同坡向丛生野核桃年龄结构及数量动态

Age Structure and Quantitative Dynamics of Cespitose Juglans regia in Different Slope Directions in Xinjiang Wild Walnut Nature Reserve

摘要:

通过对新疆野核桃自然保护区丛生野核桃（Juglans regia）进行普查，以径级结构代替年龄结构，采用匀滑技术编制种群静态生命表，并运用时间序列模型预测种群数量动态，从而获得丛生野核桃树的龄级结构与动态。结果表明，不同坡向丛生野核桃以中龄级为主，年龄结构呈两头小中间大的纺锤型；4个坡向种群年龄结构的动态指数V_pi虽大于0，但最大仅为19.10%，且V_pi'极低，最大为1.12%，阳坡种群增长趋势最高，抗干扰能力最强，种群稳定性最好，半阳坡种群增长趋势最弱，抗干扰能力最弱，种群稳定性最差；各坡向种群均存在多个死亡高峰，阳坡最高峰在15龄级，半阳坡在15和18龄级，阴坡和半阴坡均在9龄级，存活曲线更接近Deevey-Ⅱ型；在未来2、5、10龄级后，中龄级个体数量减少，老龄个体呈增加趋势，丛生野核桃种群稳定性难以长期维持。因此对丛生野核桃幼苗的保护非常关键。

Abstract:

Based on the general survey of Juglans regia in Xinjiang Wild Walnut Nature Reserve, the diameter level structure was used instead of age structure, the static life table of population was compiled by smoothing technique, and the population dynamics was predicted by time series model, so as to obtain the age level structure and dynamics of J. regia. The results showed that the middle age class was dominant in different slope directions, and the age structure was spindle-shaped with two small ends and big middle. Although the dynamic index V_pi of age structure of the four slope populations was greater than 0, the maximum was only 19.10%, and V_piʹ was extremely low, the maximum is 1.12%, the growth trend of J. regia population on sunny slope was the highest and the anti-interference ability and the population stability was the strongest, whereas the semi-sunny slope showed the lowest growth trend, the worst anti-interference ability and stability. There were multiple death peaks in all slope populations. The highest peak was at 15 age class on sunny slope, 15 and 18 age class on semi-sunny slope, and 9 age class on shady slope and semi-shady slope. The survival curves were closer to Deevey-II type. The number of individuals at middle age would decline after 2, 5 and 10 age classes in the future, while the number of old individuals would increase. Therefore, it was very critical for the protection of cespitose J. regia of young individuals.