不同整地方式对鼢鼠危害油松抑制作用研究

Inhibition of Different Soil Preparation Methods on Chinese Pine Damage by Zokors

干旱和鼠害是造林初期决定林木保存率的关键因素。鼢鼠对定植1-10a的油松被害死亡率介于25.0%-91.4%。如何将生态调控原理与抗逆造林相结合,从造林源头预防鼢鼠对林木危害是一个重要的研究课题。以穴状整地为对照,研究了深坑整地和水平沟整地造林后鼢鼠与油松动态关系。结果表明,造林初期鼢鼠密度上升,深坑整地试验区定植2a时最高,水平沟整地3a时最高,两者年均鼢鼠封洞率分别为12.5%±0.9%和9.6%±0.7%,时序动态遵从Cubic-模型。试验期内,穴状整地均有林木被害和死亡;深坑整地被害期为定植2a后,致死期在定植后4-5a;水平沟分别为定植后1a和定植后2-4a。深坑整地和水平沟整地累年被害率为1.6%±0.2%和9.9%±1.1%,对应的穴状整地为55.7%±2.3%和52.3%±7.7%;两者累年致死率分别0.5%±0.2%和2.6%±0.8%,穴状整地为39.9%±3.9%和22.7%±1.5%;处理与穴状整地差异极显著（p=0.000）。深坑整地试验区,两者年均被害死亡率分别为33.3%±16.7%和67.3%±2.8%;水平沟整地试验区为19.0%±3.8%和54.4%±1.5%,处理与穴状整地差异极显著（p=0.000）。2个试验区比较,差异不显著（p〈0.05）。综合被害预防效果分别为96.8%±1.0%和73.6%±3.2%,差异极显著（p=0.000）;综合致死预防效果95.9%±3.6%和90.7%±4.4%,差异不显著（p=0.333）;2试验区的综合被害死亡预防效果分别为63.9%±21.8%和70.7%±12.6%,差异不显著（p=0.296）。深坑整地抗逆指数逐年下降,年均12.6%±4.4%,累年75.4%±1.8%;水平沟整地定植当年的抗逆指数为负值,3a时抗逆性最强,年均9.5%±0.6%,累年57.0%±3.3%。两者累年抗逆作用差异极显著（p=0.000）,年均差异不显著（p=0.722）。表明深坑整地和水平沟整地对鼢鼠危害均有极显著的抑制作用;同时能提高林木抗逆性,降低自然死亡率。

At early planting stages,the drought and rodent pest were key factors to determine the preserving rate of the trees planted.Resulting in 25.0%-91.4% death rate of the young seedlings after 1to 10 years of planting.It is an important research topic of reducing forest damages by zokors from the combinations of ecological control with the stress-resistant forestation techniques.In this paper,two site preparation methods,deep pits and horizontal ditches were adopted to examine the dynamic relations betweenzokor damage and Pinus tabulaeformis preservation.The pit-like soil preparation method was used as the control.The results showed that the zokor density increased gradually with time in early stages after planting,the highest zokor density appeared in the second year of planting for deep pit method,and in the third year for horizontal ditch method.The dynamics of temporal series of zokor densities were in accordance with the Cubic-model.During the test period,damaged and dead trees were observed all the time for pit-like method.For deep pit method,the damage period and lethal period appeared in 2years and 4to 5years after planting;for horizontal ditch method,they were 1year and 2to 4years.The cumulative annual damage rates for deep pit and horizontal ditch methods were 1.6%±0.2% and 9.9%±1.1%,respectively,and cumulative annual lethal rates were 0.5%±0.2% and 2.6%±0.8%,respectively;while for the control,the cumulative annual damage rates were 55.7%±2.3% and 52.3%±7.7%,cumulative annual lethal rates were 39.9%±3.9% and 22.7%±1.5%,the differences between the treatments and control were very significantly different（p=0.000）.In the test region of deep pit soil preparation,both annual average tree damage mortality were 33.3% ±16.7% and 67.3%±2.8%,in the test zone of horizontal ditch soil preparation,they were 19.0%±3.8%and 54.4%±1.5%,the treatments and control were very significantly different（p=0.000）,but there was no obvious difference between two test regions（p0.05）.Synthetic damage preventive effects were 96.8%±1.0% and 73.6%±3.2%,both were very significantly different（p=0.000）,synthetic lethal preventive effect were 95.9% ±3.6% and 90.7% ±4.4%,both were not obviously different（p=0.333）.Between two test regions,synthetic preventive effects of injured death were 63.9%±21.8% and 70.7% ±12.6%,no obvious difference（p=0.296）.Annual resistant index of deep pit soil preparation decreased progressively year by year with time,annual average resistant index was 12.6%±4.4%,and cumulative annual resistant index was 5.4%±1.8%.By using horizontal ditch soil preparation,in the planting current year,the annual average resistant index was a negative value,the annual average resistant index was 9.5%±0.6%,and cumulative annual resistant index was 57.0%±3.3%%.The experimental results proved that both deep pit soil preparation and horizontal ditch soil preparation had very significantly inhibitory effects on forest damage by zokors.At the same time,these two preparation methods could increase stress resistance and reduce the forest natural mortality.