棕背(鼠平)巢区及对林木鼠害防治意义的研究

采用重捕标志法研究了棕背巢区,巢区面积7月份平均为250.89 m2,9月份平均为284.21 m2,雌雄间和季节间差异显著。棕背有集群分布现象。结合巢区面积和活动距离对鼠害防治布点规格与防治灭鼠率的关系进行了分析。     

冀北山地鼠害综合防治技术研究

针对冀北山地的森林鼠害发生规律及防治措施进行了研究,通过铗捕法和洞口统计法进行鼠害种类及密度的调查;通过踏查确定主要危害树种;采用化学、物理、营林、生物药剂、天敌等5种方法进行了防治效果对比分析。结果表明,该区域威胁森林资源安全的主要鼠害为棕背鼲,油松是其主要为害树种;7月、8月是其为害高峰期,也是防治的关键期;物理防治(树干套管)和营林措施(割灌除草)防治效果最好,分别达到83%和89%,并且具有可操作性,适合大面积推广;天敌防治见效周期较长,是解决森林鼠害的治本之道,但短期效果不太明显,生物药剂防治效果不佳。     

黑龙江省张广才岭林区棕背(鼠平)种群主要参数分析

在黑龙江省张广才岭海林林区,采用铗捕法逐月捕获棕背(鼠平),根据胴体重和繁殖情况划分棕背(鼠平)的年龄(以月为单位),计算各月新生个体的生命表、各月种群平均年龄和平均寿命.共捕棕背682只,其中雌性351只,雄性331只,雌雄性比为0.515: 0.485.5,6,7月出生的个体最长寿命为5个月,雌性平均为2.37个月,雄性平均为2.18个月.8,9月出生的个体,最长寿命超过12个月,雌性平均为3.83个月,雄性平均为4.03个月.秋生个体比春生个体寿命长.各月种群平均寿命4月份最高,为10.52个月,7月份最低,为2.94个月.     

Relationship between resistance to vole browsing and content of ether extract in the bark of larch species and hybrids

We determined the survival rate of tree families produced by the intra- and interspecific crossing of larch species damaged by browsing of vole (Clethrionomys rufocanus bedfordiae Thomas) and the contents of ether extracts (EE) in their bark. The average survival ofLarix gmelini var.japonica Pilg. (L. gmelini)×L. gmelini (G×G) was highest, followed by the hybridL. gmelini×L. leptolepis Gordon (G×L). The families of the hybrid G×L, which is considered suitable for silviculture in Hokkaido, Japan, showed significant differences in survival rates, suggesting that it is possible to produce improved varieties of the hybrid which are more resistant to vole browsing. The EE contents of the bark were under strong hereditary control, and the rank of the EE content among the various families hardly fluctuated between the location of the test fields. The correlation coefficient between the survival rates and the EE contents was highly significant (r=0.89,n=24,p<0.01), indicating that the EE content in the bark may be used as a possible index of resistance or susceptibility to vole browsing in larch plantations. A part of this report was presented at the 106th Annual Meeting of the Japanese Forestry Society, at Sapporo, April, 1995.     

贝奥不育剂林间防治效果调查

贝奥不育灭鼠剂是一种新型的植物源灭鼠剂,来源于天然植物雷公藤。2007年在内蒙古大兴安岭林区,分别采取6 m×6 m,7 m×7 m,8 m×8 m和10 m×10 m的不同投药方式,对棕背Clethrionomys rufocanusSundevall和莫氏田鼠Microtus maximowicziiSchrenck进行了林间防治试验,结果表明莫氏田鼠的适口性较好,盗食率达到75%以上,而棕背最高盗食率仅为10.1%。对莫氏田鼠采取10 m×10 m的投药方式(3 450 g/hm2)可达到较好的控制效果。     

Notes on beech (Fagus crenata Blume) seed and seedling mortality due to rodent herbivory in a northernmost beech forest, Utasai, Hokkaido

We investigated the mortality of post-dispersal seeds and current-year seedlings of a beech species (Fagus crenata Blume) at the northernmost extent of its geographical range at Utasai (Kuromatsunai), Hokkaido, Japan. Introduced seeds that were protected from rodent predation by wire cages had a higher survival rate from winter to the following spring (mean ± SD: 84 ± 16.7%,n = 10) than controls without cages (mean ± SD: 12 ± 17.9%,n = 10). Unprotected transplanted current-year seedlings with almost fully opened primary leaves never survived more than three days (0%,n = 30), while more than 80% (n = 30) of seedlings within cages survived to the end of the growing season. These results indicate that rodent herbivory is a major mortality factor that strongly prevents the establishment of beech seedlings. In a natural population, we observed that 90% of seedlings (n = 197) disappeared within 10 days after their emergence and rodent herbivory caused this heavy mortality. A herbivorous rodent, the gray-backed vole,Clethrionomys rufocanus bedfordiae, was remarkably abundant in late June (101.5 voles/ha), suggesting that this species strongly affects the formation of the seedling bank. The presence ofC. rufocanus bedfordiae may be one of the reasons for the scarcity of beech seedlings and saplings and the rarity of recruitment in this northernmost beech forest.     

Deterrent effect of rosin and wood tar against barking by the gray-sided vole (Clethrionomys rufocanus bedfordiae)

The gray-sided vole (Clethrionomys rufocanus bedfordiae Thomas) is a small wild rodent widely distributed in Hokkaido, northern Japan. Floors of forestry plantations with thick herbage provide gray-sided voles with suitable habitats. The voles eat bark in winter, and because of this, severe damage can occur in many plantations. Deterrent effects on gray-sided voles of rosin and 3 wood tars were evaluated by two-choice tests in the field. These materials were selected because they were promising and economical deterrents. In the test for each material, disks were produced from trunks of Japanese larch, and used as carriers. Pairs of carriers (a material-treated carrier and a control carrier) were fed to gray-sided voles for 24 h, and values of the eaten area of bark were compared between treated carriers and controls. Every material decreased the extent of barking. The treated carriers were significantly less eaten compared to the controls for all the materials (p<0.01 or 0.05). Deterrent effects of three fractions (neutral, phenol, and strong acid fractions) made from wood tar were also evaluated. Every fraction prevented gray-sided voles from barking. The treated carriers were significantly less eaten compared to the controls for all the fractions (p<0.05). The neutral fraction has showed an especially strong deterrent effect; thus this fraction is most promising for future use.     

Distribution of small mammals in a silvoarable agroforestry system in Northern England

The importance of agroforestry systems in temperate regions in providing habitat for small mammals has not been investigated. Numbers and densities of small mammals were assessed by live trapping in a complex farming landscape including mature hedgerows, arable fields, areas of trees planted at forestry density (2,500 trees ha–1) and trees in an agroforestry configuration (178 trees ha^–1) consisting of rows of trees separated by arable alleys. Over a 2 -year period, 1680 animals were captured; 69% were Apodemus sylvaticus L., 20% Sorex araneus L. and 10% Clethrionomys glareolus Schreber. Small numbers of Mus domesticus Rutty, Sorex minutus L., and Neomys fodiens Pennant were also caught. The density of captures of A. sylvaticus and S. araneus varied little over the whole farming landscape in contrast to C. glareolus which had a greater density of captures in mature hedgerows. However, for the small mammals collectively, away from hedgerows, the highest density of captures was found in the agroforestry tree rows (15.5 per 100 trap nights) and the least in open arable crop (4.3), with both arable alleys and forestry density trees having intermediate values (9.1 and 9.2 respectively).Densities of captures of A. sylvaticus were greater in the tree rows and arable alleys than in the forestry area and the adjacent open arable crop, whereas for S. araneus they were greater in the habitats with trees. It is clear that the range of habitats in an agroforestry system is valuable for small mammal conservation.     

幼林抚育剩余物防御幼林鼠害的研究

黑龙江省带岭林区自60年代初,每3—4年发生一次棕背(鼠平)(Clethrionomys rufocanus)幼林鼠害。我们先后使用磷化锌、氟乙酰胺和敌鼠钠等药剂灭鼠,当时虽然压低了害鼠密度,但并没有起到长期防鼠的效果,害鼠数量有逐年上升的趋势。为此,我们提出林木鼠害的综合治理问题。一、利用剩余物防御鼠害的提出     

MG复合不育剂防治棕背(鼠平)的研究

研究了MG复合不育剂对棕背Clethrionomysrufocanus数量控制及对林木危害防治效果。 4月上旬在林地投放MG复合不育剂药物饵料 ,秋季 10月份棕背数量与对照地相比较降低 70 %以上 ,第二年仍保持较低的数量水平 ;使林木被害率降至 1%以下 (对照地 6 %～ 10 5 %) ,达到了理想的防治效果。MG复合不育剂药物饵料对棕背有较好的适口性。