东方白鹳繁殖期生境选择与行为观察

自1999年至2002年对东方白鹳在黑龙江省主要繁殖地——兴凯湖自然保护区进行了生境选择研究和 繁殖行为观察。结果表明:东方白鹳的繁殖期为4~6月;东方白鹳的巢区一般选择在没有人为干扰或干扰较 小,食物丰富而又有稀疏树木或小块丛林的开阔草原和农田沼泽地带;东方白鹳的巢通常位于树顶端的枝杈 上;在整个营巢和产卵期间,均有交尾的行为发生;产卵时间多数在4月中旬。     

笼养鹩哥的繁殖行为观察

作者描述了笼养鹩哥（Gracula religiosa)的营巢、配对、产卵、孵化、育雏等繁殖行为，并对个人本配置、饲养环境、巢材、产卵日期、孵化、人工育雏等几个关键问题进行了讨论。     

肿节少穗竹出笋成竹生长规律

观测肿节少穗竹的幼竹-成竹生长过程,分析其出笋成竹的生长规律.结果表明,肿节少穗竹出笋时间约始于4月中旬,历时约45 d,出笋初期出笋较少(持续时间3d左右,占7.42％),盛期出笋数较多(持续时间15 d,占77.48％),末期出笋数下降(持续时间27 d,占15.10％),退笋原因主要是虫退,占退笋总数的73.78％,平均成竹率为64.03％.各同生群高生长呈“S”型曲线,采用逻辑斯蒂方程拟合精度较高,拐点出现的时间均是各同生群曲线高生长的关键时期,且较早同生群的竹笋自始至终要比较晚同生群要高.     

人为干扰对绵阳三江迁徙水鸟停歇的影响

采用野外直接观察法和最小接近距离试验法对绵阳三江(涪江、安昌江和芙蓉溪)的迁徙水鸟的迁徙及人为干扰对水鸟停歇的影响进行了研究。结果表明,98%的水鸟在55 m或更小的距离上通过游走或惊飞对人类的活动做出反应。干扰类型为1人行走,2人行走,3人行走;1人奔跑,2人奔跑,3人奔跑对水鸟移动的距离、移动的次数以及水鸟对人类靠近的反应均具有一定的影响。人为干扰最小接近距离试验结果表明,水鸟的反应距离是30～60 m。干扰人数为1人时的最小接近距离小于2人和3人,2人小于3人,干扰类型为行走时最小接近距离小于奔跑。记录不同停歇地水鸟的觅食、规避时间,结果为在人为干扰下,水鸟的觅食时间显著减少。     

花期不同环剥时期对冬枣坐果率产量和品质的影响

通过在冬枣的初花期、盛花初期、中期和后期的环剥试验、表明环剥时期对冬枣的果实品质、坐果率和产量有明显的影响。环剥期越早,果实品质越好;盛花初期和中期环剥坐果率和产量接近,且明显高于其他两个时期,初花期环剥坐果率和产量最低,盛花后期其次。综合比较以盛花初期环剥效果最好。     

Effects of full and partial clearing, with and without herbicide, on weed cover, light availability, and establishment success of white ash in shrub communities of abandoned pastureland in southwestern Quebec, Canada

Shrub communities established on former pasture land are currently under-used and their forestry potential is of interest to land owners wishing to increase valuable hardwood regeneration on their properties. The comparative effects of strip clearing and total clearing, both treatments applied with or without herbicide, on competing vegetation cover, light availability, and survival and growth of planted white ash (Fraxinus americana L.) were examined in two different shrub dominated sites for 3 years in southwestern Québec, Canada. Survival was high in all treatments. At the site with the richest soil and in comparison to total clearing, strip clearing produced the lowest light level in the third year, which induced lower total herbaceous weed cover. These combined effects produced the same growth results for white ash seedlings in all treatments. At the second site, with the highest woody vegetation regrowth, strip clearing has promoted seedling height growth and produced the highest height: diameter ratio for white ash. This ratio was also superior at this site in the absence of herbicide. Treatment effects were soil/site dependant. Because partial clearing in strips has never reduced tree growth in comparison to total clearing, it represents a promising method for the establishment of valuable hardwoods in shrubby vegetation, with lower management intensity and lower landscape impact than total clearing.     

高温少雨期环境因子对油茶果径生长的影响

为了探讨油茶高产稳产的水分生理生态基础,为油茶水分管理提供科学依据,在高温少雨期,以10年生油茶优良无性系为试验材料,设置无干旱胁迫、轻度干旱胁迫、中度干旱胁迫、重度干旱胁迫、浇后控水和自然状态6种土壤水分处理,观测土壤温度、气象因子和油茶果径生长量,研究环境因子对油茶果径生长的影响。结果表明:试验期(35d),各处理根据果径生长量由大到小排列,依次为轻度干旱胁迫(9.35mm)、无干旱胁迫(7.78mm)、中度干旱胁迫(3.95mm)、浇后控水(3.82mm)、自然状态(2.96mm)、重度干旱胁迫(0.90mm)。多重比较结果显示,除中度干旱胁迫与浇后控水处理间果径生长量差异不显著外,其它各处理间果径生长量差异显著。试验进行10d后重度干旱胁迫处理的果径出现负增长,20d后浇后控水处理的果径生长减缓,30d后重度干旱胁迫、浇后控水和自然状态处理的叶片出现暂时萎蔫发黄。相关性分析结果表明,果径生长量与土壤含水量、空气相对湿度呈正相关,与空气温度呈负相关。油茶果径生长对土壤水分、空气温度、空气相对湿度反应敏感,轻度干旱胁迫处理即土壤含水量为田间持水量的80%~90%为油茶果实生长最佳土壤含水量。     

Effective period of volatiles from softwood veneers embedded in tatami mats on the activity of house dust mites

To suppress the activity of house dust mites in tatami mats, where they tend to breed, tatami mats were prepared with embedded softwood veneers. The effective period of the volatiles from the veneers on the mites was then measured. To investigate the effective period of volatiles from hiba (Thujopsis dolabrata var. hondai) and hinoki (Chamaecyparis obtusa) veneers on house dust mites (Dermatophagoides pteronyssinus), 5-day exposure tests were conducted every few weeks for 54 weeks. In the exposure tests, the activity of the mites was observed after 5 days of exposure to the volatiles. Volatiles from hiba veneers strongly suppressed the activity of the mites for 15 weeks. The suppressive effect decreased gradually after that, but it was maintained for 54 weeks. Volatiles from hinoki veneers showed moderate to high suppression of mite activity for 11 weeks, but no suppressive effect was observed after that. In conclusion, embedding hiba or hinoki veneers in tatami mats is an effective method of suppressing the activity of mites for about a year or for slightly less than 3 months, respectively.Part of this paper was presented at the 51st Annual Meeting of the Japan Wood Research Society in Tokyo, April 2001     

排牙山林场杉木第1代种子园子代林成材期调查

以本地一般生产用种为对照，对靖州县排牙山林场杉木第1代种子园15个家系23年生子代测定试验林成材期的调查表明，其家系平均单株材积比对照大31．06％，其中最优家系（37号）比对照大47．55％，增产效益显著。     

The effects of herbaceous and woody competition on planted white pine in a clearcut site

We investigated the effects of herbaceous and woody vegetation control on the survival and growth of planted eastern white pine (Pinus strobus L.) seedlings through six growing seasons. Herbaceous vegetation control involved the suppression of grasses, forbs, ferns, and low-shrubs, and was maintained for 0, 2, or 4 years after white pine seedlings were planted. Woody control involved the removal of all tall-shrub and deciduous trees, and was conducted at the time of planting, at the end of the second or fifth growing seasons, or not at all. Seedling height and basal diameter responded positively and proportionally to duration of herbaceous vegetation control. Gains associated with woody control were generally not significant unless some degree of herbaceous vegetation control was also conducted. Only herbaceous control increased pine crown closure and rate of crown closure. Herbaceous control and the presence of 5000–15,000 stems per ha of young overtopping aspen were associated with reduced weevil (Pissodes strobi Peck.) injury and increased pine height growth. The study suggests that white pine restoration strategies on clearcut sites should focus on the proactive, early management of understory vegetation and the gradual reduction of overtopping cover from woody vegetation to create a seedling light environment that supports acceptable growth with minimal weevil damage.     

Evaluation of competitive effects of green alder,willow and other tall shrubs on white spruce and lodgepole pine in Northern Alberta

In boreal forests of western Canada, lodgepole pine (Pinus contorta Dougl. ex. Loud.) and white spruce (Picea glauca (Moench) Voss) often grow together with numerous tall shrubs such as green alder (Alnus crispa (Ait.) Pursh) and little-tree willow (Salix spp.). In an area south of Grande Prairie, Alberta, Canada, we examined the effects of shrubs, herbs and other trees on nutrient and light availability and growth of white spruce and lodgepole pine. For white spruce the best competition measure (tested against volume increments of the past 3 years) was visually estimated % ground cover times the height of the competitor (VCHT) with light (DIFN) ranking in third place. For lodgepole pine, DIFN was the best competition measure for predicting volume increment and the best competition index was again VCHT. Taller conifers had a stronger competitive effect than tall shrubs, with their effect on white spruce being larger than that on lodgepole pine.     

Effect of external compressive load on tangential strain behavior in Japanese larch log cross sections during radio-frequency/vacuum drying

This study investigated the effect of a compressive load of 0.092 MPa on the history of the tangential strains in Japanese larch (Larix leptolepis Gordon) log cross sections subjected to external compressive load during radio-frequency/vacuum drying. The external compressive load of 0.092 MPa played a role in inducing cracking in the outer zone of the log cross section, combining with other tensile strains. However, it also played a role in reducing the heart checks in the core of log cross section when exerted on the cross section of log cross section.