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61.
拉市海越冬末期斑头雁行为的初步研究 总被引:7,自引:0,他引:7
2004年2月18日~3月14对在拉市海越冬斑头雁的行为进行了研究,采用瞬时扫描方法进行行为取样,并对其在越冬地的行为进行观察记录。结果表明:斑头雁通常是早上7:30后飞离夜栖地,傍晚19:30以后从主要活动地飞回夜栖地。观察后期(3月7~13日)与观察前期(2月18~25日)相比,其飞离夜栖地的时间提前约20分钟,而从觅食地飞回夜栖地的时间则要晚10~25分钟。斑头雁无论取食还是夜栖,都喜集群,通常还有其他鸟类与斑头雁混群,如赤麻鸭等。3月初,有部分斑头雁开始北迁,大部分北迁是在3月中旬。越冬末期斑头雁行为时间的分配率为取食35.01%、静栖34.95%、警戒13.88%、运动8.35%、理羽6.77%、饮水0.63%、社群行为0.41%,所占比例依次减少。经对斑头雁在陆地和水域生境中的行为样本分别进行计算,表明斑头雁在这两种生境中有不同的行为时间分配模式。在陆地里,斑头雁的主要行为是取食(约占47%),而在水域中,斑头雁的主要行为是静栖(约占46%),表明斑头雁的食物主要是从陆地中获取。在一天中,斑头雁的不同行为出现的高峰时间不同,取食高峰时间和警戒高峰时间在早上9:00至10:00和傍晚17:30~19:15;静栖高峰时间在14:00~17:00;运动高峰时间在10:30~12:30;理羽高峰时间在14:30~17:00。 相似文献
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Chi?De-fuEmail author Rafael?Ocete?Rubio Yan?Shan-chun Zhang?Dan-dan Wen?Zhen-hong 《林业研究》2002,13(4):255-259
Four-armed airflow olfactometer was used to determining the foraging behavior ofPteroptrix longgiclava (Girault) (Hymenoptera: Aphelinidae) andEncarsia gigas (Tshumakova) (Hymenoptera: Aphelinidae) to the essential oils which emitted from the healthy bark ofPopulus pseudo-simonii×P. nigra, the infested bark injured byQuadraspidiotus gigas (Thiem & Gerneck), the body and scale of fixed 1st-instar-nymph ofQ. gigas. The results from these experiments showed that the volatile oils produced from the injured bark and from the scale of fixed
1st-instar-nymph had a higher attractive ability to female adults of the two species of wasps. The essential oil produced
from the scale of the pest at dosages of 3–7 μL and the essential oil emitted by injured bark at dosages of 5–9 μL had a stronger
alluring effect on the host searching behavior ofPteroptrix longgiclava. The essential oil from the body of fixed 1st-instar-nymph ofQ. gigas also had certain effect on the host locating effort ofPteroptrix longgiclava andEncarsia gigas. Those two wasps did not shown any reaction to the essential oil produced by the healthy bark of poplar.
Foundation item: This paper was supported by National Natural Science Foundation of China (39970620) and the “TRAPOYT”
Biography: CHI De-fu (1962-), male, Ph.D., Professor in Northeast Forestry University, Harbin 150040, P.R. China
Responsible editor: Chai Ruihai 相似文献
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对奢侈品消费的心理分析与探讨 总被引:2,自引:0,他引:2
快速发展的中国经济造就了一批新富阶层,而他们又引导了国内最近2年轰轰烈烈的奢侈消费风潮,形成中国庞大的奢侈品消费市场。在这个以勤俭节约为美德,视奢侈为浪费的国度里,奢侈品消费行为有何特征,本文通过对比分析中外奢侈品消费的差别,探讨在中国如何引导理性的奢侈品消费。 相似文献
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Fire plays an important role in shaping many Sierran coniferous forests, but longer fire return intervals and reductions in area burned have altered forest conditions. Productive, mesic riparian forests can accumulate high stem densities and fuel loads, making them susceptible to high-severity fire. Fuels treatments applied to upland forests, however, are often excluded from riparian areas due to concerns about degrading streamside and aquatic habitat and water quality. Objectives of this study were to compare stand structure, fuel loads, and potential fire behavior between adjacent riparian and upland forests under current and reconstructed active-fire regime conditions. Current fuel loads, tree diameters, heights, and height to live crown were measured in 36 paired riparian and upland plots. Historic estimates of these metrics were reconstructed using equations derived from fuel accumulation rates, current tree data, and increment cores. Fire behavior variables were modeled using Forest Vegetation Simulator Fire/Fuels Extension.Riparian forests were significantly more fire prone under current than reconstructed conditions, with greater basal area (BA) (means are 87 vs. 29 m2/ha), stand density (635 vs. 208 stems/ha), snag volume (37 vs. 2 m3/ha), duff loads (69 vs. 3 Mg/ha), total fuel loads (93 vs. 28 Mg/ha), canopy bulk density (CBD) (0.12 vs. 0.04 kg/m3), surface flame length (0.6 vs. 0.4 m), crown flame length (0.9 vs. 0.4 m), probability of torching (0.45 vs. 0.03), predicted mortality (31% vs. 17% BA), and lower torching (20 vs. 176 km/h) and crowning indices (28 vs. 62 km/h). Upland forests were also significantly more fire prone under current than reconstructed conditions, yet changes in fuels and potential fire behavior were not as large. Under current conditions, riparian forests were significantly more fire prone than upland forests, with greater stand density (635 vs. 401 stems/ha), probability of torching (0.45 vs. 0.22), predicted mortality (31% vs. 16% BA), and lower quadratic mean diameter (46 vs. 55 cm), canopy base height (6.7 vs. 9.4 m), and frequency of fire tolerant species (13% vs. 36% BA). Reconstructed riparian and upland forests were not significantly different. Our reconstruction results suggest that historic fuels and forest structure may not have differed significantly between many riparian and upland forests, consistent with earlier research suggesting similar historic fire return intervals. Under current conditions, however, modeled severity is much greater in riparian forests, suggesting forest habitat and ecosystem function may be more severely impacted by wildfire than in upland forests. 相似文献
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土壤中砷的来源及迁移释放影响因素研究进展 总被引:11,自引:0,他引:11
砷是一种高致癌风险的类金属,自然环境中高砷(As)含量可对人类和生态系统构成直接的健康威胁。研究自然环境中砷的来源、存在形式及影响因素有助于进一步理解环境中砷的迁移转化规律,降低人体摄入砷的风险。对文献的分析表明,铁锰氧化物矿物的还原性溶解、黄铁矿及其他硫化物矿物的氧化溶解、铝氢氧化物表面的砷还原、有机质抑制砷吸附以及Eh降低和pH升高是造成砷向环境迁移的主要原因。本文综述了环境中砷的来源及其向环境迁移的多种影响因素,分析了这些因素与砷之间的作用机制,以期为加强砷污染治理提供科学依据。 相似文献
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