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我国茸鹿杂交试验研究工作的成就及思考 总被引:10,自引:7,他引:3
我国养鹿业近40年开展了12种茸鹿的种间和亚种间的8种杂交(系)、28种组合方式的试验。选育出高产、优质、低耗的茸鹿新品种(系),对开辟茸鹿杂交育种研究的新领域具有重大的现实意义。 相似文献
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梅花鹿剖腹产诊治研究 总被引:2,自引:0,他引:2
本文是笔者在近年养鹿实践中 ,对梅花鹿剖腹产进行了诊治研究的总结。较详尽地阐述了梅花鹿剖腹产的适应症、剖腹产的手术方法和术后护理等问题。通过 1 5例难产手术证明 ,仔鹿成活率达 80 % ,母鹿成活率达 1 0 0 %。 相似文献
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We evaluated differences between the forest floors and the establishment and growth of coniferous seedlings in fenced (13 years)
and unfenced plots on Mt Ohdaigahara where the sika deer (Cervus nippon) population density is high. Large coniferous seedlings (height > 0.05 m) were less abundant in the unfenced plot, as a result
of deer browsing. Small coniferous seedlings (height < 0.05 m), however, were more abundant in the unfenced plot, where most
seedlings of Abies homolepis were found on bare ground and those of Picea jezoensis var. hondoensis were found on buttresses and fallen logs. The large area of bare ground in the unfenced plot was caused by deer browsing.
Deer therefore have an indirect effect on the emergence and growth of small coniferous seedlings by modifying the forest floor. 相似文献
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Bruno Vila Franck Torre Frdric Guibal Jean-Louis Martin 《Forest Ecology and Management》2003,180(1-3):413-424
Taking advantage of the introduction of the black-tailed deer to the Queen Charlotte Islands (British Columbia, Canada), we used dendrochronological analyses to understand the consequences of deer browsing on Sitka spruce growth. We compared shape, radial growth, height growth and age of young spruce in three sites. We identified two types of trees growing side by side: (1) stunted and heavily browsed spruce, smaller than the browsing limit and (2) escaped spruce that were taller than the browsing limit but still browsed in their lower part. The compact and heavily ramified shape in stunted spruce was the result of repeated and intense browsing. In escaped spruce this was also the case below the browsing limit (1.16 m±0.07 m), in sharp contrast with the normal shape that escaped spruce resumed above the browsing limit. We show that the release of browsing pressure, once the tree reaches the browsing limit, is characterised by an abrupt increase in radial growth. Before release, trees show a growth stagnation characterized by narrow rings (0.5 mm per year) and small annual height increments (<5 cm per year). After release, trees show a growth stabilisation characterised by wider rings (3 mm per year) and larger annual height increments (20 cm per year). We use this pattern to estimate frequency and age at release and their possible variation over time. Age differences between stunted and escaped spruce are highly significant and indicate that, despite of browsing, most if not all trees will ultimately reach the browsing limit and escape. Heavy deer pressure (30 deer per km2) delays spruce sapling recruitment by about 8 years. This delay varies in relation to site quality and seems to have increased over time, suggesting an increase in browsing pressure. 相似文献
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The strength of top-down forces in terrestrial food webs is highly debated as there are few examples illustrating the role of large mammalian carnivores in structuring biotic and abiotic systems. Based on the results of this study we hypothesize that an increase in human visitation within Zion Canyon of Zion National Park ultimately resulted in a catastrophic regime shift through pathways involving trophic cascades and abiotic environmental changes. Increases in human visitors in Zion Canyon apparently reduced cougar (Puma concolor) densities, which subsequently led to higher mule deer (Odocoileus hemionus) densities, higher browsing intensities and reduced recruitment of riparian cottonwood trees (Populus fremontii), increased bank erosion, and reductions in both terrestrial and aquatic species abundance. These results may have broad implications with regard to our understanding of alternative ecosystem states where large carnivores have been removed or are being recovered. 相似文献
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复方生茸散的生茸机理与生茸效果的实验研究 总被引:3,自引:0,他引:3
复方生茸散是以中药为主组成的复方药物添加剂,该制剂具有促进食欲,增强造血功能,促进骨髓DNA和RNA的合成,改善末梢血液循环,增加末梢血液供给,调节局部代谢,改善营养,提高机体免疫功能的作用。应用于梅花鹿的生茸期,按30g/d的剂量将复方生茸散混于精料中喂给,每天1次,连用60-75d,平均每头鹿多增鲜茸309-560g,增茸效果显著。 相似文献
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Birds in woodland can be affected by increasing deer populations through changes to vegetation structure and potential impacts on foraging resources; these effects need to be better understood. Effects of deer browsing are reported from a replicated split-plot exclusion experiment in English coppiced woodland. All stages of growth were examined up to eight years after felling. We used standardised mist-netting (totaling 1920 h) to sample birds in breeding and post-breeding periods. Deer browsing strongly altered vegetation structure by reducing canopy cover and shrub layer foliage density. However deer did not affect invertebrate density per unit of foliage, providing no evidence of an ungulate-mediated plant chemical response affecting forage quality for invertebrate herbivores. At avian guild level, significantly more ground and understorey foraging birds were captured where deer were excluded, and negative responses to browsing were more marked for pooled migrants than pooled residents. At the species level, especially pronounced negative effects were evident for dunnock (Prunella modularis) and garden warbler (Sylvia borin); approximately five times more dunnocks were captured in deer exclosures than in browsed vegetation. We also detected negative responses to browsing by nightingale (Luscinia megarhynchos) and long-tailed tit (Aegithalos caudatus). No significant positive responses to browsing were detected. For some species the use of young re-growth increased post breeding relative to the breeding period, including a marked shift by pooled residents that involved a disproportionate number of juveniles. Previous studies in North America have shown that, through vegetation modification, ungulate activity can alter woodland bird assemblages; as far as we are aware this is the first experimental demonstration of effects in Europe, and at low to moderate browsing intensity typical of the wider landscape scale. 相似文献