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991.
甘肃鼠兔贮草越冬及其生物学意义   总被引:3,自引:0,他引:3  
对采自草甸、灌丛和弃耕地3 种类型栖息地共27 个甘肃鼠兔草堆的研究结果表明, 每个草堆干重在23.8~984.2 g 之间, 平均184.2 g , 总计含有26 种双子叶植物和一些禾本科单子叶植物。分析显示, 草堆大小(食物重量) 与栖息地植被类型无关。在贮存干草堆时, 甘肃鼠兔对不同植物成分具有强烈的选择性, 其中, 单子叶植物和双子叶植物分别占总重量的8.06 %和84.61 % , 与它们各自在栖息地中的生物量百分比51.76 %和39.57 %形成鲜明对照。甘肃鼠兔对植物种类的选择性在一定程度上受栖息地植被类型的影响, 但最喜食的几种植物却基本不变, 它们是美丽风毛菊、棘豆、麻花艽、禾草、线叶龙胆。人工去除栖息地中的干草堆后, 甘肃鼠兔种群越冬存活率从对照样地的51.84 %下降到21.33 % , 表明草堆食物对其成功越冬有一定正效应。野外观察证实, 甘肃鼠兔的鸣声不及同域分布的高原鼠兔发达, 但前者具有贮存食物越冬的习性, 而后者却不贮存越冬食物, 此结果不支持“鼠兔类动物建立草堆的行为与鸣声行为平行发育”的观点。  相似文献   
992.
Using data from a global positioning system (GPS), seven adult red deer (Cervus elaphus L.) were tracked in the Parc National des Cévennes, southern France, between November 1998 and December 2000 to assess the factors affecting large-range movement patterns and habitat use. The home range varied from a single compact area for females to three distinct seasonal ranges for males, which used alternative migratory strategies (i.e. non-, downward- and upward-migrants). The migrants used mainly southerly and easterly aspects, and wintered in areas having steeper slopes than were used during summer or the rut season. For males, the time of rut migration was mid-September and they finally entered wintering ranges from mid-December to the beginning of January. Exploratory behaviour (i.e. individuals found outside the limits of their familiar area but returning to it a few days later) occurred in both sexes and for all individuals monitored during at least a 6-month period. Velocity and efficiency of exploratory movements were higher than usual movements. During these exploratory movements, hinds may have used different landscape attributes (elevation, slope, canopy cover) while stags did not. These results provide new empirical information that could be used for building and applying broad-scale spatial and landscape use models in ecological research.  相似文献   
993.
The Duke of Burgundy butterfly (Hamearis lucina) has declined severely since the 1970s and is a UK Biodiversity Action Plan Priority species. Its populations are mostly confined to scrubby calcareous grassland, where management for short-turf species can be detrimental to the butterfly. We briefly review the literature on the Duke of Burgundy and investigate their habitat preferences, survival and dispersal at a chalk grassland reserve in Bedfordshire, UK. We found that adults generally preferred more sheltered locations but that their habitat preferences were less restrictive than choice of food-plants. Females chose larger plants with longer leaves in denser patches on which to lay eggs. Adults showed reasonable dispersal ability with turnover recorded between areas isolated by scrub. Our results indicate that the species is able to use isolated areas of favourable habitat at a reserve scale and that conservation could therefore involve cyclic management to provide suitable habitat year-to-year.  相似文献   
994.
四川小相岭山系大熊猫种群及栖息地调查   总被引:2,自引:0,他引:2  
小相岭山系是现存大熊猫种群数量最少的山系之一。根据全国第3次大熊猫及其栖息地调查结果,小相岭山系大熊猫栖息地分布在石棉、冕宁和九龙三县,栖息地总面积802.04 km2,大熊猫种群数量有32只。大熊猫在3个位于小相岭山系的自然保护区内种群数量和栖息地面积分别为:四川冶勒自然保护区9只,栖息地面积168.01 km2;四川栗子坪自然保护区14只,栖息地面积306.38 km2;四川贡嘎山自然保护区1只,栖息地面积15.19 km2。在3个保护区大熊猫栖息地总面积为489.58 km2,占各山系大熊猫栖息地总面积的61.05%;有大熊猫24只,占大熊猫种群数量的75.0%。小相岭山系大熊猫meta种群栖息地片段化比较严重,它由2个种群和2个孤立分布点组成。南北方向从成都至昆明的108国道以东的种群A有大熊猫13只,栖息地面积263.54 km2, 完整性较好,大熊猫分布比较集中。108国道以西的种群B有大熊猫19只,栖息地面积为538.50 km2,栖息地破碎。该山系大熊猫数量少,栖息地片段化严重,需加强保护。
  相似文献   
995.
Tropical dry evergreen forests (TDEF) are a unique forest type found along the east coast of India. They mostly occur as small, isolated fragments of varying sizes (0.5 to ≈10 ha) and are considered as endangered forests types in peninsular India. Although plant diversity is well documented in these forests, there is a paucity of ecological studies vital for conservation and for planning restoration activities. We studied reproductive biology of 13 woody species: four trees, six shrubs, and three lianas in fragments of TDEF in southern India. The phenology of reproduction, floral biology, anthesis and sexual system of each species were recorded. The pollination mode was assessed through observations of the visitation frequency of pollinators and from the floral characters. The breeding system was determined by hand-augmented self- and cross-pollination experiments. The plants flowered during the dry season from January to July. Plants of nine species had both flowers and fruits at the same time. Twelve species were hermaphrodites and one was polygamo-dioecious. Flowers of 11 species opened at dawn and two at dusk. Four species were self-incompatible and six were self-compatible. Natural fruit set ranged from 10% to 56%, self-incompatible species having low fruit set. Cross-pollen augmentation increased fruit set, suggesting presence of outcrossing in all species. The majority of plants species (85%) had a generalized pollination system, receiving visits from diverse insects, such as social bees, solitary bees, wasps, moths and flies. However, only few of them were functionally important for the species. Two species namely: Capparis brevispina and C. zeylanica had butterflies and birds, respectively, as their main pollinators. Our data reveal that there is a predominance of outcrossing in plant species and a generalized pollination system in these forests. We suggest that restoration of TDEFs is crucial as habitats, not only for wild plants but also for pollinating insects.  相似文献   
996.
2008 年3 月和2008 年11 月,在舟山群岛以獐的足迹、粪便和卧迹等新鲜活动痕迹为依据,对獐春、秋季栖息地利用特征进行研究。共设置样方420 个,对样方内生境类型、乔木盖度、灌木盖度、草本盖度、坡位、坡度、坡向、海拔、人为干扰距离和水源距离等10 个生态因子进行测量评估。结果发现,獐春、秋两季的栖息地利用特征是(1)隐蔽和食物因子:春、秋季利用阔叶林、农田和山坡地,秋季对灌木林也有较高的利用率,而对农田的利用率下降;春、秋季乔木盖度、灌木盖度和草本盖度较低处(≤50%) 利用率较高,但春季对乔木盖度较高处(> 50% )也有较高的利用率; (2) 地形因子:春季对坡度较缓、中下坡位、海拔较低处(< 100 m)利用率较高;秋季对坡度较缓、中下坡位、海拔较低(<100 m)的南坡利用率较高; (3) 水源因子:春季利用水源距离较近(< 200 m) 的区域;秋季对水源距离较近(< 200 m)和较远(>600 m) 区域的利用率均较高; (4) 干扰因子:春季主要利用距离人为干扰近处(< 100 m),秋季主要利用距离人为干扰远(> 200 m)处。逐步判别分析显示,春、秋季獐栖息地利用特征存在显著差异,乔木盖度、坡度、坡向、海拔和人为干扰5 个因子是主要的区分因子。舟山群岛人为干扰剧烈、次生乔木和灌木较为发达以及草本植物不发达等一系列特点,造成了舟山群岛獐特殊的栖息地现状。本研究将对制订适合于海岛的动物栖息地保护对策提供理论依据,也为了解海岛生境下獐不同季节的生存状况提供科学依据。  相似文献   
997.
达乌尔鼠兔扩散过程中的生境选择   总被引:14,自引:0,他引:14  
王梦军  钟文勤 《动物学报》1998,44(4):398-405
通过调控牧压,研究了达乌尔鼠兔扩散过程中的生境选择。结果表明,放牧活动强了草原植被的斑块性,改变了植被为鼠兔提供的资源条件,导致鼠兔斑块间的扩散和扩散鼠兔对不同植被斑块的生境选择。  相似文献   
998.
凉水自然保护区松鼠巢址选择的特征   总被引:7,自引:0,他引:7  
2006 年6 月11 日至9 月27 日和2007 年8 月14 日至9 月21 日采用样线法,并结合定位观察的方法在凉水国家级自然保护区对松鼠的巢址选择进行了定量研究,共获取107 个巢样方和230 个对照样方。对每个样方分别测定了12 个巢树参数和7 个环境参数。统计分析结果表明,松鼠仅在针叶树上营巢,59.8 ± 4. 7% 的巢建于红松上,但对枝叶比红松更为浓密的云杉和臭冷杉有显著的选择性,而且显著倾向于在以云杉、臭冷杉为优势树种的生境中营巢。松鼠选择比较高大(树高21.5 ± 0.4 m)、活动通道比较多(3.6 ±0.1)的树营巢,巢树周围的树木密度(169 ± 4 株/ hm2 )和多样性(辛普森指数0.51 ± 0.01)显著高于对照样方。巢址生境多位于南向的中、下坡位。巢址高12.4 ± 0.4 m,紧贴树干,多朝南。红松树上的巢多建于树冠的中下部,云杉和臭冷杉树上的巢多建于树冠的上部。松鼠巢对包括道路在内的林隙没有显著的回避。  相似文献   
999.
Karoline Schmidt 《Oecologia》1993,95(2):226-233
In winter, red deer (Cervus elaphus hippelaphus) that are not receiving supplementary feeding emphasize and rely on energy-saving strategies. In severe winters with deep snow, they select a home-range habitat-windblown alpine pastures above the timberline-that meets the requirements of this strategy: a much lower sinking depth and good forage availability are due to patchy snow distribution, while the open area provides higher radiation, permits group formation and thus sociobiological wellbeing. The energy costs of thermoregulation are minimized by selecting slopes with south to south-west exposures, seeking thermal shelter from strong winds, while high flight distances and horizontal flight routes reduce the energy costs of fleeing. In years with little winter snowfall non-supplemented red deer prefer the greater security of forested habitats in lower areas and obtain higher food intake from slightly more nutritious meadows in the valley bottom. The food-supplemented herd has much more constant and predictable habitat use, combining an energy-saving strategy-choosing alpine pastures as low-cost winter home range-with high energy income at the feeding station.  相似文献   
1000.
We studied the pattern of bird species richness in native and exotic forest patches in Hungary. We hypothesized that species-area relationship will depend on forest naturalness, and on the habitat specialization of bird species. Therefore, we expected strong species-area relationship in native forest patches and forest bird species, and weaker relationship in exotic forest patches containing generalist species. We censused breeding passerine bird communities three times in 13 forest patches with only native tree species, and 14 with only exotic trees in Eastern Hungary in 2003. Although most bird species (92%) of the total of 41 species occurred in both exotic and native forests, the species-area relationship was significant for forest specialist, but not for generalist species in the native forests. No relationship between bird species and area was found for either species group in the forest with exotic tree species. The comparison of native versus exotic forest patches of similar sizes revealed that only large (>100 ha) native forests harbor higher bird species richness than exotic forests for the forest specialist bird species. There is no difference between small and medium forest patches and in richness of generalist species. Thus, the species-area relationship may diminish in archipelago of exotic habitat patches and/or for habitat generalist species; this result supports the warning that the extension of exotic habitats have been significantly contributing to the decline of natural community patterns.  相似文献   
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