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531.
国内外河流生态修复相关研究进展   总被引:13,自引:1,他引:13  
河流生态系统是一个复杂、多变、非线性的系统,增加了河流生态修复工作的难度。如何真正修复河流生态系统,国内外许多学者进行了大量的理论和实践研究,取得丰硕的成果和宝贵的经验。总结国外城市化对河流生态的影响、河流生态修复技术、河流生态评价及河流生态修复后评估方面的成果,旨在为我国正在广泛开展的水生态修复工作提供参考;总结国内河流生态修复已有的成果和存在的问题,并展望我国今后河流生态修复工作应重点开展的工作内容。  相似文献   
532.
张云  陈凡 《林业调查规划》2006,31(3):157-160
对大理市蝴蝶泉公园进行现场综合调查,分析目前公园难以形成优美景观的原因,进而从景观资源评价及开发建设条件分析入手,对公园进行了初步景观规划,探讨了自然景观的生态恢复与民族文化景观保护发展相结合进行规划的问题。  相似文献   
533.
由于热带季节雨林是种植砂仁最适合的场所,因此当地居民大量地将砂仁种植在季节雨林下,对其群落结构及组成造成了严重破坏,导致大量物种的流失。对遭受破坏的群落恢复状况进行调查,结果显示,由于人为活动增加了林下的透光度和生长空间,对幼树和幼苗的生长具有一定的促进作用。只要停止人为破坏活动,经过一定时间,群落仍可得到恢复。  相似文献   
534.
退化天然常绿阔叶林近自然林经营技术研究(一)   总被引:1,自引:0,他引:1  
对近自然林理论方法与实践作了系统的讨论,根据四川盆周山地退化天然常绿阔叶林的特点,编制了以常绿阔叶林为主的天然林近自然林经营方案,并开展了退化天然林恢复与重建技术的试验研究。  相似文献   
535.
Urban-rural boundaries are often abrupt and unmitigated, a trait that significantly enhances their ecological vulnerability. Nonetheless, such fringe systems enclose a high potential in furnishing buffering and resilience functions and services towards the city. Our study intends to give a contribution on the understanding of the ecological behaviour of peri-urban landscape features (PLFs) systems, showing how floristic-vegetational and landscape ecology studies can inform their multi-functional phytocoenoses ecological reconfiguring. Analyses were led among a fringe context of Milan city. An agri-environmental extra-local scale analysis framed the forthcoming finer scale results. Landscape mosaic structural and functional main traits were interpreted, outlining a current impairment of the landscape system capacity to support ecological functions across the area. In parallel, floristic traits were studied through chorological, life forms and Ellenberg’s ecogram analysis (total flora and single sub-areas values). The main phytocoenoses types were qualitatively described and related to the dynamic patterns of reference vegetation series. Results highlighted a significant deterioration of floristic-vegetational traits, if compared to the local potential. Recurrent anthropic disturbances, open space conditions were identified as the major impact factor on phytoconoeses evolution towards higher diversity, complexity and stability traits. Spontaneous recolonization processes were acknowledged as currently unable to change these trends, while past reforestation interventions showed positive effects. These results informed the building of a functional-dynamic interpretative approach, focused on the ecological roles and physical habitat conditions currently influencing phytocoenoses dynamics, and on which to intervene. Accordingly, the current and potential ecological functions of 9 key PLFs categories were inspected. Consequently, design criterions for corrective interventions were outlined. This brought to the identification of the optimal structural and functional patterns of PLFs to be integrated throughout the urban-rural boundary, as well as their floristic-vegetational design specificities, by pursuing a rebalancing effect on the peri-urban agroecosystem inner complexity and environmental stability parameters.  相似文献   
536.
Scalded lands are common in acid sulphate soil areas on the New South Wales coast, Australia. In this work, chemical characteristics of the scalded acid sulphate soils at nine sites along this coast were investigated. The investigated acid sulphate scalds are characterized by an extremely acidified topsoil layer (0–0.6 m) although they derive from the sediments of varying salinity and the metal sulphides contained in the soils have experienced different degrees of oxidation. Almost all of the investigated scalds occur in the areas that have a lower surface elevation than the surrounding areas. These hollows may act as sinks for acid sulphate materials and salts that are transported from the surrounding areas and the shallower watertables in such locations may enhance upward transport of acid and salt materials from the underlying oxidized sulphidic sediments. In general, the scalded acid sulphate soils have less organic matter and soluble phosphorus, and a greater salinity, soluble acidity, soluble Al, Mn and Zn concentrations, compared to the adjacent non‐scalded acid sulphate soils. These are most likely soil constraints for revegetation of the scalded lands and treatment will need to involve acid neutralization (e.g. application of lime) and addition of P fertilizers to reduce the soluble acidity, immobilize soluble Al, Mn and Zn, and increase P availability. The evidence also shows that the higher soluble Al concentration in the scalded soils, relative to the non‐scalded soils, is related to their lower organic matter content. Hence, rehabilitation of these scalded lands should involve the addition of organic matter to reduce soluble Al concentrations; it may also help reduce Mn and Zn toxicity, and salinity. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
537.
Rehabilitation of the post‐mining landscape of Lower Lusatia (Brandenburg, Germany) represents a complex problem: 85 per cent of this area is currently being recultivated for forests or agriculture and 15 per cent is reserved for nature development. After mining, soil conditions are dry, acidic and nutrient poor. The ‘LENAB’ project aimed at conservation strategies and management options for natural habitats. Two competing basic motives of nature conservation on a small or medium scale were defined: (1) close‐to‐naturalness (allowing natural dynamics to take place without human interference) and (2) biodiversity (selective species and habitat protection). An overall strategy for sustainability of a cultural landscape can only be applied to the entire post‐mining landscape. The application of the two basic motives leads to different management options; this is illustrated by two important vegetation types. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
538.
The use of draglines to remove overburden in Queensland opencut mines, results in landscapes that consist of long parallel tertiary overburden spoil-piles that are generally highly saline, dispersive, and highly erodible. The height of these spoil-piles may exceed 50–60 m above the original landscapes and the slopes are at the angle of repose of around 75% or 37°. Legislation and public opinion require that these highly disturbed open-cut post-mining landscapes should be satisfactorily rehabilitated into an approved post-mining land use with acceptable erosion rates. Therefore, these slopes must be reduced before the landscape can be rehabilitated. The most expensive component of the rehabilitation process is the re-shaping and preparation of the overburden to create a suitable landscape for vegetation growth. As soils and overburden varies greatly in their erodibilities, the extent and cost of earthworks can be minimized, and rehabilitation failures avoided, if soil erosion from designed landscapes can be predicted using laboratory-based parameters prior to construction of these landscapes. This paper describes the development of a model for that purpose.A catchment or landscape erosion model MINErosion 4 was developed by upscaling the existing hillslope model MINErosion 3 (So, et al., 2018) and integrate it with both ESRI ArcGIS 10.3 or QGIS 3.16 (freeware), to predict event based and mean annual erosion rate from a postmining catchment or landscape. MINErosion 3 is a model that can be used to predict event and annual erosion rates from field scale hillslopes using laboratory measured erodibility parameters or routinely measured soil physical and chemical properties, and to derive suitable landscape design parameters (slope gradient, slope length and vegetation cover) that will result in acceptable erosion rates. But it cannot be used to predict the sediment delivery from catchments or landscapes. MINErosion 4 was validated against data collected on three instrumented catchments (up to 0.91 ha in size) on the Curragh mine site in Central Queensland. The agreement between predicted (Y) and measured (X) values were very good with the regression equation of Y = 0.92X and an R2 value of 0.81 for individual storm events, and Y = 1.47X and an R2 value of 0.73 for the average annual soil loss. This is probably the first time that a catchment scale erosion is successfully predicted from laboratory measured erodibility parameters.  相似文献   
539.
Mining activities along the west coast of South Africa will lead to salinization of the soil if sea-water is used in the mining process. Laboratory studies were conducted to determine the influence of leaching depth and the amount and frequency of irrigation on the growth of Atriplex semibaccata R. Br. Leaching depth as well as the amount and frequency of irrigation had no significant effect on biomass production. However, the interaction between leaching depth and amount of irrigation did influence the biomass production of Atriplex semibaccata. Root:shoot ratio increased as the amount of irrigation decreased.  相似文献   
540.
Removal of topsoil, mainly for making bricks, is one of the main causes of soil loss around large urban centres of the Humid Pampa, Argentina. In about 7 per cent of La Plata County, the 20–40 cm thick A‐horizon has been removed for that purpose. Most of the affected areas were originally prime farmland; however, with removal of the A‐horizon they became unsuitable for agriculture, including grazing, since the exposed Bt‐horizon is unsuited for plant growth due to its high clay content (45–65 per cent) and the low nutrient levels. Since trees survive better on poor soils than do agricultural crops, the possibility of afforestating desurfaced soils has been studied. Eucalyptus are one of the major species used in tree planting programmes aimed at reclaiming degraded soils since they are fast growing and can grow to commercial size in a wide range of soils and climatic conditions. The work reported here was done in a desurfaced Vertic Argiudoll and a similar non‐desurfaced soil (control). Three Eucalyptus species were tested, i.e. E. camaldulensis, E. viminalis and E. dunnii. Their height and diameter (dbh) growth were 47.9 to 75.8 per cent less and timber volume 86.5 to 98.5 per cent less on the desurfaced soil. E. camaldulensis grew best in all the parameters in the desurfaced soil. Although tree growth was poor, afforestation may be an alternative use for desurfaced soils where agriculture and livestock breeding are not possible. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
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