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51.
吴逸群 《安徽农业科学》2011,39(28):17342-17343
2010年6~8月,利用样方和因子分析等方法对陕西黄河湿地30处苍鹭觅食生境和300个对照样方进行了研究,以及调查了植被密度、植被高度等10个参数。独立样本T检验和Mann-Whitney U-test检验表明植被密度、干扰度、苇丛高度、土壤干湿程度等4个因子在苍鹭觅食生境与对照样方间的差异达极显著水平(P〈0.01),植被盖度、苇丛密度2个因子也达到显著水平(P〈0.05),植被高度、水深和至明水面距离则无显著差异。主要成分分析表明植被因子、干扰因子、水因子在苍鹭觅食地选择中均占有重要作用。  相似文献   
52.
为陕西黄河湿地的生物多样性保护及管理工作提供参考资料,对陕西黄河湿地夏季鸟类群落结构与多样性进行了分析。结果表明:陕西黄河湿地共有鸟类61种,隶属于15目33科。湿地鸟类群落的多样性指数最高,总干渠次之,农田-居民区生境第三,黄土崖最低。在各群落类型中,湿地和总干渠鸟类群落间的相似性程度最高。  相似文献   
53.
小兴安岭沼泽甲烷通量日变化分析   总被引:3,自引:0,他引:3  
利用静态暗箱-气相色谱法,研究了小兴安岭7种沼泽类型生长季初期、中期、末期甲烷(CH_4)通量的日变化规律,结果表明:小兴安岭沼泽甲烷通量无统一的日变化规律,且与温度和水位两个环境因子的相关性较弱.7个沼泽类型中,仅毛赤杨(Alnus sibirica)沼泽和白桦(Betula platyphylla)沼泽甲烷通量峰值在生长季初期、中期、末期出现的时间大致相同,且都为单峰曲线;苔草(Carex schmidtii)沼泽、灌丛沼泽和落叶松(Larix gmelinii)-泥炭藓(Sphagnum spp.)沼泽甲烷通量的峰值在不同时期出现的时间不同,多数为单峰曲线;落叶松-苔草沼泽和落叶松-藓类沼泽甲烷通量速率较小,多数时间吸收甲烷,没有明显的日变化规律.不同类型沼泽和生长期之间甲烷通量没有统一的日变化规律,说明在进行区域甲烷排放总量的估测时,增加每天的观测频率,或者长期、大量的观测数据可能会对提高估测精度有很大帮助.  相似文献   
54.
In eastern North Carolina, USA, intensively managed pine (Pinus spp.) forests, a primary forest type in the Southeastern United States, often are established where water levels are maintained via ditching. In these landscapes, water occurs in numerous linear ditches and several small ponds (heliponds), used by helicopters for the suppression of forest fires. Changes to the physical structure of water sources may be important to bats that use these sources for drinking and foraging. Therefore, we examined bat activity in a managed pine landscape and an adjacent natural wetland in relation to water source type (heliponds, ditches, and natural wetland) and insect abundance. We sampled bat activity using remote acoustic detectors; we sampled insects using passive traps. Insect abundance did not differ among water source types. Bat activity was most concentrated at modified water sources within the managed pine landscape (heliponds and ditches). Feeding activity was highest at heliponds. Heliponds and ditches were important sources of open water and insect prey for bats in the managed pine forest landscape. We suggest management for bats in similar forest landscapes should include maintenance of open and accessible water sources such as heliponds.  相似文献   
55.
澳大利亚地处大洋洲,是世界上生物多样性最丰富的国家之一,是《生物多样性公约》、《粮食与农业植物遗传资源国际条约》、《濒危野生动植物物种国际贸易公约》的缔约国。澳大利亚1999 年颁布了《环境保护与生物多样性保护法》,2002 年制定了《环境与生物多样性保护规则》,同时昆士兰州和北部领地分别于2004 年和2006 年率先创设了《昆士兰州生物开发法案》和《北部领地生物资源法案》。本文对澳大利亚国家和地方关于遗传资源获取与惠益分享立法中遗传资源的获取、管制、惠益分享等内容的规定进行了详细研究整理,并收集整理了澳大利亚生物遗传资源获取与惠益分享案例,深入分析了澳大利亚立法实践效果,为中国生物遗传资源获取与惠益分享国家立法提供经验参考。  相似文献   
56.
57.
Soil organic carbon (SOC) and its different labile fractions are important in minimizing negative environmental impacts and improving soil quality. However, very little is known of the dynamics of SOC and its labile fractions after the cultivated wetlands have been abandoned in northeast China. The objectives of this study were (1) to estimate the dynamics of SOC after the abandonment of cultivated soil, (2) to investigate the most sensitive fraction for detecting changes in organic C due to the abandonment of cultivated soil, and (3) to explore the key factors affecting the dynamics of soil C after the abandonment of cultivated soil in the freshwater marsh region of northeast China. Our results showed that the abandonment of cultivated wetlands resulted in an increase in SOC and the availability of C. The SOC content increased to 31, 44, and 107 g kg−1 after these cultivated wetlands were abandoned for 1, 6, and 13 years, respectively, as compared to an SOC content of 28 g kg−1 in the soil that had been cultivated on for 9 years. In northeast China, where a cultivated wetland was abandoned, the initial regeneration of SOC pools was considerably rapid and in accordance with the Boltzmann equation. An analysis of the stepwise regression indicated that the dynamics of SOC (g kg−1) can be quantitatively described by a linear combination of the root density and the mean soil temperature 5 cm underground in the growing season, as expressed by the following relationship: TOC = 0.008 root density −3.264T + 96.044 (R2 = 0.67, n = 9, p < 0.05. T is the mean soil temperature 5 cm underground in the growing season), indicating that approximately 67% of the variability in SOC can be explained by these two parameters. The root biomass was the key factor affecting SOC concentration according to the observation made during the recovery of cultivated soil that was abandoned. Soil temperature indirectly influenced the SOC concentration by affecting soil microbial activity. The abandonment of cultivated wetlands resulted in an increase in the light-fraction organic C (LF-OC), microbial biomass C (MBC), and dissolved organic C (DOC) concentration. The rate of increase in LF-OC was considerably higher than that in SOC and HF-OC. Similarly, the rate of increase in MBC was also considerably higher than that in SOC in cultivated soils abandoned for 4–8 years. However, the rate of increase in DOC was far lower than that in SOC. The R2 value for the correlation between the increments of the LF-OC and SOC was significantly higher than that for the correlation between DOC and MBC (0.99 vs. 0.90), indicating that LF-OC was the most sensitive fraction for detecting changes in organic C due to the abandonment of cultivated soil.  相似文献   
58.
Seasonally managed wetlands in the Grasslands Basin on the west-side of California’s San Joaquin Valley provide food and shelter for migratory wildfowl during winter months and sport for waterfowl hunters during the annual duck season. Surface water supply to these wetlands contain salt which, when drained to the San Joaquin River (SJR) during the annual drawdown period, can negatively impact water quality and cause concern to downstream agricultural riparian water diverters. Recent environmental regulation, limiting discharges salinity to the SJR and primarily targeting agricultural non-point sources, now also targets return flows from seasonally managed wetlands. Real-time water quality management has been advocated as a means of continuously matching salt loads discharged from agricultural, wetland and municipal operations to the assimilative capacity of the SJR. Past attempts to build environmental monitoring and decision support systems (EDSS’s) to implement this concept have enjoyed limited success for reasons that are discussed in this paper. These reasons are discussed in the context of more general challenges facing the successful implementation of a comprehensive environmental monitoring, modelling and decision support system for the SJR Basin.  相似文献   
59.
吴寒 《安徽农业科学》2008,36(14):6050-6052
以景观生态学理论为基础,采用遥感(RS)和地理信息系统(GIS)相结合的方法对遥感卫星影像进行处理,获取不同年份涨渡湖天然湿地面积数据。根据所得数据,研究分析涨渡湖天然湿地近20年来的面积变化原因,讨论了影响湿地面积变化与演替的气候、水文等自然因素和人为因素,对保护生态环境,优化湖泊湿地功能具有重要的意义。  相似文献   
60.
在总结泗洪洪泽湖湿地国家级自然保护区建设成就和存在的问题的基础上,提出加强保护区建设,应当通过大力争取国际国内科研项目,切实加强对保护区开发、建设和保护的组织领导,切实加强法制建设与宣传教育等措施,有效解决保护区建设中存在的问题。  相似文献   
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