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61.
陆地生态系统是地球生物圈系统的核心组分,是人类生活、生产及社会经济活动的场所。然而,人类文明发展和科学技术进步在不断地扩大对资源的利用规模和强度,也导致了严重威胁社会可持续发展的全球气候变化、生物多样性丧失、环境污染、资源枯竭、生态系统退化等环境问题。社会公众期望生态学研究能够为区域、大陆及全球尺度的生态系统的利用和保护、维持人类社会可持续发展提供科学理论及系统性的解决方案。本研究以服务中国生态文明建设、生态安全格局构建、区域生态环境治理,以及宏观生态系统科学发展为目标,回顾了中国的区域生态环境治理成效及经验;分析了我国生态文明建设对大尺度生态系统科学研究的科技需求与时代特征,提出了利用基于自然的宏生态系统途径的新思路提升区域生态环境治理及安全格局构建的设想。在此基础上,讨论了中国的大尺度区域安全格局构建及生态环境治理的新思路、战略布局、技术途径与科技支撑体系,为中国安全、健康和美丽的国土空间利用及生态文明建设进步提供理论参考。  相似文献   
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Diversifying agricultural landscapes may mitigate biodiversity declines and improve pest management. Yet landscapes are rarely managed to suppress pests, in part because researchers seldom measure key variables related to pest outbreaks and insecticides that drive management decisions. We used a 13‐year government database to analyse landscape effects on European grapevine moth (Lobesia botrana) outbreaks and insecticides across c. 400 Spanish vineyards. At harvest, we found pest outbreaks increased four‐fold in simplified, vineyard‐dominated landscapes compared to complex landscapes in which vineyards are surrounded by semi‐natural habitats. Similarly, insecticide applications doubled in vineyard‐dominated landscapes but declined in vineyards surrounded by shrubland. Importantly, pest population stochasticity would have masked these large effects if numbers of study sites and years were reduced to typical levels in landscape pest‐control studies. Our results suggest increasing landscape complexity may mitigate pest populations and insecticide applications. Habitat conservation represents an economically and environmentally sound approach for achieving sustainable grape production.  相似文献   
64.
诱集植物在农业中的应用研究进展与展望   总被引:1,自引:0,他引:1  
全世界每年因病虫害导致严重的农业经济损失, 为了减少病虫害的发生, 实际生产中通常使用大量化学农药, 然而农药的大量施用, 不仅造成环境污染和农产品安全问题, 还会使病虫害产生抗药性, 天敌种群受损, 从而导致病虫害爆发日益严重。种植诱集植物是一种环境友好型病虫害防控方法, 该方法主要是通过诱集植物吸引虫害和降低病害, 从而减少病虫害对主栽作物的危害, 达到保护主栽作物的目的, 最终减少农业上化学农药的使用。根据诱集植物自身特性, 将其分为五种主导作用类型: 传统诱集植物、致死型诱集植物、基因工程型诱集植物、生物辅助控制型诱集植物、化学信息素辅助作用型诱集植物等, 根据种植和利用方式, 将其分为: 围种诱集、间种诱集、连作诱集、与其它方式结合等。尽管关于诱集植物的研究已有近160年历史, 但有关高效诱集植物的筛选、诱集植物与主栽作物的优化配置模式与配套种植技术、诱集植物对靶标病虫害的作用机理、诱集植物在农业生产中的生态风险评估等仍不清楚, 且诱集植物仍具有较大开发潜力和应用价值, 如(1)开发应用诱集植物的环境污染修复功能及相关技术; (2)开发应用诱集植物的景观生态与休闲旅游功能及相关技术; (3)开发利用诱集植物对土壤的养分转化与固持提升功能(如固氮、固碳、固土功能等)、生物质能源功能、节能减排功能及相关技术; (4)开发应用诱集植物及其废弃物的经济产品功能及其可持续生产技术。论文综述了近年来国内外有关诱集植物的相关研究与实践应用, 旨在为诱集植物在农业生产中进行病虫害防治研究和应用提供相关参考。  相似文献   
65.
Bats are a group of mammals well known for forming dynamic social groups. Studies of bat social structures are often based upon the frequency at which bats occupy the same roosts because observing bats directly is not always possible. However, it is not always clear how closely bats occupying the same roost associate with each other, obscuring whether associations result from social relationships or factors such as shared preferences for roosts. Our goal was to determine if bats cohabitating buildings were also found together inside roosts by using anti‐collision technology for PIT tags, which enables simultaneous detection of multiple tags. We PIT‐tagged 293 female little brown myotis (Myotis lucifugus) and installed antennas within two buildings used as maternity roosts in Yellowstone National Park. Antennas were positioned at roost entryways to generate cohabitation networks and along regions of attic ceilings in each building to generate intraroost networks based on proximity of bats to each other. We found that intraroost and cohabitation networks of buildings were significantly correlated, with the same bats tending to be linked in both networks, but that bats cohabitating the same building often roosted apart, leading to differing assessments of social structure. Cohabitation rates implied that bats associate with a greater number of their roost‐mates than was supported by observations within the roost. This caused social networks built upon roost cohabitation rates to be denser, smaller in diameter, and contain nodes with higher average degree centrality. These results show that roost cohabitation does not reflect preference for roost‐mates in little brown myotis, as is often inferred from similar studies, and that social network analyses based on cohabitation may provide misleading results.  相似文献   
66.
选择云丘山景区为研究区域,以该区域的主要植被为研究对象,采用样方法对旅游干扰对云丘山景区内植被的影响进行了研究,共设置了40个乔木样方,并利用TWINSPAN聚类分析以及旅游干扰程度(TDD)对所取样方进行分析。结果表明:TWINSPAN聚类分类将景区内的植物群落划分为5个群系,其中、群系Ⅱ中伴人植物的优势度明显高于其它。干扰程度分析表明,在景区的40个乔木样方中,只有4个样方基本没有受到干扰,有3个样方受到中度干扰,其余的33个样方均为轻度干扰。TWINSPAN聚类分析科学合理地对旅游活动作用下植被景观的类型特征进行了分析。旅游干扰程度(TDD)直观地反映出各个样方所在地植被被干扰的程度,该研究结果可为旅游管理者提供一定的理论依据。  相似文献   
67.
Abstract

The research conducted here presents a syntaxonomical revision of the montane mesophilous meadows of the Polygono bistortae-Trisetion flavescentis alliance in central Europe – the Slovak part of the western and eastern Carpathians. These typical semi-natural grasslands occur mainly as small islands over the calcareous bedrocks. Associations of this alliance have tight relationships to the Arrhenatherion, Mesobromion and Nardo-Agrostion alliances. Formal definitions based on combination of the species groups were used regarding the diversity and geographical range of the Polygono bistortae-Trisetion flavescentis alliance. Following the formal definitions from the eight associations reported previously for Slovakia, only four of them can be placed within the Polygono bistortae-Trisetion flavescentis: Campanulo glomeratae-Geranietum sylvatici, Geranio sylvatici-Trisetetum, Crepido mollis-Agrostietum capillaries and Geranio-Alchemilletum crinitae. A comparison of traditional and formalized classification, and the advantages/disadvantages of the formalized classification are discussed.  相似文献   
68.
Specific root length as an indicator of environmental change   总被引:4,自引:0,他引:4  
Abstract

Specific root length (SRL, m g?1) is probably the most frequently measured morphological parameter of fine roots. It is believed to characterize economic aspects of the root system and to be indicative of environmental changes. The main objectives of this paper were to review and summarize the published SRL data for different tree species throughout Europe and to assess SRL under varying environmental conditions. Meta-analysis was used to summarize the response of SRL to the following manipulated environmental conditions: fertilization, irrigation, elevated temperature, elevated CO2, Al-stress, reduced light, heavy metal stress and physical disturbance of soil. SRL was found to be strongly dependent on the fine root classes, i.e. on the ectomycorrhizal short roots (ECM), and on the roots <0.5 mm, <1 mm, <2 mm and 1 – 2 mm in diameter SRL was largest for ECM and decreased with increasing diameter. Changes in soil factors influenced most strongly the SRL of ECM and roots <0.5 mm. The variation in the SRL components, root diameter and root tissue density, and their impact on the SRL value were computed. Meta-analyses showed that SRL decreased significantly under fertilization and Al-stress; it responded negatively to reduced light, elevated temperature and CO2. We suggest that SRL can be used successfully as an indicator of nutrient availability to trees in experimental conditions.  相似文献   
69.
Abstract

Our study had the objective to examine whether the number of forest vascular plants in a forest-poor region may be indicative of total plant species richness and of the number of threatened plant species. We also related forest plant species richness to geological and soil variables. The analysis was based on a regional flora atlas from the Weser-Elbe region in northwestern Germany including incidence data of species in a total of 1109 grid cells (each ca. 2.8 × 2.8 km2). All taxa were classified either as forest or non-forest species. Total species richness in the grid cells ranged from 65 to 597, with a mean value of 308. The number of forest species varied between 20 and 309 (mean 176). Grid cells with or without particular geological units differed in total and forest species richness, with those containing peatland and marshland being particularly species-poor. Indicator value analysis showed that both total and forest species richness in the grid cells were related to soil acidity and nitrogen in a hump-backed manner, with the highest number of species found at moderately low values for nitrogen and at intermediate values of pH. Forest species richness was highly positively correlated with the number of non-forest species and threatened non-forest species. Indicators for high species richness were primarily those species that are confined to closed semi-natural forests with a varied topography and relatively base- and nutrient-rich soils. Grid cells including historically ancient forest exhibited a higher species richness than grid cells lacking ancient forest, indicating the importance of a long habitat continuity for a high phytodiversity. The “habitat coincidence” of high species richness is best explained by similar responses of forest species and species of other habitats to the main environmental gradients. It is suggested that the regional patterns found for the Weser-Elbe region can be transferred also to other forest-poor regions in Central Europe.  相似文献   
70.
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