生物炭添加对太湖滨岸带土壤氮矿化和淋失特征的影响

滨岸带土壤的氮矿化改变了氮元素的迁移和利用效率,与水体富营养化控制息息相关,而土地利用导致的土壤性质差异使得氮的固持和运移能力不同.因此,以太湖西部沿岸3种土地利用类型的土壤(林地、草地和耕地)为研究对象,通过培养实验和土柱淋溶实验,探究不同生物炭添加(0％、1％和5％)条件下滨岸带土壤氮矿化量的动态变化和淋失特征.结...     

湖泊水生植被恢复物种选择及群落配置分析

介绍了水生植物恢复的常用物种及生活型 ,并从群落配置的物种数 ,群落的空间配置及节律匹配等方面对水生植物群落的优化配置进行了分析和研究 ,结果表明 :1 )在水生植物群落恢复实践中 ,无论从经济角度考虑 ,还是从可操作性出发 ,均应优先考虑选择少量先锋物种 ,先恢复生态系统的基本结构和功能 ,随着生境条件的不断改善 ,逐步栽种新的物种 ,增加物种的多样性 ;2 )根据湖相生态系列在空间生境梯度上的变化 ,按水生植物生活型配置群落是群落配置的基本出发点 ;3)应根据水生植物的季节差异合理配置群落 ,使植物种群在生长期上密切衔接 ,形成常绿人工水生植被 ,这样在冬季也能较好地发挥对湖泊的净化功能     

退田还湖后替代生计的经济评估研究——以洞庭湖西畔山洲垸为例

分析了“湿地保护项目是如何改善民众生计的”这一问题。采用2000～2005年1 474个农户调查问卷作为基本数据,其中964个农户位于洞庭湖西畔山洲垸。得出6个结论：①WWF在西畔山洲垸的替代生计示范项目增加了农户的收入和福利,降低了脆弱性,增强可持续利用的自然资源基础;②妇女、老人以及低收入群体从项目中获益;③参加项目的农户比未参加项目的农户拥有更多的收入和财产;④与2000年项目开始时相比,生计水平有了持续的改善;⑤生计改善的原因是当地社区的积极参与、国家政策机遇、伙伴关系的建立、社区基层组织建设以及适应性管理方法的应用;⑥鱼类和水鸟等返回已恢复的湿地。表明该示范项目达到了自然保护目标。     

An approach for restoration of the water quality with emphasis on the removal of organochlorine pesticides and eutrophic conditions in tropical rivers

This work deals with an approach for the water quality restoration with emphasis on the removal of organochlorine pesticides and eutrophic conditions in tropical rivers, causing influence on the management of the central-regional aqueduct, as a source of water supply for human consumption (4 million people) and industrial production in the states of Carabobo, Cojedes and Aragua, Venezuela, testing the phytoremediation techniques through Vetiveria zizanioides (VZ) species and coupled bioreactors, Sequencing Batch Reactor (SBR) followed by an Upflow Anaerobic Filter in Three Separate Stages (UAF-3SS). Five rivers are involved known as Chirgua, Paito Guacara, Ereigüe, and Tucutunemo, whose waters have been classified as hypereutrophic, and containing organochlorine pesticides (OCPs). As a sample, for Tucutunemo River, OCPs included to DDT (dichlorodiphenyltrichloroethane) and its isomers and DRINs (Aldrin, Endrin and Dieldrin) dissolved in water and sorbed on sediments, which were measured during the dry and rainy seasons in the period 2013 to 2016, in three monitoring stations distributed in a reach of 15 km. The results indicated that p.p′-DDT concentration dissolved in water was increased up to 10 times from rainy to dry seasons, indicating that a permanent use of it is being carried out by farmers in the agricultural activity development. Steady concentrations of the DTT isomers (e.g., p.p′-DDD and p.p′-DDE) and Aldrin isomers (e.g., Dieldrin) demonstrated that the anaerobic and aerobic biodegradation processes occurred along the river and between climatic seasons. At experimental scale, VZ hydroponic system developed over a period of 6 months for the removal of nutrients demonstrated moderately low to high removal efficiencies. With respect coupled bioreactors, each bioreactor has been experimentally tested, demonstrating satisfactory performance in Chemical Oxygen Demand (COD) removal from industrial wastewater containing recalcitrant and inhibitory substances (46%–98%), which was estimated in the influent ranging from 3500 to 5500 mg/L, evidencing that coupling of bioreactors might lead to a effluent COD complying with environmental regulations.     

Quantifying and mapping species threat abatement opportunities to support national target setting

The successful implementation of the Convention on Biological Diversity's post-2020 Global Biodiversity Framework will rely on effective translation of targets from global to national level and increased engagement across diverse sectors of society. Species conservation targets require policy support measures that can be applied to a diversity of taxonomic groups, that link action targets to outcome goals, and that can be applied to both global and national data sets to account for national context, which the species threat abatement and restoration (STAR) metric does. To test the flexibility of STAR, we applied the metric to vascular plants listed on national red lists of Brazil, Norway, and South Africa. The STAR metric uses data on species’ extinction risk, distributions, and threats, which we obtained from national red lists to quantify the contribution that threat abatement and habitat restoration activities could make to reducing species’ extinction risk. Across all 3 countries, the greatest opportunity for reducing plant species’ extinction risk was from abating threats from agricultural activities, which could reduce species’ extinction risk by 54% in Norway, 36% in South Africa, and 29% in Brazil. Species extinction risk could be reduced by a further 21% in South Africa by abating threats from invasive species and by 21% in Brazil by abating threats from urban expansion. Even with different approaches to red-listing among countries, the STAR metric yielded informative results that identified where the greatest conservation gains could be made for species through threat-abatement and restoration activities. Quantifiably linking local taxonomic coverage and data collection to global processes with STAR would allow national target setting to align with global targets and enable state and nonstate actors to measure and report on their potential contributions to species conservation.     

Assessment of Temporal and Spatial Variation of Nitrate Removal in Riparian Zones

The aim of this study was to monitor long-term temporal and spatial groundwater NO₃^- removal efficiencies in different riparian zones via a limited number of sampling wells. Groundwater NO₃^- concentrations were measured fortnightly or monthly over a period of two years using transects of ground water sampling wells. Depending on the level of the NO₃^- load (up to 120mgNL^-1 at the input side of the riparian zone a distance of 10 to 30m was needed to remove NO₃^- from the groundwater below 11.3mgNL^-1. Considering all seasons, the mixed vegetation and grass riparian site succeeded to remove groundwater NO₃^- efficiently (92—100% within a distance of 30m. The forested riparian zone removed 72—90% of the total NO₃^- input within a distance of 30m. Evidence emerged that NO₃^- could also be removed actively at depths up to 2m, due to the presence of organically enriched layers of alluvial deposits or roots. Our four dimensional approach (three dimensional space and time), in combination with a limited number of sampling wells, was shown to be a useful monitoring tool to assess the variability of NO₃^- removal in riparian zones.     

三峡水库消落带典型主动与被动修复策略对土壤饱和导水率的影响

人工造林的主动修复与退耕还林还草的被动修复是退化生态系统典型的生态修复策略.以三峡水库运行后形成的消落带为研究对象,研究不同生态修复策略对消落带土壤饱和导水率的影响,对生态脆弱带的水土保持效应具有重要意义.选取桑树+水杉复合林(主动修复)、自然草地(被动修复)、农田(对照)为研究样地,探究了两种不同生态修复策略下三峡水...     

山-水-林-田-湖-草-海-城修复模式的实践应用 ——威海华夏城采石场生态修复及其效益评价

山-水-林-田-湖-草系统保护与修复强调生态系统整体性、系统性和稳定性,生态系统的健康稳定有利于生态系统服务功能的全面优化提升,对确保生态环境安全和社会经济健康协调发展至关重要.山东威海华夏城受大规模开山采石活动影响,区域生态环境遭到破坏,居民生产生活受到严重干扰,经过10余年生态修复,华夏城实现了生态效益与社会经济效...     

矿业废弃地不同生态修复模式下植物多样性及重金属富集迁移特征

为了筛选出适合矿业废弃地复垦生态修复的植物材料,通过在排土场布设生态修复试验,开展不同生态修复模式对植物多样性及重金属富集迁移特征影响的研究.结果 表明,不同生态修复模式下共出现存活植物8科10种,多为草本植物,乔灌草小区修复效果最佳,植物覆盖度达到100％,存活率超过69％,植物群落多样性指数表现为:乔灌草＞灌草＞乔...     

植被恢复的生态效应研究进展

植被在水土保持、水源涵养及生态系统的固碳过程中起着重要的作用。植被恢复是指运用生态学原理,通过保护现有植被、封山育林或营造人工林、灌、草植被,修复或重建被毁坏或被破坏的森林和其他自然生态系统,恢复其生物多样性及其生态系统功能。目前,植被的自然及人工恢复是改善脆弱生态系统及退化生态系统生态环境现状最有效的措施。植被在恢复过程中对地上植被生态系统,物种多样性的恢复有着重要影响,同时通过凋落物及根系的输入,可以有效改善地下生态系统,增加土壤的养分含量、改善土壤的物理结构、增加土壤生物的生物量及活性。文章以地上及地下生态系统为出发点,综述了植被恢复过程中自然及人工恢复过程中不同的植被类型、不同的恢复时间下植物物种组成和多样性、土壤理化性质及土壤微生物群落的变化。植被的自然及人工恢复在一定程度上均能增加植物物种的多样性,随着恢复年限的增加物种的组成发生改变且多样性呈增加趋势,但一些特殊环境下不当的人工恢复可造成植被演替向退化方向发展,降低生物多样性。不同的植被类型由于其生长方式的不同对土壤理化性质和土壤微生物的影响存在差异,随着恢复年限的增长,土壤理化指标及微生物学指标呈现先增加而后趋于平稳的状态。针对已有的研究进展,提出在未来的研究过程中,一方面应该增加更多的对比研究,对不同环境下,不同的恢复物种,不同的恢复方式进行更深入地探讨;另外一方面应增加不同尺度的研究,现有的研究多集中在样地尺度,未来应在更大尺度上进行分析;再者,地上及地下生态系统之间的相互关系及影响机理一直是土壤学科研究的热点,植被恢复过程中应增加更多该方面的机理研究。