西湖和东苕溪沉积物重金属化学形态分析

不同赋存形态重金属的环境行为和生态效应不同,水体沉积物中重金属的迁移转化及其潜在环境危害更大程度上取决于其赋存形态。本研究在西湖和东苕溪设置12个采样点采集沉积物样品,采用改进BCR分步提取法,提取了重金属污染物的4种化学形态,分别为弱酸提取态、可还原态、可氧化态及残渣态。结果表明:沉积物中Cd以弱酸提取态为主,对外界环境的变化极其敏感,并易于发生迁移转化,生态风险较高。Cu离子对有机质表现出极强的亲和力导致Cu的可氧化态含量较高也有一定的生态风险。Pb会被Fe-Mn氧化物所吸附导致Pb的可还原态含量较高,存在较高的潜在生态危害。Mn的弱酸提取态、可还原态和残渣态含量都较高,在迁移的过程中变化地较快,能够逐渐降低Mn对自然环境的危害。其他各重金属(As、Cr、Zn)则都以残渣态为主,潜在危害较低。     

天山东部雪冰中硝酸根浓度对中亚生物质燃烧的响应研究

研究了天山东部雪冰中NO3-浓度对中亚哈萨克斯坦生物质燃烧的响应情况.在天山乌鲁木齐河源1号冰川持续采集了52组表层雪与雪坑样本,分析了雪样中NO3-等成分的浓度,运用HYSPLIT模型模拟了空气轨迹,目的是考察雪冰中NO3-与2002年哈萨克斯坦草原大火的关系,探讨由生物质燃烧产生的NO3-在高海拔山岳冰川雪层中的沉...     

Importance of conserving large and old trees to continuity of tree-related microhabitats

Protecting structural features, such as tree-related microhabitats (TreMs), is a cost-effective tool crucial for biodiversity conservation applicable to large forested landscapes. Although the development of TreMs is influenced by tree diameter, species, and vitality, the relationships between tree age and TreM profile remain poorly understood. Using a tree-ring-based approach and a large data set of 8038 trees, we modeled the effects of tree age, diameter, and site characteristics on TreM richness and occurrence across some of the most intact primary temperate forests in Europe, including mixed beech and spruce forests. We observed an overall increase in TreM richness on old and large trees in both forest types. The occurrence of specific TreM groups was variably related to tree age and diameter, but some TreM groups (e.g., epiphytes) had a stronger positive relationship with tree species and elevation. Although many TreM groups were positively associated with tree age and diameter, only two TreM groups in spruce stands reacted exclusively to tree age (insect galleries and exposed sapwood) without responding to diameter. Thus, the retention of trees for conservation purposes based on tree diameter appears to be a generally feasible approach with a rather low risk of underrepresentation of TreMs. Because greater tree age and diameter positively affected TreM development, placing a greater emphasis on conserving large trees and allowing them to reach older ages, for example, through the establishment of conservation reserves, would better maintain the continuity of TreM resource and associated biodiversity. However, this approach may be difficult due to the widespread intensification of forest management and global climate change.     

山水林田湖草生态保护修复江苏实践与思考

“实施山水林田湖草生态保护和修复工程，全面提升自然生态系统稳定性和生态服务功能”是习近平生态文明思想的重要创新成果，为开展生态环境保护修复工作提供了重要指引和根本遵循。2019年以来，江苏省开展山水林田湖草生态保护修复省级试点工程共5类59个工程项目。在总结了试点地区工作经验做法的基础上，针对存在的生态保护修复和绿色发展协同理念认识不足、生态修复保护整体性和系统性不够、生态修复经验总结及全周期管理有待加强、打破界限的体制机制改革创新亟需完善等问题及难点，提出了相应的工作政策建议，以期打造全国生态保护修复的江苏样板。     

烟台西港倾倒区海域浮游生物的群落特征

分析了倾倒活动结束后烟台西港倾倒区海域浮游生物的群落结构特征。结果表明,浮游植物群落具有硅藻为主、甲藻为次的特征,生态性质以温带近岸性物种为主。倾倒区停用后,硅藻数量大幅增加。桡足类、浮游幼虫及毛颚类的强壮箭虫是浮游动物群落的主要组成。浮游动物丰度、生物量与浮游植物丰度变化趋势大体一致。多样性分析表明,浮游生物群落结构比较稳定,倾倒区海域生态环境质量尚好。