镇江长江豚类省级自然保护区水域生态修复效果的监测与评价

自2006年以来,长江豚类极度濒危的生存状况得到广泛关注,在其自然保护区实施一系列生态修复工程,为镇江长江豚类省级自然保护区内的江豚提供良好的生存环境。于2015—2018年在和畅洲水域建设生态浮岛、人工鱼巢和放流底栖动物进行水域生态修复,对生态修复工程进行跟踪监测和效果评价。结果表明：生态浮岛的建设可提高区域内浮游植物和浮游动物的生物多样性和群落结构复杂程度;人工鱼巢对产黏性卵鱼类具有一定增殖效果,增殖种类主要为鲤、鲫、䱗和黄尾鲴;生态浮岛和人工鱼巢的建设对鱼类均有较好的聚集效果;底栖动物增殖放流显著增加了放流物种的丰度、生物量及保护区底栖动物群落生物量,增殖放流效果评价为中等。该自然保护区水域生态修复效果明显,为工程施工影响下水生生物保护区生态修复提供科学依据。     

Beaver dams,streamflow complexity,and the distribution of a rare minnow,Lepidomeda copei

Freshwater fishes are threatened globally, and often too little is known about threatened species to effectively guide their conservation. Habitat complexity is linked to fish species diversity and persistence, and degraded streams often lack habitat complexity. Beaver Castor spp., in turn, have been used to restore streams and increase habitat complexity. The northern leatherside chub Lepidomeda copei is a rare, small‐bodied, drift‐feeding minnow that has anecdotally been observed to use complex habitats associated with beaver dams in the western United States. To investigate this anecdote, we conducted fish and habitat surveys, the latter focusing on quantifying habitat complexity, in a sub‐basin of the Upper Snake River Basin in the USA. Complementary generalised linear model and path analyses revealed that northern leatherside chub occurred more often at sites with complex streamflows, and streamflows were more complex when beaver dams were present and pools were deeper. Northern leatherside chubs were also more likely to occur when temperatures were warmer, aquatic macrophytes were abundant and stream channels were narrow and deep. The linkage between chubs, complex streamflows and beaver dams needs to be evaluated more broadly to completely understand its role in the rangewide status of the species. However, it does suggests that increased use of beaver reintroductions and dam analogues for stream restoration could be a boon for the northern leatherside chub, but such efforts should be monitored to determine their effectiveness to help adapt beaver‐based restoration approaches to best benefit the species.     

Responses of plant community to the linkages in plant-soil C:N:P stoichiometry during secondary succession of abandoned farmlands,China

Succession is one of the central themes of ecology;however,the relationship between aboveground plant communities and underground soils during secondary succession remains unclear.In this study,we investigated the composition of plant community,plant-soil C:N:P stoichiometry and their relationships during secondary succession after the abandonment of farmlands for 0,10,20,30,40 and 50 a in China,2016.Results showed that the composition of plant communities was most diverse in the farmlands after secondary succession for 20 and 50 a.Soil organic carbon and total nitrogen contents slightly decreased after secondary succession for 30 a,but both were significantly higher than those of control farmland(31.21%-139.10%and 24.24%-121.21%,respectively).Moreover,C:N ratios of soil and microbe greatly contributed to the changes in plant community composition during secondary succession of abandoned farmlands,explaining 35.70%of the total variation.Particularly,soil C:N ratio was significantly and positively related with the Shannon-Wiener index.This study provides the evidence of synchronous evolution between plant community and soil during secondary succession and C:N ratio is an important linkage between them.     

高等级公路植被护坡工程技术发展初探

依据恢复生态学原理,在探讨植被护坡技术现状的基础上,对高等级公路植被护坡工程技术中的生物治理和工程治理进行分析,提出了植被护坡工程设计原则、技术发展趋势和建议.     

西北干旱区生态环境建设支撑体系的构建

西北干旱区的自然环境脆弱性叠加不合理的水土资源开发等人类活动干扰是导致区域生态环境日趋恶化的根本原因,已严重制约社会经济的可持续发展。针对当前生态环境建设实际,提出应在实现水资源可持续利用、建立完善的管理体制及法律体系、调整产业结构、积极推进城镇化进程、大力发展科技教育等方面采取有力措施。以此为重要支撑,恢复与重建受损生态系统,改善区域生态环境,实现环境与经济社会协调发展。     

论西部大开发中张掖市生态环境建设问题

张掖市长期受干旱、大风及沙尘暴影响,生态环境极为恶劣,制约着西部大开发建设进程。其存在的重要问题是:水资源匮乏,植被破坏严重,覆盖率低等;针对具体情况提出:改善水资源条件和恢复植被是张掖地区生态环境建设的重点。     

菌根与植被恢复

菌根不仅可促进植物的营养吸收、生长发育、抗病、抗逆,而且在保持良好的土壤结构、控制水土流失方面具有直接的作用。在我国西北许多地区,菌根菌与植物间的共生关系已被中断,要恢复该地区的植被,治本的方法应是重建植物与菌根菌的共生关系,形成健康的生态系统。文中还提出了菌根技术在植被恢复中的应用策略。     

退耕还草产业化技术经济效果评价方法探讨

以平凉市退耕还草产业化技术开发为例,以产业化系统链中各子系统间的功能协调统一为依据,以退耕还草产业化机制为纽带,在研究建立平凉市退耕还草产业化技术经济效果包括4个一级指标(基础指标、配套指标、服务指标和效益指标)和17个二级指标体系的基础上,采用层次分析法(AHP法)、隶属度函数法和综合效益指数法作为退耕还草产业化技术经济效果的评价方法.经比较得出:平凉市退耕还草产业化技术开发综合指数达到0.595 1,属初步产业化阶段,相对发展指数达到27.268%,年均产业化进步速度达到6.817%.     

三江源区土壤侵蚀变化及驱动因素分析

采用修正通用土壤流失方程(revised universal soil loss equation, RUSLE)对三江源区1997-2012年的土壤侵蚀模数和土壤侵蚀量进行定量模拟,并对其生态工程实施前、后时空变化特征进行对比分析,采用空间叠加法分析降雨侵蚀力及植被覆盖度对土壤侵蚀状况的影响,利用模型参数控制法对气候变化和生态工程对土壤侵蚀变化的贡献率进行分析。结果表明:1)生态工程实施后,三江源区土壤侵蚀增加的趋势尚未得到遏制,多年平均年土壤侵蚀模数和侵蚀量较工程实施前增加6.5%,但局部地区土壤侵蚀状况有所好转,约占总面积的45%;2)长江流域在工程实施后的土壤侵蚀量与工程实施前基本持衡;黄河流域土壤侵蚀量增加明显,增幅超过45%;澜沧江流域土壤侵蚀量有所下降,降幅为9.8%;3)降水增强导致土壤侵蚀加剧的贡献率达到180%,植被恢复对土壤侵蚀变化的贡献率为-80%。全面遏制三江源区土壤侵蚀增加趋势,仍需持续努力。     

土壤侵蚀下黑龙江省人地系统适应性研究

为缓解人地关系,以对黑龙江省威胁最大的土壤侵蚀为切入点,从"三生"视角分析区域人地系统适应性,并提出基于不同修复优先级的人地系统修复方案。首先,在总结、梳理适应性内涵,整合适应性理论与方法基础上,从"三生"视角提出了基于风险扰动的适应性分析框架,将系统适应性分解为扰动、影响、响应、能力4方面,并从土壤侵蚀风险扰动出发,构建了系统适应性评价指标体系与评价模型;其次,采用极差标准化法、克里格插值法、蔡崇法法和DEA-CCR模型处理数据,利用土壤侵蚀方程测算土壤侵蚀风险,利用适应性评价模型测算适应性指数,分析土壤侵蚀风险和人地系统适应性分布情况;最后,提出基于不同修复优先级组合模式的人地系统修复方案。结果表明:黑龙江省土壤侵蚀风险区面积为1 366.61万hm2,占区域耕地面积的85.74%,高、中、低级别风险规模分别为324.02、596.33、446.26万hm2。高、较高级别人地系统适宜程度区分布在三江平原东北部和松嫩平原东南部地区,中级别分布在大兴安岭和松嫩平原南部地区,低、较低级别分布在东南部山地和松嫩平原北部地区。形成了基于不同修复优先级组合模式的人地系统修复方案,其中53个地区仅存在1种人地系统修复方案,其余27个地区在不同优先级组合模式下形成了不同的人地系统修复方案,为区域人地系统修复提供了多种选择方案。