摘要
西南地区是我国长江上游重要的生态屏障区和国家重大建设工程的重要实施区.该区域雨水丰沛、地势陡峭,工程建设产生大量弃渣,不仅占用大面积的临时性和永久性土地,还极易造成水土流失、滑坡泥石流等次生灾害,生态环境极端脆弱.为保障区域生态安全,亟须进行科学治理.基于西南地区的地质历史、气候条件和人地矛盾等实际,总结西南脆弱生态区渣场生态修复技术的研究进展.目前建设工程产生渣土的来源主要为道路修建、水电站建设、矿山开采和山区城镇基础建设等四大类项目.渣场修复作为一个系统工程,通常按照"土地整理—土壤重构—植被建设—景观再造—生态演替"的序列进行,修复技术主要分为土壤系统构建技术和植物群落构建技术两大板块.土壤系统的构建关键在于坡面整理保持水土,生土熟化和土壤改良,理化、微生物和植物措施修复重金属污染等方面.植物群落构建技术主要由选择先锋物种激发植物存活、群落配置促进持续演替、土壤种子库有效利用、植物配置促进成土等技术组成.针对目前渣场生态修复中存在的修复目标定位不清、土壤修复技术单一、物种适应难、生物入侵、群落演替难以为继等主要问题和难点,提出以区分不同生境梯度、不同生态系统类型和修复目标为核心依据的解决思路.在此基础上,展望了未来渣场修复技术、创新管理模式以及区域差异化治理策略等优化途径.(图2表4参82)
Abstract
Southwest China is a critical ecological barrier in the upper reaches of the Yangtze River and is the main implementation area for major national construction projects.Owing to abundant rainfall and steep terrain,large-scale excavation of mountains and rocks in these construction projects generates a large amount of abandoned slag.This slag not only occupies a large area of land,but also easily causes soil erosion,landslides,debris flows,and other secondary disasters,making the ecological environment extremely fragile.Scientific management is necessary to ensure regional ecological security.Scientific governance must be conducted in dreg fields to ensure the regional ecological security.According to the geological history,climatic conditions,and human-land contradiction in Southwest China,this paper summarizes the research progress of dreg-field ecological restoration technology in the southwest fragile ecological zone.Currently,most slag residue remains as leftover material in four types of construction projects in mountainous areas:roads,hydropower stations,mining,and urban infrastructure engineering.As a systematic project,restoration of dreg fields is usually carried out in accordance with the sequence of"land consolidation-soil reconstruction-vegetation construction-landscape reconstruction-ecological succession".Restoration technologies include soil system and plant community construction technologies.The key to the construction of healthy soil systems lies in slope consolidation and soil conservation,raw soil ripening and soil improvement,and physical,chemical,microbial,and plant measures to repair heavy metal pollution.Plant community establishing techniques are mainly composed of pioneer species selection to stimulate plant establishment,species configuration to promote continuous succession,effective use of soil seed banks,and plant cooperation to promote soil formation.Meanwhile,the main problems in the ecological restoration of dreg fields include unclear orientation of slag restoration,single soil repair technology,and lack of scientific design regarding plant species adaptation,biological invasion,and sustainability of succession in vegetation restoration from an ecological perspective.In future,ecological restoration of dreg fields should be based on the distinction of habitat gradients,biome types,and restoration objectives.Moreover,future restoration technology and management model innovations for dreg field remediation and the optimization of regionally differentiated management strategies in Southwest China are discussed.
基金项目
四川省科技计划项目(2018SZDZX0033)
四川省科技计划项目(2023NSFSC0203)
国家"十三五"重点研发计划项目(2017YFC0505002)
国家自然科学基金项目(31370594)
NETL
NSTL
万方数据