摘要
综述了近几十年来国内外有关森林生态系统镉污染的研究进展。森林生态系统镉污染的来源有自然来源和人为来源 ,自然森林生态系统和人工森林生态系统的镉污染来源有明显差异。林地污泥应用、污灌、含镉磷肥的施用以及大气沉降等是人工森林生态系统镉污染的主要来源。镉污染对森林生态系统中的生产者、消费者和分解者均有毒害作用。森林生态系统的结构和功能特性使其在环境镉污染监测和防治中起着重要作用。
Cadmium, one of the most toxic heavy metals, is harmful to human being, animals and plants. Forest is an important vegetation type on the earth, and forest ecosystem plays a critical role in the functions of the earth ecosystem. The present paper aims to provide a critical review on cadmium contamination in forest ecosystem and its impacts on ecosystem health.The source of cadmium in forest ecosystem is from geogenic sources as well as from human activities. There are different sources of cadmium contamination between natural forest ecosystems and man-made forest ecosystems. Cadmium contamination in man-made forest ecosystem results from several main routes: cadmium from atmospheric deposition, utilization of sewage sludge, and soil application of phosphate fertilizers with high Cd concentration. Toxicity of cadmium on producers (trees, shrub, herbage, moss), consumers (animals) and disintegrators (microorganism) in forest ecosystems is discussed. Cadmium contamination affects plants' physiological and biochemical processes such as photosynthesis, respiration, transpiration, nutrient uptake, water utilization and enzyme activities, which in turn inhibits plant growth. Animals, including herbivores, carnivores and saprovores, are damaged by cadmium contamination. Microorganisms play a critical role in biogeochemical cycles in forest ecosystems, while cadmium contamination will reduce microbial biomass and bio-diversity in forest soils. The dominant plants in forest ecosystem are woody plants which have denser branches and leaves, taller and bigger bole, deeper root, and longer age, compared to other plants. In addition, other characteristics of forest ecosystem such as complexity of community configuration, bio-diversity and strong homeostasis are beneficial to the accumulation and transformation of cadmium in forest ecosystem. Therefore, forest ecosystem has the potential to monitor and to remediate cadmium contaminated sites.At the end of this paper, four areas for further research on cadmium contamination in forest ecosystem are discussed: Ⅰ. Mechanisms of cadmium affecting the community configuration and the function of forest ecosystem; Ⅱ. Interaction between cadmium and other elements in forest ecosystem; Ⅲ. The combined effects of Cd (and other heavy metals) and acid precipitation on forest ecosystems; Ⅳ. The potential of using trees to remediate Cd-contaminated soils.
出处
《生态学报》
CAS
CSCD
北大核心
2004年第1期101-108,共8页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目 (4 0 2 0 10 5 0 )
科技部 863资助项目 (2 0 0 1AA64 5 0 10 -4 )~~
