瑞典东南部一个人工景观镶嵌体内集水区的碳收支:有助于一个核废料埋藏点的安全评估  

Carbon Budgets for Catchments Across a Managed Landscape Mosaic in Southeast Sweden:Contributing to the Safety Assessment of a Nuclear Waste Repository

作　　者：Anders Lfgren Sofia Miliander Johan Truvé Tobias Lindborg 马爱进 

机构地区：[1]斯德哥尔摩大学 [2]哥德堡大学

出　　处：《AMBIO－人类环境杂志》2006年第8期451-460,518,共10页

摘　　要：生态系统的物质收支有助于评价一个景观中可与生物体结合的污染物质的运输和累积,因为物质和能量流动最终决定环境中污染物质分配的速率。本研究比较生态系统的性质,如净初级生产量(NPP)、物质接收和进入到人类食物源的通量,这对于描述瑞典东南部的一个较大集水区域内14个集水区中可与生物体结合的放射性核素的通量和累积可能是重要的。作为有机物质的一个替代变量,碳收支主要基于碳库和通量的局地估计,这些值已通过地理信息系统(GIS),分配于一个具有不同植被类型和管理体制的景观镶嵌体中。净初级生产量以一个接近于2的因子而变化(432～709g C/m^2·a),而生态系统净生产量因集水区不同而在-124～159g C/m^2·a之间变化。碳接受主要发生于植被,而土壤有机碳库基本是碳源。大型食草动物平均消费地上部分绿色组织生产量的4.5%。当集水区存在耕地时,从农作物进入到人类的碳通量最高,按递减顺序,接着是来自于牛奶和牛肉的通量,然后是来自于打猎和浆果/真菌采摘的通量。这些结果可用于估计植被对放射性核素的潜在吸收情况,以及可与生物体结合的放射性核素对人类的潜在暴露水平。Ecosystem budgets of matter contribute to the assessment of transport and accumulation of bioavailable contaminants in a landscape,since flows of matter and energy ultimately determine the rates at which contaminants will be partitioned in the environment.This study compares ecosystem properties,such as net primary production (NPP),sequestration of matter and fluxes to food sources for humans,which are of potential interest to describe fluxes and accumulation of bioavailable radionuclides in 14 catchments within a larger catchment area in southeast Sweden.The carbon budgets,used as a proxy for organic matter,are mainly based on local estimates of pools and fluxes,which have been distributed across a landscape mosaic of different vegetation types and management regimes using a geographical information system (GIS).NPP varied by a factor close to two (432-709 g·C·m^(-2) y^(-1)),while net ecosystem production ranged between -124 and 159 g·C·m^(-2) y^(-1) for the different catchments.Carbon sequestration mainly occurred in the vegetation while the soil organic carbon pool was mainly a source of carbon.Large herbivores consumed on average 4.5 % of the above-ground green tissue production.When arable land was present in the catchment,the flux of carbon to humans was highest from crops and,in decreasing order,milk and beef,followed by the flux from hunting and berry/fungus picking.The results can be used to estimate the potential assimilation of radionuclides in vegetation and the potential exposure to humans of bioavailable radionuclides.

关 键 词：集水区域 人工景观 碳收支 东南部 安全评估 瑞典 核废料 净初级生产量 

分 类 号：X21[环境科学与工程—环境科学]