『Abstract
　Previous studies have revealed that chlorine participates in a complex biogeochemical cycle in soil, which suggests that the transport of chloride through catchments may also be influenced. The present study is based on field observations of organic carbon, chloride (Clin), and chlorinated organic carbon (Clorg) in precipitation, soil, and runoff over a 2-year period from a small, forested catchment in southeast Sweden. The study reveals that (1) the soil pool is dominated by Clorg, (2) the input via wet deposition and output of Clin via runoff is 30 times smaller than the total storage of chlorine (Clin + Clorg) in soil, and (3) the transport is dominated by Clin. The organic matter that entered the outlet of the catchment was more chlorinated in the autumn than during the rest of the year, and rain events taking place in low-flow periods had a greater influence on TOC, Clorg, and Clin than did rain events taking place in high-flow periods. The seasonal pattern in combination with the low-flow versus high-flow pattern and previous findings of increasing chlorine-to-carbon ratios with soil depth suggests that the chlorine-to-carbon ratio variation in the leached organic matter is due that water preferentially comes from deeper layers in low-flow conditions. This study provides well-founded estimates of Clorg and Clin storage and fluxes for the studied catchment; however, the processes underlying the observed seasonal Clorg variations and transportation processes need further study.

Keywords: Catchment; Chloride; Chlorine; Organic chlorine; Soil; water; Watershed』

Introduction
Materials and methods
　Catchment description
　Water discharge measurements
　Sampling procedures
　　Soil samples
　　Precipitation sampling
　　Runoff sampling
　Chemical analysis
　　Water content and loss-on-ignition in soil
　　Total nitrogen in soil
　　Clorg concentration in runoff and precipitation
　　Clorg and Clin concentrations in soil
　　Clin and nitrate concentrations in runoff and precipitation
　　Total organic carbon (TOC) concentration in runoff and precipitation
　Estimation of input and output fluxes and storage
　Statistics
Results
　Hydrology
　Soil chemistry
　Precipitation chemistry
　Runoff chemistry
　　Degree of organic matter chlorination
　　Observations during a rain event
　Chlorine budget estimates
Discussion
　A small flux in Clin and a large pool of Clorg under near steady-state conditions
　Estimating the dry deposition
　High concentrations of Clorg and TOC during dry period high flow
　Increasing chlorine-to-carbon ratios in runoff water during high-flow
　Seasonal changes in the chlorine-to-carbon ratio
Acknowledgements
References