Greenhouse gas emissions from natural ecosystems of the Norilsk Industrial District

Abstract

This paper describes the results of field measurements of methane and carbon dioxide fluxes from natural and anthropogenic-modified ecosystems located on the Norilsk industrial district. Previously, such studies have not been conducted in the area. The study points are located in different landscape regions determined by various conditions of permafrost formation. Most of the study area is located within the zone of predominantly continuous permafrost distribution. Six landscape regions were identified. Methane and carbon dioxide fluxes were measured at selected key sites typical for each region. When selecting the study points, the variety of conditions affecting methane and carbon dioxide emissions was considered. First, these include soil type (mineral or peat) and local moisture conditions. Methane and carbon dioxide fluxes were measured by dart static chamber method. Measurements of greenhouse gas concentrations in the chamber were carried out by a portable gas analyzer Li-7810 (Li-COR, USA). The results obtained show significant variability in greenhouse gas emissions for different ecosystem types. Methane uptake by soils is recorded on mineral soils and dry parts of bog ecosystems. Positive methane emissions are typical for watered areas of bog ecosystems and lakes with maximum values in the hollows. Methane fluxes range from slightly negative in dry bog areas with a median of -0.026 mgCH4/m2/h to emissions of 0.802 mgCH4/m2/h as the median for watered areas of bog ecosystems. Carbon dioxide fluxes are inversely correlated with the ecosystem moisture content and have a range from 51.6 mgCO2/m2/h (median for lakes) to 576 mgCO2/m2/h (median for mineral soils). A medium strength correlation was found between surface air temperature and intensity of methane uptake by mineral soils was found. Probability density distributions of methane and carbon dioxide fluxes have different forms.