Components of Soil Respiration and Its Temperature Sensitivity in Four Reconstructed Soils

Abstract

seasonal changes characteristics in the respiration of four reconstructed soils Abstract: seasonal changes characteristics in the respiration of four reconstructed soil masses 9 in a barren gravel land were monitored using soil carbon flux measurement system. The 10 results showed that (1) The seasonal changes in soil respiration and heterotrophic respiration 11 of four reconstructed soils of meteorite, shale, sand and soft rock were the same as the 12 seasonal change in soil temperature. Soil respiration and heterotrophic respiration increased 13 with soil temperature. It was gradually increasing, reaching the maximum in summer and 14 decreasing to the minimum in winter. Among the four reconstructed soils, the average annual 15 soil respiration of reconstructed soil with sand was 4.87 μmol•m –2 •s –1 , which was 16 significantly higher than the other reconstructed soils (p<0.05).(2) The autotrophic respiration 17 of four reconstructed soils showed obvious seasonal dynamic changes. The maximum and 18 minimum values appeared in August 2018 and January 2018, respectively. In the whole year, 19 The variation range of the annual average soil autotrophic respiration in the total respiration 20 of the reconstituted soil with addtion of meteorite, shale, sand and soft rock were 12.5-38.0%, 21 9.5-42.0%, 7.7-41.2%, and 5.0-39.3%, respectively.(3) Soil temperature was the main factor 22 affecting soil respiration. The four reconstructed respiration had a very significant correlation 23 with soil temperature (p<0.01). The relationship between reconstructed soils respiration and 24 soil temperature can be indexed function characterization. The 90% to 93% changes in soil 25 respiration of reconstructed soils were caused by soil temperature. The order of Q 10 in soils 26 respiration of four reconstructed was as follows: Sand> shale> soft rock > meteorite.