Soil organic carbon in the rocky desert of norther

Authors: Ulrike Hoffmann Aaron Yair Harald Hikel Nikolaus J Kuhn

Publish Date: 2012/04/05

Volume: 12, Issue: 6, Pages: 811-825

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Abstract

So far the soil organic carbon SOC literature is dominated by studies in the humid environments with huge stocks of vulnerable carbon Limited attention has been given to dryland ecosystems despite being often considered to be highly sensitive to environmental change Thus there is insufficient research about the spatial patterns of SOC stocks and the interaction between soil depth ecohydrology geomorphic processes and SOC stocks This study aimed at identifying the relationship between surface characteristics vegetation coverage SOC and SOC stocks in the arid northern Negev in IsraelThe study site Sede Boker is ideally suited because of wellresearched but variable ecohydrology For this purpose we sampled five slope sections with different ecohydrologic characteristics eg soil and vegetation and calculate SOC stocks To identify controlling factors of SOC stocks on rocky desert slopes we compared soil properties vegetation coverage SOC concentration and stocks between the five ecohydrologic unitsThe results show that in Sede Boker rocky desert slopes represent a significant SOC pool with a mean SOC stock of 058 kg C m−2 averaged over the entire study area The spatial variability of the soil coverage represents a strong control on SOC stocks which varies between zero in uncovered areas and 154 kg C m−2 on average in the soilcovered areas Aspectdriven changes of solar radiation and thus of water availability are the dominant control of vegetation coverage and SOC stock in the study areaThe data indicate that dryland soils contain a significant amount of SOC The SOC varies between the ecohydrologic units which reflect 1 aspectdriven differences 2 microscale topography 3 soil formation and 4 vegetation coverage which are of greatest importance for estimating SOC stocks in drylands

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