|Title||Soil food web assembly and vegetation development in a glacial chronosequence in Iceland|
|Author(s)||Leeuwen, J.P. van; Lair, G.J.; Gísladóttir, G.; Sandén, T.; Bloem, J.; Hemerik, L.; Ruiter, P.C. de|
|Source||Pedobiologia 70 (2018). - ISSN 0031-4056 - p. 12 - 21.|
Biometris (WU MAT)
Alterra - Animal ecology
|Publication type||Refereed Article in a scientific journal|
|Keyword(s)||Ecosystem functioning - Glacial succession - Iceland - Soil food web structure - Vegetation development|
Worldwide human activities threaten soil quality in terms of the soil's ability to deliver ecosystem services. This ongoing process of land degradation asks for effective strategies of soil protection. In this context, it is important to understand processes that build up and regenerate soil. The present study investigated how the soil ecosystem, including soil organisms, vegetation and soil ecological processes, develops during the process of soil formation in a chronosequence in a glacier forefield in Iceland. We hypothesised that along successional age we see increases in nutrient content, vegetation cover, and plant species richness linked to increases in soil food webs biomass and complexity. In line with our expectations all measured pools of carbon and nitrogen, and vegetation cover increased with age in the glacial forefield, but plant species richness levelled off after 30 years. Soil organisms generally increased in biomass with successional age, although some of the groups of soil organisms peaked at an intermediate successional stage. In contrast to our expectations, some of the calculated food web complexity metrics such as the number of trophic groups and trophic chain length did not increase linearly, but showed an intermediate peak or even decreased with successional age. However, plant cover and pools of carbon and nitrogen still increased after 120 years. From these results we conclude that soil ecosystem development takes more than a century under Icelandic climatic conditions to fully develop in terms of vegetation succession, food web structure and biogeochemical cycling.