Structural and functional response of soil microbiota to addition of plant substrate are moderated by soil Cu levels

Autor: Yongchao Liang, Guixin Chu, Steven A. Wakelin, Mike J. McLaughlin, K. R. Clarke, Kris Broos
Rok vydání: 2010
Předmět:
Zdroj: Biology and Fertility of Soils. 46:333-342
ISSN: 1432-0789
0178-2762
DOI: 10.1007/s00374-009-0436-1
Popis: In soils, the microbially mediated decomposition of plant residue is a key process with wide ranging effects on ecosystem functioning and stability. Understanding the impact of contamination on this process is of high importance. We investigated the effects of long-term (6 years) copper exposure on the capacity of soil microbiota to decompose newly added resources; dried and ground Medicago truncatula stubble. In addition, the effects on the microbial community structure across the three domains were explored using polymerase chain reaction–denaturing gradient gel electrophoresis rRNA gene profiling. Ecological distances in community structure between treatments was calculated (Kulczynski) and effects tested using PERMANOVA. Clear dose–response relationships were present between microbial respiration (CO2 evolution) and soil Cu level in soils receiving medic, but not under basal conditions (i.e., no medic added). These show that relatively labile forms of C are needed to drive microbial ecotoxicological responses and that microbial adaptation to the presence of Cu in the soils—after >6 years exposure—was functionally limited. Bacterial, archaeal and fungal communities showed significant (P
Databáze: OpenAIRE
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