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Functional stability of microbial communities from long‐term stressed soils to additional disturbance
Author(s) -
ToborKapłon Maria A.,
Bloem Jaap,
de Ruiter Peter C.
Publication year - 2006
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/05-398r1.1
Subject(s) - soil water , disturbance (geology) , growth rate , respiration , respiration rate , chemistry , environmental chemistry , bacterial growth , ecology , soil science , environmental science , biology , botany , bacteria , geometry , mathematics , genetics , paleontology
Functional stability, measured in terms of resistance and resilience of soil respiration rate and bacterial growth rate, was studied in soils from field plots that have been exposed to copper contamination and low pH for more than two decades. We tested whether functional stability follows patterns predicted by either the “low stress–high stability” or the “high stress–high stability” theory. Treatments consisting of soils with no or high copper load (0 or 750 kg/ha) and with low or neutral pH (4.0 or 6.1) were used. Stability was examined by applying an additional disturbance by heat (50°C for 18 h) or drying–rewetting cycles. After heating, the respiration rate indicated that the soils without copper were less stable (more affected) than the soils with 750 kg/ha. Bacterial growth rate was more stable (resistant) to heat in the pH 6.1 than in the pH 4.0 soils. Growth rate was stimulated rather than inhibited by heating and was highly resilient in all soils. The respiration rate was less affected by drying–rewetting cycles in the pH 4.0 soils than in the pH 6.1 soils. Bacterial growth rate after drying–rewetting disturbance showed no distinct pattern of stability. We found that the stability of a particular process could vary significantly, depending on the kind of disturbance; therefore, neither of the two theories could adequately predict the response of the microbial community to disturbance.