Author(s):
Varennes, A. 
; Basanta, R. ; Baath, E. ; Diaz-Ravina, M.
Date: 2010
Persistent ID: http://hdl.handle.net/10400.5/2643
Origin: Repositório da UTL
Subject(s): mine soil; remediation; organic treatments; inorganic treatments
Description
RAMIRAN International Conference In Portugal, additional research is needed if technologies based on the combined action of plants and the microbial
communities they support within the rhizosphere are to be adopted in large-scale remediation actions (Nabais et al.,
2008). Plants growing in abandoned mines are useful to indicate the mineral composition of the soil and they are
able to accumulate or exclude toxic metals (Pratas et al., 2005). Taking into account that the mine degraded soils
have low concentrations of plant nutrients, it is necessary to apply amendments to ensure plant cover when
remediation technologies are present. But soil amendments and the development of a root system might induce
shifts in the microbial community structure among the different treatments (Pérez-de-Mora et al., 2006). Moreover,
data about the toxic effects of heavy metals on soil microorganisms indicated that heavy metal-sensitive bacteria are
probably responsible for the decrease in bacterial activity and the competitive advantage of more tolerant ones
resulted in a change in community composition (Díaz-Raviña and Bååth, 1996). Hence, relationships between the
soil composition, plant species occurring above-ground and the soil microbial communities have been revealed in
many research (Kourtev et al., 2003) providing an important link between above and below-ground processes in
terrestrial ecosystems. Soil microbial community structure is increasingly being marketed as ecologically-relevant
endpoint and it can realistically be incorporated for assessing the potential risks associated with soil amendment
strategies on sustainability of soil ecosystems.
Studies of different remediation technologies with mine soils in Portugal, including amendment materials
from farming and industrial sources and the use of native plant species (Guiwei et al., 2008; de Varennes et al.,
2009) revealed differential effects of treatments on soil enzymes and microbial respiration, suggesting a change in
microbial communities. The information about this fact is scarce and had focused on soil biochemical properties,
producing no clear results. Phospholipid fatty acid (PLFA) patterns are sensitive indicators of changes in microbial
community structure. This technique has been used to elucidate different strategies employed by microorganism to
adapt to changed environmental conditions under wide ranges of soil types, management practices, climatic origins
and different perturbations (Zelles, 1999). The present study is the first attempt to characterize, by means of the
analysis of PLFA patterns, soil microbial population from a Pb-contaminated mine soil subjected to different
remediation technologies including revegetation with native herbaceous species.
