Biological and chemical factors controlling the patchy distribution of soil water repellency among plant species in a Mediterranean semiarid forest

Abstract

Natural soil water repellency is a property that has already been observed in forest soils and is characterized by its patchydistribution. Ihere are many factors involved in its development. In this work, we have studied a large numberof chemical and biological factors underthe influence of differentplantspecies (Pinus halepensis, Quercus rotundifolia, Cistus albidus and Rosmarinus officinalis) to leam which has the greatest responsibility for its presence and persistence in the top-soillayer. We obselVed strong and significant correlations between ergosterol, giomalin related soil protein (GRSP), extractable lipids, soil organic matter (SOM) content and water repellency (WR). Our results suggested lipid fraction as the principal factor. Moreover, apart from Pinus, fungal biomass seems to be also related to the SOM content. Soil WR found under Pinus appears to be the most influenced by fungi. Quality of SOM, to be precise, lipid fraction could be responsible for WR and its relationship with fungal activity.

Relationships between soil water repellency and microbial community composition under different plant species in a Mediterranean semiarid forest

“…This contribution is a continuation of previous research (Lozano et al, 2013), where we concluded that the quality of SOM, in specific a lipid fraction, could be the main factor involved in SWR. However, in the case of forested land with Pinus, it was also postulated that soil microbiology could be another major factor, but this was not investigated.…”

“…Previous research has shown that water repellent patches of soil differ from adjacent wettable soils in pH, moisture, SOM quality and quantity, and microbial biomass (Doerr et al, 2000), even beneath the same plant species (Lozano et al, 2013). When soil microorganisms decompose SOM, hydrophilic compounds are more readily degraded, potentially resulting in an accumulation of hydrophobic compounds over time.…”

“…In the current study, microbial community structure measured with phospholipid fatty acid (PLFA) analysis, was compared to the persistence of SWR. The sites studied are the same as Lozano et al (2013), which were in a Mediterranean climate and under trees (Pinus or Quercus), or shrubs. A patchy distribution of SWR was found by (Lozano et al, 2013), so the sites were sampled at different locations to give a range of SWR severity that could then be measured for microbial community structure.…”

“…The sites studied are the same as Lozano et al (2013), which were in a Mediterranean climate and under trees (Pinus or Quercus), or shrubs. A patchy distribution of SWR was found by (Lozano et al, 2013), so the sites were sampled at different locations to give a range of SWR severity that could then be measured for microbial community structure. Studying soil microbiology structure might help to understand the possible influence of SWR in soil microbiology, or in contrast, the possible influence of soil microbiology in the development of SWR.…”

Water vapour adsorption on water repellent sandy soils

“…It has been very frequently reported in literature over the last years that coniferous forest litter causes the strongest levels of SWR (e.g. de Blas et al, 2013;Flores-Mangual et al, 2013;Lozano et al, 2013), most probably due to high content of hydrophobic resins, terpens, and waxes.…”