University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Simon Obenaus
(2020):
Characterisation of serpentine soil along a gradient of total Ni concentration and soil development.
Master / Diploma Thesis - Institut für Bodenforschung (IBF),
BOKU-Universität für Bodenkultur,
pp 61.
UB BOKU
obvsg
FullText
- Abstract:
- Serpentine soils are characterized by strong chemical peculiarities like low nutrient content, a low Ca/Mg ratio and high metal contents such as Ni, Co or Cr. This barren habitat constitutes a niche for a highly adapted and robust vegetation, including both non-hyperaccumulators and hyperaccumulators. Dependency of Ni-hyperaccumulation on soil parameters has not yet been fully understood. In this context, this study aims at examining biogeochemistry of pedogenic Ni along a toposequence of serpentine soil and its relation to Ni accumulation in the hyperaccumulator Odontarrhena chalcidica (syn. Alyssum murale). Six soil samples were taken along a toposequence near Redschlag in Burgenland and a pot experiment has been set up. O. chalcidica was planted into soils obtained from the six sites and harvested after 66 days. Standard soil parameters (C, N, pH, CEC, etc.) revealed the typical infertility of serpentine soils. Ni fractions of different operational defined extractability (aqua regia, DTPA , Sr(NO3)2, H2O) were determined and the ratio between amorphous Fe-oxides and well crystallized Fe-oxides was determined, as it is a relative indicator of the degree of soil development and weathering intensity. Pearson correlation matrix was calculated for all soil physico-chemical parameters and elemental concentrations in the shoots of O. chalcidica. NiTotal and Ni associated with amorphous Fe-oxides showed to be the best indicators for Ni uptake by O. chalcidica as these two fractions showed strong correlations with NiShoot values. Furthermore, antagonistic relationships between Nishoot and Feshoot were revealed. No mobilisation of Ni by O. chalcidica could be detected since there was a depletion of Sr(NO3)2 and DTPA extractable Ni after growth of O. chalcidica, rather than an increase. Furthermore, species distribution among dissolved Ni species in soil solution showed no significant change during growth of O. chalcidica, which again suggests no mobilisation of Ni.
- Beurteilende(r): Puschenreiter Markus