2 research outputs found
SUBMERGED PEDOLOGY: THE SOILS OF MINOR ISLANDS IN THE VENICE LAGOON
Minor islands of the Venice lagoon are part of a delicate ecosystem, with
equilibrium that depends on multiple factors deriving from both the aqueous and
the terrestrial compartment, and represent useful indicators of the lagoon
ecosystem status. Over centuries, some islands emerged, some others disappeared,
others are being submerged in consequence of sea level rise, or are dismantled by
marine erosion. Ecological survey and soil sampling evidenced rather
homogeneous environment and soil characters, likely due to the same genesis from
HTM during centuries, and to environmental conditions such as moisture and
brackish groundwater. Four of the examined soils are Inceptisols, while the others
present limited horizon differentiation, and are Entisols. All the profiles reflect udic
or aquic conditions, and some of them are submerged for most time. Most soils are
moderately alkaline (7.9 250 g/kg); organic
carbon content at surface is within the normal range (8 <OC g/kg< 12), while at
depth it is low (< 8 g/kg). The soils of shallow sandbanks differ from those of the
islands having neutral pH (6.6 17 g/kg) and
carbonates. Moreover, the textural class is generally silty-loam with increasing clay
content with depth. Currently, the soils examined present hydromorphic pedofeatures,
which are the result of the most important pedogenic process in the
lagoon. Alternating reduction/oxidation processes would increase as a consequence
of sea level rise, determining reducing conditions at bottom, and conversely
enhancing salt concentration uppermost, with negative consequences for both
pedogenic evolution and vegetation survival