Root behavior of savanna species in Brazil's Pantanal wetland.

The objective of this study was to determine the maximum depth, structure, diameter and biomass of the roots of common woody species in two savanna physiognomies (savanna woodland and open woody savanna) in Brazil's Pantanal wetland. The root systems of 37 trees and 34 shrubs of 15 savanna species were excavated to measure their length and depth and estimate the total root biomass through allometric relationships with stem diameter at ground level. In general, statistical regression models between root weight and stem diameter at ground level showed a significance of P < 0.05 and R2 values close to or above 0.8. The average depths of the root system in wetland savanna woodland and open woody savanna are 0.8 ± 0.3 m and 0.7 ± 0.2 m, respectively, and differ from the root systems of savanna woody species in non-flooding areas, whose depth usually ranges from 3 to 19 m.Weattribute this difference to the adaptation of woody plant to the shallow water table, particularly during the wet season. This singularity of woody species in wetland savannas is important when considering biomass and carbon stocks for national and global carbon inventories.

Heavy Metals distribution in drainage canals sediments of the Ravenna province

This work, in collaboration with the Romagna Reclamation Consortium, has the aim of studying the heavy metals concentration distribution in the drainage canals of the Ravenna coastal basins, Italy. Particular attention was given to the area of the V Fosso Ghiaia and VI Bevanella basins, where water and sediment samples were collected in the field and integrated with existing databases. The hydrological regime is controlled and managed by the Consortium, which has divided the territory into several mechanical drainage basins. XRF was performed on 21 sediment samples and pH, EC, T°, Fe2+ and Fetot were measured on 15 water samples by probes and spectrophotometer, respectively. Heavy metals concentrations exceeding legal limits of the D.LGS n ° 152/2006 were found for As, Co, Cr, Pb and Zn. These results were then integrated with canal sediment analyses provided by the Consortium to perform a Principal Component Analysis. PCA results show that the main variable affecting heavy metals distribution is the use of fertilizers, followed by distance from sea, and altimetry, which are directly linked to salinity. Heavy metals concentrations increase with increasing use of fertilizers, which are mainly due to the widespread agricultural practices and industrial land use in the area. High heavy metals concentrations are also found in the canals interested by higher salinity (especially Pinetale Ramazzotti). In fact, the area is affected by salinization caused by a water table below sea level and upward seepage of salty oxygen-poor saline water from the bottom of the aquifer. According to the literature, iron and manganese oxides were found to be an important factor in controlling the heavy metals distribution.

Carbonate saturation in the water column of station M8_056 off Cap Sao Vincente, Portugal (Table 1)

Changes in the dissolved oxygen content, the alkalinity, and the pH in sea water near the ocean floor are interpreted in terms of chemical and biochemical processes at the sediment water interface. A simple model provides a plausible explanation of the observed phenomena. Special emphasis is given to the importance of borate corrections in the calculation of the solution effects of calcium carbonate.