The value of small size: loss of forest patches and ecological thresholds in southern Madagascar.

Many services generated by forest ecosystems provide essential support for human well-being. However, the vulnerability of these services to environmental change such as forest fragmentation are still poorly understood. We present spatial modeling of the generation of ecosystem services in a human-dominated landscape where forest habitat patches, protected by local taboos, are located in a matrix of cultivated land in southern Madagascar. Two ecosystem services dependent on the forest habitats were addressed: (1) crop pollination services by wild and semidomesticated bees (Apoidea), essential for local crop production of, for example, beans, and (2) seed dispersal services based on the presence of ring-tailed lemurs (Lemur catta). We studied the vulnerability of these ecosystem services to a plausible scenario of successive destruction of the smallest habitat patches. Our results indicate that, in spite of the fragmented nature of the landscape, the fraction of the landscape presently covered by both crop pollination and seed dispersal services is surprisingly high. It seems that the taboo system, though indirectly and unintentionally, contributes to upholding the generation of these services by protecting the forest patches. Both services are, however, predicted to be very vulnerable to the successive removal of small patches. For crop pollination, the rate of decrease in cover was significant even when only the smallest habitat patches were removed. The capacity for seed dispersal across the landscape displayed several thresholds with habitat patch removal. Our results suggest that, in order to maintain capacity for seed dispersal across the landscape and crop pollination cover in southern Androy, the geographical location of the remaining forest patches is more crucial than their size. We argue that in heavily fragmented production landscapes, small forest patches should increasingly be viewed as essential for maintaining ecosystem services, such as agricultural production, and also should be considered in the ongoing process of tripling the area of protected habitats in Madagascar.     

Characterization of dissolved organic matter from saline soils by fluorescence spectroscopy

In this paper hydrophilic (HI) and hydrophobic (HO) fractions of dissolved organic matter (DOM) extracted from soils at different degrees of salinisation were characterised by means of fluorescence spectroscopy in the emission, excitation and synchronous-scan modes. Results provided evidence of the different chemical nature of DOM fractions and allowed to distinguish hydrophilic and hydrophobic fractions extracted from the same soil substrate. The strong decrease in fluorescence intensity observed with the increasing salinity of the soils can be utilised to obtain information on the salinity level of different soil substrates by comparison of spectral fluorescence intensities.     

Detection of fetomaternal haemorrhage associated with cordocentesis using serum α-fetoprotein and the kleihauer technique

Fetomaternal haemorrhage (FMH) was studied after 46 cordocenteses. α-Fetoprotein (AFP) concentration and Kleihauer staining of maternal blood, taken both before and after the procedure, revealed increases in AFP values of more than 40 per cent in 30 per cent of the patients examined; fetal haemorrhage of more than 0.25 ml was detected in 46 per cent of the cases by the Kleihauer test. In the second trimester of pregnancy both techniques are comparable, while in the third trimester the Kleihauer technique appears to be more sensitive in detecting FMH after cordocentesis. An anterior position of the placenta is a risk factor for FMH.     

Plant Succession, Landscape Management, and the Ecology of Frugivorous Birds in Abandoned Amazonian Pastures

From towers constructed at the interface between second-growth forest and an active and an abandoned pasture, we observed inter-habitat movements of fruit-eating birds in eastern Amazônia. The abandoned pasture was composed of grasses and forbs with a scattering of shrubs and small trees. The active pasture contained a low, uniform bed of grass. A total of 47 frugivorous bird species was recorded in the second-growth forest. We observed that 18 of these species frequented the adjacent abandoned pasture but only 3 were found in the adjacent active pasture. Fruit-eating birds flying from second-growth forest typically spent only a few minutes in the abandoned pasture, and their movements were generally restricted to a pasture belt of 1–80 m along the border with the second-growth forest. Most inter-habitat movement occurred during the rainy season, which coincided with a peak in fruit availability in the abandoned pasture. Just three bird species, Ramphocelus carbo, Tachyphonus rufus , and Thraupis episcopus , accounted for an estimated 70% of the total movement of frugivores between the second-growth forest and the abandoned pasture. All three species spent most of their time in the abandoned pasture foraging on shrubs and trees but exhibited differences in their preference for specific habitat elements and in their seed-defecation habits. An understanding of bird behaviors in altered landscapes provides important information to planners and policy makers concerned with protecting regional biodiversity and maintaining landscape integrity. This research provides a rationale for placing limits on the size of clearings in the Brazilian Amazon.     

Accumulation and Depuration Kinetics of Rotavirus in Mussels Experimentally Contaminated

Bivalve mollusks as filter-feeders concentrate in their digestive tissue microorganisms likely present in the harvesting water, thus becoming risky food especially if consumed raw or poorly cooked. To eliminate bacteria and viruses eventually accumulated, they must undergo a depuration process which efficacy on viruses is on debate. To better clarify the worth of the depuration process on virus elimination from mussels, in this study we investigated rotavirus kinetics of accumulation and depuration in Mytilus galloprovincialis experimentally contaminated. Depuration process was monitored for 9 days and virus residual presence and infectivity were evaluated by real time quantitative polymerase chain reaction, cell culture and electron microscopy at days 1, 2, 3, 5, 7, 9 of depuration. Variables like presence of ozone and of microalgae feeding were also analyzed as possible depuration enhancers. Results showed a two-phase virus removal kinetic with a high decrease in the first 24 h of depuration and 5 days necessary to completely remove rotavirus.