Characterization and Risk Assessment of the Collapse of the Woody Stand of Ecosystems of the Fathala Forest (Saloum Delta Biosphere Reserve-Senegal)

The objective of this study is to characterize and assess the risk of collapse of woody plant formations in the Fathala forest. In recent years, this forest has suffered a sharp reduction in its plant cover to the point of compromising the survival of populations of certain animal species such as the Red colobuses. The methods used are respectively constituted by the transect method, the dendrometric statements method and that of establishing the red list of ecosystems of the IUCN. The specific richness comprises 56 species divided into 47 genera and 22 families. The density is higher in the unfenced area (369 ind/ha in clear forest and 53 ind/ha in gallery forest) compared to the fenced area (160 ind/ha in clear forest versus 48 ind/ha in gallery forest). A study of the plant formations shows a strong degradation of the ecosystems passing from a clear and dry Sudanese forest to a wooded savannah. The cover rate in the fenced area is 20% in gallery forests and 25% in clear forests;in the unfenced area, it is 19% and 23% in gallery forests and clear forests, respectively. The application of the IUCN criteria shows an annual rate of collapse is -6 ind/ha in gallery forests and -4 ind/ha in clear forests. The annual rate of cover collapse would be -3.75% and -2.9% for gallery forests and clear forests, respectively. These results classify the forest in the Critically Endangered category. The main factors responsible for this degradation are, among others, anthropogenic actions and climatic pejoration. These results could constitute a basic tool for undertaking an improvement in the management of this forest, which is a living environment for an animal species.

Bioclimate-Vegetation Interrelations along the Pacific Rim of North America

This study was designed to examine relationships between climate and vegetation of the Pacific rim of North America, from the Mediterranean deserts of California to Alaska’s boreal taiga. Relations were inferred from temperature and rainfall data recorded at 457 weather stations and by sampling the vegetation around these stations. Climate data were used to construct climatograms, calculate forty one variables and detect main latitudinal and longitudinal gradients. In order to identify the best functions able to relate our variables, polynomial and non-polynomial regressions were performed. The k-means algorithm was the clustering method used to validate the variables that could best support our bioclimatic classification. The variable that best fitted our classification was finally used to prepare a discriminatory key for bioclimates. Across this extensive area three macrobioclimates were identified, Mediterranean, Temperate and Bo- real, within which we were able to distinguish nine bioclimates. Finally, we relate the different types of potential natural vegetation to each of these bioclimates and describe their floristic composition and physiognomy.

Rhizosphere microbial markers (micro-markers): A new physical examination indicator for traditional Chinese medicines

Rhizosphere microorganisms,as one of the most important components of the soil microbiota and plant holobiont,play a key role in the medicinal plant-soil ecosystem,which are closely related to the growth,adaptability,nutrient absorption,stress tolerance and pathogen resistance of host plants.In recent years,with the wide application of molecular biology and omics technologies,the outcomes of rhizosphere microorganisms on the health,biomass production and secondary metabolite biosynthesis of medicinal plants have received extensive attention.However,whether or to what extent rhizosphere microorganisms can contribute to the construction of the quality evaluation system of Chinese medicinal materials is still elusive.Based on the significant role of rhizosphere microbes in the survival and quality formation of medicinal plants,this paper proposed a new concept of rhizosphere microbial markers(micro-markers),expounded the relevant research methods and ideas of applying the new concept,highlighted the importance of micro-markers in the quality evaluation and control system of traditional Chinese medicines(TCMs),and introduced the potential value in soil environmental assessment,plant pest control and quality assessment of TCMs.It provides reference for developing ecological planting of TCMs and ensuring the production of high quality TCMs by regulating rhizosphere microbial communities.

Control of aliphatic halogenated DBP precursors with multiple drinking water treatment processes： Formation potential and integrated toxicity

The comprehensive control efficiency for the formation potentials（FPs） of a range of regulated and unregulated halogenated disinfection by-products（DBPs）（including carbonaceous DBPs（C-DBPs）, nitrogenous DBPs（N-DBPs）, and iodinated DBPs（I-DBPs）） with the multiple drinking water treatment processes, including pre-ozonation, conventional treatment（coagulation–sedimentation, pre-sand filtration）, ozone-biological activated carbon（O_3-BAC） advanced treatment, and post-sand filtration, was investigated. The potential toxic risks of DBPs by combing their FPs and toxicity values were also evaluated.The results showed that the multiple drinking water treatment processes had superior performance in removing organic/inorganic precursors and reducing the formation of a range of halogenated DBPs. Therein, ozonation significantly removed bromide and iodide,and thus reduced the formation of brominated and iodinated DBPs. The removal of organic carbon and nitrogen precursors by the conventional treatment processes was substantially improved by O_3-BAC advanced treatment, and thus prevented the formation of chlorinated C-DBPs and N-DBPs. However, BAC filtration leads to the increased formation of brominated C-DBPs and N-DBPs due to the increase of bromide/DOC and bromide/DON.After the whole multiple treatment processes, the rank order for integrated toxic risk values caused by these halogenated DBPs was haloacetonitriles（HANs）》haloacetamides（HAMs） 〉haloacetic acids（HAAs） 〉 trihalomethanes（THMs） 〉 halonitromethanes（HNMs） 》I-DBPs（I-HAMs and I-THMs）. I-DBPs failed to cause high integrated toxic risk because of their very low FPs. The significant higher integrated toxic risk value caused by HANs than other halogenated DBPs cannot be ignored.