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  • Author: Dumitrascu Monica x
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Abstract

The soil degraded and changed by the anthropic activity must be monitored and the awareness of the intrinsic processes will allow a pertinent analysis of the effects of the application of the new technologies on the management and the sustainability of the soil.

Two natural and anthropic Phaeozems were analyzed from the point of view of chemical, microbiological characteristics, quality and composition of organic compounds.

Total values of microbial biomass and bacterial and fungal counts were generally twice higher in Calcaric Phaeozems than in Verti-Stagnic Phaeozems.

The content of humic precursors in Calcaric Phaeozems was quantitatively higher than that determined in Verti-stagnic Phaeozems, with a total content of phenols of 14.6mgGAExg−1d.m., polysaccharides and proteins of 97mgxg−1, respectivelly 16.6mgxl−1.

The ascending chromatograms showed specific distribution and higher density of the organic compounds in the CAFT sub-fraction of the Verti-stagnic Phaeozems. Pfeiffer specific chromatograms revealed an enzyme activity much higher than average at the Verti-stagnic Phaeozems, with a well-characterized functional diversity. The nutritional reserve appeared increased but poorly diversified in the Calcaric Phaeozems. Humification processes are intense, colloidal substances are present, the mineral component is very well integrated in the organic material at the Verti-stagnic Phaeozems and complex protein content is well revealed especially in the Calcaric Phaeozems.

Capillary dynamolysis reflected a characteristic pattern of Phaeozems soils, with particularities for each soil type, represented by colors, contours and particular forms of the specific structures developed.

Both soils presented good conditions for sustaining vegetation either natural or cultivated but results indicated that anthropic intervention determined a more dynamic mineralization of organic matter. Further monitoring of soil organic matter dynamics is needed and adjusting management practices for conservation of biodiversity and global ecosystem protection against the effect of anthropic intervention.

Abstract

Soils from rural zones with high natural value (HNV) agriculture systems are an important source of beneficial microbial species that can be useful for various biotechnological purposes, such as transfer of suppressiveness against plant pathogens from suppressive to disease-inducing soils by using inoculation with antagonistic selected strains.

The main goal of the paper was to present the results of the research carried out on strains isolated from soil microbial populations in HNV agriculture system (Mureș county, Romania) responsible for specific suppressiveness against soil-borne phytopathogens. The dual culture method was used for assessing the mechanisms involved in antagonism against a plant pathogenic strain from genus Fusarium.

The global microbial activity measured as soil respiration was intense. Total counts of bacteria and fungi estimated by dilution plate were also high.

The community of heterotrophic aerobic bacteria included 13 species. Associations of fluorescent pseudomonads and actinomycetes were dominant and presented antagonistic activity against Fusarium.

Twenty fungal species presented cellulolytic capability evidenced by growth on culture media with cellulose as sole source of carbon. Over cellulolytic capacity, the selected isolate of Trichoderma viride presented antagonistic activity against pathogenic Fusarium strain. Both biochemical mechanism and hyperparasitism were evidenced as involved in its antifungal activity.

Abstract

Geographical factors play an essential role in the occurrence and spread of invasive species worldwide, and their particular analysis at regional and local scales becomes important in understanding species development patterns. The present paper discusses the relationships between some key geographical factors and the Invasive Terrestrial Plant Species (ITPS) distribution, and their environmental implications in a few protected areas in Romania. The authors focused their attention on three of the foremost invaders (i.e. Amorpha fruticosa, Ailanthus altissima and Fallopia japonica) making use of the information provided by the scientific literature and some illustrative examples developed in the framework of the FP7 enviroGRIDS project. The study is aimed to increase the knowledge of the ITPS and, specifically, to contribute to the geographical understanding of the role played by the driving factors in their distribution and spread in various habitats and ecosystems. The results will further support the control efforts in protected areas where, often, valuable native species are at risk of being replaced by non-native species.

Abstract

The green economy emerges differently depending on each region particular features, as well as local economic strengths and weaknesses; solar energy however, represents the way regional and local natural potentials are valorized. The current paper brings to our attention aspects related to the economic and legislative factors influencing the use and territorial distribution of solar energy, as a component of the Romanian renewable energy industry at all territorial levels: the national characteristics of the use of renewable energy resources are highlighted through the analysis of dynamics of official statistical variables (National Institute of Statistics); at regional and county levels, the analysis highlights the territorial differences in the use of solar energy; analysis at local level reveals the environmental and socio-economic effects of the of solar energy use (i.e. photovoltaic parks), as indicated by the information provided by a questionnaire survey carry out in Giurgiu County (case study).