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The purpose of the present study was to isolate and characterize ailanthone-rich materials from the bark of the deciduous tree Ailanthus altissima (Mill.) Swingle and to assess their herbicide activity on selected herbaceous species. Ailanthone-rich fractions were obtained from A. altissima bark by extraction with dichloromethane and ethyl acetate and subsequent purification of these crude extracts, and of the remaining water mixture after solvent extraction, by means of gel permeation chromatography. A number of fractions were isolated and characterized for ailanthone content. A dichloromethane fraction was shown to contain 92% w/w of ailanthone, as demonstrated by HPLC and NMR analysis. A significant pre-emergence herbicide activity was found for most of the extracts which was directly correlated to ailanthone concentration. A remarkable combined pre- and post-emergence herbicide activity was found for a specific fraction. These results indicate that the bark of A. altissima may represent an interesting source for the production of natural herbicides for use in agriculture.

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The growing interest in the development of chains for the use of agroforestry biomass for energy demand, is due to the awareness they are a crucial element to mitigate the global climatic change effects. The true effort is to have a reliable estimation of biomass availability by some instruments like forest management plans, which allow to locate the forest supply and to know the forest biomass availability in a medium period. In this paper we carried out a decision analysis by geographic information system, in Tuscia Romana area comprising 11 municipalities for a total amount of 813 km 2 . An estimation was carried out taking into account the bibliographic data on the analyzed species, reporting the biomass in weight taken out by the forest cut utilization. A comparison was also performed in field on chestnut trees cut in a sampling area near Bracciano and in a close sawmill. The results show long, medium and short-term dynamics, but some critical points were found related to the process of estimation and to the real procurement of biomass in some years. The results suggest to be care in a possible project of a biomass plant.

Thinning is an essential practice in Mediterranean pine forests management but is rarely applied because of the high harvesting costs. The new market of bioenergy products could give a profit to wood biomass harvesting activities, though the drawbacks of elevated supply chain costs, related to technical problems and lack of knowledge about the wood quality have to be overcome in advance. This study analyzed technical, economic, energy and environmental factors of a pine stand thinning in Central Italy, where collected biomass was directed to energy, in order to give a decisional support to reach economical profitability and environmental sustainability in thinning practices. The introduction of Full Tree System maximized the recovery of available biomass, full tree chipping produced material with Heating Value superior than single tree components. The use of a felling frame in motor-manual felling in comparison with the traditional chainsaw reduced operator effort, increasing the number of felled trees per hour, when the stump diameter remained under 15 cm. The energy wood supply chain is not sustainable from an economic point of view, the profitability could be reached only acting on suggested technical levers and particularly reducing costs of hauling operation. The estimation of output/input energy ratio in the supply chain underlined the feasibility of thinning practices for energy. The assessment of CO2 emissions confirmed the environmental sustainability of biomass supply chain in energy when compared to traditional fossil fuels. Study conclusions provide the guidelines for thinning treatment in Mediterranean pine stands, in order to reach environmental and economic sustainability of these practices