Universidad de Talca
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    Effect of cover and fertilization on the early development of Nothofagus alessandrii nursery container seedlings
    Autores: Santelices, R.; Cerrillo, R.M.N.; Drake, F.; Mena, C.
    Nothofagus alessandrii is an endangered species. Yet, available information for the propagation and nursery cultivation of this species is conspicuously lacking. To this end, we studied the effect of cover and fertilization on early growth of nursery seedlings over one growing season. Using a split plot experimental design with completely random fixed-effect blocks we monitored seedling growth with three levels of shade (plastic net Raschel (R) of 35, 50, y 80 %) and three doses of slow-release fertilizer (4, 6, and 10 g of Osmocote (R) per litter of growth media). Results demonstrated a significant effect of shade treatments on seedling development. Differences between seedlings treated with 35-50 % when compared with those treated with 80 % cultivated were observed on the evaluated attributes. In general, fertilization did not affect seedling development. In conclusion, it is more efficient to cultivate N. alessandrii nursery seedlings at 35 % shade and 4 g L-1 fertilization. Under this scenario, it is possible to produce plants, on average, with 28 cm in stem length; 4 mm of root collar diameter; 3.2 g plant(-1) total biomass; and quality indices of 6.9 (slenderness), 2.2 (root-shoot), and 2.1 (Dickson).
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    Green area and vegetation cover indexes for Parral city (Chile) using Photointerpretation and GIS
    Autores: Mena, C.; Ormazabal, Y.; Morales, Y.; Santelices, R.; Gajardo, J.
    he importance of the green areas is increasing since they are an important factor in the health and welfare of urban population. Therefore, in Parral city, in Central Chile, it was quantified and analyzed the availability of green areas and vegetation cover, using aerial photographs scale 1: 10000 and Geographic Information Systems (GIS). In a first stage, urban street trees were quantified through a simple random sample of twenty-four units with field measurements combined with measurements on aerial photographs, from which it was obtained the surface provided. Subsequently, through the creation of GIS layers, the surface of existing green areas and available open spaces were obtained. In addition, through supervised digital classification, the surface covered by urban forestry in private spaces was calculated. Quantity indexes show that Parral city currently has 12.72 ha of green areas, equivalent to 4.82 m(2)/hab, which implies a green area frequency of 0.022 m(2)/m(2). These values could be improved, if the available open space are incorporated and thereby reach 12.06 m(2) per inhabitant. In relation with availability indexes it was established that the average of accessibility to a green area is 327.2 m. Moreover, assuming a buffer of 200 m around the green areas, it was determined that there are 5160 houses with the basic service (56.4%). By incorporating the available open spaces, these values decrease significantly obtaining an average of accessibility to a green area of 213.7 m and coverage of basic service of 79.2%. Finally, it was estimated that the existing vegetation within the urban blocks (urban forest in private spaces) represents an important resource 17.8 times larger than urban street trees, so it should be considered within the municipal plans and policies.