Search results for "FOREST"
showing 10 items of 3780 documents
Interesterification of rapeseed oil catalyzed by tin octoate
2014
The interesterification of rapeseed oil was performed for the first time by using tin octoate as Lewis acid homogeneous catalysts and methyl or ethyl acetate as acyl acceptors in a batch reactor, within the temperature range 393–483 K. The yields in fatty acid ethyl esters (FAEE) and triacetin (TA) after 20 h of reaction time increased from 8% and 2%–to 61% and 22%, respectively, when the reaction temperature increased from 423 to 483 K. An optimum value of 40 for the acyl acceptor to oil molar ratio was found to be necessary to match good fatty acid alkyl ester yields with high enough reaction rate. The rate of generation of esters was significantly higher when methyl acetate was used as a…
High variability of edge effects on forest vegetation diversity
2012
National audience; The influence of edges on vegetation diversity in forest fragments is an important issue for biodiversity conservation because of the large part of temperate woodlands concerned. In numerous empirical studies, a general pattern has been identified; it is described as two zones: the edge where plant distribution is linked to the distance from the forest border, the core area where the variability of vegetation is not linked to this distance. We present results of a study aiming at measuring the edge effects on vegetation in forest fragments in south-western France and at identifying potential factors of their variability. Vegetation was sampled in 28 transects constituted …
From the safeguard of Caretta caretta nesting sites to in-situ conservation of locally endangered plants: combined effects of the LIFE Project al Spi…
2013
Hot spots, indicator taxa, complementarity and optimal networks of taiga
2000
If hot spots for different taxa coincide, priority-setting surveys in a region could be carried out more cheaply by focusing on indicator taxa. Several previous studies show that hot spots of different taxa rarely coincide. However, in tropical areas indicator taxa may be used in selecting complementary networks to represent biodiversity as a whole. We studied beetles (Coleoptera), Heteroptera, polypores or bracket fungi (Polyporaceae) and vascular plants of old growth boreal taiga forests. Optimal networks for Heteroptera maximized the high overall species richness of beetles and vascular plants, but these networks were least favourable options for polypores. Polypores are an important gro…
Biodiversità: manuale per l’uso. Illustrato con 100 foto di Toni Puma.
2010
I Lepidotteri Ropaloceri (Insecta Lepidoptera) del bosco della Ficuzza: stato delle conoscenze e possibili relazioni tra il loro status e i cambiamen…
2012
Risultati dell’indagine preliminare per l’individuazione dei boschi vetusti in Sicilia
2015
La gran parte degli ecosistemi forestali del Mediterraneo è stata modificata ed utilizzata dall’uomo da millenni. I sistemi forestali più vicini alle condizioni di naturalità sono quelli non più gestiti e/o sottoposti ad un efficace regime di protezione e che tendono a recuperare caratteri strutturali e di funzionamento ecosistemico simili a quelli delle formazioni primarie originali. In Sicilia le conoscenze sulla presenza e diffusione dei boschi vetusti sono ad uno stadio preliminare. Nel più recente inventario forestale regionale è stata effettuata una prima selezione di 18 soprassuoli forestali considerati potenzialmente vetusti, che ricoprono 472 ettari di superficie. Sulla base dell’a…