Über die Beziehungen zwischen einigen biotischen und abiotischen Faktoren im Latemar-Forst (Bozen)
An investigation has been carried out in the forest of Latemar (the Italian central eastern Alps), dominated byPicea excelsa withAbies alba, Larix europaea andPinus cembra, on the interactions between humus type (tabs 1, 2), litter and understory (including natural regeneration) composition on one hand and tree layer canopy and altitude on the other hand. Starting from ecological profiles, entropy-species (fig. 2, tab. 3) and entropy-factor have been calculated for the factors examined (tab. 4). This way it has been possible to determine the mutual information, the correct ecological profiles and the species groups index for the humus type (tab. 5), height (tab. 6) and canopy (tab. 7), which has allowed to grade species behaviour as regards investigated factors and consequently to single out three groups of species with similar ecological requirements (tab. 8). Moreover litter-humus entropy (tab. 9) and the same cybernetic parameters have been determined for the factor humus. The distribution of each group of species index is characterized by different combination of local factors (tab. 8): Humus type variations depend to a great extent on tree layer canopy and, through this layer, on the resulting litter composition and density: the “correcting” action of grasses with a low C:N on humus evolution is evident (tab. 10). From the silvicultural standpoint, leaving out uniform methods on large areas and chiefly clearcuts, an elastic treatment seems to be recommended, adhering to the actual conditions of forest and soil structure in order to achieve the density with major chances to secure favourable conditions of bioclimate, understory, humus and consequently regeneration. In the “semplified” forest ecosystem, as the investigated one, where natural levels of consumers (herbivores and carnivores) are actually missing, functionality may be secured through proper cuts only and by regularly restoring the nutrients of the litter, here almost entirely vegetal, to the cycle.
Application de la Theorie de L’information a L’etude de L’homogeneite et de la Structure de la Vegetation
Depuis que les botanistes ont commence a etudier l’ensemble de la vegetation, et non plus seulement les especes prises isolement, ils ont porte leur attention sur l’homogeneite et sur la structure du tapis vegetal (Wahlenberg) et plus de deux cent references pourraient etre citees sur ce sujet. L’estimation quantitative de cette homogeneite a ete tentee des 1901 par Jaccard. De nos jours, il ne se passe guere de mois sans qu’une publication soit consacree a ce probleme, et Nordhagen (1927) a fait preuve d’une grande clairvoyance en ecrivant: »Le probleme de l’homogeneite est le probleme central de la phytosociologie«.
Bestimmungsbuch und Systematik der Böden Europas
Libro de 392 paginas, publicado en Stutgart por el Consejo Superior de Investigaciones Cientificas en 1952. Ferdinand Enke Verlag (Editorial) - Incluye 3 figuras en las paginas 33, 34 y 35; ademas incorpora XXVI (26) laminas a todo color excepto la I y la II.