Accepted 13 May 2009 Copyright © EEF ISSN 1399-1183 Mediterranean savannas are landscapes with a continuous herbaceous cover and scattered trees. Savannas are usually intermingled with patches of woodland, shrub-land, treeless grasslands, and crop-lands forming a complex mosaic. Heterogeneity in topography, soil and climate, interactions among species, and the superimposed selective activity of...

Niger, like other Sahelian countries, has experienced severe droughts that have led to the disappearance of vegetation cover in most regions and populations adopt restoration techniques. This is case practice assisted natural regeneration (ANR) developed Maradi region. The objective this study therefore quantify fresh organic matter (FOM) woody plants ANR fields. fields were selected two terroi...

the establishment and survival of seedlings is one of the main objectives of forest management which ensures continues production. the aim of this article is the investigation of dead trees effect on beech and hornbeam seedlings in masal's forests. for this reason, 30 dead trees were selected, and the control trees were selected in four aspects around the dead trees. they were the same as ...

This paper reviews P´olya urn models and their connection to random trees. Basic results are presented, together with proofs that underly the historical evolution of the accompanying thought process. Extensions and generalizations are given according to chronology: • P´olya-Eggenberger’s urn • Bernard Friedman’s urn • Generalized P´olya urns • Extended urn schemes • Invertible urn schemes ...

A degraded oak savanna in southwestern Wisconsin is being restored using intensive cutting of undesirable shrubsbuckthorn (Rhamnus cathartica), prickly ash (Zanthoxylum americanum), honeysuckle (Lonicera spp.)-and selective removal of trees that are crowding the open-grown bur (Quercus macrocar/Ja) and white (Q. alba) oaks. Land use records and historic aerial photographs have been used to guid...