For horocyclic products of percolation subtrees of regular trees, we show almost sure amenability. Under a symmetry condition concerning the growth of the two percolation trees, we show the existence of an increasing Følner sequence (which we call strong amenability).

the effects of initial spacing layout on some allometric characteristics of 12-year-old quercus castaneifolia trees grown in central mazandaran, north of iran were examined. trees were planted in 5 different layouts (1?1, 1.5?1.5, 2?2.5, 2?3 and 4?4 m). tree height, diameter at breast height, natural pruning height and the survival of trees were recorded in each sample plot. tree basal area and...

soil is known as a suitable reservoir for carbon sequestration. the objective of this study was to investigate the capability of haloxylon on sequestration of carbon in sand dunes of yahya abad, sabzevar, in northeastern iran. eighty soil samples were taken from two depths of 0-5 and 5-10 cm under and between haloxylon trees. eight soil profiles under and between haloxylon trees were described ...

the present experiment was carried out to investigate the nutritive value of banana tree leaves and stems silage by use of in vitro gas production and as well in situ nylon bag techniques. experimental treatments were comprised of: 1- stems and leaves of banana trees (control), 2- stems and leaves of banana trees’ silage without addition of any additive, 3- stems and leaves of banana trees’ sil...

this study investigated the factors influencing the decision to plant almonds in the saman region of chaharmahal-bakhtiari province in central iran through conducting an economic survey in 2005. using portfolio investment theory and econometric model esti-mation (shively, 1998), this paper identifies the most important factors influencing the in-dividual farmer’s decision concerning the number ...

We endow the space of rooted planar trees with structure a Hopf algebra. prove that variations such lead to algebras on spaces labeled trees, [Formula: see text]-trees, increasing and sorted trees. These structures are used construct different types permutations. In particular, we obtain new characterizations Malvenuto–Reutenauer Loday–Ronco via

We tested which factors explain the distribution pattern of the epiphytic moss Neckera pennata on three spatial scales using the framework of generalized linear models. First, we tested which factors explained its occurrence in forest stands in a 2500 ha landscape. At this scale, we also tested the effect of the historic landscape structure. We recorded its occurrence in all suitable stands. Th...