Mixed-species growth models are needed as a synthesis of ecological knowledge and for guiding forest management. Individual-tree models have been commonly used, but the difficulties of reliably scaling from the individual to the stand level are often underestimated. Emergent properties and statistical issues limit the effectiveness of reductionist approaches. A more holistic modelling of aggreg...

hyrcanian forests are the most valuable forests in the north of iran and industrial harvesting occurs only in this area. it is a productive region near the southern coast of caspian sea. in these forests mixed beech stands mostly shown uneven-aged structure that is managed under selection system. in order to determine the priority of uneven aged method not only from an ecological view, but also...

The Community Preventive Services Task Force concludes there is insufficient evidence to determine the effectiveness of stand-alone mass media campaigns to increase physical activity at the population level. Additional research is needed to determine effectiveness.

This paper presents a set-up optimization system developed to calculate reduction for each stand of a four stand tandem cold mill installed at Cosipa plant, Brazil. This optimization system is composed of an initialization phase and an optimization phase. The initialization phase consists of a non-iterative calculation procedure, proposed as an alternative for the iterative algorithm presented ...

Knowledge is limited about whether root nutrient concentrations are affected by mixtures of tree species and interspecific root competition. The goal of this field study was to investigate root nutrient element concentrations in relation to root and ectomycorrhizal (EM) diversity in six different mixtures of beech (Fagus sylvatica), ash (Fraxinus excelsior) and lime (Tilia sp.) in an old-growth...

Large areas of forests in the Pacific Northwest are being transformed to younger forests, yet little is known about the impact this may have on hydrological cycles. Previous work suggests that old trees use less water per unit leaf area or sapwood area than young mature trees of the same species in similar environments. Do old forests, therefore, use less water than young mature forests in simi...

Patterns of biomass and carbon (C) storage distribution across Chinese pine (Pinus tabulaeformis) natural secondary forests are poorly documented. The objectives of this study were to examine the biomass and C pools of the major ecosystem components in a replicated age sequence of P. tabulaeformis secondary forest stands in Northern China. Within each stand, biomass of above- and belowground tr...

A sub-micronewton level thrust stand is used to evaluate the performance of five different microthrusters. Using a torsional balance design, the JPL microthrust stand (μTS) is capable of measuring steady-state thrust as low as 1 μN with sub-micronewton resolution and an impulse as low as 1 μNs with sub-micronewton-second resolution. The μTS can support a test object with a mass as large as 10 k...

This paper investigates the spatial organization and dynamics of retail markets using establishment level data on entry, exit, and location choice in the retail alcoholic beverage industry. Establishments are classi ̄ed into two groups based on ̄rm a±liation: chain vs. stand-alone stores. Stand-alone stores are further broken down into two categories according to product lines o®ered: diversi ̄ed...