introduction amount and vertical distribution of leaf area are essential for estimating interception and utilization of solar radiation of crop canopies and, consequently dry matter accumulation (valentinuz & tollenaar, 2006). vertical distribution of leaf area is leaf areas per horizontal layers, based on height (boedhram et al., 2001). above-ground biomass is one of the central traits in func...

We evaluated the abundance of nonnative plants on fuel breaks and in adjacent untreated areas to determine if fuel treatments promote the invasion of nonnative plant species. Understanding the relationship between fuel treatments and nonnative plants is becoming increasingly important as federal and state agencies are currently implementing large fuel treatment programs throughout the United St...

Global climate has changed over the past century. Precipitation amounts and intensities are increasing. In this study we investigated the response of seven soil erosion models to a few basic precipitation and vegetation related parameters using common data from one humid and one semiarid watershed. Perturbations were made to inputs for rainfall intensities and amounts, and to ground surface cov...

infiltration rate of water into the soil depends on the factors such as rock and litter cover, canopy cover, rainfall intensity, coarse material, land slope, soil texture and amount of initial soil moisture. the most important factors that are effective in the water infiltration rate of rangelands are livestock trampling and vegetation reduction due to the overgrazing. in present study, through...

this research aimed to evaluate the effect of planting seasons (autumn and spring) on 10 accessions of two species of astragalus effusus and astragalus brachyodontus in the field condition (homand absard station, damavand). after preparing the seedbed, the plant species were planted on two lines in 2 m, where the spacing between the lines of each accession was 0.5 m, and the spacing between the...

Question: How are the effects of mineral soil properties on understory plant species richness propagated through a network of processes involving the forest overstory, soil organic matter, soil nitrogen, and understory plant abundance? Location: North-central Arizona, USA. Methods: We sampled 75 0.05-ha plots across a broad soil gradient in a Pinus ponderosa (ponderosa pine) forest ecosystem. W...