The Caspian (Hyrcanian) lowland forest zone in northern Iran is characterized by small remnant alder forest communities, dominated or subdominated with an Euxino-Hyrcanian element, Alnus glutinosa ssp. barbata. The first floristic inventory of these alder forests in northern Iran is presented. The floristic catalogue is based on the data of 133 phytosociological releves in eight different alder...

forest reserves are one of the most important approaches in ecosystem management in iran. in order to determine the effects of reserve management on plants diversity (woody plants and ground flora) in three zones (core zone, buffer zone, and transmission zone of chamhesar pear forest reserve), we mapped land form units. then 18 main sampling units (20×50=1000 m2) distributed randomly were chose...

Between 1945 and 1965, 1.82 million hectares, or about 17 percent of the total commercial forestland in Oregon, were treated with 2.02 million kg DDT. Detectable residues of this insecticide might be present in forest soils, even those which have never received a direct application of insecticide. Forest floor and mineral soil samples were collected along four east-west transects across the Coa...

The contribution of the understorey vegetation to the spectral reflectance from the top of a forest canopy was investigated by the use of a forest canopy reflectance model. Detailed field data, i.e. forest leaf area index (LAI), tree structural parameters like the height, diameter and crown length of the trees, and the composition, distribution and reflectance of the forest floor, was collected...

We propose a novel methodology, forest floor, to visualize and interpret random forest (RF) models. RF is a popular and useful tool for non-linear multi-variate classification and regression, which yields a good trade-off between robustness (low variance) and adaptiveness (low bias). Direct interpretation of a RF model is difficult, as the explicit ensemble model of hundreds of deep trees is co...

The Lake Tahoe basin, located along the California and Nevada border between the Carson and Sierra Nevada mountain ranges, represents a complex forested ecosystem consisting of numerous sub-watersheds and tributaries that discharge directly to Lake Tahoe. This synthesis focuses on historical and current nutrient pools and the effects of biomass management in watersheds of the basin relative to ...

Soil nutrient concentrations decreased in an aggrading southern Appalachian forest over a 20-year period. Construction of nutrient budgets showed significant nutrient sequestration aboveground including increased forest floor mass. We hypothesized that the changes in forest floor mass resulted from decreased litter decomposition rates because of decreased litter quality. In 1992 and 1993, we re...

Management of ungulates is contested ground that lacks stakeholder agreement on desirable population sizes and management approaches. Unfortunately, we often miss information about extent of local impacts, for example on plant communities, to guide management decisions. Typical vegetation impact assessments like the woody browse index do not assess herbaceous plants, and differences in browse s...