We examined UV-B radiation flux and its environmental control within and among streams of northern Michigan. UV-B flux was estimated in streams by plastic dosimetry strips, which allow for the simultaneous and repeated in situ measurement of solar radiation. During the summer of 2004, UV-B flux was measured across depth gradients and along longitudinal transects in seven streams, which were cho...

We examined patterns of shrub species diversity relative to landscape-scale variability in environmental factors within two watersheds on the coastal flank of the Santa Ynez Mountains, California. Shrub species richness and dominance was sampled at a hierarchy of spatial units using a highpowered telescope from remote vantage points. Explanatory variables included field estimates of total canop...

The main objective of this study was to develop a nondestructive method for monitoring cotton growth and N status using a digital camera. Digital images were taken of the cotton canopies between emergence and full bloom. The green and red values were extracted from the digital images and then used to calculate canopy cover. The values of canopy cover were closely correlated with the normalized ...

Estimation of forest canopy cover has recently been included in many forest inventory programmes. In this study, after discussing how canopy cover is defined, different ground-based canopy cover estimation techniques are compared to determine which would be the most feasible for a large scale forest inventory. Canopy cover was estimated in 19 Scots pine or Norway spruce dominated plots using th...

Water erosion causes severe soil damage in northern forests of Iran which is associated with different rut depths in skid trails. The aim of this study was to assess rutting and soil displacement on skid trails to mitigate water erosion. Therefore the research was carried out in eight parcels of district No 3 of Shafarood Forest in the North of Iran. In order to evaluate the amount of erosion i...

Two tributary streams (Fourmile branch and Pen branch) located on the US Department of Energy’s Savannah river site in west-central South Carolina, USA received thermal discharges from nuclear production reactors for over 30 years. Effluent releases produced stream water temperatures of over 50°C and stream flows of ten times above their base level. Consequently, existing plant and animal commu...