This research aims to evaluate the effects of seed scarification on five perennialAstragalus species including A. effusus, A. vegetus, A. subsecundus, A. brevidens and A.cyclophyllon in the field conditions. Seeds were sown after scarification with sandpaper byhand in the field of Homand Absard Rangeland Research Station, Damavand, Iran in autumnin 2008. The seeds were sown using split plot des...

the current study aims to ordinate ecological groups in the wetlands of northern and eastern slopes of the sabalan mountain and investigate their relationship with environmental variables. the location of wetlands was found using field surveys and satellite images. in total, 32 wetland sites were identified for the sampling purpose. 320 sample plots (relevé) were selected using the systematic-r...

Mangrove forests are one of the most productive and carbon dense ecosystems that are only found at tidally inundated coastal areas. Forest canopy height is an important measure for modeling carbon and biomass dynamics, as well as land cover change. By taking advantage of the flat terrain and dense canopy cover, the present study derived digital surface models (DSMs) using stereo-photogrammetric...

.......................................................................................................................................... 1 Acknowledgements ......................................................................................................................... 2 Introduction .........................................................................................................

Changes to land use and disturbance frequency threaten disturbance-dependent Lepidoptera within sandplain habitats of the northeastern United States. The frosted elfin (Callophrys irus) is a rare and declining monophagous butterfly that is found in xeric open habitats maintained by disturbance. We surveyed potential habitat for adult frosted elfins at four sites containing frosted elfin populat...

The effects of soil disturbance on the nematode community were assessed at 30 sites on the outer coastal plain of Mississippi, representing four ages since soil disturbance plus a control group of six undisturbed sites. Thirty-five taxa were encountered, dominated in abundance and taxonomic richness by plant and bacterial feeders. Nematodes were more abundant and more taxonomically rich in site...

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...

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 ...