We compared the distribution of sympatric Ixodes scapularis Say and Amblyomma americanum (L.) within several suitable forested habitats at different spatial scales and characterized differences in microhabitat features accounting for the observed distribution of questing ticks. We used automatic data loggers placed in the shrub and litter layers to contrast mesoclimate and microclimate conditio...

A detailed sensitivity analysis investigating the effect of woody elements introduced into the Discrete Anisotropic Radiative Transfer (DART)model on the nadir bidirectional reflectance factor (BRF) for a simulated Norway spruce canopy was performed at a very high spatial resolution(modelling resolution 0.2 m, output pixel size 0.4 m). We used such a high resolution to be able to parame...

Title of Document: ENHANCEMENT OF A CANOPY REFLECTANCE MODEL FOR UNDERSTANDING THE SPECULAR AND SPECTRAL EFFECTS OF AN AQUATIC BACKGROUND IN AN INUNDATED TIDAL MARSH Kevin Ross Turpie, Ph.D., 2012 Directed By: Professor Michael Kearney, Department of Geographical Sciences The presence of water produces unique specular and spectral characteristics in an inundated tidal marsh canopy. The aquatic ...

Prediction of soil characteristics over large areas is desirable for environmental modeling. In arid environments, soil characteristics often show strong ecological connectivity with natural vegetation, specifically biomass and/or canopy cover, suggesting that the soil characteristics may be predicted from vegetation data. The objective of this study was to predict soil infiltration characteris...

Relationship between fraction of radiation absorbed by photosynthesizing maize and soybean canopies and NDVI from remotely sensed data taken at close range and from MODIS 250 m resolution data" a b s t r a c t a r t i c l e i n f o The fraction of incident photosynthetically active radiation absorbed by the photosynthesizing tissue in a canopy (fAPAR) is a key variable in the assessment of vege...

We installed a field experiment to support the development of protocols to restore longleaf pine (Pinus palustris Mill.) to existing mature loblolly pine (P. taeda L.) stands at Camp Lejeune, NC. Seven canopy treatments included four uniform and three gap treatments. The four uniform treatments were defined by target residual basal area (BA) [control (uncut), BA9, BA4.5, and BA0 (clearcut) m2/h...

A new moisture adjusted vegetation index (MAVI) is proposed using the red, near infrared, and shortwave infrared (SWIR) reflectance in band-ratio form in this paper. The effectiveness of MAVI in retrieving leaf area index (LAI) is investigated using Landsat-5 data and field LAI measurements in two forest and two grassland areas. The ability of MAVI to retrieve forest LAI under different backgro...

Alterations in under-canopy resource availability associated with elevated ponderosa pine (Pinus ponderosa Dougl.) abundance can negatively influence understory vegetation. Experimental evidence linking under-canopy resource availability and understory vegetation is scarce. Yet this information would be beneficial in developing management strategies to recover desired understory species. We tes...

Researches have shown that 3D vegetation structure exerts a strong influence on radiation transmission and changes radiation and energy balance at the land surface. Vegetation spatial structure including plant height, biomass, vertical and horizontal heterogeneity, is an important factor influencing the exchanges of matter and energy between the landscape and atmosphere, and the biodiversity of...

PURPOSE: This technical note uses a modeling approach to examine the impacts of suspended sediment concentrations and current velocity on the persistence of submersed macrophytes in a shallow aquatic system. Studies were conducted on Peoria Lake, Illinois, spanning historical times when a meadow-forming species (Vallisneria americana) successively thrived and disappeared, and current times when...