The losses of water by evapotranspiration and evaporation from soil were investigated during two seasons from wheat and lupin crops sown at two times. Evapotranspiration was measured using ventilated chambers and microlysimeters were used within the chambers to measure evaporation from the soil surface. These techniques allowed the partitioning of evapotranspiration into its two components. In ...

Investigating patterns of phylogenetic structure across different life stages of tree species in forests is crucial to understanding forest community assembly, and investigating forest gap influence on the phylogenetic structure of forest regeneration is necessary for understanding forest community assembly. Here, we examine the phylogenetic structure of tree species across life stages from see...

Solar radiation directly and indirectly drives a variety of ecosystem processes. Our aim was to evaluate how tree canopy architecture affects near-ground, incoming solar radiation along gradients of increasing tree cover, referred to as the grassland–forest continuum. We evaluated a common type of canopy architecture: tall trees that generally have their lowest level of foliage high above, rath...

Pfender, W. F., Gent, D. H., and Mahaffee, W. F. 2012. Sensitivity of disease management decision aids to temperature input errors associated with sampling interval and out-of-canopy sensor placement. Plant Dis. 96:726-736. Many plant disease epidemic models, and the disease management decision aids developed from them, are created based on temperature or other weather conditions measured in or...

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 ...

A complex geometric model for describing the 3D structure of plant canopies is presented. The Botanical Plant Modelling System (BPMS) allows a complete (topologically accurate) 3D geometric description of a canopy to be constructed. The model can be used for simulating the optical scattered radiation field of plant canopies, soil, or other topography through Monte Carlo ray tracing, which provi...

BACKGROUND The diversity and composition of the microbial community of tree leaves (the phyllosphere) varies among trees and host species and along spatial, temporal, and environmental gradients. Phyllosphere community variation within the canopy of an individual tree exists but the importance of this variation relative to among-tree and among-species variation is poorly understood. Sampling te...

Trees exposed to elevated CO2 partial pressure ([CO2]) generally show increased rates of photosynthesis and growth, but effects on leaf respiration are more variable. The causes of this variable response are unresolved. We grew 12-year-old sweetgum trees (Liquidambar styraciflua L.) in a Free-Air CO2 Enrichment (FACE) facility in ambient [CO2] (37/44 Pa daytime/nighttime) and elevated [CO2] (57...

Genetic variation in branchlet nutrient (N, P, K, Na, Ca, Mg, Mn and Fe) concentrations and mineral concentration (sum of branchlet P, K, Na, Ca, Mg, Mn and Fe concentrations) of 8-9-year-old hoop pine (Araucaria cunninghamii Ait. ex D. Don) half-sib families was assessed for four canopy positions at a wet site (23 families) and two canopy positions at an N- and water-limiting dry site (22 fami...

As noted by previous researchers, the chimpanzee postcranial anatomy reflects a compromise between the competing demands of arboreal and terrestrial locomotion. In this study, we measured the distance climbed and walked per day in a population of wild chimpanzees and used published equations to calculate the relative daily energy costs. Results were used to test hypotheses regarding the arborea...