Trees play a crucial role in the water, carbon and nitrogen cycle on local, regional and global scales. Understanding the exchange of momentum, heat, water, and CO 2 between trees and the atmosphere is important to assess the impact of drought, deforestation and climate change. Unfortunately, ground measurements of tree properties such as mass and canopy interception of precipitation are often ...

Maximum water temperatures in streams throughout the western USA typically occur in late summer and early autumn, coinciding with low stream flow. However, in the spring-fed Big Springs Creek in northern California, where constant-temperature groundwater springs provide relatively stable stream flow throughout the year, peak water temperatures and maximum diurnal variability occur in spring. We...

We propose to develop, parameterize, and evaluate a global modeling system for simulating land-atmosphere exchanges of water, energy, and carbon that will be applied in both a prognostic climate model (Community Climate System Model, CCSM) and in a global operational diagnostic (data assimilation) model (Land Information System, LIS). The model will be based on improvements to the Community Lan...

The primary role of a crop canopy is to capture sunlight that can be converted to biomass, including sucrose stored in stalks. Canopy development also has a bearing on the amount of water used by the crop and how soon weeds are shaded out. Cultivars are known to differ in the rate of canopy closure in the field, and also differ in traits that determine canopy development, such as leaf size and ...

E (Rn G) cp{es[T(z)] e(z)}/ra (ra rc)/ra [1] Precision irrigation requires a method of quantifying the crop water status or root zone depletion of water to determine when and how where E is the latent heat of vaporization (J m 2 s 1), much water to apply to the soil. Changes in canopy resistance (rc) the change of saturation vapor pressure with temperaand canopy temperatures have the potential ...

Seagrasses serve an important function in the ecology of Florida Bay, providing critical nursery habitat and a food source for a variety of organisms. They also create significant benthic structure that induces drag, altering local hydrodynamics that can influence mixing and nutrient dynamics. Thalassia testudinum seagrass meadows were investigated to determine how shoot density and morphometri...

canopy temperature (ct) is used as a selection tool to improve crop adaptation to drought. the aim of this work was to investigate association of some photosynthetic characters with ct during grain filling in three cereal species. for this objective, a two-year study (2009-2011) was carried out in kurdistan province in western iran. four genotypes of triticale, three cultivars of bread wheat, a...

Thermal imaging has been used in the past for remote detection of regions of canopy showing symptoms of stress, including water deficit stress. Stress indices derived from thermal images have been used as an indicator of canopy water status, but these depend on the choice of reference surfaces and environmental conditions and can be confounded by variations in complex canopy structure. Therefor...

Remote sensing has been proposed as a method for implementing an inseason spring wheat (Triticum aestivum) nitrogen (N) fertilization program. However, in fields where yields are influenced by both water and N stress, accurate N recommendations require that that the N and water stress signals be separated from each other. The objective of this study was to determine the impact of water and N st...