Extreme heat events will become more frequent under anthropogenic climate change, especially in Mediterranean ecosystems. Microhabitats can considerably moderate (buffer) the effects of extreme weather events and hence facilitate the persistence of some components of the biodiversity. We investigate the microclimatic moderation provided by two important microhabitats (cavities formed by the lea...

Leaf area index (LAI) is an important ecological parameter that characterizes the interface between a vegetation canopy and the atmosphere. Indirect measurements of LAI using optical techniques such as the LAI-2000 plant canopy analyzer have been routinely conducted for different vegetation canopies including forests and agricultural crops. However, little attention has been paid to shrub canop...

Accurate simulations of terrestrial carbon assimilation and canopy transpiration are needed for both climate modeling and vegetation dynamics. Coupled stomatal conductance and carbon assimilation (A gs) models have been widely used as part of land surface parameterizations in climate models to describe the biogeophysical and biogeochemical roles of terrestrial vegetation. Differences in various...

[1] The bulk velocity Ub in streams is conventionally estimated from Manning’s equation, but difficulties remain in parameterizing the roughness coefficient n when the streambed is covered with vegetation. A two-layer velocity model is proposed to determine n and Ub for the submerged vegetation case. The modeled n is derived as a function of flow and vegetation properties that can be inferred f...

1 This paper describes mean and turbulent flow and mass transport in the presence of aquatic 2 vegetation. Within emergent canopies, the turbulent length-scales are set by the stem diameter and 3 spacing, and the mean flow is determined by the distribution of canopy frontal area. Sparse 4 submerged canopies enhance bed roughness and near-bed turbulence, but the velocity profile 5 remains logari...

An analytical model was developed to describe in-canopy vertical distribution of ammonia (NH(3)) sources and sinks and vertical fluxes in a fertilized agricultural setting using measured in-canopy mean NH(3) concentration and wind speed profiles. This model was applied to quantify in-canopy air-surface exchange rates and above-canopy NH(3) fluxes in a fertilized corn (Zea mays) field. Modeled a...

Vegetation structure, including forest canopy height, is an important input variable to fire behavior modeling systems for simulating wildfire behavior. As such, forest canopy height is one of a nationwide suite of products generated by the LANDFIRE program. In the past, LANDFIRE has relied on a combination of field observations and Landsat imagery to develop existing vegetation structure produ...

re-vegetation of bare soil is believed to increase, or at least maintain the organic matter levels of soil. the aim of this study was to investigate the soil characteristics changes, nutrient pool sizes and their availability under mid canopy, and canopy gap positions of saltbush in an area re-vegetated with atriplex lentiformis. some of the physical and chemical soil characteristics (the parti...

Regeneration success of canopy dominants is linked to multiple factors, including the ability of their seedlings to survive browsing and to utilize available resources in the understory. In remnant upland northern white cedar Thuja occidentalis L. forests, e€ects of browsing on recruitment of cedar seedlings were evaluated at 7 sites, including known deer yards, located on a portion of the Lake...

A topic of recurring interest in ecological research is the degree to which vegetation structure influences the distribution and abundance of species. Here we test the applicability of remote sensing, particularly novel use of waveform lidar measurements, for quantifying the habitat heterogeneity of a contiguous northern hardwoods forest in the northeastern United States. We apply these results...