We compare the turbulence statistics of the canopy/roughness sublayer (RSL) and the inertial sublayer (ISL) above. In the RSL the turbulence is more coherent and more efficient at transporting momentum and scalars and in most ways resembles a turbulent mixing layer rather than a boundary layer. To understand these differences we analyse a large-eddy simulation of the flow above and within a veg...

Over the past two decades, several inverse methods have been proposed to estimate scalar source and sink strengths from measured mean concentration profiles within the canopy volume (hereafter termed the ‘inverse’ problem). These inverse methods commonly assumed neutral atmospheric stability conditions for the entire canopy volume. For non-neutral conditions, atmospheric stability corrections i...

Using analyses of data from extant direct numerical simulations and large-eddy simulations of boundary-layer and channel flows over and within urban-type canopies, sectional drag forces, Reynolds and dispersive shear stresses are examined for a range of roughness densities. Using the spatially-averaged mean velocity profiles these quantities allow deduction of the canopy mixing length and secti...

In contrast to herbaceous canopies and forests, savannas are grassland ecosystems with sparsely distributed individual trees, so the canopy is spatially heterogeneous and open, whereas the woody cover in savannas, e.g., tree cover, adversely affects ecosystem structures and functions. Studies have shown that the dynamics of canopy structure are related to available water, climate, and human act...

Understanding changes in community composition caused by invasive species is critical for predicting effects on ecosystem function, particularly when the invasive threatens a foundation species. Here we focus on dynamics of forest structure, composition and microclimate, and how these interact in southern Appalachian riparian forests following invasion by hemlock woolly adelgid, HWA, Adelges ts...

A whole procedure of fully automatic 3D single tree modelling based on LIDAR point cloud is introduced in the paper. The evaluation of the procedure is then delivered by verifying the modelling results with field collecting data in sample plots. With the procedure, individual trees are extracted not only from the top canopy layer but also from the sub canopy layer, 3D shape of the extracted ind...

We investigated changes in chlorophyll a fluorescence from alternate leaf surfaces to assess the intraleaf light acclimation patterns in combination with natural variations in radiation, leaf angles, leaf mass per area (LMA), chlorophyll content (Chl) and leaf optical parameters. Measurements were conducted on bottom- and top-layer leaves of Tilia cordata Mill. (a shade-tolerant sub-canopy spec...

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...

High rural concentrations of ozone (O3) are thought to be stratospheric in origin, advected from upwind urban sources, or photochemically generated locally by natural trace gas emissions. Ozone is known to be transported vertically downward from the above-canopy atmospheric surface layer and destroyed within stomata or on other biological and mineral surfaces. However, here the authors report m...

In urban areas, main air flows from prevailing winds are strongly modified, depending on constructions’ morphology and urban microclimate’s effects. The meteorological data on the wind speed are often available from outside city centres whereas this wind speed is tough to assess in the urban canopy layer. The meteorological models which are developed from regional level to urban canopy layer le...