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...

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. [1] This paper describes the transition from open channel flow to flow over submerged vegetation using velocity mea...

We examined the effects of shade from multiple kelp canopy layers (surface Macrocystis pyrifera canopy, understory Pterygophora californica canopy), both individually and in combination, on an understory algal assemblage in a central Californian kelp forest. The removal of both kelp canopies resulted in a dense recruitment of the understory brown alga Desmarestia ligulata that formed a third ca...

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...

The distribution and abundance of Ascophyllum nodosum, Fucus serratus and F. vesiculosus were described at four sheltered, rocky shores in the south of the Isle of Man. Canopy removal experiments were performed at mid tide level of one sheltered, canopy dominated shore to investigate the interactions between the dominant canopy alga, Ascophyllum nodosum and the competitively inferior canopy spe...

Aquatic flow over a submerged vegetation canopy is a ubiquitous example of flow adjacent to a permeable medium. Aquatic canopy flows, however, have two important distinguishing features. Firstly, submerged vegetation typically grows in shallow regions. Consequently, the roughness sublayer, the region where the drag length scale of the canopy is dynamically important, can often encompass the ent...

The concept of canopy spectral invariants states that simple algebraic combinations of leaf and canopy spectral transmittance and reflectance become wavelength independent and determine a small set of canopy structure specific variables. This set of structural variables specify the spectral response of a vegetation canopy to the incident solar radiation and allow for a simple and accurate param...

Quercus-Pinus forests of the eastern USA cover millions of hectares and span a variety of ecoregions. Understanding the influence of natural disturbance on developmental and successional pathways is important for managers that wish to sustain Pinus spp. in these mixtures. Quantifying developmental and successional patterns in this forest type can help assess the need to actively manage natural ...