نتایج جستجو برای: canopy structure
تعداد نتایج: 1579939 فیلتر نتایج به سال:
Quantifying the mechanistic links between carbon fluxes and forest canopy attributes will advance understanding of leaf-to-ecosystem scaling and its potential application to assessing terrestrial ecosystem metabolism. Important advances have been made, but prior studies that related carbon fluxes to multiple canopy traits are scarce. Herein, presenting data for 128 cold temperate and boreal for...
Results from two nested-grid large-eddy simulations comparing cases with and without a plant canopy are presented. Through comparisons of numerically generated mean and turbulence statistics, the in uence of a plant canopy with a leaf area index of two is shown to modify the air ow compared with an identical case without plants. Investigations of instantaneous elds and spatial spectra show...
Recent work has established the utility of waveform sampling lidar for predicting forest structural attributes. Nevertheless, serious obstacles to its wide-spread use still exist. They include the lack of waveform sampling lidar sensors capable of measuring forest canopy structure over large extents, and the practical difficulty of developing widely applicable relationships to predict forest st...
© The Ecological Society of America www.frontiersinecology.org T is a crucial need to understand ecological water balances, both in the present and in the future. This balance is currently shifting, as economies rapidly develop and urbanization accelerates (Hubacek and Sun 2005). In the future, global climate change and the resulting uncertainties will only add to the urgency of finding accurat...
Isolated canopy gaps involving one to several trees occur continuously and frequently in many moist and wet neotropical forests (sensu Holdridge et al. 1971), shaping tree community structure through a shifting mosaic of patches of high resource availability for small and young trees (Denslow 1980). Though there are few relevant data (Jans et al. 1993), forests with significant seasonal drought...
Accurate estimation of terrestrial gross primary productivity (GPP) remains a challenge despite its importance in the global carbon cycle. Chlorophyll fluorescence (ChlF) has been recently adopted to understand photosynthesis and its response to the environment, particularly with remote sensing data. However, it remains unclear how ChlF and photosynthesis are linked at different spatial scales ...
The use of lidar and radar instruments to measure forest structure attributes such as height and biomass are being considered for future Earth Observation satellite missions. Large footprint lidar makes a direct measurement of the heights of scatterers in the illuminated footprint and can yield information about the vertical profile of the canopy. Synthetic Aperture Radar (SAR) is known to sens...
The CORSAR project (Carbon Observation and Retrieval from SAR), which is supported by the UK Natural Environment Research Council (NERC), has the objective to examine polarimetric decomposition and polarimetric SAR interferometry methods for estimating the effects of canopy structure in biomass-backscatter relationships. Forest canopy height is a useful input parameter to yield models, carbon c...
Land surface albedo describes the fraction of incoming solar energy reflected at a given point and time, and hence determines the surface temperature and evapotranspiration. It is strongly dependent on the solar zenith angle and the three-dimensional structure of vegetation canopy (e.g., Yang et al. 2001; Schaaf et al. 2002). The land surface albedo in regional and global models can be specifie...
Despite advances in Earth observation and modeling, estimating tropical biomass remains a challenge. Recent work suggests that integrating satellite measurements of canopy height within ecosystem models is a promising approach to infer biomass. We tested the feasibility of this approach to retrieve aboveground biomass (AGB) at three tropical forest sites by assimilating remotely sensed canopy h...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید