نتایج جستجو برای: canopy gap

تعداد نتایج: 154523  

Journal: :caspian journal of enviromental sciences 0

canopy gaps are one of the most important structural features of forest ecosystems, and studying of them can have useful results and implications for forest management. the aim of this study is investigation of characteristics and regeneration within canopy gaps in an intact beech stand in the shastkalateh experimental forest of hyrcanian region, north of iran. all canopy gaps and related fores...

Journal: :Applied optics 1995
J M Chen J Cihlar

Optical instruments currently available for measuring the leaf-area index (LAI) of a plant canopy all utilize only the canopy gap-fraction information. These instruments include the Li-Cor LAI-2000 Plant Canopy Analyzer, Decagon, and Demon. The advantages of utilizing both the canopy gap-fraction and gap-size information are shown. For the purpose of measuring the canopy gap size, a prototype s...

KH. Sagheb-Talebi M. Amiri R. Rahmani

Canopy gaps are one of the most important structural features of forest ecosystems, and studying of them can have useful results and implications for forest management. The aim of this study is investigation of characteristics and regeneration within canopy gaps in an intact beech stand in the Shastkalateh Experimental Forest of Hyrcanian region, north of Iran. All canopy gaps and related fores...

2007
Chad S. Boyd Jon D. Bates Rick F. Miller

Sagebrush cover is often estimated with the use of the line intercept method. However, a lack of standardized protocols may lead to variable estimates of sagebrush canopy cover. Our objectives were to determine the influence of gap size on 1) sagebrush canopy cover estimates, 2) time needed to read a transect, and 3) among-observer variability in sagebrush canopy cover estimates. We utilized 5-...

2016
Nazha El Allaoui Teresa Serra Jordi Colomer Marianna Soler Xavier Casamitjana Carolyn Oldham

The systematic creation of gaps within canopies results in fragmentation and the architecture of fragmented canopies differs substantially from non-fragmented canopies. Canopy fragmentation leads to spatial heterogeneity in hydrodynamics and therefore heterogeneity in the sheltering of canopy communities. Identifying the level of instability due to canopy fragmentation is important for canopies...

Journal: :Remote Sensing 2014
Pyare Pueschel Glenn Newnham Joachim Hill

The characterization of canopy structure is crucial for modeling eco-physiological processes. Two commonly used metrics for characterizing canopy structure are the gap fraction and the effective Plant Area Index (PAIe). Both have been successfully retrieved with terrestrial laser scanning. However, a systematic assessment of the influence of the laser scan properties on the retrieval of these m...

1999
Dale G. Brockway Kenneth W. Outcalt

Naturally regenerated seedlings of longleaf pine are typically observed to cluster in the center of tree fall canopy gaps and be encircled by a wide zone from which they are generally excluded. Twelve representative canopy gaps distributed across 600 ha of a naturally regenerated uneven-aged longleaf pine forest in the sandhills of north central Florida were examined to determine which abovegro...

2014
G. P. Asner C. B. Anderson R. E. Martin D. E. Knapp R. Tupayachi F. Sinca

Elevation gradients provide opportunities to explore environmental controls on forest structure and functioning. We used airborne imaging spectroscopy and lidar (light detection and ranging) to quantify changes in threedimensional forest structure and canopy functional traits in twenty 25 ha landscapes distributed along a 3300 m elevation gradient from lowland Amazonia to treeline in the Peruvi...

2006
Wei Wang Scott B. Franklin Yi Ren John R. Ouellette

Gap characteristics and effects of gaps on plasticity of Fargesia qinlingensis and tree regeneration were studied under canopy, and in small, medium, and large gaps in a mixed hardwood-conifer forest in the Qinling Mountains, China. Gap formation was mainly tree snapping (40%). Gapmakers were dominated by Betula albosinensis and Abies fargesii (85%). Gap area ranged from 23.8 to 594.2 m and ave...

2011
Jodi A. Forrester David J. Mladenoff Stith T. Gower Jennifer L. Stoffel

Coarse woody debris (CWD) and canopy gaps are thought to be important structural components that influence forest ecosystem processes, yet few studies have assessed whether these features interact to influence decay dynamics, and we know of none that does so under controlled experimental canopy gap conditions. By manipulating forest structure to create canopy openings, we tested whether canopy ...

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