Data/hora: 08/06/2024 01:21:32

Biblioteca(s): 	Embrapa Amazônia Oriental.	
Data corrente: 	24/06/2005	
Data da última atualização: 	08/11/2022	
Autoria: 	ASNER, G. P.; PALACE, M.; KELLER, M.; PEREIRA JÚNIOR, R.; SILVA, J. N. M.; ZWEEDE, J. C.	
Afiliação: 	GREGORY P. ASNER, Stanford University; MICHAEL PALACE, University of New Hampshire; MICHAEL KELLER, University of New Hampshire; RODRIGO PEREIRA JUNIOR, Fundação Floresta Tropical; JOSÉ NATALINO MACÊDO SILVA, Embrapa Amazônia Oriental; JOHAN C. ZWEEDE, Fundação Floresta Tropical.	
Título: 	Estimating canopy structure in an Amazon forest from laser range finder and IKONOS satellite observations.	
Ano de publicação: 	2002	
Fonte/Imprenta: 	Biotropica, v. 34, n. 4, p. 483-492, Dec. 2002.	
DOI: 	10.1111/j.1744-7429.2002.tb00568.x	
Idioma: 	Inglês	
Conteúdo: 	Canopy structural data can be used for biomass estimation and studies of carbon cycling, disturbance, energy balance, and hydrological processes in tropical forest ecosystems. Scarce information on canopy dimensions reflects the difficulties associated with measuring crown height, width, depth, and area in tall, humid tropical forests. New field and spaceborne observations provide an opportunity to acquire these measurements, but the accuracy and reliability of the methods are unknown. We used a handheld laser range finder to estimate tree crown height, diameter, and depth in a lowland tropical forest in the eastern Amazon, Brazil, for a sampling of 300 trees stratified by diameter at breast height (DBH). We found significant relationships between DBH and both tree height and crown diameter derived from the laser measurements. We also quantified changes in crown shape between tree height classes, finding a significant but weak positive trend between crown depth and width. We then compared the field-based measurements of crown diameter and area to estimates derived manually from panchromatic 0.8 m spatial resolution IKONOS satellite imagery. Median crown diameter derived from satellite observations was 78 percent greater than that derived from field-based laser measurements. The statistical distribution of crown diameters from IKONOS was biased toward larger trees, probably due to merging of smaller tree crowns, underestimation of understory trees, and overestimation of individual crown dimensions. The median crown area derived from IKONOS was 65 percent higher than the value modeled from field-based measurements. We conclude that manual interpretation of IKONOS satellite data did not accurately estimate distributions of tree crown dimensions in a tall tropical forest of eastern Amazonia. Other methods will be needed to more accurately estimate crown dimensions from high spatial resolution satellite imagery.	
Palavras-Chave: 	Cobertura; Telemetro.	
Thesagro: 	Biomassa; Floresta Tropical; Satélite; Sistema de Informação.	
Categoria do assunto: 	K Ciência Florestal e Produtos de Origem Vegetal	
Registro original: 	Embrapa Amazônia Oriental (CPATU)	
Exemplares: 	CPATU - (36456-1) - UPC - AP - PP - 574.05 - B1 -  - DIS