Solar radiation transmission through conifer canopies

Hardy, Janet P.; Melloh, Rae A.; Koenig, George G.; Marks, Danny; Winstral, A. H.; Pomeroy, John W.; Link, Timothy E.

doi:10.1016/j.agrformet.2004.06.012

Cited by 164 publications

(145 citation statements)

References 24 publications

Supporting

Mentioning

125

Contrasting

Unclassified

Order By: Relevance

“…In an analogy to the aforementioned non-contact method, hemispherical photographs can offer gap fraction data (canopy openness, see Fig. 1) that allow for the estimation of PAI, transmitted radiation and other parameters (Koike 1989;Hardy et al 2004). The images need to be processed to separate pixels representing plant material and pixels representing the sky according to their grey values and a simple threshold procedure (e.g.…”

Section: Hemispherical Photographymentioning

confidence: 99%

Review of ground-based methods to measure the distribution of biomass in forest canopies

Seidel

Fleck

Leuschner

et al. 2011

Annals of Forest Science

View full text Add to dashboard Cite

& Context Ecological research and an effective forest management need accurate information on the structure of the forest canopy to understand the biochemical, physiological and biogeochemical processes within a forest. & Research question This paper reviews the currently available instruments for measuring the distribution of biomass within forest canopies. We compare the most well-established approaches and present the different measurable parameters. A special focus lies on the resolution of the obtained data. & Results It was found that only 3D laser scanners offer data with the resolution required by ecologists, private landholders, the forest industry and the public to detect trends in tree growth patterns and canopy interactions in all three spatial dimensions. But data validation, data analysis and parameter extraction are still under development, and the price of the instrument is quite high. & Conclusion Research should focus on the parameter extraction from terrestrial laser scanner data as this could allow the calculation of functional attributes for different sections of a canopy on a high spatial resolution. It could also help ecologists characterize the structure of forest stands in a quick and precise way.

show abstract

Section: Hemispherical Photographymentioning

confidence: 99%

Review of ground-based methods to measure the distribution of biomass in forest canopies

Seidel

Fleck

Leuschner

et al. 2011

Annals of Forest Science

View full text Add to dashboard Cite

show abstract

“…6). In clear days PAR penetration depends signifi cantly on stand structure (eff ect of sunfl ecks and penumbra eff ect) (Gendron et al, 2001;Matthew et al, 2003;Hardy et al, 2004;Yirdaw and Luukkanen, 2004;Leuchner et al, 2011;Nilson et al, 2011;Prévost and Raymond, 2012). Signifi cantly diff erent correlations in the 4 th phenological phase, both in clear and in overcast day, could be due to a lower sun elevation, and therefore diff erent PAR penetration into the stand canopy.…”

Section: Resultsmentioning

confidence: 99%

“…The assimilation activity is strongly dependent on the accessibility of solar radiation and its absorption plays a key role in a set of physiological processes connected with forest stand biomass production. The radiation fi eld within the forest stand canopy is spatially and temporally highly variable (Reifsnyder et al, 1971;Baldocchi et al, 1984;Grant, 1997;Shaw, 2002;Fladeland et al, 2003;Hardy et al, 2004;Leuchner et al, 2011). The solar radiation distribution within and below the canopy of the forest stand depends on the seasonal/daily changes in the angle of incidence of solar beams, on the actual cloud cover leading to diff erent ratio between direct and diff use solar radiation, and on the seasonal changes in the stand canopy architecture (composition, density, phenological development etc.)…”

mentioning

confidence: 99%

Transmittance of young Norway spruce stand canopy for photosynthetically active radiation during the growing season

Marková¹,

Kubásek²

2013

Acta Univ. Agric. Silvic. Mendelianae Brun.

View full text Add to dashboard Cite

MARKOVÁ IRENA, KUBÁSEK JIŘÍ: Transmittance of young Norway spruce stand canopy for photosynthetically active radiation during the growing season. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 2013, LXI, No. 1, pp. 129-135 Analysis of transmittance of young Norway spruce stand canopy for photosynthetically active radiation (PAR) was made at the study site of Bílý Kříž (the Moravian-Silesian Beskids Mts., the Czech Republic) at diff erent sky conditions during the growing season in 2010. For the description of PAR transmittance diff erent phenological phases of the spruce stand development in clear and overcast days were chosen. The mean daily PAR transmittance of the spruce canopy was signifi cantly higher in overcast days compared with clear ones. Diff use PAR thus penetrated into lower parts of the canopy more effi ciently than direct one. PAR transmittance of young Norway spruce stand canopy was diff erent in individual phenological phases of the spruce stand canopy which was caused by changes in the stand structure during the growing season. Thus monitoring of transmittance of young Norway spruce stand canopy for PAR can help to describe the development of spruce stand canopy. overcast and clear days, phonological phases

show abstract

“…A quantidade da radiação interceptada pela floresta é determinada por características da copa, assim como pela localização e pelo tamanho das clareiras existentes no dossel (Hardy et al, 2004). O índice de área foliar (IAF) é um parâmetro importante na avaliação da estrutura do dossel, por caracterizar sua arquitetura e estar relacionado com a produção de biomassa vegetal (Linhares et al, 2000;Villa Nova et al, 2003;Xavier & Vettorazzi, 2003).…”

Section: Introductionunclassified

Métodos indiretos de estimação da cobertura de dossel em povoamentos de clone de eucalipto

Monte

Reis

et al. 2007

Pesq. agropec. bras.

View full text Add to dashboard Cite

Resumo -O objetivo deste trabalho foi avaliar o potencial de uso de fotografias digitais na estimação do índice de cobertura de dossel (ICD), em substituição ao índice de área foliar (IAF Indirect methods to estimate canopy coverage of clonal eucalypt plantationsAbstract -The objective of this work was to evaluate methods to process digital photographs in order to estimate the canopy coverage index (CCI), to replace the use of leaf area index (LAI). Digital photographs with 640x480 and 1,280x960 pixels were processed with the Erdas Imagine, Gap Light Analyzer and Sidelook softwares. Leaf area index, using the LAI-2000, and digital photographs were obtained from pruned and thinned Eucalyptus grandis clone plantations at 81 and 93 months of age. Significant correlations were observed between LAI and CCI. Greater sized photographs (1,280x980 pixels) allowed better differentiation between sky and canopy pixels. Canopy Coverage Index obtained from digital photographs processed with the Sidelook was better correlated with LAI than that obtained by Erdas Imagine and Gap Light Analyzer. It is possible to use digital photography for eucalypt forest CCI estimation.

show abstract

Solar radiation transmission through conifer canopies

Cited by 164 publications

References 24 publications

Review of ground-based methods to measure the distribution of biomass in forest canopies

Review of ground-based methods to measure the distribution of biomass in forest canopies

Transmittance of young Norway spruce stand canopy for photosynthetically active radiation during the growing season

Métodos indiretos de estimação da cobertura de dossel em povoamentos de clone de eucalipto

Contact Info

Product

Resources

About