Airborne discrete-return LIDAR data in the estimation of vertical canopy cover, angular canopy closure and leaf area index

2011 ◽  
Vol 115 (4) ◽  
pp. 1065-1080 ◽  
Author(s):  
Lauri Korhonen ◽  
Ilkka Korpela ◽  
Janne Heiskanen ◽  
Matti Maltamo
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Canopy Cover ◽  
Lidar Data ◽  
Canopy Closure ◽  
Area Index

scholarly journals Automated computation of leaf area index from fruit trees using improved image processing algorithms applied to canopy cover digital photograpies

2016 ◽  
Vol 123 ◽  
pp. 195-202 ◽  
Author(s):  
Marco Mora ◽  
Felipe Avila ◽  
Marcos Carrasco-Benavides ◽  
Gonzalo Maldonado ◽  
Jeissy Olguín-Cáceres ◽  
...  
Keyword(s):  
Image Processing ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Canopy Cover ◽  
Fruit Trees ◽  
Area Index ◽  
Image Processing Algorithms ◽  
Processing Algorithms

Principal Canopy Factors of Sweet Corn and Relationships to Competitive Ability with Wild-Proso Millet (Panicum miliaceum)

Weed Science ◽  
2009 ◽  
Vol 57 (3) ◽  
pp. 296-303 ◽  
Author(s):  
Yim F. So ◽  
Martin M. Williams ◽  
Jerald K. Pataky ◽  
Adam S. Davis
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Competitive Ability ◽  
Sweet Corn ◽  
Canopy Closure ◽  
Crop Canopy ◽  
Area Index ◽  
Canopy Development ◽  
Proso Millet ◽  
Principal Factors

Univariate analyses fail to account for covariance among phenomorphological traits implicated in crop competitive ability. A more complete analysis of cultivar–weed interactions would reduce a number of important traits to a few underlying principal factors responsible for sweet corn competitiveness. Twenty-three commercial sweet corn hybrids from nine seed companies were grown in the presence and absence of wild-proso millet to (1) quantify the extent to which phenomorphological traits vary in sweet corn, (2) identify underlying principal factors that describe variation in crop canopy development, and (3) determine functional relationships between crop canopy factors and competitive ability. A principal component factor analysis revealed that 7 of the 18 weed-free crop traits measured at silking loaded highly (0.65 to 0.90) into the first factor, including plant height, shoot biomass, per plant leaf area, leaf area index, and intercepted light, as well as thermal time from emergence to silking and emergence to maturity. All seven traits were highly correlated (0.38 to 0.93) and were interpreted as a “late canopy and maturity” factor. Another five traits formed two additional principal factors that were interpreted as an early “seedling quality” factor (e.g., kernel mass, seedling vigor, and height at two-leaf stage) and a mid-season “canopy closure” factor (e.g., leaf area index and intercepted photosynthetically active radiation at six-leaf stage). Relationships between principal factors and competitive abilities were quantified using least-squares linear regression. Cultivars with greater loadings in the late canopy and maturity and canopy closure factors were more competitive with wild-proso millet. In contrast, crop competitive ability declined with cultivars that loaded highly into the seedling quality factor. The analyses showed that sweet corn's ability to endure weed interference and suppress weed fitness relates uniquely to three underlying principal factors that capture crop canopy development around emergence and near canopy closure and during the reproductive phase.

scholarly journals Pasture damage and regrowth from cattle treading

2000 ◽  
pp. 155-160 ◽  
Author(s):  
T.N. Pande ◽  
I. Valentine ◽  
K. Betteridge ◽  
A. Mackay ◽  
D. Horne
Keyword(s):  
Growth Rate ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Canopy Cover ◽  
Control Treatment ◽  
Research Station ◽  
Area Index ◽  
Hill Country ◽  
Grazed Pasture ◽  
Tiller Density

Two experiments were conducted to describe the damage and regrowth of pasture after a single, severe cattle treading event during winter. One experiment was conducted on hill country at AgResearch's Ballantrae Hill Country Research Station, and the other on the No. 4 Dairy Unit at Massey University. Herbage growth rate, canopy cover, tiller density and leaf area index were studied and compared in grazed, cattle-trodden and untrodden (control) pastures. At Ballantrae, the control treatment was sheep-grazed pasture, and at Massey University, it was cattle-grazed, but untrodden pasture under the electric fence. A single cattle treading event on winter-wet soils reduced hill pasture growth rates in spring to 11 kg DM/ha/day compared to 18 kg DM/ha/day in undamaged pasture on slopes, and to 21 kg DM/ ha/day compared to 39 kg DM/ha/day on tracks. Spring dairy pasture growth rate to 7 weeks after treading was 33 kg DM/ha/day compared to 51 kg DM/ha/day in undamaged pasture. Damage reduced canopy cover to 60% on hill pasture tracks and to 43% in dairy pasture, compared to covers of 95% and 90% in undamaged pastures, respectively. It was concluded that the low spring herbage growth rate following a single, severe winter treading of pasture on wet soil was due mainly to significantly reduced tiller numbers, and a decrease in leaf area index and canopy cover. Treading had no significant effect on the size of individual tillers. Keywords: cattle treading, hill country, pasture, pugging

scholarly journals Estimation of Biomass and Leaf Area Index in the Western Ghats Forest Ecosystem by the Integrated Analysis of Hyperspectral Data and Space Borne LiDAR Data

2019 ◽  
pp. 1-12
Author(s):  
Indu Indirabai ◽  
M. V. Harindranathan Nair ◽  
Jaishanker R. Nair ◽  
Rama Rao Nidamanuri
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Forest Ecosystem ◽  
Western Ghats ◽  
Hyperspectral Data ◽  
Spectral Information ◽  
Lidar Data ◽  
Biophysical Parameters ◽  
Area Index ◽  
The Western Ghats

The Western Ghats regions of India are characterised by highly complex and biodiverse forest ecosystem with heterogeneous tree species. The integration of LiDAR data with multispectral remote sensing has limitations in the case of spectral information abundance. The objective of this study was to undertake biophysical characterisation in the Western Ghats regions of India by the integration of GLAS ICESat data and AVIRIS-NG hyperspectral data. The methodology of the study includes pre-processing of the hyperspectral and ICESat GLAS data followed by the integration of the two data sets based on pixel based fusion strategy in order to estimate the biophysical parameters of forests. Biomass was estimated by Support Vector Regression method. The structural characteristics extracted from the LiDAR data are integrated with spectral characteristics from the AVIRIS NG imagery based on the pixel level so that biophysical characteristics including canopy height, biomass, Leaf Area Index are estimated. The integrated product on further analysis revealed the applicability of this approach to extract more spectral information and forest parameters. The key findings of the study include biophysical parameters both structural as well as abundant spectral information can be retrieved successfully by the methodology used which have strong correlation with the in situ measurements. The study concluded that biophysical parameters including Leaf Area Index, biomass and canopy height can be effectively estimated by the integration of AVIRIS-NG imagery and GLAS data, which cannot be possible when used independently. It is recommended to have continuous retrieval of LiDAR foot prints instead of discrete, to make modelling of the biophysical parameters a little more effective.

Canopy Cover and Leaf Area Index Relationships for Wheat, Triticale, and Corn

2012 ◽  
Vol 104 (6) ◽  
pp. 1569-1573 ◽  
Author(s):  
David C. Nielsen ◽  
Juan J. Miceli-Garcia ◽  
Drew J. Lyon
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Canopy Cover ◽  
Area Index

Leaf heteroblasty in eucalypts: biogeographic evidence of ecological function

2018 ◽  
Vol 66 (3) ◽  
pp. 191 ◽  
Author(s):  
Carolyn Vlasveld ◽  
Benjamin O'Leary ◽  
Frank Udovicic ◽  
Martin Burd
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Unit Area ◽  
Leaf Shape ◽  
Eucalyptus Species ◽  
Canopy Closure ◽  
Area Index ◽  
Leaf Mass ◽  
Adult Leaf ◽  
Shape And Size

Leaves that develop on seedlings, young saplings or regenerative shoots of many eucalypt species are strikingly different in morphology from the typical leaves of more mature plants; a developmental pattern known as heteroblasty. We measured dimorphism between juvenile and adult leaves in shape and size, leaf mass per unit area, and vein frequency in a continent-wide sample of Angophora, Corymbia and Eucalyptus species. We tested whether heteroblasty in this group is an adaptation to shading by comparing the degree of juvenile–adult leaf dimorphism with the canopy closure (measured by the leaf area index) of the habitat in which species occurred. No pattern emerged for heteroblasty in leaf shape and size or leaf mass per unit area, but there was a significant relationship (accounting for phylogenetic relationships) between the degree of juvenile–adult dimorphism in vein frequency and habitat leaf area index. Juvenile leaves tended to have more widely spaced veins than adult leaves of the same species, in regions with more closed vegetative canopies. This evidence suggests that eucalypt heteroblasty is, at least in part, a hydraulic adaptation to the different conditions faced by younger and older plants in higher productivity regions with denser vegetation.

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