Results 31 to 40 of about 5,471 (263)

Understorey plant community and light availability in conifer plantations and natural hardwood forests in Taiwan [PDF]

, 2015
Questions: What are the effects of replacing mixed species natural forests with Cryptomeria japonica plantations on understorey plant functional and species diversity?
Anderson M.C., Boufford D.E., Chang N.H., Chang‐Yang C.H., Chazdon R.L., Chen W.C., Cheng C.T., Chu P.C., Delta‐T, Horng F.H., Hsia Y.J., Kimmins J.P., Kuo S.R., Kuo Y.L., Kuo Y.L., Kuo Y.L., Kuo Y.L., Liang J.C., Lin K.C., Lin T.C., Liou C.Y., TFB, TFB, TFRI, Wang H.H., Williams H.   +25 more
core   +2 more sources

Low-cost unmanned aerial vehicle-based digital hemispherical photography for estimating leaf area index: a feasibility assessment

International Journal of Remote Sensing, 2020
Unmanned aerial vehicles (UAVs) have the potential to provide highly detailed information on vegetation status useful in precision agriculture.
Luke A. Brown, David H. Sutherland, Jadunandan Dash   +2 more
openaire   +4 more sources

Mortality and crown conditions on Quercus robur L. permanent plots - a 20-year overview [PDF]

, 2014
Pedunculate oak (Quercus robur L.) forests in Slovenia are experiencing widespread mortality. Changes in lowlands are reflected in decline of complete forest complexes, high mortality, uneven stand structure and associated forest regeneration problems ...
Čater, Matjaž
core   +3 more sources

Biophysical Variable Retrieval of Silage Maize with Gaussian Process Regression and Hyperparameter Optimization Algorithms

Remote Sensing, 2023
Quantification of vegetation biophysical variables such as leaf area index (LAI), fractional vegetation cover (fCover), and biomass are among the key factors across hydrological, agricultural, and irrigation management studies. The present study proposes
Elahe Akbari, Ali Darvishi Boloorani, Jochem Verrelst, Stefano Pignatti, Najmeh Neysani Samany, Saeid Soufizadeh, Saeid Hamzeh   +6 more
doaj   +1 more source

Hemispherical photography to estimate biophysical variables of cotton

Revista Brasileira de Engenharia Agrícola e Ambiental
The Leaf Area Index (LAI) is a key parameter to evaluate the vegetation spectral response, estimating plant nutrition and water requirements. However, in large fields is difficult to obtain accurate data to LAI determination.
Ziany N. Brandão, João H. Zonta
doaj   +1 more source

Validating canopy clumping retrieval methods using hemispherical photography in a simulated Eucalypt forest [PDF]

, 2017
The so-called clumping factor (Ω) quantifies deviation from a random 3D distribution of material in a vegetation canopy and therefore characterises the spatial distribution of gaps within a canopy.
Armston, Armston, Bréda, Chen, Chen, Chen, Chen, Chen, Chen, Chen, Chianucci, de Wit, Disney, Fernandes, Fournier, Franklin, Frazer, GCOS, Gonsamo, Gonsamo, Gonsamo, Jacobs, John D. Armston, Jonckheere, Jonckheere, Jupp, Kalácska, Kucharik, Lang, Law, Leblanc, Leblanc, Leblanc, Leblanc, Leblanc, Lewis, Lola Suarez, Macfarlane, Mariela Soto-Berelov, Mathias Disney, Michael J. Hill, Miller, Monsi, Monteith, Morisette, Newnham, Neyman, Nilson, Nilson, Phil Wilkes, Piayda, Pielou, Pisek, Pisek, Pisek, Pisek, Ross, Ryu, Schaefer, Simon D. Jones, Spanner, Walter, Weiss, Widlowski, William Woodgate, Wilson, Woodgate, Woodgate, Woodgate, Woodgate, Zhao, Zheng   +71 more
core   +4 more sources

Influence of levelling technique on the retrieval of canopy structural parameters from digital hemispherical photography

Agricultural and Forest Meteorology, 2017
Digital hemispherical photography is a simple, non-destructive method for estimating canopy biophysical parameters for ecological applications and validation of remote sensing products. Determination of optimum and repeatable acquisition procedures is well documented in the literature but so far this has not focused on evaluating the levelling ...
Niall Origo, Kim Calders, Joanne Nightingale, Mathias Disney   +3 more
openaire   +2 more sources

AN INTERCOMPARISON OF PASSIVE TERRESTRIAL REMOTE SENSING TECHNOLOGIES TO DERIVE LAI AND CANOPY COVER METRICS [PDF]

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2012
Forest indicators such as Leaf Area Index (LAI) and vegetation cover type are recognised as Essential Climate Variables (ECVs) which support the '…research, modelling, analysis, and capacity-building activities…' requirements of the United Nations ...
W. L. Woodgate
doaj   +1 more source

Estimating Savanna Clumping Index Using Hemispherical Photographs Integrated with High Resolution Remote Sensing Images

Remote Sensing, 2017
In contrast to herbaceous canopies and forests, savannas are grassland ecosystems with sparsely distributed individual trees, so the canopy is spatially heterogeneous and open, whereas the woody cover in savannas, e.g., tree cover, adversely affects ...
Jucai Li, Wenjie Fan, Yuan Liu, Gaolong Zhu, Jingjing Peng, Xiru Xu   +5 more
doaj   +1 more source

Evaluation of Digital Hemispherical Photography and Plant Canopy Analyzer for Measuring Vegetation Area Index of Orange Orchards

Journal of Agronomy, 2009
This study presents the results of an evaluation of two indirect methods (Plant Canopy Analyser (PCA) and hemispherical photographs) for measuring vegetation area index VAI of two orange orchards, differing by their ground fraction cover (fc). The evaluation is based on reference data obtained by destructive measurements on limited samples, which allow
Khabba, S., /Duchemin, Benoît, Hadria, R., Er-Raki, S., Ezzahar, J., /Chehbouni, Abdelghani, Larouni, A., Hanich, L.   +7 more
openaire   +2 more sources