Leaf Area Index Variations in Ecoregions of Ardabil Province, Iran

The leaf area index (LAI) is an important vegetation biophysical index that provides broad information on the dynamic behavior of an ecosystem’s productivity and related climate, topography, and edaphic impacts. The spatiotemporal changes of LAI were assessed throughout Ardabil Province—a host of re...

Full description

Bibliographic Details
Main Authors: Lida Andalibi, Ardavan Ghorbani, Mehdi Moameri, Zeinab Hazbavi, Arne Nothdurft, Reza Jafari, Farid Dadjou
Format: Article
Language:English
Published: MDPI AG 2021-07-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/13/15/2879
_version_ 1797525163313463296
author Lida Andalibi
Ardavan Ghorbani
Mehdi Moameri
Zeinab Hazbavi
Arne Nothdurft
Reza Jafari
Farid Dadjou
author_facet Lida Andalibi
Ardavan Ghorbani
Mehdi Moameri
Zeinab Hazbavi
Arne Nothdurft
Reza Jafari
Farid Dadjou
author_sort Lida Andalibi
collection DOAJ
description The leaf area index (LAI) is an important vegetation biophysical index that provides broad information on the dynamic behavior of an ecosystem’s productivity and related climate, topography, and edaphic impacts. The spatiotemporal changes of LAI were assessed throughout Ardabil Province—a host of relevant plant communities within the critical ecoregion of a semi-arid climate. In a comparative study, novel data from Google Earth Engine (GEE) was tested against traditional ENVI measures to provide LAI estimations. Moreover, it is of important practical significance for institutional networks to quantitatively and accurately estimate LAI, at large areas in a short time, and using appropriate baseline vegetation indices. Therefore, LAI was characterized for ecoregions of Ardabil Province using remote sensing indices extracted from Landsat 8 Operational Land Imager (OLI), including the Enhanced Vegetation Index calculated in GEE (EVI<sub>G</sub>) and ENVI5.3 software (EVI<sub>E</sub>), as well as the Normalized Difference Vegetation Index estimated in ENVI5.3 software (NDVI<sub>E</sub>). Moreover, a new field measurement method, i.e., the LaiPen LP 100 portable device (LP 100), was used to evaluate the accuracy of the derived indices. Accordingly, the LAI was measured in June and July 2020, in 822 ground points distributed in 16 different ecoregions-sub ecoregions having various plant functional types (PFTs) of the shrub, bush, and tree. The analyses revealed heterogeneous spatial and temporal variability in vegetation indices and LAIs within and between ecoregions. The mean (standard deviation) value of EVI<sub>G</sub>, EVI<sub>E</sub>, and NDVI<sub>E</sub> at a province scale yielded 1.1 (0.41), 2.20 (0.78), and 3.00 (1.01), respectively in June, and 0.67 (0.37), 0.80 (0.63), and 1.88 (1.23), respectively, in July. The highest mean values of EVI<sub>G</sub>-LAI, EVI<sub>E</sub>-LAI, and NDVI<sub>E</sub>-LAI in June are found in Meshginshahr (1.40), Meshginshahr (2.80), and Hir (4.33) ecoregions and in July are found in Andabil ecoregion respectively with values of 1.23, 1.5, and 3.64. The lowest mean values of EVI<sub>G</sub>-LAI, EVI<sub>E</sub>-LAI, and NDVI<sub>E</sub>-LAI in June were observed for Kowsar (0.67), Meshginshahr (1.8), and Neur (2.70) ecoregions, and in July, the Bilesavar ecoregion, respectively, with values of 0.31, 0.31, and 0.81. High correlation and determination coefficients (r > 0.83 and R<sup>2</sup> > 0.68) between LP 100 and remote sensing derived LAI were observed in all three PFTs (except for NDVI<sub>E</sub>-LAI in June with r = 0.56 and R<sup>2</sup> = 0.31). On average, all three examined LAI measures tended to underestimate compared to LP 100-LAI (r > 0.42). The findings of the present study could be promising for effective monitoring and proper management of vegetation and land use in the Ardabil Province and other similar areas.
first_indexed 2024-03-10T09:09:52Z
format Article
id doaj.art-1edd81d09a5d40a8b20888f8fed51753
institution Directory Open Access Journal
issn 2072-4292
language English
last_indexed 2024-03-10T09:09:52Z
publishDate 2021-07-01
publisher MDPI AG
record_format Article
series Remote Sensing
spelling doaj.art-1edd81d09a5d40a8b20888f8fed517532023-11-22T06:05:31ZengMDPI AGRemote Sensing2072-42922021-07-011315287910.3390/rs13152879Leaf Area Index Variations in Ecoregions of Ardabil Province, IranLida Andalibi0Ardavan Ghorbani1Mehdi Moameri2Zeinab Hazbavi3Arne Nothdurft4Reza Jafari5Farid Dadjou6Department of Natural Resources, University of Mohaghegh Ardabili, Ardabil 56199-11367, IranDepartment of Natural Resources, Water Management Research Center, University of Mohaghegh Ardabili, Ardabil 56199-11367, IranDepartment of Natural Resources, Water Management Research Center, University of Mohaghegh Ardabili, Ardabil 56199-11367, IranDepartment of Natural Resources, Water Management Research Center, University of Mohaghegh Ardabili, Ardabil 56199-11367, IranDepartment of Forest and Soil Sciences, University of Natural Resources and Life Sciences (BOKU), 331180 Vienna, AustriaDepartment of Natural Resources, Isfahan University of Technology, Isfahan 84156-83111, IranDepartment of Natural Resources, University of Mohaghegh Ardabili, Ardabil 56199-11367, IranThe leaf area index (LAI) is an important vegetation biophysical index that provides broad information on the dynamic behavior of an ecosystem’s productivity and related climate, topography, and edaphic impacts. The spatiotemporal changes of LAI were assessed throughout Ardabil Province—a host of relevant plant communities within the critical ecoregion of a semi-arid climate. In a comparative study, novel data from Google Earth Engine (GEE) was tested against traditional ENVI measures to provide LAI estimations. Moreover, it is of important practical significance for institutional networks to quantitatively and accurately estimate LAI, at large areas in a short time, and using appropriate baseline vegetation indices. Therefore, LAI was characterized for ecoregions of Ardabil Province using remote sensing indices extracted from Landsat 8 Operational Land Imager (OLI), including the Enhanced Vegetation Index calculated in GEE (EVI<sub>G</sub>) and ENVI5.3 software (EVI<sub>E</sub>), as well as the Normalized Difference Vegetation Index estimated in ENVI5.3 software (NDVI<sub>E</sub>). Moreover, a new field measurement method, i.e., the LaiPen LP 100 portable device (LP 100), was used to evaluate the accuracy of the derived indices. Accordingly, the LAI was measured in June and July 2020, in 822 ground points distributed in 16 different ecoregions-sub ecoregions having various plant functional types (PFTs) of the shrub, bush, and tree. The analyses revealed heterogeneous spatial and temporal variability in vegetation indices and LAIs within and between ecoregions. The mean (standard deviation) value of EVI<sub>G</sub>, EVI<sub>E</sub>, and NDVI<sub>E</sub> at a province scale yielded 1.1 (0.41), 2.20 (0.78), and 3.00 (1.01), respectively in June, and 0.67 (0.37), 0.80 (0.63), and 1.88 (1.23), respectively, in July. The highest mean values of EVI<sub>G</sub>-LAI, EVI<sub>E</sub>-LAI, and NDVI<sub>E</sub>-LAI in June are found in Meshginshahr (1.40), Meshginshahr (2.80), and Hir (4.33) ecoregions and in July are found in Andabil ecoregion respectively with values of 1.23, 1.5, and 3.64. The lowest mean values of EVI<sub>G</sub>-LAI, EVI<sub>E</sub>-LAI, and NDVI<sub>E</sub>-LAI in June were observed for Kowsar (0.67), Meshginshahr (1.8), and Neur (2.70) ecoregions, and in July, the Bilesavar ecoregion, respectively, with values of 0.31, 0.31, and 0.81. High correlation and determination coefficients (r > 0.83 and R<sup>2</sup> > 0.68) between LP 100 and remote sensing derived LAI were observed in all three PFTs (except for NDVI<sub>E</sub>-LAI in June with r = 0.56 and R<sup>2</sup> = 0.31). On average, all three examined LAI measures tended to underestimate compared to LP 100-LAI (r > 0.42). The findings of the present study could be promising for effective monitoring and proper management of vegetation and land use in the Ardabil Province and other similar areas.https://www.mdpi.com/2072-4292/13/15/2879LaiPenmanagement toolsremote sensingvegetation indicesspatiotemporal changes
spellingShingle Lida Andalibi
Ardavan Ghorbani
Mehdi Moameri
Zeinab Hazbavi
Arne Nothdurft
Reza Jafari
Farid Dadjou
Leaf Area Index Variations in Ecoregions of Ardabil Province, Iran
Remote Sensing
LaiPen
management tools
remote sensing
vegetation indices
spatiotemporal changes
title Leaf Area Index Variations in Ecoregions of Ardabil Province, Iran
title_full Leaf Area Index Variations in Ecoregions of Ardabil Province, Iran
title_fullStr Leaf Area Index Variations in Ecoregions of Ardabil Province, Iran
title_full_unstemmed Leaf Area Index Variations in Ecoregions of Ardabil Province, Iran
title_short Leaf Area Index Variations in Ecoregions of Ardabil Province, Iran
title_sort leaf area index variations in ecoregions of ardabil province iran
topic LaiPen
management tools
remote sensing
vegetation indices
spatiotemporal changes
url https://www.mdpi.com/2072-4292/13/15/2879
work_keys_str_mv AT lidaandalibi leafareaindexvariationsinecoregionsofardabilprovinceiran
AT ardavanghorbani leafareaindexvariationsinecoregionsofardabilprovinceiran
AT mehdimoameri leafareaindexvariationsinecoregionsofardabilprovinceiran
AT zeinabhazbavi leafareaindexvariationsinecoregionsofardabilprovinceiran
AT arnenothdurft leafareaindexvariationsinecoregionsofardabilprovinceiran
AT rezajafari leafareaindexvariationsinecoregionsofardabilprovinceiran
AT fariddadjou leafareaindexvariationsinecoregionsofardabilprovinceiran