A Bibliometric Visualization Review of the MODIS LAI/FPAR Products from 1995 to 2020

Kai Yan,Hongliang Fang,Yuri Knyazikhin,Ranga B Myneni,Dongxiao Zou,Marie Weiss,Miina Rautiainen,Guangjian Yan

doi:10.34133/2021/7410921

Abstract

The MODIS LAI/FPAR products have been widely used in various fields since their first public release in 2000. This review intends to summarize the history, development trends, scientific collaborations, disciplines involved, and research hotspots of these products. Its aim is to intrigue researchers and stimulate new research direction. Based on literature data from the Web of Science (WOS) and associated funding information, we conducted a bibliometric visualization review of the MODIS LAI/FPAR products from 1995 to 2020 using bibliometric and social network analysis (SNA) methods. We drew the following conclusions: (1) research based on the MODIS LAI/FPAR shows an upward trend with a multiyear average growth rate of 24.9% in the number of publications. (2) Researchers from China and the USA are the backbone of this research area, among which the Chinese Academy of Sciences (CAS) is the core research institution. (3) Research based on the MODIS LAI/FPAR covers a wide range of disciplines but mainly focus on environmental science and ecology. (4) Ecology, crop production estimation, algorithm improvement, and validation are the hotspots of these studies. (5) Broadening the research field, improving the algorithms, and overcoming existing difficulties in heterogeneous surface, scale effects, and complex terrains will be the trend of future research. Our work provides a clear view of the development of the MODIS LAI/FPAR products and valuable information for scholars to broaden their research fields.

Highlights

Leaf area index (LAI) is defined as the one-sided green leaf area per unit ground horizontal area for broadleaf canopies and as the projected needle leaf area for coniferous canopies [1]
On the occasion of the 20th anniversary of the Moderate Resolution Imaging Spectroradiometers (MODIS) LAI/fraction of photosynthetically active radiation (FPAR) products, we aim to understand how research grants have been related to these products and to quantify the disciplines that benefited from MODIS LAI/FPAR during the past two decades
We found that the number of funding reported from the literature of China grants greatly exceeded that of other countries (Figure 2)

Summary

Introduction

Leaf area index (LAI) is defined as the one-sided green leaf area per unit ground horizontal area for broadleaf canopies and as the projected needle leaf area for coniferous canopies [1]. The fraction of photosynthetically active radiation (FPAR) is defined as the fraction of incident photosynthetically active radiation (in the range of 400-700 nm) absorbed by the green elements of a vegetation canopy under specified illumination conditions [2,3,4,5] Both the LAI and FPAR are expressed as a nondimensional value. Changes in FPAR have been used as indicators of desertification and to monitor the productivity of agricultural, forest, and natural ecosystems [14] Both LAI and FPAR have been recognized as two of the essential climate variables for the Global Climate Observing System (GCOS) (https://gcos.wmo.int/en/ essential-climate-variables) of the United Nations [15]

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