Towards forage resource monitoring in subtropical savanna grasslands
- Forage supply of savanna grasslands plays a crucial role for local food security and consequently, a reliable monitoring system could help to better manage vital forage resources. To help installing such a monitoring system, we investigated whether in-situ hyperspectral data could be resampled to match the spectral resolution of multi- and hyperspectral satellites; if the type of sensor affected model transfer; and if spatio-temporal patterns of forage characteristics could be related to environmental drivers. We established models for forage quantity (green biomass) and five forage quality proxies (metabolisable energy, acid/neutral detergent fibre, ash, phosphorus). Hyperspectral resolution of the Hyperion satellite mostly resulted in higher accuracies (i.e. higher R-2, lower RMSE). When applied to satellite data, though, the greater quality of the multispectral Sentinel-2 satellite data leads to more realistic forage maps. By analysing a three-year time series, we found plant phenology and cumulated precipitation to be the mostForage supply of savanna grasslands plays a crucial role for local food security and consequently, a reliable monitoring system could help to better manage vital forage resources. To help installing such a monitoring system, we investigated whether in-situ hyperspectral data could be resampled to match the spectral resolution of multi- and hyperspectral satellites; if the type of sensor affected model transfer; and if spatio-temporal patterns of forage characteristics could be related to environmental drivers. We established models for forage quantity (green biomass) and five forage quality proxies (metabolisable energy, acid/neutral detergent fibre, ash, phosphorus). Hyperspectral resolution of the Hyperion satellite mostly resulted in higher accuracies (i.e. higher R-2, lower RMSE). When applied to satellite data, though, the greater quality of the multispectral Sentinel-2 satellite data leads to more realistic forage maps. By analysing a three-year time series, we found plant phenology and cumulated precipitation to be the most important environmental drivers of forage supply. We conclude that none of the investigated satellites provide optimal conditions for monitoring purposes. Future hyperspectral satellite missions like EnMAP, combining the high information level of Hyperion with the good data quality and resolution of Sentinel-2, will provide the prerequisites for installing a regular monitoring service.…
Author details: | Jessica FernerORCiD, Anja LinstädterORCiDGND, Christian RogassORCiD, Karl-Heinz SüdekumORCiD, Sebastian SchmidtleinORCiD |
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DOI: | https://doi.org/10.1080/22797254.2021.1934556 |
ISSN: | 2279-7254 |
Title of parent work (English): | European journal of remote sensing |
Subtitle (English): | going multispectral or hyperspectral? |
Publisher: | geoLAB, Laboratory of Geomatics |
Place of publishing: | Florence |
Publication type: | Article |
Language: | English |
Date of first publication: | 2021/06/17 |
Publication year: | 2021 |
Release date: | 2024/09/06 |
Tag: | Africa; biomass; forage; nutritive value; production; rangelands; remote-sensing based monitoring |
Volume: | 54 |
Issue: | 1 |
Number of pages: | 21 |
First page: | 364 |
Last Page: | 384 |
Funding institution: | German Federal Ministry of Education and Research (BMBF) through WASCALFederal Ministry of Education & Research (BMBF); German Federal Ministry of Education and Research (BMBF) through WASCAL WRAP 2.0 project GreenGaDeFederal Ministry of Education & Research (BMBF); Bundesministerium fur Bildung und ForschungFederal Ministry of Education & Research (BMBF) [01LG1202A, 01LG2078A] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Biochemie und Biologie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
Peer review: | Referiert |
Publishing method: | Open Access / Gold Open-Access |
DOAJ gelistet | |
License (German): | CC-BY - Namensnennung 4.0 International |