Analysing long-term spatiotemporal land surface phenology patterns over the Iberian Peninsula using 250 m MODIS EVI2
Jose A Caparros-Santiago1, Victor Rodriguez-Galiano1
1Department of Physical Geography and Regional Geographic Analysis, Universidad de Sevilla, 41004 Seville, Spain.
The Science of the Total Environment
|September 23, 2024
Summary
This study mapped Iberian Peninsula land surface phenology over 21 years using satellite data. Results show regional variations in growing season start and end, with potential improvements using higher-resolution imagery.
Area of Science:
- Ecology and Environmental Science
- Remote Sensing
- Climate Change Impact
Background:
- Iberian Peninsula ecosystems are highly vulnerable to global warming, impacting their services.
- Seasonal variations and land surface phenology (LSP) in these ecosystems remain understudied.
- Understanding phenological shifts is crucial for predicting ecosystem responses to climate change.
Purpose of the Study:
- To characterize land surface phenology (LSP) patterns in the Iberian Peninsula from 2001-2021.
- To analyze three key phenometrics: start of season (SOS), end of season (EOS), and length of season (LOS).
- To compare satellite-derived phenometrics with in-situ human phenological observations.
Main Methods:
- Utilized 8-day composite EVI2 (Two-band Enhanced Vegetation Index) data from MOD09Q1 (250m resolution) over 21 years.
- Calculated SOS, EOS, and LOS for Iberian ecosystems.
- Employed Pearson's correlation, p-value, and absolute differences to assess phenometric-phenophase consistency.
Main Results:
- Generally later SOS and EOS dates were observed in Alpine and Atlantic regions; SOS in March-April, EOS in October-December.
- Natural vegetation types exhibited similar phenological dynamics, with earlier phenometric dates in Mediterranean savannas, grasslands, and scrublands.
- Strong correlations between SOS and leaf unfolding were found for Atlantic vegetation, but weaker correlations for Mediterranean deciduous types; EOS consistency was unclear.
Conclusions:
- Land surface phenology varies significantly across Iberian biogeographic regions and vegetation types.
- Satellite-derived phenometrics generally align with in-situ observations, particularly for spring phenophases in Atlantic vegetation.
- Higher spatial resolution satellite data is recommended to improve consistency for EOS and autumn phenophases, especially in heterogeneous Mediterranean ecosystems.
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