- Title
- The Grass is not Always Greener on the Other Side: Seasonal Reversal of Vegetation Greenness in Aspect-driven Semiarid Ecosystems
- Creator
- Kumari, Nikul; Saco, Patricia M.; Rodriguez, Jose F.; Johnstone, Samuel A.; Srivastava, Ankur; Chun, Kwok P.; Yetemen, Omer
- Relation
- ARC.DP140104178 http://purl.org/au-research/grants/arc/DP140104178
- Relation
- Geophysical Research Letters Vol. 47, Issue 15, no. e2020GL088918
- Publisher Link
- http://dx.doi.org/10.1029/2020GL088918
- Publisher
- Wiley-Blackwell
- Resource Type
- journal article
- Date
- 2020
- Description
- Our current understanding of semiarid ecosystems is that they tend to display higher vegetation greenness on polar-facing slopes (PFS) than on equatorial-facing slopes (EFS). However, recent studies have argued that higher vegetation greenness can occur on EFS during part of the year. To assess whether this seasonal reversal of aspect-driven vegetation is a common occurrence, we conducted a global-scale analysis of vegetation greenness on a monthly time scale over an 18-year period (2000-2017). We examined the influence of climate seasonality on the normalized difference vegetation index (NDVI) values of PFS and EFS at 60 different catchments with aspect-controlled vegetation located across all continents except Antarctica. Our results show that an overwhelming majority of sites (70%) display seasonal reversal, associated with transitions from water-limited to energy-limited conditions during wet winters. These findings highlight the need to consider seasonal variations of aspect-driven vegetation patterns in ecohydrology, geomorphology, and Earth system models.
- Subject
- ecosystem; hillslope aspect; NDVI; remote sensing; semiarid; vegetatio greenness
- Identifier
- http://hdl.handle.net/1959.13/1434931
- Identifier
- uon:39555
- Identifier
- ISSN:0094-8276
- Language
- eng
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