| Title: |
Annual precipitation explains variability in dryland vegetation greenness globally but not locally |
| Authors: |
Ukkola, AM; De Kauwe, MG; Roderick, ML; Burrell, A; Lehmann, P; Pitman, AJ |
| Source: |
urn:ISSN:1354-1013 ; urn:ISSN:1365-2486 ; Global Change Biology, 27, 18, 4367-4380 |
| Publisher Information: |
Wiley |
| Publication Year: |
2021 |
| Collection: |
UNSW Sydney (The University of New South Wales): UNSWorks |
| Subject Terms: |
37 Earth Sciences; 4101 Climate Change Impacts and Adaptation; 31 Biological Sciences; 41 Environmental Sciences; 13 Climate Action; Climate Change; Droughts; Ecosystem; Seasons; Soil; Water; Earth system models; drylands; precipitation; space-for-time substitution; vegetation; anzsrc-for: 37 Earth Sciences; anzsrc-for: 4101 Climate Change Impacts and Adaptation; anzsrc-for: 31 Biological Sciences; anzsrc-for: 41 Environmental Sciences; anzsrc-for: 05 Environmental Sciences; anzsrc-for: 06 Biological Sciences |
| Description: |
Dryland vegetation productivity is strongly modulated by water availability. As precipitation patterns and variability are altered by climate change, there is a pressing need to better understand vegetation responses to precipitation variability in these ecologically fragile regions. Here we present a global analysis of dryland sensitivity to annual precipitation variations using long-term records of normalized difference vegetation index (NDVI). We show that while precipitation explains 66% of spatial gradients in NDVI across dryland regions, precipitation only accounts for 75%) dryland regions. We observed this weaker temporal relative to spatial relationship between NDVI and precipitation across all global drylands. We confirmed this result using three alternative water availability metrics that account for water loss to evaporation, and growing season and precipitation timing. This suggests that predicting vegetation responses to future rainfall using space-for-time substitution will strongly overestimate precipitation control on interannual variability in aboveground growth. We explore multiple mechanisms to explain the discrepancy between spatial and temporal responses and find contributions from multiple factors including local-scale vegetation characteristics, climate and soil properties. Earth system models (ESMs) from the latest Coupled Model Intercomparison Project overestimate the observed vegetation sensitivity to precipitation variability up to threefold, particularly during dry years. Given projections of increasing meteorological drought, ESMs are likely to overestimate the impacts of future drought on dryland vegetation with observations suggesting that dryland vegetation is more resistant to annual precipitation variations than ESMs project. |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/pdf |
| Language: |
unknown |
| Relation: |
https://hdl.handle.net/1959.4/103833; https://doi.org/10.1111/gcb.15729 |
| DOI: |
10.1111/gcb.15729 |
| Availability: |
https://hdl.handle.net/1959.4/103833; https://unsworks.unsw.edu.au/bitstreams/65c153df-7124-4211-86e7-31479dbba411/download; https://doi.org/10.1111/gcb.15729 |
| Rights: |
open access ; https://purl.org/coar/access_right/c_abf2 ; No Licence ; free_to_read ; This is the peer reviewed version of the following article: Ukkola, A. M., De Kauwe, M. G., Roderick, M. L., Burrell, A., Lehmann, P., & Pitman, A. J. (2021). Annual precipitation explains variability in dryland vegetation greenness globally but not locally. Global Change Biology, 27(18), 4367–4380., which has been published in final form at https://doi.org/10.1111/gcb.15729. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited. |
| Accession Number: |
edsbas.2CB1BC8C |
| Database: |
BASE |