Land surface phenology and temperature variation in the International Geosphere–Biosphere Program high‐latitude transects
Abstract The International Geosphere–Biosphere Program has delineated five study areas that form a northern high‐latitude network for the analyses of vegetation and carbon dynamics. We examined the magnitude and significance of changes in the land surface phenologies of ecoregions within these trans...
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crwiley:10.1111/j.1365-2486.2005.00949.x 2024-06-23T07:57:08+00:00 Land surface phenology and temperature variation in the International Geosphere–Biosphere Program high‐latitude transects De Beurs, Kirsten M. Henebry, Geoffrey M. 2005 http://dx.doi.org/10.1111/j.1365-2486.2005.00949.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2486.2005.00949.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2486.2005.00949.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Global Change Biology volume 11, issue 5, page 779-790 ISSN 1354-1013 1365-2486 journal-article 2005 crwiley https://doi.org/10.1111/j.1365-2486.2005.00949.x 2024-06-13T04:23:20Z Abstract The International Geosphere–Biosphere Program has delineated five study areas that form a northern high‐latitude network for the analyses of vegetation and carbon dynamics. We examined the magnitude and significance of changes in the land surface phenologies of ecoregions within these transects using the NASA Pathfinder Advanced Very High‐Resolution Radiometer Land dataset. We applied the seasonal Mann–Kendall (SMK) trend test, a robust and nonparametric approach, to determine the significance of trends in the normalized difference vegetation index (NDVI) over the five transects. The SMK trend test provides an important alternative over the frequently used but unreliable trend analysis based on linear regression. In addition, we modeled the land surface phenology using quadratic or nonlinear spherical models to relate the NDVI data to accumulated growing degree‐days (base 0°C). Nonlinear spherical models parsimoniously describe the green‐up dynamics in taiga and tundra ecoregions. Models for each ecoregion within each transect were fitted separately for two time periods (1985–1988 and 1995–1999) and their parameter coefficient estimates were compared. In 10 of 24 ecoregions that comprise 72% of the land area in the transects, the date of the peak NDVI value was significantly earlier (range 2–18 days) in the second study period than in the first study period. This progression was more pronounced in North America than in Siberia (weighted average of 9.3 vs. 6.3 days earlier). Understanding of what constitutes significant change in land surface phenology amidst background variation is a critical component of global change science. A diversity of datasets, techniques, and study areas has led to a range of conclusions about boreal phenology. We discuss statistical pitfalls in standard analyses and offer a framework to conduct statistically reliable change assessments of land surface phenologies. Article in Journal/Newspaper taiga Tundra Siberia Wiley Online Library Kendall ENVELOPE(-59.828,-59.828,-63.497,-63.497) Global Change Biology 11 5 779 790 |
institution |
Open Polar |
collection |
Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract The International Geosphere–Biosphere Program has delineated five study areas that form a northern high‐latitude network for the analyses of vegetation and carbon dynamics. We examined the magnitude and significance of changes in the land surface phenologies of ecoregions within these transects using the NASA Pathfinder Advanced Very High‐Resolution Radiometer Land dataset. We applied the seasonal Mann–Kendall (SMK) trend test, a robust and nonparametric approach, to determine the significance of trends in the normalized difference vegetation index (NDVI) over the five transects. The SMK trend test provides an important alternative over the frequently used but unreliable trend analysis based on linear regression. In addition, we modeled the land surface phenology using quadratic or nonlinear spherical models to relate the NDVI data to accumulated growing degree‐days (base 0°C). Nonlinear spherical models parsimoniously describe the green‐up dynamics in taiga and tundra ecoregions. Models for each ecoregion within each transect were fitted separately for two time periods (1985–1988 and 1995–1999) and their parameter coefficient estimates were compared. In 10 of 24 ecoregions that comprise 72% of the land area in the transects, the date of the peak NDVI value was significantly earlier (range 2–18 days) in the second study period than in the first study period. This progression was more pronounced in North America than in Siberia (weighted average of 9.3 vs. 6.3 days earlier). Understanding of what constitutes significant change in land surface phenology amidst background variation is a critical component of global change science. A diversity of datasets, techniques, and study areas has led to a range of conclusions about boreal phenology. We discuss statistical pitfalls in standard analyses and offer a framework to conduct statistically reliable change assessments of land surface phenologies. |
format |
Article in Journal/Newspaper |
author |
De Beurs, Kirsten M. Henebry, Geoffrey M. |
spellingShingle |
De Beurs, Kirsten M. Henebry, Geoffrey M. Land surface phenology and temperature variation in the International Geosphere–Biosphere Program high‐latitude transects |
author_facet |
De Beurs, Kirsten M. Henebry, Geoffrey M. |
author_sort |
De Beurs, Kirsten M. |
title |
Land surface phenology and temperature variation in the International Geosphere–Biosphere Program high‐latitude transects |
title_short |
Land surface phenology and temperature variation in the International Geosphere–Biosphere Program high‐latitude transects |
title_full |
Land surface phenology and temperature variation in the International Geosphere–Biosphere Program high‐latitude transects |
title_fullStr |
Land surface phenology and temperature variation in the International Geosphere–Biosphere Program high‐latitude transects |
title_full_unstemmed |
Land surface phenology and temperature variation in the International Geosphere–Biosphere Program high‐latitude transects |
title_sort |
land surface phenology and temperature variation in the international geosphere–biosphere program high‐latitude transects |
publisher |
Wiley |
publishDate |
2005 |
url |
http://dx.doi.org/10.1111/j.1365-2486.2005.00949.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2486.2005.00949.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2486.2005.00949.x |
long_lat |
ENVELOPE(-59.828,-59.828,-63.497,-63.497) |
geographic |
Kendall |
geographic_facet |
Kendall |
genre |
taiga Tundra Siberia |
genre_facet |
taiga Tundra Siberia |
op_source |
Global Change Biology volume 11, issue 5, page 779-790 ISSN 1354-1013 1365-2486 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1365-2486.2005.00949.x |
container_title |
Global Change Biology |
container_volume |
11 |
container_issue |
5 |
container_start_page |
779 |
op_container_end_page |
790 |
_version_ |
1802650605019201536 |