by Staff Writers
Zurich, Switzerland (SPX) Apr 17, 2013
The climate governs the seasonal activity of vegetation; humankind influences it. In the humid mid-latitudes, temperature is the largest influencing factor for plant growth. In predominantly dry areas, however, it is the availability of water and in the high latitudes incident solar radiation.
Without a doubt, humankind also has a modifying impact on the ecosystem. Satellites have been recording how the vegetation on the Earth's surface is changing since the 1980s.
Within the last thirty years, for instance, vegetation activity has increased in the northern hemisphere but declined in the southern hemisphere. Until recently, it was not possible to quantify the extent to which climate variability, human activity or a combination of the two factors were responsible for this.
An interdisciplinary team headed by geographers Rogier de Jong, Michael Schaepman and mathematician Reinhard Furrer from the University of Zurich, however, has now developed a model together with Dutch colleagues that can illustrate the influences of human activity and climate variability on vegetation separately.
To this end, they used satellite data on the vegetation increase or decline from the last thirty years, climate measurements and models, and data on the kind of land cover. The scientists demonstrate that around 54 percent of the changes in global vegetation activity can be attributed to climate variability.
Over 30 percent of the changes caused by human activity
"We assume that this was caused by clear cutting, the transformation of rainforest into plantations or changes in agriculture in general," explains de Jong. Around ten percent cannot be explained fully by climatology or human activity.
"We suspect that this is due to unexplained effects of the interactions between humans and the climate," says Head of the RSL Michael Schaepman.
Schaepman and his team will pursue these interactions further under the newly created research priority program "Global Change and Biodiversity" at the University of Zurich.
de Jong, R., Schaepman, M.E., Furrer, R., de Bruin, S., and Verburg, P. (2013). Spatial Relationship between Climatologies and Changes in Global Vegetation Activity. Global Change Biology; de Jong, R., Verbesselt, J., Zeileis, A., and Schaepman, M.E. (2013). Shifts in Global Vegetation Activity Trends. Remote Sensing, (5) (3), 1117-1133; University Research Priority Program "Global Change and Biodiversity".
University of Zurich
Earth Observation News - Suppiliers, Technology and Application
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement|