The vanishing white: management of stressors causing reduction of pale vegetation surfaces in the Arctic and the Qinghai-Tibetan Plateau

Informations

Funding country

Norway

Acronym

-

URL

-

Start date

1/1/2019

End date

12/31/2022

Budget

791,136 EUR

Fundings

Abstract

The potential for carbon sequestration is limited for alpine and arctic vegetation in comparison to more productive ecosystem in warmer regions. Since international climate policy has focussed primarily on carbon sequestration, possible climate mitigation efforts in cold regions have received little attention. Increasing concentrations of greenhouse gases in the atmosphere are only one of several factors causing global warming. Another important factor is the reflectivity of solar radiation reaching the Earth's surface, known as albedo. Some arctic and alpine vegetation types have pale surfaces with high albedo. In this project, known by the acronym VANWHITE, our primary objective is to increase the knowledge on this potentially important climate-mitigating ecosystem service by undertaking detailed field analyses at high northern latitudes and the Tibetan Plateau, supplemented with extensive remote sensing analyses. Typically, pale ecosystems are dominated by lichens. These are easily visible on landscape images as cream to straw yellow surfaces. In addition, many vascular plants and mosses are pale. Exploring how climate change and other pressures have led to changes in the distribution and state of pale vegetation surfaces is an important objective of the project. Herbivory, pollution, extreme weather, industrial development and tourism are among the pressures that we include in our analyses. The climate-mitigating services provided by light vegetation types are being compared with other types of ecosystem services from the same land areas. A key question is how, in the best possible way, one can balance the need for locally important provisioning services and globally important regulating services, while at the same time maintaining ecosystems in good states. The project consortium is multidisciplinary, consisting primarily of Norwegian and Chinese scientists with high competence in global change biogeochemistry, biophysics, ecology, geophysics, economy, land management, earth observation, and social sciences. A kick-off meeting was held in Tromsø in February 2019. The meeting planned for 2020 was cancelled due to the pandemic. Instead, virtual meetings have aided regular communication between partners. As of 1 October 2021, the project consortium has published 11 scientific studies in international scientific journals, including three in Nature journals. In the study published in Nature Reviews Earth & Environment, updated data and models for the regulating role of the earth's vegetation on the climate system were presented. Global greening since the early 1980s may have reduced global warming, possibly by as much as 0.25 °C. The study shows that high northern latitudes have become considerably greener since 1982, meaning increasing plant biomass, and that this trend will accelerate during this century, even at low emission rates (RCP 2.6). This publication has already been cited 169 times and is regarded as a "Hot paper" according to the Web of Science, which means that is in the top 0.1 % of papers in the academic field of geosciences published in the past two years. In the perspective paper published in Nature Climate Change in January 2020, we show that not all vegetated Arctic lands become greener despite the extensive warming. Large regions have a reduced vegetation cover following extreme climatic events. The study highlights the challenges of observing and interpreting vegetation changes and identifies prioritized areas for future research of the vast Arctic areas. With 118 citations, it is regarded as a "Highly cited" paper in the academic field of Environment and Ecology, according to the Web of Science, which means that is in the top 1.0 % of papers within this field. These topics were further highlighted and discussed in an editorial for the journal Environmental Research Letters. This editorial focused on the fact that large parts of the Arctic are not covered through ground-based environmental and ecological monitoring, and that remote sensing combined with increasing ground-truthing will, during the next few decades, strongly improve our understanding of the rapid vegetation processes of the Arctic. During 2021, project partners have undertaken a significant amount of field and modelling work. This will feed into the project's upcoming scientific publications, which will largely focus on the climate-mitigating function of light vegetation types in the Arctic and at the Tibetan plateau, and how these vegetation types will develop during the next decades under contrasting scenarios.