globalchange  > 影响、适应和脆弱性
DOI: 10.1111/gcb.13464
论文题名:
Mapping gains and losses in woody vegetation across global tropical drylands
作者: Tian F.; Brandt M.; Liu Y.Y.; Rasmussen K.; Fensholt R.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2017
卷: 23, 期:4
起始页码: 1748
结束页码: 1760
语种: 英语
英文关键词: deforestation ; drylands ; nonphotosynthetic woody component ; remote sensing ; shrub encroachment ; trend analysis ; wood biomass ; woody vegetation
英文摘要: Woody vegetation in global tropical drylands is of significant importance for both the interannual variability of the carbon cycle and local livelihoods. Satellite observations over the past decades provide a unique way to assess the vegetation long-term dynamics across biomes worldwide. Yet, the actual changes in the woody vegetation are always hidden by interannual fluctuations of the leaf density, because the most widely used remote sensing data are primarily related to the photosynthetically active vegetation components. Here, we quantify the temporal trends of the nonphotosynthetic woody components (i.e., stems and branches) in global tropical drylands during 2000–2012 using the vegetation optical depth (VOD), retrieved from passive microwave observations. This is achieved by a novel method focusing on the dry season period to minimize the influence of herbaceous vegetation and using MODerate resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data to remove the interannual fluctuations of the woody leaf component. We revealed significant trends (P < 0.05) in the woody component (VODwood) in 35% of the areas characterized by a nonsignificant trend in the leaf component (VODleaf modeled from NDVI), indicating pronounced gradual growth/decline in woody vegetation not captured by traditional assessments. The method is validated using a unique record of ground measurements from the semiarid Sahel and shows a strong agreement between changes in VODwood and changes in ground observed woody cover (r2 = 0.78). Reliability of the obtained woody component trends is also supported by a review of relevant literatures for eight hot spot regions of change. The proposed approach is expected to contribute to an improved assessment of, for example, changes in dryland carbon pools. © 2016 John Wiley & Sons Ltd
资助项目: This research is partly funded by the China Scholarship Council (CSC, number 201306420005) and the Danish Council for Independent Research (DFF) Sapere Aude program under the project entitled “Earth Observation based Vegetation productivity and Land Degradation Trends in Global Drylands”. M. B. is the recipient of the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant agreement (project number 656564). Y.Y.L. is the recipient of an Australian Research Council Discovery Early Career Researcher Award (DECRA) Fellowship (project number DE140100200). We thank the Centre de Suivi Ecologique (Senegal) and especially Abdoulaye Wele and Abdoul Aziz Diouf for collecting and providing the field data on woody cover and leaf biomass and Neha Joshi, University of Copenhagen, for helpful discussions on the properties of passive microwave and radar observations. Finally, the anonymous reviewers are thanked for their constructive comments.
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60991
Appears in Collections:影响、适应和脆弱性

Files in This Item:

There are no files associated with this item.


作者单位: Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark; ARC Centre of Excellence for Climate Systems Science & Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia

Recommended Citation:
Tian F.,Brandt M.,Liu Y.Y.,et al. Mapping gains and losses in woody vegetation across global tropical drylands[J]. Global Change Biology,2017-01-01,23(4)
Service
Recommend this item
Sava as my favorate item
Show this item's statistics
Export Endnote File
Google Scholar
Similar articles in Google Scholar
[Tian F.]'s Articles
[Brandt M.]'s Articles
[Liu Y.Y.]'s Articles
百度学术
Similar articles in Baidu Scholar
[Tian F.]'s Articles
[Brandt M.]'s Articles
[Liu Y.Y.]'s Articles
CSDL cross search
Similar articles in CSDL Cross Search
[Tian F.]‘s Articles
[Brandt M.]‘s Articles
[Liu Y.Y.]‘s Articles
Related Copyright Policies
Null
收藏/分享
所有评论 (0)
暂无评论
 

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.