Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1088/1748-9326/aad5d2 |
Evidence of vegetation greening at alpine treeline ecotones: three decades of Landsat spectral trends informed by lidar-derived vertical structure | |
Bolton, Douglas K.1; Coops, Nicholas C.1; Hermosilla, Txomin1; Wulder, Michael A.2; white, Joanne C.2 | |
2018-08-01 | |
发表期刊 | ENVIRONMENTAL RESEARCH LETTERS
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ISSN | 1748-9326 |
出版年 | 2018 |
卷号 | 13期号:8 |
文章类型 | Article |
语种 | 英语 |
国家 | Canada |
英文摘要 | Monitoring changes in vegetation at high-latitude and alpine treeline ecotones is critical for characterizing changes to carbon and energy budgets, plant species richness, and habitat suitability and is often considered a bellwether of a changing climate. Herein, we used transects of airborne laser scanning (ALS) data to identify alpine treeline ecotones in the Yukon Territory of Canada, and assessed changes in vegetation greenness using a time-series of Landsat imagery over a 30 year period from 1985 to 2015. Specifically, we calculated the enhanced vegetation index (EVI) from annual Landsat composites and assessed temporal trends within 500mof detected forest-lines (i.e., transition point from continuous forest into treeline ecotones) using Theil-Sen's nonparametric regression. Across 74 detected treeline ecotones, 27.5% of Landsat pixels displayed a significant positive trend in EVI and 5.6% of pixels displayed a significant negative trend (p < 0.05). By using ALS data to determine vegetation structural class, we found that non-treed pixels had the highest percentage of significant positive trends in vegetation greenness (40.8%), followed by shrubs (30.5%), with lower percentages in sparse forests (18.9%) and open/dense forests (13.3%). These results suggest herbaceous and shrub vegetation types are undergoing the most significant changes in greenness, likely due to increases in shrub cover and herbaceous biomass in areas associated with these alpine treeline ecotones. The limited increases in EVI in forests likely indicates that vegetation cover is changing less rapidly in forests than in shrub and herbaceous vegetation types. Moreover, EVI may not be capturing increased height growth in forests near the treeline. Combining ALS data and Landsat time-series data provides a useful approach to locate and characterize alpine treeline ecotones, and enables the direct assessment of which vegetation structural classes are experiencing the greatest greening trends, thereby providing new insights to ecosystem change. |
英文关键词 | remote sensing forest structure tundra climate change time-series |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000442007400001 |
WOS关键词 | SURFACE-REFLECTANCE COMPOSITES ; GROWING-SEASON LENGTH ; TIME-SERIES ; SHRUB EXPANSION ; CLIMATE-CHANGE ; CANADA ; TUNDRA ; IMAGERY ; ZONE ; RESPONSES |
WOS类目 | Environmental Sciences ; Meteorology & Atmospheric Sciences |
WOS研究方向 | Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/31029 |
专题 | 气候变化 |
作者单位 | 1.Univ British Columbia, Dept Forest Resources Management, Integrated Remote Sensing Studio, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada; 2.Nat Resources Canada, Pacific Forestry Ctr, Canadian Forest Serv, 506 West Burnside Rd, Victoria, BC V8Z 1M5, Canada |
推荐引用方式 GB/T 7714 | Bolton, Douglas K.,Coops, Nicholas C.,Hermosilla, Txomin,et al. Evidence of vegetation greening at alpine treeline ecotones: three decades of Landsat spectral trends informed by lidar-derived vertical structure[J]. ENVIRONMENTAL RESEARCH LETTERS,2018,13(8). |
APA | Bolton, Douglas K.,Coops, Nicholas C.,Hermosilla, Txomin,Wulder, Michael A.,&white, Joanne C..(2018).Evidence of vegetation greening at alpine treeline ecotones: three decades of Landsat spectral trends informed by lidar-derived vertical structure.ENVIRONMENTAL RESEARCH LETTERS,13(8). |
MLA | Bolton, Douglas K.,et al."Evidence of vegetation greening at alpine treeline ecotones: three decades of Landsat spectral trends informed by lidar-derived vertical structure".ENVIRONMENTAL RESEARCH LETTERS 13.8(2018). |
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