Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1111/gcb.13547 |
The case for increasing the statistical power of eddy covariance ecosystem studies: why, where and how? | |
Hill, Timothy1; Chocholek, Melanie2; Clement, Robert3 | |
2017-06-01 | |
发表期刊 | GLOBAL CHANGE BIOLOGY
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ISSN | 1354-1013 |
EISSN | 1365-2486 |
出版年 | 2017 |
卷号 | 23期号:6 |
文章类型 | Article |
语种 | 英语 |
国家 | England; Scotland |
英文摘要 | Eddy covariance (EC) continues to provide invaluable insights into the dynamics of Earth's surface processes. However, despite its many strengths, spatial replication of EC at the ecosystem scale is rare. High equipment costs are likely to be partially responsible. This contributes to the low sampling, and even lower replication, of ecoregions in Africa, Oceania (excluding Australia) and South America. The level of replication matters as it directly affects statistical power. While the ergodicity of turbulence and temporal replication allow an EC tower to provide statistically robust flux estimates for its footprint, these principles do not extend to larger ecosystem scales. Despite the challenge of spatially replicating EC, it is clearly of interest to be able to use EC to provide statistically robust flux estimates for larger areas. We ask: How much spatial replication of EC is required for statistical confidence in our flux estimates of an ecosystem? We provide the reader with tools to estimate the number of EC towers needed to achieve a given statistical power. We show that for a typical ecosystem, around four EC towers are needed to have 95% statistical confidence that the annual flux of an ecosystem is nonzero. Furthermore, if the true flux is small relative to instrument noise and spatial variability, the number of towers needed can rise dramatically. We discuss approaches for improving statistical power and describe one solution: an inexpensive EC system that could help by making spatial replication more affordable. However, we note that diverting limited resources from other key measurements in order to allow spatial replication may not be optimal, and a balance needs to be struck. While individual EC towers are well suited to providing fluxes from the flux footprint, we emphasize that spatial replication is essential for statistically robust fluxes if a wider ecosystem is being studied. |
英文关键词 | carbon carbon dioxide CO2 eddy covariance effect size flux latent replication sensible significant |
领域 | 气候变化 ; 资源环境 |
收录类别 | SCI-E |
WOS记录号 | WOS:000400445900003 |
WOS关键词 | CARBON-DIOXIDE EXCHANGE ; SPATIAL VARIABILITY ; CO2 EXCHANGE ; TEMPORAL VARIABILITY ; TURBULENT FLUXES ; WATER-VAPOR ; UNCERTAINTY ; FOREST ; ENERGY ; PSEUDOREPLICATION |
WOS类目 | Biodiversity Conservation ; Ecology ; Environmental Sciences |
WOS研究方向 | Biodiversity & Conservation ; Environmental Sciences & Ecology |
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/16624 |
专题 | 气候变化 资源环境科学 |
作者单位 | 1.Exeter Univ, Dept Geog, Rennes Dr, Exeter EX4 4RJ, Devon, England; 2.Univ St Andrews, Dept Earth & Environm Sci, Irvine Bldg,North St, St Andrews KY16 9AL, Fife, Scotland; 3.Univ Edinburgh, Sch Geosci, Crew Bldg,Alexander Crum Brown Rd, Edinburgh EH9 3FF, Midlothian, Scotland |
推荐引用方式 GB/T 7714 | Hill, Timothy,Chocholek, Melanie,Clement, Robert. The case for increasing the statistical power of eddy covariance ecosystem studies: why, where and how?[J]. GLOBAL CHANGE BIOLOGY,2017,23(6). |
APA | Hill, Timothy,Chocholek, Melanie,&Clement, Robert.(2017).The case for increasing the statistical power of eddy covariance ecosystem studies: why, where and how?.GLOBAL CHANGE BIOLOGY,23(6). |
MLA | Hill, Timothy,et al."The case for increasing the statistical power of eddy covariance ecosystem studies: why, where and how?".GLOBAL CHANGE BIOLOGY 23.6(2017). |
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