气候变化领域集成服务门户(CCPortal): Valid inferences about soil carbon in heterogeneous landscapes

CCPortal

DOI	10.1016/j.geoderma.2022.116323
	Valid inferences about soil carbon in heterogeneous landscapes
	Stanley, Paige; Spertus, Jacob; Chiartas, Jessica; Stark, Philip B.; Bowles, Timothy
发表日期	2023
ISSN	0016-7061
EISSN	1872-6259
卷号	430
英文摘要	Using soil organic carbon (SOC) to generate carbon offsets requires reliably quantifying SOC sequestration. However, accuracy of SOC measurement is limited by inherent spatial heterogeneity, variability of laboratory assays, unmet statistical assumptions, and the relatively small magnitude of SOC changes over time, among other things. Most SOC measurement protocols currently used to generate offsets for C markets do not adequately address these issues, threatening to undermine climate change mitigation efforts. Using analyses and simulations from 1,117 soil samples collected from California crop and rangelands, we quantified measurement errors and sources of uncertainty to optimize SOC measurement. We demonstrate that (1) spatial heterogeneity is a primary driver of uncertainty; (2) dry combustion assays contribute little to uncertainty, although inorganic C can in-crease error; (3) common statistical methods-Student's t-test and its relatives-can be unreliable for SOC (e.g. at low to medium sample sizes or when the distribution of SOC is skewed), which can lead to incorrect in-terpretations of SOC sequestration; and (4) common sample sizes (10-30 cores) are insufficiently powered to detect the modest SOC changes expected from management in heterogeneous agricultural landscapes. To reduce error and improve the reliability of future SOC offsets, protocols should: (1) require power analyses that include spatial heterogeneity to determine minimum sample sizes, rather than allowing arbitrarily small sample sizes; (2) minimize the use of compositing; (3) require dry combustion analysis, by the same lab for all assays; and (4) use nonparametric statistical tests and confidence intervals to control Type I error rates. While these changes might increase costs, they will make SOC estimates more accurate and more reliable, adding credibility to soil man-agement as a climate change mitigation strategy.
英文关键词	Soil carbon; Spatial heterogeneity; Valid inference; Measurement; Carbon markets
语种	英语
WOS研究方向	Soil Science
WOS类目	Science Citation Index Expanded (SCI-EXPANDED)
WOS记录号	WOS:000915627200001
来源期刊	GEODERMA
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/281233
作者单位	University of California System; University of California Berkeley; University of California System; University of California Berkeley; University of California System; University of California Davis
推荐引用方式 GB/T 7714	Stanley, Paige,Spertus, Jacob,Chiartas, Jessica,et al. Valid inferences about soil carbon in heterogeneous landscapes[J],2023,430.
APA	Stanley, Paige,Spertus, Jacob,Chiartas, Jessica,Stark, Philip B.,&Bowles, Timothy.(2023).Valid inferences about soil carbon in heterogeneous landscapes.GEODERMA,430.
MLA	Stanley, Paige,et al."Valid inferences about soil carbon in heterogeneous landscapes".GEODERMA 430(2023).