干旱区生态环境知识资源中心(Arid): Estimating above ground biomass as an indicator of carbon storage in vegetated wetlands of the grassland biome of South Africa

Arid

DOI	10.1016/j.jag.2019.01.021
	Estimating above ground biomass as an indicator of carbon storage in vegetated wetlands of the grassland biome of South Africa
	Naidoo, Laven 1; van Deventer, Heidi 1,2; Ramoelo, Abel 3,5; Mathieu, Renaud 1,4; Nondlazi, Basanda 1; Gangat, Ridhwannah 2
通讯作者	Naidoo, Laven
来源期刊	INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION
ISSN	0303-2434
出版年	2019
卷号	78 页码:118-129
英文摘要	Wetlands store higher carbon content relative to other terrestrial ecosystems, despite the small extent they occupy. The increase in temperature and changes in rainfall pattern may negatively affect their extent and condition, and thus the process of carbon accumulation in wetlands. The introduction of the Sentinel series (S1 and S2) and WorldView space-borne sensors (WV3) have enabled monitoring of herbaceous above ground biomass (AGB) in small and narrow wetlands in semi-arid areas. The objective of this study was to assess (i) the capabilities of the high to moderate resolution sensors such as WV3, S1A and S2A in estimating herbaceous AGB of vegetated wetlands using SAR backscatter, optical reflectance bands, vegetation spectral indices (including Leaf Area Index or LAI measurements) and band ratio datasets and (ii) whether significant differences exists between the AGB ranges of wetland and surrounding dryland vegetation. A bootstrapped Random Forest modelling approach, with variable importance selection, was utilised which incorporated ground collected grass AGB for model calibration and validation. WorldView-3 (WV3) yielded the highest AGB prediction accuracies (R-2 = 0.63 and RMSE = 169.28 g/m(2)) regardless of the incorporation of bands only, indices only or the combination of bands and indices. In general, the optical sensors yielded higher modelling accuracies (improvement in R-2 of 0.04-0.07 and RMSE of 11.48-17.28 g/m(2)) than the single Synthetic Aperture Radar (SAR) sensor but this was marginal depending on the scenario. Incorporating Sentinel 1A (S1) dual polarisation channels and Sentinel 2A (S2) reflectance bands, in particular, yielded higher accuracies (improvement in R-2 of 0.03-0.04 and RMSE of 5.4-16.88 g/m(2)) than the use of individual sensors alone and was also equivalent to the performance of the high resolution WV3 sensor results. Wetlands had significantly higher AGB compared to the surrounding terrestrial grassland (with a mean of about 80 g/m(2) more). Monitoring herbaceous AGB at the scale of the wetland extent in semi-arid to arid grasslands enables improved understanding of their carbon sequestration potential, the contributions to global carbon accounting policies and also serving as a proxy for functional intactness.
英文关键词	Vegetation biomass AGB Wetland types Carbon sequestration Remote sensing Earth observation Sentinel sensors
类型	Article
语种	英语
国家	South Africa
收录类别	SCI-E
WOS记录号	WOS:000463131700011
WOS关键词	ABOVEGROUND BIOMASS ; AQUATIC VEGETATION ; INNER-MONGOLIA ; MPUMALANGA ; TEMPERATURE ; LAI ; ECOSYSTEMS ; INVERSION ; RAINFALL ; INDEXES
WOS类目	Remote Sensing
WOS研究方向	Remote Sensing
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/216342
作者单位	1.CSIR, Ecosyst Earth Observat, Pretoria, South Africa; 2.Univ Witwatersrand, Sch Geog Archaeol & Environm Studies, Private Bag 3, ZA-2050 Johannesburg, South Africa; 3.Univ Limpopo, Risk & Vulnerabil Assessment Ctr, Private Bag X1106, ZA-0727 Polokwane, South Africa; 4.Univ Pretoria, Dept Geog Geoinformat & Meteorol, Private BagX20, ZA-0028 Hatfield, South Africa; 5.Sci Serv, South African Natl Pk, POB 787, ZA-0001 Pretoria, South Africa
推荐引用方式 GB/T 7714	Naidoo, Laven,van Deventer, Heidi,Ramoelo, Abel,et al. Estimating above ground biomass as an indicator of carbon storage in vegetated wetlands of the grassland biome of South Africa[J],2019,78:118-129.
APA	Naidoo, Laven,van Deventer, Heidi,Ramoelo, Abel,Mathieu, Renaud,Nondlazi, Basanda,&Gangat, Ridhwannah.(2019).Estimating above ground biomass as an indicator of carbon storage in vegetated wetlands of the grassland biome of South Africa.INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION,78,118-129.
MLA	Naidoo, Laven,et al."Estimating above ground biomass as an indicator of carbon storage in vegetated wetlands of the grassland biome of South Africa".INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION 78(2019):118-129.