气候变化领域集成服务门户(CCPortal): Expanding networks of field hedges in densely populated landscapes in the Sahel

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DOI	10.1016/j.foreco.2019.03.016
	Expanding networks of field hedges in densely populated landscapes in the Sahel
	Hiernaux P.; Adamou K.; Moumouni O.; Turner M.D.; Tong X.; Savadogo P.; Mougin E.; Malam Issa O.
发表日期	2019
ISSN	0378-1127
起始页码	178
结束页码	188
卷号	440
英文摘要	Changing woody plant density across agricultural landscapes of the Sudano-Sahelian region is a debated issue. This paper reports the results of an investigation on the contribution of field hedges to overall woody plant density. Hedges separating individual cropped parcels were studied within village agropastoral territories in the Dantiandou district in western Niger. In 1992, field hedges were mapped over the study area using aerial photography and in 2016, using high resolution Google Earth imagery. In 1992, field hedge length was equal to 1006 km within 435 km 2 of croplands, equivalent to 2.3 km km −2 . In 2016, 17.5% of these hedges had disappeared, but 1591 km of new hedges were observed resulting in an increased density of hedges to 5.6 km km −2 . In 24 years, hedges had increased at a mean annual rate of 3.7% likely associated with the splitting of crop fields by inheritance. The composition and productivity of hedges were also monitored in 1996, 2010 and 2015. All trees (maximum height ≥ 4 m), shrubs (<4 m) and tussock perennial grasses were recorded within twelve field hedge samples of 200 m each. Field measurements were used to estimate basal area, crown area, foliage mass and wood mass of each woody plant within the sampled hedges. No significant trends were found between 1996 and 2015 in woody plant density, basal area, crown cover, wood and foliage masses across all monitored hedges. However, overall means hide a slight decrease in tree contributions, while shrub contributions first increased and then decreased. They also mask contradictory trends among sites most likely related to different rates of shrub coppicing and tree cutting. The woody species composition of the hedges is poor with an increase of Combretum glutinosum to the detriment of Guiera senegalensis over the study period. Multiplying the hedge sample statistics by the changing lengths of field hedges in the study area provides estimates of the contribution of the hedge woody plants to the woody plant population at a landscape scale. Between 1992 and 2016, field hedges contributed to increases of woody plant density by 3.9%, basal areas by 5.4%, crown cover by 2.7%, leading to 6.1% annual increase in foliage mass and 8.8% increase in wood mass. © 2019 Elsevier B.V.
英文关键词	Agroforestry; Bocage; Deforestation; Hedgerow; Land tenure; Tropical Africa
语种	英语
scopus关键词	Aerial photography; Antennas; Deforestation; Plants (botany); Population statistics; Agroforestry; Bocage; Hedgerow; Land tenure; Tropical Africa; Wooden fences; aerial photography; agricultural land; agroforestry; clearcutting; deforestation; hedgerow; land tenure; landscape change; software; woody plant; Air Craft; Basal Area; Deforestation; Density; Mass; Plants; Tropics; Wood; Niger [Nigeria]; Nigeria; Sahel [Sub-Saharan Africa]; Combretum glutinosum; Poaceae
来源期刊	Forest Ecology and Management
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156062
作者单位	Pastoral Conseil, 30 chemin de Jouanal, Caylus, 82160, France; Groupe de Recherche, d'Etudes et d'Action pour le Développement (GREAD), Niamey, Niger; Department of Geography, University of Wisconsin, Madison, United States; Department of Geosciences and Natural Resource Management (IGN), University of Copenhagen, Copenhagen, 1350, Denmark; World Agroforestry Centre (ICRAF), West and Central Africa Regional Office – Sahel Node, BP E5118 Bamako, Mali; Geosciences Environnement Toulouse (GET), Observatoire Midi-Pyrénées, UMR 5563 (CNRS/UPS/IRD/CNES), 14 Avenue Edouard Belin, Toulouse, 31400, France; Institut d'Ecologie et des Sciences de l'Environnement de Paris (IEES-Paris), UMR 242 (IRD, SU, CNRS, INRA, USPC, UPEC), 32 av., H. Varagnat, Bondy, 93143, France
推荐引用方式 GB/T 7714	Hiernaux P.,Adamou K.,Moumouni O.,et al. Expanding networks of field hedges in densely populated landscapes in the Sahel[J],2019,440.
APA	Hiernaux P..,Adamou K..,Moumouni O..,Turner M.D..,Tong X..,...&Malam Issa O..(2019).Expanding networks of field hedges in densely populated landscapes in the Sahel.Forest Ecology and Management,440.
MLA	Hiernaux P.,et al."Expanding networks of field hedges in densely populated landscapes in the Sahel".Forest Ecology and Management 440(2019).