Temporal and phenological profiles of open and dense Caatinga using remote sensing:response to precipitation and its irregularities  

作　　者：Janisson Batista de Jesus Tatiana Mora Kuplich íkaro Daniel de Carvalho Barreto Cristiano Niederauer da Rosa Fernando Luis Hillebrand 

机构地区：[1]Postgraduate Program in Remote Sensing,Federal University of Rio Grande Do Sul,Av.Bento Goncalves,CEP 91501-970,Porto Alegre,Rio Grande do Sul 9500,Brazil [2]National Institute for Space Research(INPE)Southern Regional Centre(CRS),CEP 97105-970,Santa Maria,Rio Grande do Sul,Brazil [3]Postgraduate Program in Applied Biometrics and Statistics,Rural Federal University of Pernambuco,Dom Manuel de Medeiros,s/n,Dois Irmaos,CEP 52171-900,Recife,Pernambuco,Brazil

出　　处：《Journal of Forestry Research》2021年第3期1067-1076,共10页林业研究（英文版）

基　　金：National Council for Scientific and Technological Development(CNPq);the Coordination of Superior Level StaffImprovement-Brazil(CAPES)。

摘　　要：Caatinga is a typical biome of Brazil's semiarid regions and subject to climate changes.Research is needed on the relation of its features to climate events.This study analyzed the infl uence of rainfall and its irregularities in open and dense woody Caatinga vegetation.Phenological curves were generated by means of Normalized Difference Vegetation Index(NDVI)time profiles in the Grota do Angico Conservation Unit study area in Sergipe State.Rainfall data from 2000 to 2018 were collected and phenological curves generated using various estimate methods that produced the following variables:[start of season,end of season,peak of season position,length of season,mean growing season and maximum seasonal].Rainfall showed a standard intra-annual behavior,with inter-annual variations related to irregularities infl uencing Caatinga response.Dense Caatinga vegetation had higher values of NDVI in all periods,even in anomalous years compared to open Caatinga,in addition to having longer leaf coverage over the year,with an anticipated start and a more extended seasonal end.The analysis of the rainfall regime made it possible to assess its infl uence on the Caatinga and phenological profiles proved to be fundamental to understand periods of physiological change of open and dense Caatinga.These results indicate that dense Caatinga maintains physiological activity longer,which may be associated with greater moisture maintenance in a semiarid region.In addition,because it has a greater leaf cover for longer periods,the soil may be preserved and maintain its characteristics longer,reducing the effects of desertification.The results may be associated with the type of forest management and conservation in this region.The total or partial suppression of individual remnants of Caatinga should be avoided,since the most open areas have lower photosynthetic capacity,affected to a considerable extent from the effects of adverse climatic conditions.Additionally,open Caatinga has a reduced capacity for regenerating naturally and its use by

关 键 词：SEMIARID Tropical dry forest NDVI MODIS Phenopix 

分 类 号：Q948[生物学—植物学]