Effects of Nitrogen and Phosphorus Application on Spectral Characteristics of Six Typical Grassland Dominant Species in Loess Hilly-gully Region
Exploring the spectral feature responses and differences of dominant species in grassland commu-nities after fertilization is important for accurately evaluating the effects of grassland fertilization.Spectral characteristics of six dominant species(Bothriochloa ischaemum,Stipa bungeana,Lespedeza davurica,Po-tentilla tanacetifolia,Artemisia mongolica and Artemisia sacrorum)in the loess-hilly region was deter-mined and analyzed,and seven spectral parameters were also extracted for evaluating the differences among the dominant species after N and P fertilizer applications.Compared to no fertilization,the individual appli-cation of N or P fertilizers reduced the spectral reflectance of the six dominant species at"Blue Valley","Green Peak"and"Red Valley".The amplitude(AMP)and red edge area(Sred)of each dominant species generally showed an increasing trend following N and P co-application,and the difference vegetation index(DVI)values of B.ischaemum,L.davurica,P.tanacetifolia and A.sacrorum exhibited an increasing trend.All these findings indicated that the spectral characterization parameters could effectively reflect the effects of N and P fertilization on grassland dominant species in loess hilly-gully region,and vegetation in-dex such as DVI,NDVI and GNDVI were more suitable to evaluate the response and differences among grassland dominant species to N and P fertilization than RVI.
Red edge parameterVegetation indexSpectral characteristicGrassland communityLoess Plat-eau