...ng spring migration timing of geese_.pdf

...ng spring migration timing of geese_.pdf tài liệu, giáo án, bài giảng , luận văn, luận án, đồ án, bài tập lớn về tất...

Green wave indices for predicting spring migration timing of geese Mitra Shariati Najafabadi Skidmore, A.K., Darvishzadeh, R., Kölzsch, A., Vrieling, A., Nolet, B.A., Exo, K.M., Meratnia, N., Havinga, P., Stahl, J., Toxopeus, A.G INTRODUCTION  Green wave hypothesis  Fertility & Mortality Decrease  Life Expectancy Increase  Arctic nesting geese • Partially capital breeders • Timing of optimal breeding condition  Climate change  An accurate understanding of the timing of the spring migration INTRODUCTION  Satellite-derived NDVI time series • Near-infrared (NIR) and red reflectance • Reasonable estimates of biomass • Photosynthetically active radiation • Direct measure of plant phenology  Growing degree days (GDD) • Sum of mean daily temperature • Indirect measure of plant development INTRODUCTION  Hypothesis: timing of geese migration, with respect to the green wave phenology, would be predicted more accurately by NDVI than GDD MATERIALS AND METHODS – green wave indices  Satellite-derived green wave index (GWI) • MODIS 16-day composite NDVI dataset with a 1-km spatial resolution • GWIt= (NDVIt-NDVImin)/ (NDVImax-NDVImin) ì100 Date of 50% GWI MATERIALS AND METHODS – green wave indices  The rate of change in temperature acceleration (GDDjerk) • GLDAS on a fixed grid of 0.25° and at a 3-hour temporal resolution • GDD = (TAVG,k − TBASE ) • GDDjerk: the third derivative of the sigmoid function through the data points that plot the day k against GDDk • Date of first peak in GDDjerk MATERIALS AND METHODS – satellite tracking data  12 female barnacle geese, Branta leucopsis  30 g solar GPS/ARGOS transmitters  Tracked from 2008-2011 MATERIALS AND METHODS – delineation of stopover, and breeding sites  Stopover: birds stopped for longer than 48 hours within a radius of 30 km  Breeding site: sites used for to 26 days within a radius of 30 km in the second half of June/ end of June  64 stopover sites and 30 breeding sites MATERIALS AND METHODS – statistical analysis  Fertility & Mortality Decrease  Linear mixed-effect model  Life Expectancy Increase  Cross-validation with the leave-one-out procedure  Bland-Altman plot with the 95% limits of agreement % 30 25 20 15 10 THE WORLD 22.0 11.0 2009 2050 Results – arrival date at the stopover sites  Fertility & Mortality Decrease ModelExpectancy Increase  Life GWI Fixed effect Parameter ±SE t-value p-value -95% CI +95% CI Intercept 21±9.76 2.15