Growth response of temperate mountain grasslands to inter-annual variations in snow cover duration.

摘要: Abstract. A remote sensing approach is used to examine the direct and indirect effects of snow cover duration weather conditions on growth response mountain grasslands located above tree line in French Alps. Time-integrated Normalized Difference Vegetation Index (NDVIint), as a surrogate for aboveground primary productivity, were derived from 13-year long time series Moderate-resolution Imaging Spectroradiometer (MODIS). regional-scale meteorological forcing that accounted topographical was provided by SAFRAN–CROCUS–MEPRA model chain. hierarchical path analysis developed analyze multivariate causal relationships between variables proxies productivity. Inter-annual variations productivity primarily governed year-to-year length snow-free period much lesser extent temperature precipitation during growing season. prolonged reduces number magnitude frost events initial but this has negligible impact NDVIint compared strong negative effect delayed melting. The maximum NDVI slightly responded increased summer weak. spanning peak standing biomass first snowfall two-thirds explained high sensitivity autumn rainfall control timing snowfall. ability plants maintain green tissues whole along with relatively low responsiveness led conclusion driver inter-annual grasslands.