Assessing spatial and temporal patterns in land surface phenology for the Australian Alps (2000–2014)

Elevation is a key environmental factor influencing both biological and ecological phenomena in mountain environments. Mountains are useful areas for studying impacts associated with climatic change, as their significant biological diversity often varies in conjunction with elevation. While previous studies have used remote sensing to quantify the impacts of elevation differences on land surface phenology descriptors in mountains, they have focused almost exclusively on the Northern Hemisphere. This study fills this gap by presenting a 15-year phenological time-series for the Australian Alps derived using data from the MODerate Resolution Imaging Spectroradiometer (MODIS). Phenological descriptors were estimated from the MODIS time-series and they corresponded with the start, end and duration of the growing period (SGP, EGP and DGP, respectively) for the major vegetation communities in the Australian Alps. Results indicated that the descriptor corresponding with the start of the growing period was more sensitive to changes in elevation, while the results for the end of the growing period descriptor were more uniform, particularly at lower elevations. For all but the highest elevation areas in the Australian Alps, the results indicated an overall trend towards an earlier start and later end to the growing period, culminating in a longer duration of the growing period. These findings are consistent with those previously reported in the literature, though they are likely influenced by the fire history of the alpine areas.