Phenological characterization of a sky island: insights into vegetation patterns across space and time

摘要

Remotely sensed vegetation phenology data is often used to examine landscape-level vegetation interactions with climate and other drivers. Understanding vegetation phenology of sky islands is important for assessing the effect of predicted climate change (e.g. prolonged droughts) in these biologically diverse areas. We used Normalized Difference Vegetation Index (NDVI) time series data to derive phenological metrics (pheno-metrics), quantifying seasonal timing and magnitude, for Arizona's Santa Rita Mountains. Preliminary results suggest that these metrics are rich sources of information for characterizing landscape vegetation dynamics. Principal Components Analysis of twelve pheno-metrics showed spatial pattern in all twelve components, suggesting unique information and minimal noise in each metric. Classifications of the pheno-metrics showed yearly variation in spatial patterns and rough similarity to patterns in the Southwest Regional GAP Analysis Project vegetation classification. Further exploration of the spatial and temporal patterns of sky island pheno-metrics could enhance understanding of the phenology of arid ecosystems.