Widespread Mismatch Between Phenology and Climate in Human‐Dominated Landscapes

Abstract

Plants track changing climate partly by shifting their phenology, the timing of recurring biological events. It is unknown whether these observed phenological shifts are sufficient to keep pace with rapid climate changes. Phenological mismatch, or the desynchronization between the timing of critical phenological events, has long been hypothesized but rarely quantified on a large scale. It is even less clear how human activities have contributed to this emergent phenological mismatch. In this study, we used remote sensing observations to systematically evaluate how plant phenological shifts have kept pace with warming trends at the continental scale. In particular, we developed a metric of spatial mismatch that connects empirical spatiotemporal data to ecological theory using the “velocity of change” approach. In northern mid‐to high‐latitude regions (between 30–70°N) over the last three decades (1981–2014), we found evidence of a widespread mismatch between land surface phenology and climate where isolines of phenology lag behind or move in the opposite direction to the isolines of climate. These mismatches were more pronounced in human‐dominated landscapes, suggesting a relationship between human activities and the desynchronization of phenology dynamics with climate variations. Results were corroborated with independent ground observations that indicate the mismatch of spring phenology increases with human population density for several plant species. This study reveals the possibility that not even some of the foremost responses in vegetation activity match the pace of recent warming. This systematic analysis of climate‐phenology mismatch has important implications for the sustainable management of vegetation in human‐dominated landscapes under climate change.Plants are expected to track warming climate partly by shifting their phenology, the timing of recurring biological events. Despite numerous reports on phenological shifts driven by climate change, it is unknown whether these observed shifts are sufficient to keep pace with rapid warming trends at large spatial scales. It is even less clear how human activities contribute to the emergent climate‐phenology mismatch. Using global remote sensing data, we employed a novel approach to systematically evaluate how plant phenological shifts have kept pace with warming trends at a continental scale. We found a net lag between phenological shift and climate change, which increases with population density, suggesting a relationship between human activities and the decoupling of phenology dynamics and climate variation. Results were corroborated with independent ground observations that show how the mismatch of spring phenology increases with human population density for several plant species. This systematic analysis of climate‐phenology mismatch informs the sustainable management of vegetation in human‐dominated landscapes under climate change. Rapidly shifting vegetation phenology has not kept pace with the recent climate change Climate‐phenology mismatch is more pronounced in human‐dominated landscapes with increasing human population density