Phenological Changes in the Southern Hemisphere

Lynda E Chambers,Elvira S Poloczanska,Eric J Woehler,Joel M Durant,Marie R Keatley,Lesley Hughes,Christophe Barbraud,Linda J Beaumont,Valeria Ruoppolo,Matt Low,Patricia C Morellato,Ralph E T Vanstreels,Anton C Wolfaardt,Robert J M Crawford,Res Altwegg,Phoebe Barnard

doi:10.1371/journal.pone.0075514

Abstract

Current evidence of phenological responses to recent climate change is substantially biased towards northern hemisphere temperate regions. Given regional differences in climate change, shifts in phenology will not be uniform across the globe, and conclusions drawn from temperate systems in the northern hemisphere might not be applicable to other regions on the planet. We conduct the largest meta-analysis to date of phenological drivers and trends among southern hemisphere species, assessing 1208 long-term datasets from 89 studies on 347 species. Data were mostly from Australasia (Australia and New Zealand), South America and the Antarctic/subantarctic, and focused primarily on plants and birds. This meta-analysis shows an advance in the timing of spring events (with a strong Australian data bias), although substantial differences in trends were apparent among taxonomic groups and regions. When only statistically significant trends were considered, 82% of terrestrial datasets and 42% of marine datasets demonstrated an advance in phenology. Temperature was most frequently identified as the primary driver of phenological changes; however, in many studies it was the only climate variable considered. When precipitation was examined, it often played a key role but, in contrast with temperature, the direction of phenological shifts in response to precipitation variation was difficult to predict a priori. We discuss how phenological information can inform the adaptive capacity of species, their resilience, and constraints on autonomous adaptation. We also highlight serious weaknesses in past and current data collection and analyses at large regional scales (with very few studies in the tropics or from Africa) and dramatic taxonomic biases. If accurate predictions regarding the general effects of climate change on the biology of organisms are to be made, data collection policies focussing on targeting data-deficient regions and taxa need to be financially and logistically supported.

Highlights

The relationship between the timing of life-cycle events and seasonal climatic patterns is a fundamental biological process in both natural and managed systems
The majority of datasets were from three regions: Australia/New Zealand, South America and the Antarctic/ subantarctic (Table 1); relatively few came from studies undertaken in the tropics or from Africa
The dominant patterns to emerge from our study, consistent with findings from the northern hemisphere [9,16,17,18,36], include a) dramatic biases in the regional availability of data and reported taxa, b) an advance in the timing of spring events, c) an expectation of mismatches in the timing of key life history events between trophic levels, d) substantial differences in the magnitude of phenological changes between taxonomic groups and regions, and e) phenological changes are often correlated with temperature

Summary

Introduction

The relationship between the timing of life-cycle events and seasonal climatic patterns (i.e. phenology) is a fundamental biological process in both natural and managed systems. Phenology is a major driver in determining population dynamics, species interactions, animal movement and the evolution of life histories [1,2]. Population-limiting factors are closely linked to seasonal or interannual phenological events, and shifts in phenology can affect ecosystems through changes in ecological interactions such as predator-prey and plant-pollinator dynamics [3,4,5,6] and the epidemiology of infectious diseases [7,8]. Changing phenologies will contribute to shifts in species distributions, population viability and reproductive successes [10,11] and in turn will affect climate via biogeochemical processes and the physical properties of the biosphere [12]. Phenological changes will have profound consequences for human societies and economies, including agricultural production [13], fisheries production [14] and human health [15]

Methods

Results

Conclusion