Southern hemisphere plants show more delays than advances in flowering phenology

Abstract

1. Shifts in flowering phenology have been studied in detail in the northern hemisphere and are a key plant response to climate change. However, there are relatively fewer data on species' phenological shifts in the southern hemisphere.2. We combined historic field data, data from herbarium specimens dating back to 1842 and modern field data for 37 Australian species to determine whether species were flowering earlier in the year than they had in the past. We also combined our results with data compiled in the southern and northern hemispheres, respectively, to determine whether southern hemisphere species are showing fewer advances in flowering phenology through time.3. Across our study species, we found that 12 species had undergone significant shifts in flowering time, with four species advancing their flowering and eight species delaying their flowering. The remaining 25 species showed no significant shifts in their flowering phenology. These findings are important because delays or lack of shifts in flowering phenology can lead to mismatches in trophic interactions between plants and pollinators or seed dispersers, which can have substantial impacts on ecosystem functioning and primary productivity. Combining our field results with data compiled from the literature showed that only 58.5% of southern hemisphere species were advancing their flowering time, compared with 81.6% of species that were advancing their flowering time in the northern hemisphere. Our study provides further evidence that it is not adequate for ecologists to assume that southern hemisphere ecosystems will respond to future climate change in the same way as ecosystems north of the Equator.

China's subtropical deciduous plants are more sensitive to climate change than evergreen plants by flowering phenology

“…On the contrary, a higher proportion of deciduous species which are sensitive to climate change in species composition would make the phenological response of deciduous to climate change significantly different from those of evergreens. These speculations are supported by several previous studies (Everingham et al., 2021; Li et al., 2019; Piao et al., 2019). For example, Li et al.…”

“…On the contrary, a higher proportion of deciduous species which are sensitive to climate change in species composition would make the phenological response of deciduous to climate change significantly different from those of evergreens. These speculations are supported by several previous studies (Everingham et al, 2021;Li et al, 2019;Piao et al, 2019). For example, Li et al (2019) and Piao et al (2019) found that over 80% of species in the Northern Hemisphere have advanced phenology due to global warming, whereas the remaining species have either no response to global change or even delayed flowering phenology.…”

“…For example, Li et al (2019) and Piao et al (2019) found that over 80% of species in the Northern Hemisphere have advanced phenology due to global warming, whereas the remaining species have either no response to global change or even delayed flowering phenology. However, global climate changes have advanced phenology in only 58.5% of the total species in the Southern Hemisphere (Everingham et al, 2021). Our study covered six local sampling sites with different species compositions due to the differences in sub-climatic and topographic factors, which led to the fluctuation of robustness among the overall and locals.…”

“…Accelerated global climate change has been shown to have caused notable changes in plant phenological events since the turn of the 20th century (Bock et al., 2014; Du et al., 2017; Menzel et al., 2006; Wang et al., 2019). The changes in flowering phenology have an impact on reproductive competition and phenological niche differentiation, which in turn affect biodiversity, community structure and ecological functioning (Everingham et al., 2021; Piao et al., 2019). Yet, very little is known about the subtropics because the majority of studies on flowering phenology have been concentrated on temperate and frigid regions at the middle and high latitudes of the Northern Hemisphere (Du, Yang, et al., 2019; Song et al., 2021).…”

Leveraging natural history collections to understand the impacts of global change

“…In particular, nonnative plants tended to have much more variability in their phenological sensitivity. Everingham et al (2023), also in Journal of Ecology , raise the important point that phenological shifts might vary between the northern and southern hemispheres; they showed that fewer than 60% of species in the southern hemisphere were advancing flowering times, compared to more than 80% of species in the northern hemisphere.…”