Prediction of Arctic plant phenological sensitivity to climate change from historical records

Abstract

The pace of climate change in the Arctic is dramatic, with temperatures rising at a rate double the global average. The timing of flowering and fruiting (phenology) is often temperature dependent and tends to advance as the climate warms. Herbarium specimens, photographs, and field observations can provide historical phenology records and have been used, on a localised scale, to predict species' phenological sensitivity to climate change. Conducting similar localised studies in the Canadian Arctic, however, poses a challenge where the collection of herbarium specimens, photographs, and field observations have been temporally and spatially sporadic.We used flowering and seed dispersal times of 23 Arctic species from herbarium specimens, photographs, and field observations collected from across the 2.1 million km 2 area of Nunavut, Canada, to determine (1) which monthly temperatures influence flowering and seed dispersal times; (2) species' phenological sensitivity to temperature; and (3) whether flowering or seed dispersal times have advanced over the past 120 years. We tested this at different spatial scales and compared the sensitivity in different regions of Nunavut. Broadly speaking, this research serves as a proof of concept to assess whether phenology-climate change studies using historic data can be conducted at large spatial scales. Flowering times and seed dispersal time were most strongly correlated with June and July temperatures, respectively. Seed dispersal times have advanced at double the rate of flowering times over the past 120 years, reflecting greater late-summer temperature rises in Nunavut. There is great diversity in the flowering time sensitivity to temperature of Arctic plant species, suggesting climate change implications for Arctic ecological communities, including altered community composition, competition, and pollinator interactions.Intraspecific temperature sensitivity and warming trends varied markedly across Nunavut and could result in greater changes in some parts of Nunavut than in others. K E Y W O R D SArctic, climate change, flowering time, herbarium specimen, Nunavut, seed dispersal time, temperature sensitivity

Plant phenological sensitivity to climate change on the Tibetan Plateau and relative to other areas of the world

“…We then compared our site‐level phenological sensitivity with the global‐level phenological sensitivity in the global dataset to see how the phenological response of alpine plants on the Tibetan Plateau varies from other places. Furthermore, we extracted plant phenology sensitivity data from two additional studies conducted at high‐latitude arctic areas (Panchen and Gorelick , Prevéy et al. ), to compare our results with other cold and climate‐sensitive ecosystems.…”

“…High‐latitude and alpine ecosystems are sensitive to changes in temperature and precipitation (Bliss , Inouye and Wielgolaski , Wielgolaski and Inouye , Panchen and Gorelick , Prevéy et al. ) and especially in different forms of precipitation such as snowfall (Chen et al.…”

“…High-latitude and alpine ecosystems are sensitive to changes in temperature and precipitation (Bliss 1971, Panchen and Gorelick 2017, Prev ey et al 2017) and especially in different forms of precipitation such as snowfall (Chen et al 2015a); thus, they can act as early-warming ecosystems when attempting to understand the consequences of global changes. The Tibetan Plateau covers 2.5 million km 2 , is located at 4000 m elevation, and has been called "the third pole" of the world (Qiu 2008).…”

Patterns and biases in an Arctic herbarium specimen collection: Implications for phenological research

“…The high proportion of flowering specimens provides a great opportunity for Arctic flowering phenological studies. Given the rapidly changing Arctic climate (AMAP, ; Stocker et al., ), there is potential to use Arctic herbarium specimens to address questions on the flowering‐time responses of Arctic plants to climate change and relate these responses to evolutionary and life history trait patterns (Molau et al., ; Davies et al., ; Mazer et al., ; Panchen and Gorelick, ; Park et al., ). However, given the significant difference we found in mean flowering times of herbarium‐ versus field‐based observations, increased caution may be required for Arctic environments.…”

“…Herbarium specimens are often collected in flower or fruit and thus provide evidence of the species’ flowering or fruiting time at the specified collection location and year. Specimens have been used to correlate phenological patterns with time, geography, climate, and species’ life history traits at various scales (Lavoie, ; Kharouba and Vellend, ; Panchen and Gorelick, ; Willis et al., ; Gallinat et al., ; Jones and Daehler, ). In particular, the long time series presented by herbarium collections allows the detection of the consequences of climate change (Lavoie, ; James et al., ; Jones and Daehler, ).…”