Biological indicators of climate change: evidence from long-term flowering records of plants along the Victorian coast, Australia

Abstract

We investigate the utility of using historical data sources to track changes in flowering time of coastal species in south-eastern Australia in response to recent climate warming. Studies of this nature in the southern hemisphere are rare, mainly because of a paucity of long-term data sources. Despite this, we found there is considerable potential to utilise existing data sourced from herbaria collections and field naturalists’ notes and diaries to identify native plant species suitable as biological indicators of climate change. Of 101 candidate species investigated in the present study, eight were identified as showing a general trend towards earlier flowering over time, indicating a correlation with increasing temperatures. There was some evidence to suggest that species which flower in spring and summer may be more sensitive to changes in temperature. There was a high level of uncertainty regarding the detection of trends, which was a function of the accessibility, abundance and accuracy of the various data sources. However, this uncertainty could be resolved in future studies by combining the datasets from the present study with field monitoring of phenological cycles in climatically different locations. Data held by community groups could be made more accessible if there was a concerted effort to fund collation and digitisation of these records. This might best be achieved by working with community groups, and facilitated through the recent establishment of a community phenological observation database in Australia.

Herbarium specimens show contrasting phenological responses to Himalayan climate

“…Although phenological analyses of herbarium data offer unique insights into past responses, they model past responses only, and long-term phenological observation is necessary to fully understand present responses and model those in the future. To complement the herbarium data and test our models, we are directly monitoring Rhododendron phenology on Yulong Mountain, conducting artificial warming experiments, and documenting indigenous peoples' observations of change.This study joins other work from the past decade showing the value of herbarium collections to infer long-term phenology (10,11,43,48,(51)(52)(53)(54)(55)(56)(57)(58)(59)(60)(61)(62)(63). These have increasingly shown that not only can the "messy" data from herbarium collections be used to infer phenology, but that these data can reveal the complex effects on phenology of geography (43), pollination (62), morphological traits (48, 52), and, in this study, the contrasting response of warming across different seasons.…”

Interdisciplinary approaches: towards new statistical methods for phenological studies

“…The relevance of herbarium collections to a range of ecological conservation and biological studies has been, to date, largely underappreciated in Australia (Rumpff et al 2008). Indeed the application of herbarium vouchered specimens to comparative phenological studies is a relatively recent approach (Borchert 1996;Primack et al 2004;Bolmgren and Lonnberg 2005;Lavoie and Lachance 2006;Primack and Miller-Rushing 2009;Gallagher et al 2009;MacGillivray et al 2010).…”

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

“…The timing of flowering and fruiting (phenology) is often influenced by temperatures in the month or two preceding flowering or fruiting (Fitter, Fitter, Harris, & Williamson, 1995;Panchen & Gorelick, 2015;Panchen, Primack, Aniśko, & Lyons, 2012). Phenological temperature sensitivity has been used to identify plants that are indicators of climate change and the responsiveness of plants to climate change (Bertin, 2015;Gallagher, Leishman, & Hughes, 2009;Menzel et al, 2006;Panchen et al, 2012;Rumpff, Coates, & Morgan, 2010;Springate & Kover, 2014). Herbarium specimens, pressed plants often collected in flower or fruit, provide a reliable historical record of flowering and fruiting phenology for use in phenology-climate change studies (Davis, Willis, Connolly, Kelly, & Ellison, 2015).…”