Ecological Archives A025-053-A4
Fabrice Requier, Jean-Franc, Ois Odoux, Thierry Tamic, Nathalie Moreau, Mickaël Henry, Axel Decourtye, and Vincent Bretagnolle. 2015. Honey bee diet in intensive farmland habitats reveals an unexpectedly high flower richness and a major role of weeds. Ecological Applications 25:881–890. http://dx.doi.org/10.1890/14-1011.1
Appendix D. Annual phenological deviation estimated by cumulative temperature sum from a national French meteorological station (http://climat.meteofrance.com/) located in Niort, on the northern edge of the study area.
Substantial inter-annual variations in seasonal dynamics of colonies (e.g., honey reserves) have already been identified (Odoux et al. 2014), which are likely to have been caused by climatic conditions and plant phenology. The cumulative sum of temperatures above 0°C was used as a proxy of year conditions, as this parameter is known to directly influence plant flowering phenology (Price and Waser 1998, Cleland et al. 2007).
We first cumulated sum of temperatures above 0°C yearly for the period 1986-2012, and averaged year values to derive a baseline value. Then, each year value between 2008 and 2012 was subtracted to the baseline value to account for the potential effect of annual climatic conditions. We calculated the temperature×days dynamic for each year and for the average. The day difference of a given year to the average (i.e., the residual) provided a proxy of year deviation compared to mean (see Fig.1 below), and we used this proxy as an annual phenological index in order to rescale the seasonal patterns of pollen and nectar collects.
Fig. D1. Temporal dynamic of the cumulated sum of temperatures above 0°C (log10 transformed) for each year between 2008 and 2012 and for the average period of 1986–-2012.
Literature cited
Cleland, E. E., I. Chuine, A. Menzel, H. A. Mooney and M. D. Schwartz. 2007. Shifting plant phenology in response to global change. Trends in Ecology and Evolution 22:357–365.
Odoux, J. F., P. Aupinel, S. Gateff, F. Requier, M. Henry and V. Bretagnolle. 2014. ECOBEE: a tool for long-term bee colony monitoring at landscape scale in West European intensive agrosystems. Journal of Apicultural Research. 53:57–66.
Price, M. V., and N. M. Waser. 1998. Effects of experimental warming on plant reproductive phenology in a subalpine meadow. Ecology 79:1261–1271.