PARENT SESSION
Oral Session 142: Mammalian Ecology.
Presiding: S Vignieri and D Berteaux
Friday, August 6, 8:30 AM to 12:00 PM, Meeting Room F 151.
Porcupine feeding scars and climatic data show ecosystem effects of the solar cycle.
Berteaux, Dominique1, Klvana, Ilya1, Cazelles, Bernard2, 1 Université du Québec, Rimouski2 École Normale Supérieure, Paris
ABSTRACT- Using North American porcupine (Erethizon dorsatum) feeding scars on trees as an index of past porcupine abundance, we have found that porcupine populations have fluctuated regularly over the past 130 years in the Bas St. Laurent region of eastern Quebec, Canada, with superimposed periodicities of 11 and 22 years. Wavelet, coherency, and phase analyses showed that this porcupine population cycle has closely followed the 11 and 22-year solar activity cycles. Fluctuations in local winter precipitation and spring temperature were also cyclic and closely related to both the solar cycle and the porcupine cycle. Our results suggest that the solar cycle has sufficiently important effects on the climate along the southern shore of the St. Lawrence estuary to influence terrestrial ecosystem functioning, to the point of setting the rhythm of population fluctuations of the most abundant mammalian herbivore in the ecosystem we studied. This constitutes the strongest available evidence of an effect of solar variability on ecological systems at the decadal time scale and local spatial scale, which confirms results obtained at greater temporal and spatial scales.
Key words: climatic oscillations, population cycles, solar cycle