Early physiological responses of Abies alba and Rubus fruticosus to ungulate herbivory

Autor: François Pellissier
Rok vydání: 2012
Předmět:
Zdroj: Plant Ecology. 214:127-138
ISSN: 1573-5052
1385-0237
DOI: 10.1007/s11258-012-0151-0
Popis: For the last 50 years, Chamois (Rupicapra rupicapra) population exponentially increased in the French Alps. This herbivore faces a food shortage in the winter; its diet mainly includes woody species (Abies alba Mill.) and brambles (Rubus fruticosus). The physiological response following simulated herbivory of these two plants was assessed. More precisely, the effects of leaf clipping and ungulate saliva application on the epidermal flavonoids and chlorophyll contents were considered as an induced structural response. The chlorophyll fluorescence (Fv/Fm) was also measured to provide information on the photosynthesis status as an induced functional response. The non-invasive techniques used in this experiment highlighted an induced response, emerging during the days following the simulated herbivory. R. fruticosus was drastically affected, photosynthesis was disturbed (decreased Fv/Fm) and mortality began on day 5 reaching 100 % less than 1 week later. Physiological parameters were also affected in A. alba (slight decrease of Fv/Fm and lower content of flavonoids), but this species recovered and survived no matter what the stressing treatment was. These results did not point out an efficient repulsive-induced response of A. alba and R. fruticosus to herbivory. The existence of constitutive defences such as prickles (R. fruticosus) or low-digestible tannins (A. alba) is no more efficient to escape from ungulates consumption. Nevertheless, in spite of the increase of the ungulates exponential demography, these two plants do not face rarefaction problem in the French Alps. Thus, survival of A. alba stands is probably linked to the recovery ability of saplings, when R. fruticosus stands maintain themselves thanks to the strong resprouting capacity of this species.
Databáze: OpenAIRE
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