1. Centre for Functional Ecology; Department of Life Sciences; University of Coimbra; Calçada Martim de Freitas 3000-456 Coimbra (Portugal)
2. Escola Superior Agrária; Instituto Politécnico de Coimbra; Bencanta 3045-601 Coimbra (Portugal)
3. Department of Biological Sciences; University of Cape Town; Rondebosch 7700 (South Africa)