... scenarios (e.g., MacCall 20 02; Parma 20 02a, 20 02b) is becoming more common, as empirical evidenceis gained in their support (Francis and Hare 19 94, 19 98). 11 411 $ $CH4 10 -27 -05 08: 41: 35 PS ... Bartell et al. 19 99; Drago et al. 20 01; Everbecq et al. 20 01; Gin et al. 20 01; Ha˚kanson and Bou-lion 20 03; Karim et al. 20 02; Pei and Wang 20 03). Becauseof the diversity and site-specificity ... general meth-odology and underlying supply and demand functionalforms are well established in the literature and have been 11 411 $ $CH4 10 -27 -05 08: 41 :23 PS84 Ecosystems and Human Well-being:...