2Costanza R, d' Arge R, Rudolf de Groot, et al. The value of the world' s ecosystem services and natural capital[J] . Nature, 1997, 387:253 - 260.
3Pagiola S, Arcenas A, Platais G. Can payments for en- vironmental services help reduce poverty. An exploration of the issues and the evidence to date from Latin America [J] . World Development, 2005, (2): 237 - 253.
