8Press M C, Phoenix G K. Impacts of parasitic plants on natural communities [ J ]. New phytologist, 2005,166 ( 3 ) : 737- 751.
9Cole LC. The measurement of interspecific association [ J]. Ecology, 1949,30(4) :411-424.
10Simaes M, Sim6es L C, Vieira M J. Species association increases biofilm resistance to chemical and mechanical treat- ments [ J ]. Water research, 2009,43 ( 1 ) : 229-237.