highly significantp<0.001
Within the CCA the overall RDA model of assemblage structure versus sample year was highly significant ( R 2 = 0.23, p<0.001) as were pairwise comparisons between individual years (2002 vs 2003 R 2 = 0.22, 2003 vs. 2004 R 2 = 0.12; p<0.001 for both).