The wide range of between-site similarities could be related to microhabitat differences, variation among sampling methods, or sampling at different times throughout the season.
The lack of variation of radiolabel content among sampling locations indicated the 24 samples analyzed in the present study provided an unbiased representation of a) internode location, b) cultivar, c) developmental stage, and d) intracellular compartment.
Statistical analysis was performed to access the variation in metals concernments in different types of samples as well as variation among sampling seasons.
The results of DAPC and STRUCTURE generally identified divisions among sampling locations in a congruent manner, the exception of the Nome sample location (sample location 14), which the DAPC analysis resolved as a distinct genetic cluster.
Patterns in both species richness and cover were complicated by differences among sampling years in precipitation and among zones in substrate and sampled area.
Fish diversity or richness varied among sampling locations, season and years (Table 2).
Metallothionein concentrations were positively correlated with copper residues, but no significant differences among sampling points were observed.
In the present study, monoculture treatments had significantly higher levels of soluble reactive phosphorus than the polyculture with no significant differences among sampling times.
We also used a set of spatial variables to quantify and partial out the effects of spatial autocorrelation of species composition among sampling locations.
Despite the significant differences in temperature among sampling hours, the average temperature (23 °C) was lower than the acceptable limits (25 32 °C) for warm water fish growth in aquaculture pond waters (Boyd 1990 , 1998.
