Phosphate Uptake in Arctic Plants in Relation to Phosphate Supply: The Role of Spatial and Temporal Variability

Phosphate uptake was measured on absorptive tissue of twelve tundra species representing five growth forms. The species were sampled from four different communities that differed by more than an order of magnitude in soil phosphate availability. Phosphorus (P) fertilization of vascular species significantly increased shoot P concentrations in species except those occurring in the most P-rich soil. Phosphate uptake varied over 10-fold across all species, which is as much variation as between tundra and taiga species. Within a single community where all growth forms were present and when species from all sites were compared, there was no distinct separation in uptake capacity among growth forms. Rather, absorption capacity was closely correlated with soil phosphate availability. In vascular species, individuals from high-P soil had higher phosphate absorption rate than did conspecifics and congeners from low-P soil