Figure 8.

Conceptual diagram showing two potential scenarios of hydrologic influences on bacterial community composition between alpine and subalpine lakes. Our original hypothesis (A) displays the early summer visit on the left with high hydrologic connectivity both between lakes and with the terrestrial environment represented by a thick vertical stream line connecting the lakes and large inflow arrows. Lower inter-lake connectivity and hydrologic connection with the terrestrial environment hypothesized for the late summer visit are depicted on the right with a thinner vertical stream line and smaller inflow arrows. Blue is indicative of alpine community conditions, and green is indicative of subalpine (below treeline) conditions. The alternate hypothesis (B) is based on the observed patterns found in this study. The early summer visit depicted on the left, shows bacterial communities of alpine and subalpine lakes represent the same dissimilarity as their surrounding terrestrial environments when hydrologic connectivity is high. Yet, by the late summer when hydrologic connectivity is low both between lakes and with the terrestrial environment, the community composition of the lakes no longer reflect the differences found in the terrestrial environment.