SUPPLEMENTARY MATERIAL FOR ONLINE PUBLICATION
Appendix S1 - References Reviewed to Determine Charophyte Lower and Upper Colonization Limits in Figure4
Chambers PA, Kalff J (1985) Depth distribution and biomass of submersed aquatic macrophyte communities in relation to Secchi depth. Canadian Journal of Fisheries and Aquatic Sciences, 42, 701–709.
Middelboe AL, Markager S (1997) Depth limits and minimum light requirements of
freshwater macrophytes. Freshwater Biology, 37, 553–568.
Schwarz A-M, de Winton M, Hawes I (2002) Species-specific depth zonation in New Zealand charophytes as a function of light availability. Aquatic Botany, 72, 209–217.
Blindow I, Schütte M (2007) Elongation and mat formation of Charaaspera under different light and salinity conditions.Hydrobiologia, 584, 69–76.
Figure S1–Average monthly vertical light attenuation coefficient (E0) estimated in each year from May (white) to October (black). See main text for estimation method.
Figure S2 - (a) Photosynthetic active radiation (PAR) reaching different lake depths over the
summer (sum of Jun-Aug values) in 2003 (dashed line) compared with the long-term average
(solid line). (b)PAR reaching lake bottom in summer months of 2003 (triangles) versus the respective long-term means (circles). Year 1986 was excluded because of missing PAR data in July.
Figure S3 - Time series of Jun-Jul average water temperature in the epilimnion (black circles) and hypolimnion (grey triangles). The vertical dashed line indicates the year 2003.
Figure S4 –Select results of model sensitivity analysis showing the effect of changes inmodel parameters within the range of values considered for Lake Scuro. Effects of changes in the parameter p are shown for (a) hv=0.2 and E0=0.8 and (b) hv=0.6 and E0=0.8. Effects of changes in the parameter E0 are shown for (c) hv=0.2 and p=4 and (d) hv=0.6 and p=4. Effects of changes in the parameter hv are shown for (e) E0=0.8 and p=4 and (f) E0=0.8 and p=3. Vegetation is reported as percentage cover of lake bottom. The occurrence of alternative equilibria is indicated by distinct surfaces in light and dark gray, respectively.See main text for definitions of model parameters.
Figure S5 - Time series of (a) summer (Jun-Aug) averages of dissolved oxygen percentage saturation and chlorophyll-a, (b) annual average abundances of selected zooplankton taxa:Conochilus gr. unicornis-hippocrepis(left y-axis), Diaphanosomabrachyurum(right y-axis), and (c) maximum abundances of Eudiaptomus intermedius: maximum total population densities in May-Jul of each year (black circles) and maximum nauplii densities in Aug-Oct (grey triangles).The vertical dashed line indicates the year 2003.
Figure S6 – Boxplots of monthly densities of Keratella cochlearis (white) and Conochilus gr. unicornis-hippocrepis (grey) recorded between 1986 and 2012, with densities recordedin 2003 shown as black squares and grey triangles, respectively. Boxes indicate the first and third quartiles, whereas the horizontal thick line shows the median. Whiskers indicate the most extreme values less than 1.5 times the interquartile range, and open circles represent values outside 1.5 times the interquartile range.
Figure S7 – Lake Scuro Parmense at minimum water level during summer 2003
Figure S8 – Nitella gracilis mat at Lake Scuro Parmense in summer 2008
Figure S9 –Lake Scuro Parmense at average water level in the years after 2003