Data from: Multi-decadal changes in phytoplankton biomass in northern temperate lakes as seen through the prism of landscape properties

Ecologists collectively predict that climate change will enhance
phytoplankton biomass in northern lakes. Yet there are unique variations
in the structures and regulating functions of lakes to make this
prediction challengeable and, perhaps, inaccurate. We used archived
Landsat TM/ETM+ satellite products to estimate epilimnetic chlorophyll-a
concentration (Chl-a) as a proxy for phytoplankton biomass in 281 northern
temperate lakes over 28 years. We explored the influence of climate (air
temperature, precipitation) and landscape proxies for nutrient sources
(proportion of wetlands in a contributing catchment, size of the littoral
zone, potential for wind-driven sediment resuspension as estimated by the
dynamic ratio) or nutrient sinks (lake volume) in a random forest model to
explain heterogeneity in peak Chl-a. Lakes with higher Chl-a (median Chl-a
= 2.4 μg L-1, n = 40) had smaller volumes (< 44 × 104 m3)
and were more sensitive to increases in temperature. In contrast, lakes
with lower Chl-a (median Chl-a = 0.6 μg L-1, n = 241) had larger volumes
(≥ 44 × 104 m3), contributing catchments with smaller proportions of
wetlands (< 4.5% of catchment area, n = 70), smaller littoral zones
(< 16.4 ha, n = 137), minimal wind-driven sediment resuspension (as
defined by the dynamic ratio; < 0.45, n = 232), and were more
sensitive to increases in precipitation. Lakes with larger volumes were
generally less responsive to climate factors; however, large volume lakes
with a significant proportion of wetlands and larger littoral zones
behaved similarly to lakes with smaller volumes. Our finding that lakes
with different landscape properties respond differently to climate factors
may help predict the susceptibility of lakes to eutrophication under
changing climate conditions.