Data from: Winners and losers in subarctic moth communities in a changing climate: Marine Regime shifts as predictors for terrestrial insect biomass

Understanding the role of climate change in the globally reported declines
of insect populations is difficult due to complex interactions between
climate and other drivers such as agricultural practices and changes in
land use practice. We focused on subarctic moth communities in
northernmost Finland, a region with significant climatic changes and
minimal human impact. We use moth species abundance data from 45 years of
light-trap monitoring at the Kevo Subarctic Research Institute. TRIM
analyses showed a positive trend in total moth biomass between 1972 and
2017. However, excluding the autumnal moth (Epirrita autumnata), the
increase in biomass was not significant. There were large differences in
biomass trends between different groups based on life-history traits.
Species overwintering as eggs, feeding as larvae on both herbaceous and
woody plants, and generalists feeding on at least three plant genera had
significant positive population trends. Moths overwintering as larvae,
species feeding only on herbaceous plants, and specialists feeding on only
one plant genus had negative trends. Nine groups had no significant
trends. Linear mixed models revealed significant correlations between
Regime shifts in the Baltic Sea and biomass in five moth groups.
Temperature and degree day variables were also important. A negative
relation between a positive spring NAO and moth biomass was implied. Our
results suggest that large-scale oceanic climate patterns, such as Regime
Shifts and the North Atlantic Oscillation (NAO), can be useful proxies for
predicting the effects of complex climatic phenomena on terrestrial
ecosystems.