Fig. 2: Ecosystem carbon flux dependence on modified Arrhenius constraints and the effect of ALAN.
From: Widespread influence of artificial light at night on ecosystem metabolism
a,c,e, The symbols are half-hourly FLUXNET2015 measurements for NEE (gold symbols) (a), daytime GPP (blue symbols) (c) and nighttime Re (magenta symbols) (e) for 86 sites across North America and Europe. The linear regression lines in a, c and e indicate fixed-effect relationships of fundamental constraints on ecosystem carbon fluxes according to the modified Arrhenius function (null models as in equation (1)). b,d,f, The box plots display the distribution of measured fluxes across bins of the modified Arrhenius function (axes labels and units in b, d and f are the same as in a, c and e, respectively) grouped by ALAN intensity to illustrate variation in carbon fluxes relative to energetic constraints as a function of ALAN. The boxes represent interquartile ranges (IQR), the horizontal lines denote medians, the whiskers extend to 1.5 × IQR and the points indicate outliers.
