Fig. 1: The three conceptual scenarios described in Box 1 give rise to distinct changes in biodiversity patterns.
From: Disproportionate declines of formerly abundant species underlie insect loss
a–d, Effects of three conceptual scenarios by which species change over time (all species decline in proportion to each other (scenario 1, red); abundant species decline more than rare species do (scenario 2, turquoise); or rare species decline more than abundant species do (scenario 3; gold)) on population abundances (a), four biodiversity metrics (b), the numbers of species in different SAD intervals (c) and the mean population abundance trends of species in these abundance intervals (d). For biodiversity metrics that depend on species counts (species richness and evenness (b) and species richness per SAD interval (c)), a small amount of error was added. The insets in b represent modelled slope estimates in relation to 0 at the dashed line. Simpson diversity was converted to its effective number of species28. See ‘Extraction and calculation of biodiversity metrics’ in the Methods for an explanation of the biodiversity metrics. Note that because this simple conceptual model is intended to mimic a real dataset to some extent, the trends should be interpreted qualitatively rather than quantitively.
