Later-minus-earlier ozone abundance contrasts had opposite signs in US and European samples from a 2024 invertebrate data release

We tested an era contrast in ozone abundance response ratios in a public invertebrate synthesis. We used 69 records from 15 publications in the USA and Europe. Equal publication weights gave later-minus-earlier mean log response ratios of +0.250 in the USA and -0.578 in Europe. Only the European primary interval excluded zero. Role adjustment gave +0.439 and -0.421, with both intervals including zero. Beneficial invertebrates occurred only in the earlier US sample and only in the later European sample. Keeping only roles found in both eras gave uncertain contrasts. Removing aphid mass made the adjusted European interval negative. Thus the evidence does not show a repeated negative era contrast across regions, and outcome definition matters. Publication year does not measure ecological time. Few papers, changing measurements, study selection and possible dependence between papers limit inference. Climate interactions were not tested. The package includes code, aggregate results, source hashes, a figure and independent numerical checks.

ozone · invertebrates · abundance · publication year · observation bias · regional replication · evidence synthesis