Current and next-year ozone and moisture products gave no clear injury slope difference in four eastern US forest samples in 1994-2010

We tested whether a current-year ozone and soil moisture product had a different leaf-injury slope from the next-year product. We used 3,717 consecutive-year records from a verified public-data panel in two eastern US regions and two periods from 1994 to 2010. Joint models removed site and year effects and controlled survey timing, plant and species counts, and temperature. Current-minus-future slopes were +0.096, +0.044, +0.102 and -0.051 injury probability per 10 ppm-h ozone per one moisture SD. All four two-way cluster 95 percent intervals included zero. Curved exposure terms and before-visit exposures also gave no clear contrast. A closer-monitor early Northeast result had a positive marginal interval but not a four-test interval. Thus this analysis did not establish a distinct current-year product slope. It does not establish equal slopes or disprove ozone damage. Selected repeat visits, few time clusters, coarse exposure, unknown missed injury and reuse of rounded source records limit inference. Code, aggregate evidence and verified-source retrieval instructions are included.

ozone · soil moisture · foliar injury · negative control · time order · observation bias · regional replication