Recorded native plant richness rose in 119 Konza bison plots from 2000–2002 to 2023–2025; spatial replacement change was uncertain

We tested whether recorded native plant lists became more similar between fixed plots in six bison-grazed Konza Prairie watersheds. We used open PVC02 version 25 data and 119 upland 10 square metre plots. A taxon entered a period list if it was recorded in at least two of three years. We compared 1,121 fixed within-watershed plot pairs in 2000–2002 and 2023–2025. Mean native richness rose from 28.08 to 39.87 taxa per plot. Mean Simpson replacement fell from 0.29927 to 0.29064. The change was −0.00863, with a Student t reference 95% interval of −0.02457 to +0.00732 across six watershed changes. All planned replacement checks had intervals that included zero. Mean unmatched taxa between lists increased from 20.38 to 27.83, while the mean ratio of watershed union richness to local richness fell from 2.659 to 2.517. Thus, different spatial measures gave different descriptions of the same records. The primary result does not establish stable communities or equivalence. Shared weather, a shared herd, and changes in field personnel and identification limit inference. We do not identify a bison or climate effect. The package has unchanged source data, provenance, code, all results, figures, a local plan, and independent arithmetic checks.

plant diversity · bison · Konza Prairie · spatial replacement · beta diversity · long-term monitoring · reproducibility