The initial generalized linear model of harvested dry mass per point-intercept across species and plots showed the expected positive linear relationship, but with much un-explained variation (R2 = 0.517). The subsequent ANOVA showed species identity to be the by far most important factor accounting for the residual variation, explaining 56.4% of the deviance. In contrast, treatment explained less than 2% of the total deviance. Thus, there was a significant degree of variation in mass per intercept across species, justifying the attempt of making single-species calibration models.
In the 24 quadrats recorded i 2020, a total of 60 plant species were found, of which 35 occurred in more than three quadrats. For 22 species, linear regression models of biomass on intercepts yielded a p-value < 0.05 as were accepted as single-species prediction models. Five genera with more than one species present yielded acceptable models, i.e. Agrostis, Carex, Galium, Festuca and Juncus (effusus-type) and, similarly, the four functional types as well as for total biomass and for standing litter. The regression models are presented in Supplementary materials (Appendix 2: Table S1).
Grazing treatments