Table 1 Total herb layer (THL) cover classes in the Swiss National Forest Inventory (NFI) and in this study. The column frequency presents the number of occurrences of a cover class on the 405 subplots. The column frequency - non-woody presents the number of subplots with measured woody and non-woody shrub biomass or without shrub occurrence within a cover class. The column mean cover subplot present cover data for 405 subplots. The column mean cover reference plot present cover data for 135 reference plots with 27 plots within each cover class
NFI THL Cover class | NFI Definition (THL cover, %) | This study | Frequency | Frequency – non-woody | Mean cover subplot (% ± SD) | Mean cover reference plot (% ± SD) |
|---|---|---|---|---|---|---|
1 | < 1 | No | na | na | na | na |
2 | 1–9 | Yes | 76 | 62 | 5.6 ± 2.2 (76) | 6.6 ± 1.7 (27) |
3 | 10–25 | Yes | 92 | 64 | 17.2 ± 5.4 (92) | 18.2 ± 4.1 (27) |
4 | 26–50 | Yes | 81 | 55 | 39.3 ± 7.8 (81) | 38.4 ± 5.3 (27) |
5 | 51–75 | Yes | 75 | 42 | 64.5 ± 7.2 (75) | 64.4 ± 4.5 (27) |
6 | 76–100 | Yes | 81 | 32 | 92.9 ± 6.4 (81) | 90.4 ± 7.7 (27) |