Red-listed species and indicators: vascular plants in woodland key habitats and surrounding production forests in Sweden

Abstract

The estimated number of woodland key habitats (WKHs) in Sweden is 60 000–70 000. WKHs according to definition should contain red-listed species, but this is rarely investigated. Indicator species are used as one tool to identify the WKHs. In two forest regions in south-east Sweden with contrasting proportions of WKHs, red-listed and indicator vascular plant species were recorded in line transects and as a comparison also in surrounding production forests. 2370 recordings were made in 25 WKHs (45 ha) and in 74 ha production forest. Differences in vascular plant flora were small between WKHs and production forests within areas but were substantial for production forests between areas. Only one red-listed vascular plant species was found and in very small numbers. The results indicate that vascular plants are not optimal to use as indicators of WKHs and some species ought to be omitted from the indicator list. Methods to discern indicator species are discussed and the results are applied to practical forestry and conservation.