Bryophyte and macrolichen diversity show contrasting elevation relationships and are negatively affected by disturbances in laurel forests of Madeira island

Abstract

Abstract Questions Studies on bryophyte and lichen diversity patterns along elevational gradients are scarce, although this approach can serve as space‐for‐time substitution to predict diversity changes because of climate warming. Therefore, we investigated bryophytes and macrolichens in disturbed and undisturbed stands along an elevational gradient in the unique laurel forest of Madeira island by addressing the following questions: (a) how does the species richness of functional‐taxonomic bryophyte and macrolichen groups differ with elevation; (b) how is the species richness of these groups affected by disturbances? Location UNESCO World Natural Heritage site laurel forest of Madeira island (Madeira, Portugal). Methods We analyzed species richness of bryophytes and macrolichens in 92 plots in response to elevation and to disturbances. Results Bryophyte species richness showed a mid‐elevational peak, while macrolichen richness increased with elevation. Disturbed plots harbored on average 20% less bryophyte and macrolichen species than undisturbed plots. Conclusions The laurel forest of Madeira island is a bryophyte and lichen diversity hotspot. Our findings indicate future biodiversity threats by changing environmental conditions. This calls for the need for a strict protection status of the laurel forest on Madeira island to minimize human‐related disturbances, for the development of management measures that could mitigate climate change effects by maximizing habitat suitability and for the implementation of species conservation programs to prevent future extinctions, in particular of endemic species.