Historical plant records enlighten the conservation efforts of ferns and Lycophytes' diversity in tropical China.

Historical records, e.g., herbarium vouchers, contain information about species distribution since the early days of the scientific exploration of floras until today. These data provide crucial evidence to map the biodiversity of the area of interest and most importantly enable the evaluation of the conservation effectiveness for a given group of organisms. This study aimed to explore the ferns and lycophytes' diversity of Xishuangbanna Dai Autonomous Prefecture in tropical China with special emphasis on conservation efforts provided by the currently established protected areas (PAs). Instead of relying exclusively on current observation, the database was compiled from digitalized herbarium vouchers and publications being explored with special attention on the temporal and spatial dimensions of collecting efforts. Utilizing the indices including species richness, weighed endemism, corrected weighted endemism, and beta diversity, hotspots of ferns and lycophytes' diversity were identified. In turn, the proportion of hotspots located outside PAs was estimated as a measure of conservation gaps in Xishuangbanna. Our results revealed a long collecting history of ferns and lycophytes in Xishuangbanna and this prefecture accumulated a considerable number of historical records covering 20.2 % of Chinese and 3.6% of global fern diversity. The accumulation of historical records showed strong parallelism to the historical events shaping modern China. The spatial distribution of ferns and lycophytes in Xishuangbanna was characterized by a concentration of species richness in southern valleys and endemism in western and northern mountains. In terms of conservation, existing PAs showed higher effectiveness in the protection of species richness, whereas lower effectiveness was observed in the protection of endemism and beta diversity. Our research provided a key reference for understanding the diversity and conservation of ferns and lycophytes in Xishuangbanna, as well as highlighting the locality for future collecting and conservation efforts. [ABSTRACT FROM AUTHOR]