Taxonomic distinctness of climbing plants and epiphytes in central-Chilean forests: an alternative diversity measure from unequal species lists

Protected wild areas aim to conserve biodiversity. However, a lack of monitoring limits the availability of biological information needed to achieve this goal. This study used taxonomic distinctness (Δ+), its variance (Λ+), and a combined metric of both measures as alternative methods to monitor the diversity of climbing plants and vascular epiphytes in the absence of standardized data over time and space. The study was conducted in five forested small protected areas within the biodiversity hotspot of central Chile. The method involved updating the species inventory and comparing it with those from previous studies. The results showed that epiphytes followed a general pattern of increasing diversity towards the south along the latitudinal gradient (Δ+ between 54.95 and 73.3), while climbers remained more stable (Δ+ between 70.33 and 72.33). The combined analysis of both indices (Δ+ and Λ+) suggested that both climbers and epiphytes gained taxonomic diversity over time at most sites (p < 0.05). Sites that did not follow this general pattern may reflect differences in sampling design between the original and current inventories, which may have influenced the results. This observation requires further investigation as anthropogenic pressures may explain these variations. Future research should focus on long-term monitoring of the taxonomic distinctness of both assemblages to assess their responses to environmental disturbance and climate change, thereby providing a basis for developing more effective conservation strategies.