In spite of their small global area and restricted distributions, tropical montane forests (TMFs) are biodiversity hotspots
and important ecosystem services providers, but are also highly vulnerable to climate change. To protect and preserve
these ecosystems better, it is crucial to inform the design and implementation of conservation ...
In spite of their small global area and restricted distributions, tropical montane forests (TMFs) are biodiversity hotspots
and important ecosystem services providers, but are also highly vulnerable to climate change. To protect and preserve
these ecosystems better, it is crucial to inform the design and implementation of conservation policies with the best
available scientific evidence, and to identify knowledge gaps and future research needs. We conducted a systematic
review and an appraisal of evidence quality to assess the impacts of climate change on TMFs. We identified several skews
and shortcomings. Experimental study designs with controls and long-term (≥10 years) data sets provide the most
reliable evidence, but were rare and gave an incomplete understanding of climate change impacts on TMFs. Most studies
were based on predictive modelling approaches, short-term (<10 years) and cross-sectional study designs. Although these
methods provide moderate to circumstantial evidence, they can advance our understanding on climate change effects.
Current evidence suggests that increasing temperatures and rising cloud levels have caused distributional shifts (mainly
upslope) of montane biota, leading to alterations in biodiversity and ecological functions. Neotropical TMFs were the
best studied, thus the knowledge derived there can serve as a proxy for climate change responses in under-studied regions
elsewhere. Most studies focused on vascular plants, birds, amphibians and insects, with other taxonomic groups poorly
represented. Most ecological studies were conducted at species or community levels, with a marked paucity of genetic
studies, limiting understanding of the adaptive capacity of TMF biota. We thus highlight the long-term need to widen
the methodological, thematic and geographical scope of studies on TMFs under climate change to address these uncertainties. In the short term, however, in-depth research in well-studied regions and advances in computer modelling
approaches offer the most reliable sources of information for expeditious conservation action for these threatened forests.