Lianas enhance microclimate buffering in tropical forests

Coppieters, K.; Visser, M.D.; Verbeeck, H.; Schnitzer, S.A.; Walle, E. van de; Frenne, P. De; Meunier, F.

doi:doi:10.1016/j.agrformet.2026.111102

Forest microclimates play a crucial role in regulating multiple ecosystem processes and in maintaining suitable conditions for forest functioning and biodiversity. However, liana (woody vine) abundance is increasing in many forests, especially in the tropics and due to climate change, altering forest structure and influencing the forest energy balance. Yet, we do not know how lianas influence forest microclimate buffering. Here, using a large-scale liana removal experiment in a tropical forest, we show that lianas consistently lowered mean daytime understorey air temperatures year-round, compared to the liana absent plots. The additional microclimate cooling by lianas was most pronounced in the dry season, when lianas reduced the mean daytime offset from -0.82 degrees C to -1.02 degrees C (similar to 25 % of additional buffering), and during the hottest part of the day, when liana presence resulted in 31 % of additional buffering compared to liana absent plots. This stronger liana...Show moreForest microclimates play a crucial role in regulating multiple ecosystem processes and in maintaining suitable conditions for forest functioning and biodiversity. However, liana (woody vine) abundance is increasing in many forests, especially in the tropics and due to climate change, altering forest structure and influencing the forest energy balance. Yet, we do not know how lianas influence forest microclimate buffering. Here, using a large-scale liana removal experiment in a tropical forest, we show that lianas consistently lowered mean daytime understorey air temperatures year-round, compared to the liana absent plots. The additional microclimate cooling by lianas was most pronounced in the dry season, when lianas reduced the mean daytime offset from -0.82 degrees C to -1.02 degrees C (similar to 25 % of additional buffering), and during the hottest part of the day, when liana presence resulted in 31 % of additional buffering compared to liana absent plots. This stronger liana-induced cooling implies reduced energy reaching the forest floor, consistent with enhanced canopy interception: higher albedo reduces total energy input, while canopy absorption retains more of the remaining flux in the upper canopy. In addition, increased daytime evapotranspiration could further dissipate energy as latent heat, or both mechanisms may act in combination. Beyond effects on air temperature, lianas also tended to reduce maximum soil temperatures during the dry season. Together, these findings show that lianas have a strong impact on forest microclimate temperatures, particularly during hot and dry periods. As such extreme conditions are projected to become more intense and frequent, our work suggests that lianas will likely play a much more nuanced role under future climate change than previously thought - reducing forest carbon uptake while buffering temperature extremes.Show less

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Lianas enhance microclimate buffering in tropical forests