Lianas (woody vines and climbing monocots) are increasing in abundance in many tropical forests with uncertain consequences for forest functioning and recovery following disturbances. At a global scale, these increases are likely driven by disturbances and climate change. Yet, our understanding of the environmental variables that drive liana prevalence at regional scales is incomplete and geographically biased towards Latin America. To address this gap, we present a comprehensive study evaluating the combined effects of climate, soil, disturbance and topography on liana prevalence in the Australian Wet Tropics. We established 31 20 × 20 m vegetation plots along an elevation gradient in low disturbance (canopy closure ≥ 75%) and high disturbance (canopy closure ≤ 25%) forest stands. In these plots, all tree and liana (defined as all woody dicot vines and climbing monocots, i.e., rattans) stems ≥ 1 cm DBH were measured and environmental data were collected on climate, soil and topography. Generalised linear models were used with multi‐model averaging to quantify the relative effects of the environmental variables on measures of liana prevalence (liana–tree basal area ratio, woody vine basal area and stem density and rattan stem density). Liana prevalence decreased with elevation but increased with disturbance and mean annual precipitation. The increase in the liana–tree ratio with precipitation was more pronounced for highly disturbed sites. Like other tropical regions, disturbance is an important driver of liana prevalence in Australian rainforests and appears to interact with climate to increase liana–tree ratios. The observed increase in liana–tree ratio with precipitation contrasts findings from elsewhere but is confounded by correlated changes in elevation and temperature, which highlights the importance of regional studies. Our findings show that forests with high disturbance and climatic conditions favourable to lianas are where lianas most likely to outcompete trees and impede forest recovery.
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机译：在许多热带森林中，藤本植物（木本藤本植物和攀缘单子叶植物）的数量正在增加，这对干扰后森林的功能和恢复的影响不确定。在全球范围内，这些增长可能是由干扰和气候变化驱动的。然而，我们对在区域尺度上推动藤本植物流行的环境变量的理解并不完整，并且在地理上偏向于拉丁美洲。为了解决这一差距，我们提出了一项综合研究，评估气候、土壤、干扰和地形对澳大利亚湿热带地区藤本植物普遍性的综合影响。我们在低干扰 （树冠关闭≥ 75%） 和高干扰 （树冠关闭 ≤ 25%） 林分中沿海拔梯度建立了 31 个 20 × 20 m 植被样地。在这些样地中，测量了胸径≥ 1 cm 的所有乔木和藤本植物（定义为所有木本双子叶植物藤本植物和攀缘单子叶植物，即藤）茎，并收集了有关气候、土壤和地形的环境数据。广义线性模型与多模型平均一起使用，以量化环境变量对藤本植物流行率测量的相对影响（藤本-树木基部面积比、木本藤本植物基部面积和茎密度以及藤茎密度）。藤本植物的患病率随海拔升高而降低，但随着干扰和年平均降水量的增加而增加。在高度受干扰的地点，藤本植物-树木比率随降水的增加更为明显。与其他热带地区一样，干扰是澳大利亚热带雨林藤本植物普遍存在的重要驱动因素，并且似乎与气候相互作用以增加藤本植物与树木的比例。观察到的藤本植物-树木比例随降水的增加与其他地方的发现形成鲜明对比，但被海拔和温度的相关变化所混淆，这突出了区域研究的重要性。我们的研究结果表明，在高度干扰和气候条件有利于藤本植物的森林中，藤本植物最有可能胜过树木并阻碍森林恢复。
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