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Abstract. Interactions between wind and trees control energy exchanges between theatmosphere and forest canopies. This energy exchange can lead to thewidespread damage of trees, and wind is a key disturbance agent in many ofthe world's forests. However, most research on this topic has focused onconifer plantations, where risk management is economically important, ratherthan broadleaf forests, which dominate the forest carbon cycle. This studybrings together tree motion time-series data to systematically evaluate thefactors influencing tree responses to wind loading, including data from bothbroadleaf and coniferous trees in forests and open environments. We found that the two most descriptive features of tree motion were (a) the fundamental frequency, which is a measure of the speed at which a treesways and is strongly related to tree height, and (b) the slope of the powerspectrum, which is related to the efficiency of energy transfer from wind totrees. Intriguingly, the slope of the power spectrum was found to remainconstant from medium to high wind speeds for all trees in this study. Thissuggests that, contrary to some predictions, damping or amplificationmechanisms do not change dramatically at high wind speeds, and therefore winddamage risk is related, relatively simply, to wind speed. Conifers from forests were distinct from broadleaves in terms of theirresponse to wind loading. Specifically, the fundamental frequency of forestconifers was related to their size according to the cantilever beam model(i.e. vertically distributed mass), whereas broadleaves were betterapproximated by the simple pendulum model (i.e. dominated by the crown).Forest conifers also had a steeper slope of the power spectrum. We interpretthese finding as being strongly related to tree architecture; i.e. conifersgenerally have a simple shape due to their apical dominance, whereasbroadleaves exhibit a much wider range of architectures with more dominantcrowns.