Forest vulnerability to drought is expected to increase under anthropogenic climate change, and drought-induced mortality and community dynamics following drought have major ecological and societal impacts. Here, we show that tree mortality concomitant with drought has led to short-term (mean 5 y, range 1 to 23 y after mortality) vegetation-type conversion in multiple biomes across the world (131 sites). Self-replacement of the dominant tree species was only prevalent in 21% of the examined cases and forests and woodlands shifted to nonwoody vegetation in 10% of them. The ultimate temporal persistence of such changes remains unknown but, given the key role of biological legacies in long-term ecological succession, this emerging picture of postdrought ecological trajectories highlights the potential for major ecosystem reorganization in the coming decades. Community changes were less pronounced under wetter postmortality conditions. Replacement was also influenced by management intensity, and postdrought shrub dominance was higher when pathogens acted as codrivers of tree mortality. Early change in community composition indicates that forests dominated by mesic species generally shifted toward more xeric communities, with replacing tree and shrub species exhibiting drier bioclimatic optima and distribution ranges. However, shifts toward more mesic communities also occurred and multiple pathways of forest replacement were observed for some species. Drought characteristics, species-specific environmental preferences, plant traits, and ecosystem legacies govern postdrought species turnover and subsequent ecological trajectories, with potential far-reaching implications for forest biodiversity and ecosystem services.

Despite the acknowledged importance of frugivores as seed dispersal agents we still lack a general understanding of the mechanisms by which these animals could shape plant populations and communities. We used a spatially explicit stochastic simulation to explore how frugivore movement decisions interact with landscape properties, thus affecting plant population dynamics through dispersal. The model simulated bird movement, foraging, seed deposition and plant recruitment. We assumed that plants lived only for one season and that recruitment was a function of local seed density. We also considered the effect of perches as non‐food landscape features. Our simulation experiments consisted in varying the parameters governing bird foraging decisions in relation to 1) how fruit abundance biased their movement, and 2) how the willingness to visit a plant or perch decreased with distance to current location. Simulated plant population dynamics was strongly influenced by bird behavior. The scale of foraging decisions had a much stronger effect on plant dynamics than biases due to fruit abundance. Birds tended to concentrate their activities in the center of the landscape where plants became more abundant, increasing local competition. The presence of perches reduced this tendency resulting in larger population sizes. The importance of perches highlights the fact that behaviors other than foraging can have a strong impact on the patterns of seed deposition and hence on plant population dynamics. Several recent studies have combined animal movement data with seed retention time in order to predict seed dispersal kernels. These studies usually emphasize the ecological implications of the scale and shape of such kernels. However, our simulation results reveal that movement directionality and the fact that birds moved mostly among plants and perches can have a major impact on plant population dynamics.

The natural variation in leaf and plant longevity in Arabidopsis thaliana was analysed in a set of 45 ecotypes and 155 recombinant inbred lines derived from a Cape Verde Islands (Cvi) x Landsberg erecta (Ler) cross. Post-bolting longevity was inversely related to time to flowering and rosette leaf number in the set of 45 ecotypes, with Cvi having the longest and Ler the shortest post-bolting longevity. The recombinant inbred line population was tested under low or high soil nutrient levels (LN or HN, respectively). Three quantitative trait loci (QTL), one in chromosome 3 and two in chromosomes 1 and 5, were associated with longevity of the 6th rosette leaf under LN and HN, respectively. Four QTL for post-bolting longevity were found in chromosomes 1, 3, 4, and 5, and two in chromosomes 1 and 5 under LN and HN, respectively. An epistatic interaction affecting post-bolting longevity under LN, but not HN, was detected. Ler and Cvi carry a mix of increasing and decreasing alleles for the QTL affecting longevity of the 6th leaf and post-bolting longevity. Longevity of the 6th rosette leaf was associated with different QTL than post-bolting longevity, and it was affected by different QTL depending on nutrient availability. By contrast, the major QTL affecting post-bolting longevity exerted significant effects irrespective of soil nutrient availability.