In an era of rapid environmental change, accurate data on ecological dynamics are essential to understanding the resistance and resilience of ecological systems, and the services they provide, to multiple global change drivers. Field data collection …
As the climate changes, warmer spring temperatures are causing earlier leaf-out and commencement of net carbon dioxide (CO2) sequestration in temperate deciduous forests, resulting in a tendency towards increased growing season length and annual CO2 …
Rising temperatures are profoundly influencing forests on many scales with potentially strong variation vertically across forest strata. Using published research and new analyses, we evaluate how environmental conditions, leaf temperatures, and …
Plant diversity varies immensely over large-scale gradients in temperature, precipitation, and seasonality at global and regional scales. One hypothesis predicts that the many defensive compounds found in plants’ metabolomes should increase in richness and decrease in interspecific similarity with precipitation, temperature, and plant diversity. To test this prediction, we compared patterns of chemical and morphological trait diversity of 140 woody plant species among seven temperate forests in North America representing 16.2 °C variation in mean annual temperature (MAT), 2,115 mm variation in mean annual precipitation (MAP), and from 10 to 68 co-occurring species. Our results are consistent with the hypothesis that plant metabolomes play a more important role in community assembly in wetter and warmer climates, even at temperate latitudes, and suggest that metabolomic traits can provide unique insight to studies of trait-based community assembly.
Tree-ring records from a long-term forest monitoring plot in NW Virginia (USA) reveal that tree height and leaf drought tolerance traits influenced growth responses during and after significant droughts in the meteorological record. As climate change-induced droughts intensify, tall trees with drought-sensitive leaves will be most vulnerable to immediate and longer-term growth reductions.
From 3 decades (1987–2019) of forest monitoring data in the Blue Ridge Mountains ecoregion, we found exotic forest insects and pathogens (EFIP) substantially affected at least eight tree genera. Several taxa were lost from our monitoring plots but not completely extirpated from the region. Despite these losses, both total AGB and alpha-diversity were largely recovered through increases in sympatric genera. These results indicate that EFIP have been an important force shaping forest composition, carbon cycling, and diversity.
Forest-savanna mosaics are maintained by fire-mediated positive feedbacks; whereby forest is fire suppressive and savanna is fire promoting. Forest-savanna transitions therefore represent the interface of opposing fire regimes. Within the transition there is a threshold point at which tree canopy cover becomes sufficiently dense to shade out grasses and thus suppress fire. Changes in fire behavior were not associated with changes in total grass biomass. Grass composition mediated fire-behavior within the savanna prior to reaching the suppression threshold, and grass species composition was mediated by tree canopy cover which was in turn mediated by fire-behavior. These findings highlight how biotic and abiotic controls interact and amplify each other in this mosaicked landscape to facilitate forest and savanna co-existence.
Vegetation green leaf phenology directly impacts gross primary productivity (GPP) of terrestrial ecosystems. Satellite observations of land surface phenology (LSP) provide an important means to monitor the key timing of vegetation green leaf …