Deciduous forest responses to temperature, precipitation, and drought imply complex climate change impacts

Abstract

Changes in spring and autumn phenology of temperate plants in recent decades have become iconic bio-indicators of rapid climate change. These changes have substantial ecological and economic impacts. However, autumn phenology remains surprisingly little studied. Although the effects of unfavorable environmental conditions (e.g., frost, heat, wetness, and drought) on autumn phenology have been observed for over 60 y, how these factors interact to influence autumn phenological events remain poorly understood. Using remotely sensed phenology data from 2001 to 2012, this study identified and quantified significant effects of a suite of environmental factors on the timing of fall dormancy of deciduous forest communities in New England, United States. Cold, frost, and wet conditions, and high heat-stress tended to induce earlier dormancy of deciduous forests, whereas moderate heat-and drought-stress delayed dormancy. Deciduous forests in two eco-regions showed contrasting, nonlinear responses to variation in these explanatory factors. Based on future climate projection over two periods (2041-2050 and 2090-2099), later dormancy dates were predicted in northern areas. However, in coastal areas earlier dormancy dates were predicted. Our models suggest that besides warming in climate change, changes in frost and moisture conditions as well as extreme weather events (e.g., drought-and heat-stress, and flooding), should also be considered in future predictions of autumn phenology in temperate deciduous forests. This study improves our understanding of how multiple environmental variables interact to affect autumn phenology in temperate deciduous forest ecosystems, and points the way to building more mechanistic and predictive models.Land-surface phenology | dormancy date | frost | New England P lant phenological shifts in recent decades are iconic bio-indicators of climate change (1-4). These phenological changes in turn have cascading ecological effects on species demography, biotic interactions, and ecosystem functions (5-8). Whereas mechanisms of spring phenology (i.e., bud burst, leafing out, and flowering) are well studied (9-13), fall phenology (i.e., leaf senescence and dormancy, indicated by visual signals from leaf coloration and leaf drop) remains little studied (14-16). Changes in timing of autumn phenology play a significant role in growing season length prediction, C and N cycling, and biotic interactions (8,(17)(18)(19). Furthermore, delayed leaf coloration and more muted autumn foliage in response to climate change will likely significantly affect the multibillion dollar fall foliage ecotourism industry (20)(21)(22). Although delayed leaf coloration and leaf drop in deciduous forests have been observed across the northern hemisphere in recent decades (14,23,24), the full range of environmental triggers and how they influence fall phenological changes now or in the future remain poorly understood.Autumn phenology of deciduous woody plant species in temperate regions is the timing of the developmental stages of...

Antagonistic effects of growing season and autumn temperatures on the timing of leaf coloration in winter deciduous trees

“…Based on the daily average temperature data, we computed the growing season mean air temperature ( T gs ) from the first LU date to the first LC date for the four tree species at each station and in each year. The autumn low temperature was calculated by mean daily minimum air temperature from September 1 to October 31, while the summer drought ( D summ ) was estimated by the number of events with ≥7 consecutive days without precipitation from June 1 to August 31 (Xie et al., ).…”

“…Following up with the hypothesis of a main control of the timing of leaf senescence by warm‐temperature accumulation, a later leaf coloration date could be due to the fact that the leaves heat sum is not met as early as in previous years because of cool summer temperatures (Estrella & Menzel, ; Worrall, ). A more recent study based on remotely sensed phenology data indicates that high heat‐stress in summer tended to induce earlier dormancy of deciduous forests (Xie, Wang, & Silander, ). This heat‐stress effect could generally shorten leaf life‐span by means of increasing (or disrupting) leaf metabolic and senescence rates (Lim, Kim, & Gil Nam, ; Pearl, ).…”

Explaining European fungal fruiting phenology with climate variability

“…, Parmesan and Hanley , Xie et al. ) could affect the intra‐annual timing of fungal fruiting via photosynthetic and litter dynamics coupled to nutrient cycling and ecological mismatch. Early‐season plant species are often considered more attuned to abiotic conditions, and thus more sensitive to climatic changes, than are mid‐ to late‐season species (Pau et al.…”

Geographical and climatic gradients of evergreen versus deciduous broad‐leaved tree species in subtropical China: Implications for the definition of the mixed forest

“…For example, shifts in forest characteristics from deciduous to evergreen dominance have been shown to contribute to seasonal changes in energy, water, and carbon balance that have been reported in many tropical and subtropical forests (Bohlman, ; Ge, Wang, Xu, & Xie, ; Singh & Kushwaha, ; Zhou et al., ). Therefore, an in‐depth understanding of how geographical patterns in evergreenness and deciduousness are affected by climate will improve our ability to predict how vegetation patterns will respond to future climate change (Ge et al., ; Ouédraogo et al., ; Xie, Wang, & Silander, ).…”