The shifting phenological landscape: Within‐ and between‐species variation in leaf emergence in a mixed‐deciduous woodland

Abstract

Many organisms rely on synchronizing the timing of their life‐history events with those of other trophic levels—known as phenological matching—for survival or successful reproduction. In temperate deciduous forests, the extent of matching with the budburst date of key tree species is of particular relevance for many herbivorous insects and, in turn, insectivorous birds. In order to understand the ecological and evolutionary forces operating in these systems, we require knowledge of the factors influencing leaf emergence of tree communities. However, little is known about how phenology at the level of individual trees varies across landscapes, or how consistent this spatial variation is between different tree species. Here, we use field observations, collected over 2 years, to characterize within‐ and between‐species differences in spring phenology for 825 trees of six species (Quercus robur, Fraxinus excelsior, Fagus sylvatica, Betula pendula, Corylus avellana, and Acer pseudoplatanus) in a 385‐ha woodland. We explore environmental predictors of individual variation in budburst date and bud development rate and establish how these phenological traits vary over space. Trees of all species showed markedly consistent individual differences in their budburst timing. Bud development rate also varied considerably between individuals and was repeatable in oak, beech, and sycamore. We identified multiple predictors of budburst date including altitude, local temperature, and soil type, but none were universal across species. Furthermore, we found no evidence for interspecific covariance of phenology over space within the woodland. These analyses suggest that phenological landscapes are highly complex, varying over small spatial scales both within and between species. Such spatial variation in vegetation phenology is likely to influence patterns of selection on phenology within populations of consumers. Knowledge of the factors shaping the phenological environments experienced by animals is therefore likely to be key in understanding how these evolutionary processes operate.

Incubation behavior adjustments, driven by ambient temperature variation, improve synchrony between hatch dates and caterpillar peak in a wild bird population

“…A total of 200 of these ambient temperature iButtons were distributed in a grid system across Wytham woods with positions chosen to reflect the density of nest boxes. For further details, see (Cole & Sheldon, ).…”

The forgotten season: the impact of autumn phenology on a specialist insect herbivore community on oak

“…Trees show high intraspecific variation in spring and autumn phenology (Crawley & Akhteruzzaman, 1988;Vitasse et al, 2009;Cole & Sheldon, 2017). Such differences show a substantial genetic component (Faticov et al, 2019), and persist over time (Crawley & Akhteruzzaman, 1988).…”

“Green pointillism”: detecting the within-population variability of budburst in temperate deciduous trees with phenological cameras

“…Whatever their causes, the year-to-year variations of WPVbb have potentially strong ecological implications, influencing the competition of trees for resource (light, water and nutrient) acquisition and transfer throughout the food web (van Dongen et al , 1997; Thackeray et al , 2016). Unfortunately, WPVbb has seldom been documented to date in natural tree populations (but see Denéchère et al , 2019), probably because its quantification remains laborious based on ground phenological observations, which are still needed for observing individual trees (Chesnoiu et al , 2009; Cole & Sheldon, 2017; Delpierre et al , 2017). Indeed, quantifying WPVbb requires observing bud development on a relatively high number of trees per population ( ca .…”