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

• Published in: Ecology and evolution Vol. 7; no. 4; pp. 1135 - 1147
• Main Authors: Cole, Ella F., Sheldon, Ben C.
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.02.2017; John Wiley and Sons Inc
• Subjects: Acer pseudoplatanus; Beech; Betula pendula; Birds; budburst date; Corylus avellana; Covariance; Deciduous forests; Emergence; Fagus sylvatica; Fraxinus excelsior; Herbivores; individual variation; Insects; Interspecific; Landscape; Leaves; Matching; Original Research; Phenology; Quercus robur; small spatial scale; Soil temperature; spring timing; Synchronism; Temperate forests; Trees; Trophic levels; Variation; small spatial scale; individual variation; spring timing; budburst date; phenology
• ISSN: 2045-7758; 2045-7758
• DOI: 10.1002/ece3.2718

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. Little is known about how timing of leaf emergence 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 two spring seasons, of 825 trees of six species in a 385‐ha deciduous woodland to show that small‐scale spatial patterns in budburst date are driven largely by consistent individual differences, rather than environmental factors. We found no evidence for interspecific covariance of budburst timing over space within the woodland. This work suggests that phenological landscapes are highly complex, varying over small spatial scales both within and between species.