Drought and reproductive effort interact to control growth of a temperate broadleaved tree species (Fagus sylvatica).
Interannual variation in radial growth is influenced by a range of physiological processes, including variation in annual reproductive effort, although the importance of reproductive allocation has rarely been quantified. In this study, we use long stand-level records of annual seed production, radial growth (tree ring width) and meteorological conditions to analyse the relative importance of summer drought and reproductive effort in controlling the growth of Fagus sylvatica L., a typical masting species. We show that both summer drought and reproductive effort (masting) influenced growth. Importantly, the effects of summer drought and masting were interactive, with the greatest reductions in growth found in years when high reproductive effort (i.e., mast years) coincided with summer drought. Conversely, mast years that coincided with non-drought summers were associated with little reduction in radial growth, as were drought years that did not coincide with mast years. The results show that the strength of an inferred trade-off between growth and reproduction in this species (the cost of reproduction) is dependent on environmental stress, with a stronger trade-off in years with more stressful growing conditions. These results have widespread implications for understanding interannual variability in growth, and observed relationships between growth and climate.
St Catherine's College, Manor Road, Oxford OX1 3UJ, UK.|Fitzwilliam College, Storey's Way, Cambridge CB3 0DG, UK.
Andrew J
AJ
Hacket-Pain
Division of Geography and Environmental Management, Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK.
Jonathan G A
JGA
Lageard
School of Life Sciences, Keele University, Keele, Staffordshire ST5 5BG, UK.|Harvard Forest, Harvard University, Harvard Forest, 324 North Main Street, Petersham, MA 01366, USA.
Peter A
PA
Thomas
D002980:Climate; D055864:Droughts; D029964:Fagus / Q000254:growth & development* / Q000502:physiology*; D012098:Reproduction; D012621:Seasons; D014197:Trees / Q000254:growth & development / Q000502:physiology
cost of reproduction; masting; resource allocation; ring width; trade-off; tree growth