A Garden Experiment on Susceptibility to Rabbit-Grazing, Sapling Growth Rates, and Age at First Reproduction for Eleven European Woody Species

Abstract

Eleven European shrub and tree species have been grown for 13 years in a randomized array (with 2 or 3 provenances for 5 of 11 species) in an experimental garden in southern England. A plague of rabbits in the second year damaged a greater proportion of plants in species with faster height growth, including those that are the commonest colonizers of pastures; most plants recovered rapidly. Apparently, resilience rather than resistance enables these plants to be invaders of abandoned grasslands. Among the shrubs there was little evidence of a trade-off between initial rate of height growth and final height. The small tree Crataegus monogyna overtook the tallest shrub (Cornus sanguinea) in the 12th year. Among the shrubs, after 12 years, there was a trend for basal area to be greater in taller species; the trees had notably low basal area for their height. Most individuals of the shrub species reproduced before those of Crataegus and Sorbus aria (in 3-6 years rather than 5-13). Among the shrubs, the earliest to reproduce were fast-growing (Rosa conina, then Ligustrum vulgare, Prunus spinosa and Rhamnus catharticus), but then species with a wide range of growth rates all reproduced at the same time (Euonymus europaeus, Juniperus communis and Viburnum opulus slow-growing, Cornus sanguinea and V. lantana fast-growing). The results are discussed in relation to theories of resource allocation, and the behaviour of the particular species in the field.

Key words

Age of reproduction - defences - growth-rate - herbivory - resistance - resilience - shrubs