文摘
Co-occurring species may have differing growth responses to the seasonal timing of climatic events. In this study, we used dendrochronology to examine the importance of seasonal climate on radial stem growth of three co-occurring species in Florida scrub, myrtle oak (Quercus myrtifolia Willd.), Chapman oak (Quercus chapmanii Sarg.), and south Florida slash pine (Pinus elliottii Engelmann var. densa Little & K.W. Dorman). Response to seasonal climatic events varied for the co-occurring scrub species. Radial growth of both oaks was influenced strongly by spring precipitation. Spring droughts decreased oak growth, but growth increased with large spring precipitation events. Slash pine growth was influenced strongly by precipitation in both the spring and late summer. Spring droughts decreased slash pine total and latewood growth, but increased summer precipitation resulted in greater than normal growth. Earlywood growth of slash pine was correlated positively with the Ni?o 3.4 index: colder, wetter winters tended to be associated with increased earlywood growth. These differences between species in growth responses to seasonal climate may be explained by differences in growth phenology. If spring precipitation decreases as predicted by climate models for central Florida, decreased growth would be expected for all three species. Precipitation events later in the year may offset growth reductions caused by spring droughts for slash pine because slash pine growth occurs throughout the year.