Interspecific Variation in Rates of Trunk Wound Closure in a Panamanian Lowland Forest

Abstract

We evaluated the ability to close wounds inflicted with a drill to the trunks of seven common tree species from Barro Colorado Nature Monument, Panama. We predicted that species lacking wood antimicrobial activity would rapidly close wounds to prevent pathogen entrance, while those species with wood antimicrobial defenses need not necessarily exhibit fast wound closure. The species studied were Alseis blackiana, Gustavia superba, Miconia argentea, Poulsenia armata, Protium panamense, P. tenuifolium, and Tetragastris panamensis. Callus, resins, and latex were all involved in wound closure, but mechanisms varied among species: after 3 months, the only pioneer species, Miconia, had minimal diameter closure; Alseis showed intermediate closure only by callus; and the other five species (which did not differ) had almost completely plugged their wounds by means of combined callus and resin production (Tetragastris and both species of Protium), latex (Poulsenia), or callus and woody flakes (Gustavia). Our initial prediction was supported for Gustavia and Poulsenia (i.e., rapid wound closure and no wood antimicrobial activity) but not for Tetragastris and Protium (that showed both rapid wound dosure and strong wood antimicrobial activity); Miconia showed slow wound dosure and no wood antimicrobial activity. Only for Alseis, was wound dosure rate proportional to stem diameter growth.