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 54 deep forest Enterolobium DHJanzen100822.jpg high resolution
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| This large Enterolobium cyclocarpum (Fabaceae) tree is deep in what seems to be well-developed forest (Bosque San Emilio in Sector Santa Rosa of the ACG). It is about 100 years old. However, it would have started in a open sunny pasture, and what is evident is that the high concentration of animal-dispersed tree species in its vicinity were created by it. It will eventually die of old age here, leaving no offspring at the site, and removing one of the pieces of evidence that the site was once a pasture or other kind of opening. Why do its offspring not survive below it? There are several reasons. If there were many large mammals remaining in this forest, they might well consume all of the fallen fruits and defecate the surviving seeds elsewhere. In the absence of large mammals, Liomys mice will cut nearly all of the seeds out of the fruits and eat them later in their burrows. If any seeds are missed, they will germinated but the seedlings be killed by a (host specific?) fungus that lives in the soil below seed-bearing adults, a fungus that appears to be maintained by the occasional seedling that appears and dies. And if any seedlings make it through all of this, they will not be able to survive in the intense shade cast by the adult tree and the many other adjacent tree species that are somewhat to much more shade tolerant in some or all of their life stages. The site can obviously grow a gorgeous tree, if the conditions are right, but they really are not right once the tree gets established. | ||
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