Persea - Distribution and Ecology

Distribution and Ecology

The species of Persea have a disjunct distribution, with about 70 Neotropic species, ranging from Brazil and Chile in South America to Central America and Mexico, the Caribbean, and the southeastern United States; a single species, P. indica, endemic to the Macaronesian islands, in the North West coast of Africa area, including Madeira and the Canary Islands; and 80 species inhabiting east and southeast Asia. None of the species is very tolerant of severe winter cold, with the hardiest, P. borbonia, P. ichangensis and P. lingue, surviving temperatures down to about -12°C; they also require continuously moist soil, and do not tolerate drought. A number of these species are found in forests that face threats of destruction or deforestation; for example, P. meyeniana in Central Chile.

The Family Lauraceae was part of Gondwanaland flora and many genera also, migrated to South America via Antarctica in ocean landbridges by Paleocene time. There they spread over most of the continent. When the North American and South American tectonic plates joined in late Neogene, volcanic mountain building created island chains which later formed the meso-American landbridge. Pliocene elevation created new habitats for speciation. While some genera died out in increasingly xerophytic mainland Africa, starting with the freezing of Antarctica about 20 million years ago and the formation of the Benguela current, others, which also reached south and meso-America, like Beilschmiedia and Nectandra are still surviving today in Africa in a number of species. The genus Persea, however, died out in Africa, except for Persea indica, surviving in the fog shrouded mountains of the Canary Islands, which with Madagascar constitutes Africa's Laurel forest plant refugia.

Fossil evidence indicates that the genus originated in West Africa during the Paleocene, and spread to Asia, to South America, and to Europe and thence to North America. It is thought that the gradual drying of Africa, west Asia, and the Mediterranean from the Oligocene to the Pleistocene, and the glaciation of Europe during the Pleistocene, caused the extinction of the genus across these regions, resulting in the present distribution.

Since this habitat is constantly threatened by encroching agriculture, the laurel forest animal or vegetal species had already become rare in many of its former habitats and are threatened by habitat loss.

The fruit in species of persea genus is a berry.

In meso-America, the genus Persea proliferated into many new species and the berries of some of them constitute a valuable food supply for the quetzal, that lives in the montane rainforests of meso-America.

The quetzal favorite fruits are berries of relatives of the avocado family. Their differing maturing times in the cloudforest determine the migratory movements of the quetzals to differing elevation levels in the forests. With a gape width of 21 mm, the quetzal swallows the small berry (aquacatillo) whole, which he catches while flying through the lower canopy of the tree, and then regurgitates the seed within 100 meters from the tree. Wheelright in 1983 observed that parent quetzals take far less time intervals to deliver fruits to the young brood than insects or lizards, reflecting the ease of procuring fruits, as opposed to capturing animal prey. Since the young are fed exclusively berries in the first 2 weeks after hatching, these berries must be of high nutritional value. Usually only the total percentage of water, sugar, nitrogen, crude fats and carbohydrates are reported by ornithologists Persea species are used as food plants by the larvae of some Lepidoptera species including Giant Leopard Moth, Coleophora octagonella (feeds exclusively on P. carolinensis) and Hypercompe indecisa.