Florida strangler fig

Appearance

''Ficus aurea'' is a tree which may reach heights of 30 m . It is monoecious: each tree bears functional male and female flowers. Figs are generally evergreen, but ''F. aurea'' is briefly leafless in winter at the northern end of its range in Florida. The size and shape of the leaves is variable. Some plants have leaves that are usually less than 10 cm long while others have leaves that are larger. The shape of the leaves and of the leaf base also varies—some plants have leaves that are oblong or elliptic with a wedge-shaped to rounded base, while others have heart-shaped or ovate leaves with cordate to rounded bases. ''F. aurea'' has paired figs which are green when unripe, turning yellow as they ripen. They differ in size ; figs are generally sessile, but in parts of northern Mesoamerica figs are borne on short stalks known as peduncles.

Distribution

''Ficus aurea'' ranges from Florida, across the northern Caribbean to Mexico, and south across Central America. It is present in central and southern Florida and the Florida Keys,...hieroglyph snipped... The Bahamas, the Caicos Islands, Hispaniola, Cuba, Jamaica, the Cayman Islands, San Andrés , southern Mexico,...hieroglyph snipped... Belize, Guatemala, Honduras, Nicaragua, El Salvador, Costa Rica and Panama. It grows from sea level up to 1,800 m above sea level, in habitats ranging from Bahamian dry forests, to cloud forest in Costa Rica.

''Ficus aurea'' is found in central and southern Florida as far north as Volusia County; it is one of only two native fig species in Florida. The species is present in a range of south Florida ecosystems, including coastal hardwood hammocks, cabbage palm hammocks,
tropical hardwood hammocks and shrublands, temperate hardwood hammocks and shrublands...hieroglyph snipped... and along watercourses. In The Bahamas, ''F. aurea'' is found in tropical dry forests on North Andros, Great Exuma and Bimini. ''F. aurea'' occurs in 10 states in Mexico, primarily in the south, but extending as far north as Jalisco. It is found in tropical deciduous forest, tropical semi-evergreen forest, tropical evergreen forest, cloud forest and in aquatic or subaquatic habitats.

Habitat

''Ficus aurea'' is a strangler fig—it tends to establish on a host tree which it gradually encircles and "strangles", eventually taking the place of that tree in the forest canopy. While this makes ''F. aurea'' an agent in the mortality of other trees, there is little to indicate that its choice of hosts is species specific. However, in dry forests on Great Exuma in The Bahamas, ''F. aurea'' establishes exclusively on palms, in spite of the presence of several other large trees that should provide suitable hosts. Eric Swagel and colleagues attributed this to the fact that humus accumulates on the leaf bases of these palms and provides a relatively moist microclimate in a dry environment, facilitating seedling survival.

Figs are sometimes considered to be potential keystone species in communities of fruit-eating animals because of their asynchronous fruiting patterns. Nathaniel Wheelwright reports that Emerald Toucanets fed on unripe ''F. aurea'' fruit at times of fruit scarcity in Monteverde, Costa Rica. Wheelwright listed the species as a year-round food source for the Resplendent Quetzal at the same site. In the Florida Keys, ''F. aurea'' is one of five fruit species that dominate the diet fed by White-crowned Pigeons to their nestlings. ''F. aurea'' is also important in the diet of mammalian frugivores—both fruit and young leaves are consumed by black howler monkeys in Belize....hieroglyph snipped...

The interaction between figs and fig wasps is especially well-known . In addition to its pollinators , ''F. aurea'' is exploited by a group of non-pollinating chalcidoid wasps whose larvae develop in its figs. These include gallers, inquilines and kleptoparasites as well as parasitoids of both the pollinating and non-pollinating wasps.

The invertebrates within ''F. aurea'' syconia in southern Florida include a pollinating wasp, ''P. mexicanus'', up to eight or more species of non-pollinating wasps, a plant-parasitic nematode transported by the pollinator, mites, and a predatory rove beetle whose adults and larvae eat fig wasps.
Nematodes: ''Schistonchus aureus'' is a plant-parasitic nematode associated with the pollinator ''Pegoscapus mexicanus'' and syconia of ''F. aurea''.
Mites: belonging to the family Tarsonemidae have been recognized in the syconia of ''F. aurea'' and ''F. citrifolia'', but they have not been identified even to genus, and their behavior is undescribed.
Rove beetles: ''Charoxus spinifer'' is a rove beetle whose adults enter late-stage syconia of ''F. aurea'' and ''F. citrifolia''. Adults eat fig wasps; larvae develop within the syconia and prey on fig wasps, then pupate in the ground.

As a large tree, ''F. aurea'' can be an important host for epiphytes. In Costa Rican cloud forests, where ''F. aurea'' is "the most conspicuous component" of intact forest, trees in forest patches supported richer communities of epiphytic bryophytes, while isolated trees supported greater lichen cover.

Florida International University ecologist Suzanne Koptur reported the presence of extrafloral nectaries on ''F. aurea'' figs in the Florida Everglades. Extrafloral nectaries are structures which produce nectar but are not associated with flowers. They are usually interpreted as defensive structure and are often produced in response to attack by insect herbivores. They attract insects, primarily ants, which defend the nectaries, thus protecting the plant against herbivores.

Reproduction

Figs have an obligate mutualism with fig wasps, ; figs are only pollinated by fig wasps, and fig wasps can only reproduce in fig flowers. Generally, each fig species depends on a single species of wasp for pollination. The wasps are similarly dependent on their fig species in order to reproduce. ''Ficus aurea'' is pollinated by ''Pegoscapus mexicanus'' .

Figs have complicated inflorescences called syconia. Flowers are entirely contained within an enclosed structure. Their only connection with the outside is through a small pore called ostiole. Monoecious figs like ''F. aurea'' have both male and female flowers within the syconium. Female flowers mature first. Once mature, they produce a volatile chemical attractant. Female wasps squeeze their way through the ostiole into the interior of the syconium. Inside the syconium, they pollinate the flowers, lay their eggs in some of them, and die. The eggs hatch and the larvae parasitise the flowers in which they were laid. After four to seven weeks , adult wasps emerge. Males emerge first, mate with the females, and cut exit holes through the walls of the fig. The male flowers mature around the same time as the female wasps emerge. The newly emerged female wasps actively pack their bodies with pollen from the male flowers before leaving through the exit holes the males have cut and fly off to find a syconium in which to lay their eggs. Over the next one to five days, figs ripen. The ripe figs are eaten by various mammals and birds which disperse the seeds.

Uses

The fruit of ''Ficus aurea'' is edible and was used for food by the indigenous people and early settlers in Florida; it is still eaten occasionally as a backyard source of native fruit. The latex was used to make a chewing gum, and aerial roots may have been used to make lashings, arrows, bowstrings and fishing lines. The fruit was used to make a rose-coloured dye. ''F. aurea'' was also used in traditional medicine in The Bahamas and Florida. Allison Adonizio and colleagues screened ''F. aurea'' for anti-quorum sensing activity , but found no such activity.

Individual ''F. aurea'' trees are common on dairy farms in La Cruz, Cañitas and Santa Elena in Costa Rica, since they are often spared when forest is converted to pasture. In interviews, farmers identified the species as useful for fence posts, live fencing and firewood, and as a food species for wild birds and mammals.

''Ficus aurea'' is used as an ornamental tree, an indoor tree and as a bonsai. Like other figs, it tends to invade built structures and foundations, and need to be removed to prevent structural damage. Although young trees are described as "rather ornamental", older trees are considered to be difficult to maintain and are not recommended for small areas. However, it was considered a useful tree for "enviroscaping" to conserve energy in south Florida, since it is "not as aggressive as many exotic fig species," although it must be given enough space.

At Cherrapunji, India, people are using strangler fig for centuries to build living bridges over the rivers.