The Moreton Bay fig (Ficus macrophylla), also called the Australian banyan, is a large evergreen banyan tree of the family Moraceae. Its common name is derived from Moreton Bay in Queensland, Australia.
It is commonly used as a decorative plant, but its enormous size as an adult means that it is probably not suitable for any less than the biggest gardens and public parks. In addition to its size, the Moreton Bay fig kills other trees as a part of its maturing process, and so can be destructive to native ecology.
Description
The Moreton Bay fig is recognizable for its beautiful buttress roots, which are also known for damaging municipal footpaths. The Moreton Bay fig is an evergreen tree that can reach heights of 60 m (200 ft). The trunk can be massive, with thick, prominent buttressing, and reach a diameter of 2.4 m (8 ft). The rough bark is grey-brown, and marked with various blemishes. It has leathery leaves that can reach a foot in length, which give it its scientific name Ficus macrophylla, meaning “big-leafed fig.” Its branches are strong and flexible.
It has small round fruits that begin as green and turn purple when ripe. They often have off-color splotches or blemishes. The fruit, as in all fig trees, is actually an inverted inflorescence called a syconium. This structure is hollow, and on the inside are dozens of tiny light-colored flowers; each one may develop into an individual fruit within the larger fig. A tiny hole in the fig, called an ostiole, can be found on its end. This permits fig wasps to enter the structure.
Growth
Ficus macrophylla is a strangler fig; seed germination usually takes place in the canopy of a host tree and the seedling lives as an epiphyte until its roots establish contact with the ground. It then enlarges and strangles its host, eventually becoming a freestanding tree by itself.
This plant may live for more than a century.
Sexual Dimorphism
The Moreton Bay fig is monoecious, meaning male and female flowers are found on the same plant. Because the fruit is actually an inverted inflorescence, it forms from multiple flowers; as a result, a single fruit from the Moreton Bay fig may have both male and female flowers.
Habitat
Preferred Habitat
The Moreton Bay fig inhabits warm to temperate regions and tolerates both wet and dry rainforests. It has an aggressive root system that can be damaging to its surroundings, so it usually lives within large areas and may destroy other trees nearby; however, to mature properly, it does need a host tree. As a result, it prefers forests and other woodland. Once it reaches its full size, it is often an emergent, its crown towering above the rest of the canopy.
Natural range
The Moreton Bay fig is a native of most of the eastern coast of Australia, from the Atherton Tableland in the north to the Illawarra in New South Wales, and Lord Howe Island.
Introduced
Ficus macrophylla is widely used as a feature tree in public parks and gardens in warmer climates such as California, Portugal, Sicily, and Australia. It has been naturalized in Hawaii and New Zealand, and garden escapees are sometimes reported from Turkey. There are Moreton Bay figs growing on other Pacific islands, as well as throughout Asia, Africa, and the Iberian Peninsula.
Isla Nublar, an island in the Gulf of Fernandez, also had Moreton Bay figs introduced as ornamental plants in the 1980s. They were planted by International Genetic Technologies for the Jurassic Park theme park, and were grown in the Velociraptor paddock and primary herbivore paddock. These were lush forested areas near the Jungle River, where the figs would have plenty of host trees. The figs could have only propagated if their symbiotic fig wasp, Pleistodontes froggatti, was introduced to Isla Nublar alongside them and thrived there.
Between 2002 and 2015, the island was extensively terraformed and built up into the larger Jurassic World theme park, and many of the figs were probably torn down. At that point, a more environmentally conscious leadership may also have strove to protect Isla Nublar’s native ecosystem from these invasive plants. Any survivors were possibly destroyed in the 2018 eruption of Mount Sibo, which burned down most of the forests.
Ecology
Activity Patterns
During the day, the Moreton Bay fig performs photosynthesis to produce energy.
Diet and Feeding Behavior
In order to access sunlight, which it requires in order to convert carbon dioxide and water into carbohydrates, the Moreton Bay fig grows as an epiphyte on larger plants. Eventually, it will put down aerial roots which grow thicker upon reaching the ground. These support its increasing weight, and the tree becomes so large that it kills its host. By this point, it has grown big enough to tower above the canopy and obtain all the sunlight it needs.
Social Behavior
Most plants utilize chemical signals, such as hormones, to communicate. Specifics of how the Moreton Bay fig does this are not currently known.
Reproduction
A mature Moreton Bay fig will produce a huge number of fruits. It will start the fruiting process at any time of the year, but is most productive from February to May. In actuality, the “fruits” are an inverted form of inflorescence called a syconium. Tiny flowers are found on the inner surface, and these are pollinated exclusively by a species of fig wasp called Pleistodontes froggatti. The female wasp lays her eggs within the fig while depositing pollen into the female flowers, and then dies; her body is digested for nutrients by the fig. Her offspring mature rapidly, and the wingless males immediately mate with the females inside of the fig. The male wasps then begin to burrow out of the fig, creating an escape route for the females who are now laden with pollen from the male flowers. The females disperse to begin the process again, and the males die shortly after leaving the fig.
Once the fruit has ripened, it is fed upon by numerous animals such as birds and monkeys, which serve to disperse the seeds that result from the wasps’ pollination. Because each individual flower can develop into a tiny fruit inside the fig, it can produce a great number of seeds.
Communication
Many plants communicate with one another using chemical signals. Figs in particular have symbiotic relationships with fig wasps, and their fruits have evolved over at least eighty-three million years to signal to the wasps. When the fig is receptive to pollen, the ostiole loosens slightly to allow the wasps in.
Ecological Interactions
Moreton Bay figs are considered strangler figs, meaning that they begin their life cycle as an epiphyte on another tree. In their native habitat, common hosts include the red cedar (Toona ciliata), hoop pine (Araucaria cunninghamii), white booyong (Argyrodendron trifoliolatum), lacebark (Brachychiton discolor), and giant stinging tree (Dendrocnide excelsa). While younger, they may protect the host tree against strong winds during storms. Eventually they grow large enough to strangle their host, becoming a free-standing tree. Their buttress roots can also disrupt their immediate environment. This makes the Moreton bay fig an ecological threat to some plant life in places where it is introduced, such as Isla Nublar. However, it also provides some benefits to animals. Its fruits are often eaten by birds, and its enormous size allows it to be a habitat for small creatures. On Isla Nublar, its foliage may also serve as food for Brachiosaurus, and its buttress roots make for sheltered areas where small dinosaurs such as Velociraptor can lay eggs.
Fruit-eating birds such as the collared aracari (Pteroglossus torquatus), as well as some bats and monkeys, would have distributed the seeds on Isla Nublar. It has other dispersal species in its native range: these include the green catbird (Ailuroedus crassirostris), topknot pigeon (Lopholaimus antarcticus), Australiasian figbird (Sphecotheres vieilloti), pied currawong (Strepera graculina), and gray-headed flying fox (Pteropus poliocephalus), among many others. The huge amounts of fruit it produces make it one of the most important species in its rainforest environment.
Pollination is carried out by Pleistodontes froggatti, a species of fig wasp. Once a wasp has died inside a fruit, the fig will produce the enzyme ficacin to digest the carcass, nourishing the tree. Other non-pollinating wasps may inhabit the tree, as do nematode worms that are parasitic on P. froggatti and other wasps. Thrips, plant-lice, and moth larvae feed on the leaves. Longhorn beetle larvae parasitize the tree, and the brown root rot fungus (Phellinus noxius) also affects it.
Cultural Significance
Symbolism
The broad, spreading canopies of banyan figs have inspired humans for many thousands of years, and are thought to symbolize longevity or immortality and connection. While other fig species produce abundant edible fruit and thus are considered symbols of prosperity in some cultures, the Moreton Bay fig’s fruit is not considered good eating and so it does not share this attribute.
As a type of strangler fig, it can also be seen alternately as a parasite or a support system, depending on the extent of its growth, and can be used artistically to symbolize either.
In Captivity
This is a surprisingly easy tree to cultivate, as it will capitalize on any available hosts to grow upward. Bear in mind, though, that this tree can easily reach massive sizes. In order to truly flourish, it will need a support structure to rely on until it reaches its adult size. In the wild, it uses other trees for this, often suffocating its host eventually. In captivity it may be provided with other structures that help it grow during its younger stages. Cultivated Moreton Bay figs are sometimes used as landmarks or as street-lining trees, or simply as decorative plant life.
There are two major obstacles to bear in mind when cultivating this tree, and both have to do with its destructive potential. First, keeping the Moreton Bay fig in gardens with other tree species may result in the death of your other trees, as new young figs will take root and suffocate their hosts. Second, the Moreton Bay fig may also damage garden infrastructure using its massive buttress roots. Precautions should be taken to protect both the plant life and structures such as roads, paths, and pipes.
The fruit will attract wildlife, but can become messy because vast amounts of it will fall on the ground and get crushed. In order to breed the tree, you will need to introduce its pollinator, the wasp Pleistodontes froggatti. If the tree is reproducing, keep a watchful eye out for young trees establishing themselves outside of the garden’s boundaries; birds may disperse the seeds over some distance and this tree is known to become invasive given the right circumstances. Should you manage to keep it under control, though, this species can be quite successful in dry and warm climates, and is tolerant of salt spray from the ocean as well as a limited degree of frost exposure. It may live for a hundred years or more, guaranteeing that people may enjoy it for generations.
It can be grown indoors in medium to high light, and can be grown as a larger bonsai.
Science
Like other fig species, the Moreton Bay fig helps to illustrate the coevolution of figs and fig wasps, as well as the ecological relationships that strangler figs have with their host trees. This species is capable of shaping its environment in a number of ways, making it a wealth of ecological and evolutionary knowledge. In particular, the coevolutionary relationship between Ficus macrophylla and Pleistodontes froggatti is endlessly fascinating to biologists.
Politics
This plant has the potential to become an invasive species. It was deliberately introduced in some parts of the world, most notably Hawaii, where its fig wasp pollinator was also deliberately introduced. The fig wasp was not introduced to New Zealand on purpose, but instead dispersed there over the ocean on wind currents. Moreton Bay figs are considered naturalized in Hawaii and New Zealand, but can still damage native ecology. In order to become invasive, these trees must have their fig wasps present, so keeping these insects under control can restrict the spread of the tree.
Resources
The Moreton Bay fig has always been one of Australia’s most important species. Australian Aboriginal peoples used its fibers to make fishing nets for generations before European people colonized the region. While many rainforests were clear-cut by the British, some large Moreton Bay figs were left standing as landmarks. Once larger cities were built in Australia, this tree was used decoratively.
Since then, the Moreton Bay fig has been introduced to warm climates around the world. It is slightly frost-tolerant, lives well in dry conditions, and can survive salt spray from the ocean, making it an adaptable species. Today it is naturalized in Hawaii and New Zealand, and has become invasive in some areas such as Isla Nublar. Because of its enormous size, only large and well-funded properties can house it. This is a financially significant tree, causing damage to pipes, paths, roads, and other infrastructure with its roots.
The wood of this tree is used to make cases, though it is not common as a timber source otherwise. The figs are valuable as they attract wildlife, but while they are technically edible to humans, most people find them dry and distasteful. Contrary to common belief, the figs do not actually contain dead wasps; the figs produce an enzyme called ficacin from its latex which digests the dead wasp bodies.
Safety
The sprawling canopy of this tree makes it tempting to climb. While it is sturdy and unlikely to fall at any given time, so long as the tree is healthy, care should still be taken. Bring proper tree-climbing gear if you intend to venture high into its crown, and never climb alone. Wear safety equipment to protect yourself from scratches and scrapes; be especially sure to protect your head in the even that you accidentally lose purchase on its trunk or branches.
Behind the Scenes
The Moreton Bay fig tree has become naturalized in Hawaii, where Jurassic Park was filmed. In real life, it thrives on the islands because Pleistodontes froggatti was intentionally introduced to the island in 1921 to allow the trees to reproduce. It grows on introduced and native trees.
