Plant Provides Housing for Many Species

Biological Strategy

Ant plants

Sherry Ritter

Image: Claude Mondestin / Pixabay / Free non-commercial use

Cooperate/Compete Between Different Species

From parasitism to mutualisms, there are endless interactions between organisms in nature. Interactions between species that lead to a negative outcome for one species are known as competition. Cooperation occurs when organisms work together for the benefit of each organism or species. While competition often occurs over resources or mates, the more biologists have begun to look for examples of cooperation in nature, the more they have found. For example, around 90% of plants have a beneficial partnership with fungi. Fungi provide the plant with nutrients such as nitrogen and phosphorus, in exchange for sugars from the plant.

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Maintain Biodiversity

The greater the amount of genetic and species variation in an ecosystem, the more resilient that ecosystem is to disturbances. Variation in ecosystems across the Earth also contributes to the Earth’s resilience to unpredictable changes. This variation is called biodiversity. Because living systems compete with each other for scarce resources, maintaining biodiversity involves creating conditions for a large variety of species to successfully co-occur and reproduce. For example, within a wetland, there are different vegetation types. This diversity results in a complex mosaic of microenvironments as the vegetation types alter air flows, light regimes, and water temperatures and chemistry. Because organisms vary in their ideal environmental conditions, these micro-environments increase the diversity of plants in the wetland. In turn, having a wetland in an otherwise dry area increases biodiversity at an even larger scale.

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Flowering Plants

Clade Angiosperms (“receptacle seed”): Dandelions, oaks, grasses, cacti, apples

With 416 families containing some 300,000 known species, angiosperms are the most diverse group of plants, and they can be found around the globe in a wide variety of habitats. They are characterized by seeds that grow enclosed in ovaries, which are enclosed in flowers. The floral organs then develop into fruits of myriad kinds and dimensions, from simple seed casings on maples to elaborate fleshy growths like papayas. The oldest flower known from fossils, Montsechia vidalii, appeared during the Jurassic Period 130 million years ago. They are the primary food source for herbivorous animals, which in turn makes them the indirect food source for carnivores as well.

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An ant-plant maintains biodiversity through symbiotic relationships with 50 species.

Sometimes, a single species of plant or animal can have a huge effect on the other species in an area. For example, a beaver colony can create slow-water habitat for fish, birds, frogs, otters, and other species. In coastal mangrove forests of Papua New Guinea, in the southwestern Pacific Ocean north of Australia, researchers found that a single species of plant supports dozens of other species.

This plant species is Hydnophytum moseleyanum. It’s one of many organisms, called epiphytes, that grow on the surfaces of plants. Mosses, ferns, and bromeliads are examples of epiphytes. These organisms use the plant as a way to get higher in the canopy of a forest to gain access to nutrients and moisture from rain or fog, but they rarely harm the plant.

Hydnophytum moseleyanum is an ant plant, which is a plant that lives in a mutualistic relationship with ants. In this type of relationship, the plant provides a sheltered place for the ants to live, while the ants provide nutrients to the plant. This kind of ant plant has a swollen stem containing cavities, some smooth and some warty. The ants live in the smooth cavities and deposit wastes in the warty ones. The plant absorbs nutrients from that waste.

Hydnophytum moseleyanum and some of the ants associated with it form another type of relationship with other species. It’s called commensalism, where the plant gets nothing from the other species but provides them living space and the moisture within it. The other species probably also get some resources from the ants. Scientists found 50 species living on Hydnophytum moseleyanum, all using the swollen stem. Eleven of those species were ants and the most common were from the genus Philidris, which has the mutualistic relationship with the ant plant.

The other 39 species include, for example, cockroaches, termites, springtails, sow bugs, crickets, silverfishes, wasps, and even a few crabs and lizards. This combination of mutualism and commensalism appears to play an important role in supporting many organisms and maintaining species diversity in the mangrove forests.

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Section through the stem of Hydnophytum moseleyanum

Image: Tony Rodd / CC BY NC SA - Creative Commons Attribution + Noncommercial + ShareAlike

Ant-plant Hydnophytum moseleyanum showing the enlarged stem.

Image: David Rentz /

One of the 50 species found in Hydnophytum moseleyanum.

Last Updated May 20, 2020

References

“There are many ecological studies of ants occupying the myrmecophytes in relation to the interactions between hosts and symbionts. However, the other occupants of myrmecophytes have been scarcely studied. It is very important to investigate all the occupants and arboreal fauna to clarify their symbiotic relationships. We surveyed the complete occupant fauna inhabiting the epiphytic myrmecophytes, Hydnophytum moseleyanum in mangrove forests in Papua New Guinea. A diverse fauna was revealed, that was composed of 11 ant species and 39 species of other animal groups. Almost all the occupant species would be commensals facultatively utilizing the space inside the myrmecophytes for their inhabitation. The existence of the epiphytic myrmecophytes should play a significant role for the maintenance of arboreal biodiversity because myrmecophytes provide the shelters and moisture for arboreal animals and markedly increase potential sites for their dwelling.” (Maeyama et al. 1997:93)

Journal article