Forest ants remain virtually invisible to the casual observer, but that doesn’t mean their actions on the ground go unnoticed. They manifest themselves in a dazzling array of wildflowers in the spring with trillium, wild ginger, violets and leeches all testament to their tireless work.
some species of Aphaenogasteras these ants are known scientifically, they play a vital role in plant diversity in forests, according to a recently published research. They do this in part by dispersing the seeds far and wide.
“Not many people have heard of them, but they are the seed engine in motion and are called ‘key dispersers’“, says Carmela Buono, doctoral student in biological sciences at the University of Binghamton, in the United States, who led the research.
Forest flowers and ants, a mutual relationship
Many understory plant species, such as flowers, rely on a mutual relationship with ants to disperse their seeds, and northeastern North America is a hotspot for this form of ant-plant mutualism, Buono and colleagues found.
“These plants evolved with seeds that have a fatty appendage attached to them that is very attractive to forest ants.”, says the scientist. “Ants need fat as well as protein and sugar, and foods high in fat are hard to find in the forest.”.
Living on logs, in leaf litter and under rocks, forest ants scour the surroundings for these fatty seeds, which they transport back to their nests, where they protect them from rodents and other animals.
“Once the fatty appendages have been consumed, the ants, in a kind of insect cleaning, remove the seeds from the nest, dispersing them away from the original plant.”, explain the scientists.
It is a mutually beneficial arrangement for both the plants and the ants.
“There are so many interesting and intricate parts of this interaction that depend on what types of seeds the ants prefer, which is why you can get this beautiful mix of flower species in the forests.says Bono.
Greater presence of ants in primary forests
This relationship is especially pronounced in primary forests with greater species diversity, which secondary forests created on former agricultural land often lack due to their different topography. The soil in these newer forests tends to be full of holes left by uprooted tree roots and mounds created by the removal of roots and soil.
“Species within the two forest types are also different, with fast colonizers moving into younger forests. An established forest generally has a greater number of shade-tolerant plants in the understory.”, say the scientists behind the research.
competition with slugs
Colonizers of regenerated forests include invasive slugs with which forest ants must compete for fatty seed appendages. These slugs usually live near the edges of forests, near open meadows and farmland.
“There are slightly fewer forest ants in secondary forests, perhaps due to their displacement during years of agricultural use. Differences in forest canopy and the amount of light reaching the forest floor could also play a role, but this remains to be explored.”, say scientists.
Information like this is crucial to effective conservation efforts, which is why we shouldn’t ignore the role of insects like ants in biodiversity.
“ants are beneficial”, emphasizes Buono. “They are not as charismatic as the butterflies or the bees that help pollinate the flowers, but they are just as important.”.