Protection of land crabs critical to the conservation of coastal tropical forests

From an article by Morgan ERickson-Davis and Jeremy Hance on Mongabay.com:

The impact of land crabs on the near-ocean forests in which they live has long been overlooked, with emphasis placed instead on water levels, salinity, and other abiotic influences. However, a new research synthesis published in Biological Reviews shows that land crab influence is among the most important factors affecting tropical forest growth along coasts, on islands, and in mangroves.

Land crabs come in a variety of species from the tiny Ecuadorian Hermit Crab, which weighs less than an ounce, to the Coconut Crab which, at 38lbs, is the world's largest terrestrial invertebrate. While many species are similar in appearance to their aquatic relatives, land crabs exhibit an array of unique adaptations, the most notable and universal being an inflatable organ covering their gills which acts as a lung. In addition to an ability to extract oxygen from the air, many species of land crabs can extract moisture from their surroundings (from the soil they burrow into or the food they eat, for example), necessitating their return to the sea only to reproduce.

Most species of land crabs are omnivorous and can have quite an impact on terrestrial vegetation, so much so that many populations have become pests to farmers who grow crops near tropical coasts. Even so, the crabs' role in the development of coastal ecosystems has only begun to be understood. "Land crabs are found in coastal forests which have been understudied due to inaccessibility in remote areas and habitat loss (deforestation) in developed areas." says Dr. Erin Lindquist, professor at Meredith College and coauthor of the recently published synthesis. "In addition there has been little groundwork on the natural history of land crabs."

However, recent research has begun to reveal the true nature of the crabs' impact on their environment.