How moss creates better soil and helps fight climate change
Mosses are among the most common and overlooked plants on earth. A large new study is finally giving moss the recognition it deserves, highlighting its importance in maintaining the planet's ecosystems and its potential to reduce its carbon footprint.
Moss can be found everywhere, from deserts to arctic regions. Despite their ubiquity , mosses are often overlooked, whereas the role of vascular plants in improving soils and maintaining plant diversity and ecosystems has been well studied.
Vascular plants have both lignified (wood-like) tissue, which transports water and minerals throughout the plant, and non-lignified tissue, which aids in photosynthesis. In contrast, mosses are non-vascular plants that absorb water and nutrients through their surfaces. Their roots also differ, with growths called rhizomes anchoring them to the soil surface.
As the name suggests, soil moss grows on the surface of the soil. They are also among the most widespread land plants, but how they affect ecosystems is poorly studied. Now, the most comprehensive global field study of moss, led by researchers at the University of New South Wales in Sydney, has examined soil moss in its natural habitat to determine its importance to the planet.
"We were initially interested in how natural systems of undisturbed native vegetation differed from man-made systems such as parks and gardens," said David Eldridge, lead and corresponding author of the study. "So, for this study, we wanted to look at more details about mosses and their actual role in providing essential services to the environment."
The researchers collected moss samples from soil in more than 123 ecosystems on Earth, from dense rainforests to deserts to icy landscapes. They found that moss covers an incredible 30,000 square miles (60,000 square kilometers) of Earth, nearly the size of Canada or China.
The researchers found that soil moss benefits soil and neighboring plants in 24 ways, including maintenance of soil biodiversity, nutrient cycling, decomposition of organic matter, maintenance of microbial populations and control of soil pathogens.
"We looked at what happened in soils that were dominated by mosses, and what happened in soils that didn't have mosses," Eldridge said. "We were surprised to find that mosses were doing all these amazing things."
In addition, the researchers found that mosses are critical for controlling climate-changing carbon dioxide. Globally, they say, soil mosses have the potential to absorb 708 million metric tons (643 million tons) of carbon dioxide from the atmosphere compared to moss-free soils .
"Of all global emissions from land-use change, such as grazing, clearing vegetation and agriculture-related activities, we think mosses absorb six times as much carbon dioxide," Eldridge said.
Based on their findings, the researchers hope people don't overlook the benefits of moss and think twice before removing it from their gardens.
"People thought that if moss was growing on the soil, it meant the soil was sterile or something was wrong," Eldridge said. "But it's actually doing great things, in terms of the chemistry of the soil, like adding more carbon and nitrogen, and being a major stabilizer when there's a lot of disturbance."
The researchers intend to continue their research to see if moss can rejuvenate soil in urban environments as it can in natural areas.
"We're also keen to develop strategies for reintroducing moss into degraded soils to speed up the regeneration process," Eldridge said. "Mosses may well provide the perfect tool to initiate soil restoration in severely degraded urban and natural areas."
The study was published in the journal Nature Geoscience .
Article source: UNSW Sydney
