Nav: Home

Invasive tropical legume alters soil nitrogen dynamics

October 13, 2016

As global change continues to be studied, the scientific community needs quantitative assessments to inform mitigation decisions and predict outcomes. Because restoration and management plans designed to address global change issues are resource-limited, decision-makers require empirical information to best prioritize. Invasive alien species comprise one of the components of global change that results from the human footprint. For this global threat, information is needed to identify the most problematic species and determine the means by which they damage invaded ecosystems.

Islands are highly vulnerable to the changes that result from invasive species. However, the actual research devoted to landscape-level processes following the influence of invasive species has been heavily biased toward continental localities. Recent research by the University of Guam has addressed this bias. The experimental results appeared in the September 2016 issue of the international journal Communicative & Integrative Biology.

Authors Thomas Marler, Nirmala Dongol, and Gil Cruz compared soils in sites where the woody legume tree Leucaena leucocephala had displaced native tree species with adjacent sites where a healthy native forest tree cover persisted. Under these small island conditions, a clear divergence in several components of the chemical profile were revealed. As predicted, various workings of the nitrogen cycle were among the most affected soil traits.

Habitats that are dominated by legume trees tend to exhibit greater soil nitrogen than habitats that do not contain legume trees. The Guam team found the opposite. "We were surprised to find that the soils influenced by this non-native legume tree contained less nitrogen than the soils beneath native tree cover," said Marler. The research further revealed how various components of the nitrogen pool may explain the unexpected results.

The microbiological processes that take stable forms of soil nitrogen and transform them into more mobile forms were elevated in the soils influenced by the invasive legume tree. These same transformations were muted in the soils beneath the diverse native tree cover, allowing more of the nitrogen to remain in the stable forms that extend the soil residence time.

This research on one of the most problematic invasive plant species in western Pacific islands illuminates several important issues. First, Leucaena leucocephala trees may exert their greatest influence on soil chemistry by changing the pools of soil microorganisms that control the transformations in soil chemistry. Second, the international coalition of invasion ecologists need to consider augmenting measurements of static ecosystem traits with measurements of dynamic ecosystem traits. Third, planners that implement future restoration plans for Guam, which include landscape-scale efforts to remove invasive plant species, need to consider legacy effects of invasive plants. Eradicating the alien plants alone cannot restore habitats, as the transformed soil properties of invaded ecosystems may not be restored for many years following selective plant removal.
-end-


University of Guam

Related Invasive Species Articles:

Invasive species that threaten biodiversity on the Antarctic Peninsula are identified
Mediterranean mussels, seaweed and some species of land plants and invertebrates are among the 13 species that are most likely to damage the ecosystems on the Antarctic Peninsula.
Research networks can help BRICS countries combat invasive species
BRICS countries need more networks of researchers dedicated to invasion science if they wish to curb the spread of invasive species within and outside of their borders.
Look out, invasive species: The robots are coming
Researchers published the first experiments to gauge whether biomimetic robotic fish can induce fear-related changes in mosquitofish, aiming to discover whether the highly invasive species might be controlled without toxicants or trapping methods harmful to wildlife.
Monster tumbleweed: Invasive new species is here to stay
A new species of gigantic tumbleweed once predicted to go extinct is not only here to stay -- it's likely to expand its territory.
DNA tests of UK waters could help catch invasive species early
A team of scientists led by the University of Southampton have discovered several artificially introduced species in the coastal waters of southern England, using a technique that could help the early detection of non-native species if adopted more widely.
For certain invasive species, catching infestation early pays off
An international research team led by invasion ecologist Bethany Bradley at UMass Amherst has conducted the first global meta-analysis of the characteristics and size of invasive alien species' impacts on native species as invaders become more abundant.
Study offers insight into biological changes among invasive species
A remote island in the Caribbean could offer clues as to how invasive species are able to colonise new territories and then thrive in them, a new study by the University of Plymouth suggests.
The invasive species are likely to spread to a community not adapted to climate change
Laboratory experiment to indicate how invasive species are to spread new areas.
Invasive species and habitat loss our biggest biodiversity threats
Invasive species and habitat loss are the biggest threats to Australian biodiversity, according to new research by the Threatened Species Recovery Hub in partnership with The University of Queensland.
Forget 'needle in a haystack'; try finding an invasive species in a lake
When the tiny and invasive spiny water flea began appearing in UW-Madison researchers' nets in 2009, scientists began to wonder how Lake Mendota, one of the most-studied lakes in the world, went from flea-free to infested seemingly overnight, undetected by trained technicians.
More Invasive Species News and Invasive Species Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Space
One of the most consistent questions we get at the show is from parents who want to know which episodes are kid-friendly and which aren't. So today, we're releasing a separate feed, Radiolab for Kids. To kick it off, we're rerunning an all-time favorite episode: Space. In the 60's, space exploration was an American obsession. This hour, we chart the path from romance to increasing cynicism. We begin with Ann Druyan, widow of Carl Sagan, with a story about the Voyager expedition, true love, and a golden record that travels through space. And astrophysicist Neil de Grasse Tyson explains the Coepernican Principle, and just how insignificant we are. Support Radiolab today at Radiolab.org/donate.