University of Rhode Island ecologist Laura Meyerson and colleague Jim Cronin from Louisiana State University conducted an ambitious large-scale National Science Foundation funded study on native and invasive Phragmites australis (common reed) in North America and Europe. They found that the intensity of plant invasions by non-native species can vary considerably with changes in latitude.
“When looking at a continental scale invasion in particular, we can’t assume that the invasion is uniform across the region because of latitudinal differences in species interactions like herbivore pressure and resistance to herbivory,” said Meyerson, URI associate professor of habitat restoration ecology.
“Some biogeographic regions may be more susceptible to invasions while others are more resistant. So, if we don’t look at invasions at a macro scale, such as for an entire continent, we might misinterpret the invasion process and the strength of its impacts.
“Our continental-scale biogeographic perspective allowed us to have some insights into the heterogeneity of invasions that are not possible for smaller scale studies,” she added.
The research was published this month in the journal Ecology.
In their study of native and non-native sub-species of P. australis on both continents, they also found that herbivores feed upon the native Phragmites in North America at a much greater rate than on the invasive Phragmites.
“Our native Phragmites in North America is getting hammered by both native and introduced insects, whereas the invasive Phragmites in North America suffers far less herbivory than it does in its native Europe,” she said. “That’s partly because when invasives are introduced to a new place, they leave their enemies behind and can devote their resources to greater growth.”
To determine whether differences occurred in resistance to herbivory, Meyerson and Cronin surveyed 13 patches of native Phragmites and 17 patches of non-native Phragmites along the East Coast from Canada to Florida. They conducted similar surveys of 21 patches of Phragmites in Europe from Norway to southern Portugal. (The native European species and the invasive non-native species in North America are the same lineage.)
At each site Meyerson and Cronin measured plant biomass and defenses against herbivores and quantified insect damage by galling, chewing and sucking (aphids) insects to measure the effects of herbivory on Phragmites fitness. They found that chewing and galling insects consumed a greater quantity of the native and non-native plants in the southern part of North America, while aphids were more prevalent at higher latitudes.
“Interactions between herbivores and native plants were much stronger than interactions between herbivores and invasive plants at lower latitudes, making the southern region more susceptible to invasive species,” Cronin said. “This means that the invasive plants suffer less herbivory at lower latitudes than the native plants, giving the invasive Phragmites a greater opportunity to invade.
“This pattern weakens at higher latitudes suggesting that herbivores may be more important in limiting invasion success in the north,” he added.
Based on their results, Meyerson and Cronin believe that efforts to identify an insect that could be used as an agent of biocontrol for the invasive Phragmites may do more damage to the native species than to the invasive variety.
“Because we found that all of the insects perform better on the native than on the invasive type, it suggests to us that if a biocontrol is released in North America, it’s going to harm the native Phragmites more than the invasive,” they said. “Our data suggests that it would be ill advised to release a biocontrol agent against Phragmites.”
Public Information Officer
Todd McLeish | newswise
Global threat to primates concerns us all
19.01.2017 | Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung
Reducing household waste with less energy
18.01.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
23.01.2017 | Process Engineering
23.01.2017 | Physics and Astronomy
23.01.2017 | Life Sciences