Researchers from the Swedish University of Agricultural Sciences are now able to demonstrate that organisms in the Swedish soil most likely contribute to the success of this exotic tree species.
A Pinus contorta landscape in northern British Columbia, Canada, which is the general region where much of the Swedish P. contorta originated.
Photo: Michael Gundale
When the researchers studied the growth of the lodgepole pine in sterilized and unsterilized Swedish and Canadian soil samples, they discovered clear differences in growth: it grew better in soil inoculated with Swedish soil biota compared to Canadian soil biota.
These results improve our understanding of why some exotic tree species and invasive plants at times can function so well in new environments.
Plants are often moved away from their natural provenance, and sometimes they become stronger competitors in their new habitat. This may be welcomed by agriculture and forestry, while an introduced plant spreading uncontrollably in nature can become a major concern. The reason why plants sometimes function very differently in a new environment is a question that many researchers are currently focusing on.
Michael Gundale and his colleagues from the Swedish University of Agricultural Sciences (SLU) have focused on what the organisms found in Swedish and Canadian soils mean for the growth of the lodgepole pine*. There is a multitude of life forms in soil, some of which may be harmful (such as diseases and herbivores), and some of which may be beneficial (such as mycorrhizal fungi). By conducting a series of experiments on young plants, the researchers have shown that the growth of the lodgepole pine is greatly affected by which organisms live in the soil.
A first greenhouse trial indicated that the plants grew much better in soil samples from the areas in northern Sweden where the lodgepole pine has been introduced, compared with the soil samples from its original habitat in Canadian British Columbia. When the experiment was repeated in soil samples that had been sterilised through gamma irradiation, the growth was no longer affected by the soil being Swedish or Canadian. It also turned out that sterilised soil (regardless of origin) inoculated with Canadian organisms showed stunted growth, while “Swedish inoculation” improved growth.
“We have therefore clear evidence that differences in soil organisms between Pinus contorta’s Canadian and Swedish ranges have a great impact on the trees growth,” says Michael Gundale. “One plausible explanation is that plants growing in Canadian soil are exposed to antagonistic microorganisms that are specialised to lodgepole pine, while the Swedish soil offers an enhanced mutualism with mycorrhizal fungi. But we have not yet had the opportunity to examine this.”
Earlier experiments have looked at why a certain species does better in a new environment than in its natural habitat. However, these experiments have often only looked at one or a few of the many factors that could contribute to such a success, and no statements can therefore be made in respect to the importance of various factors in relation to each other. What makes this SLU study unique is that the researchers have not only examined the importance of soil biota, but have also considered a number of other factors that could also affect growth differences between the countries; they used soil samples from several places in Sweden and Canada, collected seeds from several areas, tested different fertilisation levels and took into account chemical and physical variations in the soil. However, the importance of Swedish and Canadian soil biota for growth remained the same, regardless of how all of these other factors were altered.
“I would love to conduct an equivalent study on Swedish pines,” concludes Michael Gundale. “If it were to turn out that the Swedish pines (Pinus sylvestris) are equally stunted by the indigenous soil organisms, it would be interesting to examine which soil biota are responsible for it, and what could be done to protect the plants.”
* The lodgepole pine (Pinus contorta) originates from western North America. In the north of Sweden, the lodgepole pine has been planted on hundreds of thousands of acres. This introduction started in the 1970s and, at the time, it was thought that a natural rejuvenation could only take place in connection with a fire - which would prevent an uncontrollable spread. This however has not proven to be entirely true.The article
doi: 10.1111/nph.12699.Further information:
+46 (0)90-786 84 27, Michael.Gundale@slu.se
Pressofficer David Stephansson; David.Stephansson@slu.se, +46-72 511 69 90
Press images may be published without charge in articles about these findings, please acknowledge the photographer.
Harnessing a peptide holds promise for increasing crop yields without more fertilizer
25.11.2015 | University of Massachusetts at Amherst
Study shows how crop prices and climate variables affect yield and acreage
18.11.2015 | University of Illinois College of Agricultural, Consumer and Environmental Sciences
Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.
Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...
The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...
Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.
In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...
In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.
Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...
Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...
25.11.2015 | Event News
17.11.2015 | Event News
21.10.2015 | Event News
26.11.2015 | Ecology, The Environment and Conservation
26.11.2015 | Materials Sciences
26.11.2015 | Earth Sciences