Further up

While various research studies have confirmed the shift of some plant species to higher altitudes, their physiological response has rarely been observed and the relationship between low atmospheric pressure and the adaptation mechanisms of plants has never been studied in depth until now.

Inside terraXcube’s hypobaric chambers, a number of species that can be found in the Val di Mazia (1500 m.a.s.l) are being artificially brought to higher altitudes with other factors such as temperature, humidity and the amount of light being kept constant. "In this way we are able to observe, over the course of a few weeks, how the lower atmospheric pressure present at high altitudes will affect how plants function," explains Matteo Dainese. In particular, changes in the mechanisms regulating photosynthetic activity and transpiration will be observed. "Transpiration in vascular plants regulates gas exchange between the plant and the atmosphere. During the day, C02 enters the plant organism and water in the form of condensation escapes," says the researcher. Plants regulate these exchanges by keeping the stomata, small pores found mainly on the underside of leaves, open or closed. "Our hypothesis is that plants transpire more at higher altitudes, becoming more vulnerable to water stress." These studies will reveal which plants are adaptable and which are likely to go into stress at high altitudes.

The groundbreaking experiment took place in the terraXcube Small Cubes, four chambers each capable of independently replicating different environmental conditions typical of the Alps. In one chamber, atmospheric pressure typical of the Val di Mazia - 1500 m.a.s.l, where the plants were collected, was recreated. In a second chamber, the lowest altitude found in South Tyrol - that of Bolzano at 200 m.a.s.l, was kept constant. In a third, the plants were taken to an altitude of 2,500 m.a.s.l. "According to various climate models, this is one of the most radical - but still plausible - scenarios we could have around the year 2100. The RCP8.5 scenario, inevitable if there is no mitigation of global emissions, predicts a temperature increase of between 4 °C and 7 °C by the end of the century. This means that plant species could move 600-1000 meters higher,' says Matteo Dainese.

Some research suggests that soil microorganisms may have a mediating function in the adaptation mechanisms of plants in new habitats. Microbiologists from the University of Innsbruck have joined the study to evaluate just this, how altitude affects soil microbes, both alone and in their interaction with plants. "The hypothesis is that certain microorganisms are more adaptable to life at high altitude than others. And, that these microorganisms can help plants cope with new environmental conditions,' explains Paul Illmer, head of the soil microbiology and climate change research group at the University of Innsbruck. In the different simulated altitude scenarios, some plants will be grown in sterilized soil - without a microbial component whilst others will be grown on soil from the Mazia Valley, containing the microorganisms typical of their natural habitat. In addition, different microbial cultures containing both fungi and bacteria will also be tested. “The aim is to understand which micro-organisms are most adaptable to altitude and which are most effective in mitigating the effects of altitude in plants”.