University of Arizona’s Biosphere provides an amazing opportunity for researchers to observe and study the interactions between water, microbes, soil and plants. This is now possible thanks to the realistic manmade hillside setting, which will help improving global climate models.
The world’s largest artificial watershed is covered by six-tons of ground-up volcanic rock and has three identical hillslopes, each being 100 feet long and 40 feet wide, that form the Landscape Evolution Observatory, or LEO .
The slopes are equipped with more than 1800 sensors and samplers each, which track the water flow through the soil. As the Biosphere 2 Science Director Peter Troch, a professor in the UA’s department of hydrology and water resources states, this is currently one-of-a-kind tool for studying interactions between different components of the landscape.
In addition, Troch points out that no one has looked into how exactly each element affects the other. While geochemists, ecologists, and hydrologists study individual processes, now there is a real chance to combine the information and provide grounds for testing the influence of climate change on the environment. It also allows scientists to adjust the conditions and factors, and therefore observe the scenarios and test the predictability of the computer models. This is something that is not possible in the natural world.
While building the LEO, the team has also developed a computer model that takes into account hydrology, biogeochemistry, ecology and other fields, in order to simulate all processes in a landscape.
Stephen DeLong, an assistant research professor at Biosphere 2 with a joint appointment in the department of geosciences explained that to build the three hillslopes was particularly challenging not only from scientific, but also from engineering point of view, because everything needed to be built from scratch.
Each slope is supported by a steel construction, covered by 650 tons of soil. Changes in weight due to rainwater or evaporation are tracked by balancing scale, while steel cylinders provide structural support. The size and the slope angle are also carefully estimated and monitored, because, as Troch explained, rate of change of landscapes depends on this the most.
Currently scientists at University of Arizona are testing the quantity of water and nutrients plants need in order to adjust to changing conditions. According to Troch, LEO gives the opportunity to assess the entire landscape rather than look at individual species.
The data is collected in an open database that can be accessed by researchers from around the world and used to validate models. DeLong is certain that this will allow scientists from diverse disciplines to join forces and work together to solve global issues.
Over the next 10 years, the team plans to have answers to key questions concerning landscapes change under the influence of droughts, heat, rainstorms.
Currently the scientists are looking at microbes in soils and how they might accelerate chemical weathering. Later on, they are planning to add vascular plants in order to assess changes in hydrology.