A warming climate is likely to drive species to higher, cooler altitudes. A new study highlights a less obvious, yet crucial way in which their new habitat could differ from the one they leave behind.
Mountains are home to many living species, with biodiversity typically peaking at mid-altitudes. Scientists have long struggled to explain why this is the case, invoking factors such as low temperatures at high elevations or human disturbance further down.
According to new research, mid-altitudes host the largest number of species because the size and the connectedness of similar habitats are greatest there. One implication of their findings, presented in the Proceedings of the National Academy of Sciences, is that moving to higher elevations to adapt to a warming climate could drive species into habitats with a whole different set of spatial properties.
Many factors determine the number species that can co-exist on a patch of land. Large areas with similar properties typically host more species than small ones. And their biodiversity can be increased further if many similar habitats are connected.
In mountainous terrain, other factors come into play, such as temperature, biological productivity, and exposition. By transposing the findings from flat land to mountainous terrain, a team of researchers from across Switzerland has found a new way to explain the observation that biodiversity in mountainous terrain tends to peak at mid-altitudes.
“In mountainous terrain, peaks and valleys are isolated habitats, like islands in the ocean, whereas mid-elevation sites form well-connected patches,” explains Enrico Bertuzzo, a researcher at the Ecohydrology Lab at EPFL and first author of the study. “Given that habitat area and connectivity foster biodiversity, whereas isolation favors the dominance of few species, we hypothesized that topography itself could be playing a key role in regulating how biodiversity varies with elevation.”
Biodiversity is often studied on idealized cone-shaped mountains, where similar habitats are assumed to be found at similar altitudes. In this case, habitats get smaller with increasing altitude, and their species richness is predicted to decrease, leading biodiversity to peak at foot of the cone and steadily decrease with elevation. Instead, Bertuzzo and his coauthors took a more laborious approach.
“Rather than simplifying mountainous terrain to perfect cones or regular hills, our starting point was to consider it in all of its complexity,” explains Florian Altermatt from the Institute of Evolutionary Biology and Environmental Studies at the University of Zurich.
To test their intuition that the very structure a landscape can shape biodiversity patterns, Bertuzzo and his coauthors let loose a large number of virtual species on a mountainous terrain in a computer simulation. Each virtual species was assigned an optimal altitude at which it could thrive, and these altitudes were distributed uniformly across all the elevations considered. When the researchers let the virtual species compete for habitats on landscapes modeled on real-life ones, their simulations confirmed their intuition: topography alone was enough to explain biodiversity patterns observed in nature.
“Other factors, like temperature, productivity, etc., are obviously also important, but they inevitably act on top of the unavoidable effect provided by the landscape structure,“ says Altermatt.
These findings are of particular relevance in a warming world. “Understanding the relation between elevation and biodiversity is crucial to predict how the distribution of species will change in response to climate change,” says Bertuzzo.
“Warmer temperatures will cause species' niches to shift upwards. The same ecological community will therefore move up the mountain, where it will find a different spatial composition, both in terms of available area and connectivity. Our findings underscore the importance of considering these factors to predict future changes.”
This study was carried out by researchers from the Laboratory for Ecohydrology at the EPFL, the Department of Aquatic Ecology at the Swiss Federal Institute of Aquatic Science and Technology (Eawag), the Department of Evolutionary Biology and Environmental Studies at the University of Zürich, and the Department of Civil and Environmental Engineering at Princeton University.
Enrico Bertuzzo, Francesco Carrara, Lorenzo Maric, Florian Altermatt, Ignacio Rodriguez-Iturbe, and Andrea Rinaldoa. Geomorphic controls on elevational gradients of species richness. Proceedings of the National Academy of Sciences. February 1, 2016. doi: 10.1073/pnas.1518922113
Prof. Andrea Rinaldo
Labor für Ökohydrologie
Tel. +41 21 693 80 34
Mobile +41 79 226 70 83
Prof. Florian Altermatt
Institut für Evolutionsbiologie und Umweltwissenschaften
Tel. +41 58 765 55 92
Kurt Bodenmüller | Universität Zürich
As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation
29.03.2017 | University of Hawaii at Manoa
Researchers discover dust plays prominent role in nutrients of mountain forest ecoystems
29.03.2017 | University of Wyoming
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences