The complexity of ecological systems, expressed in the large variation in morphology, physiology and behavior of individuals of different species, individuals of the same species, or even the same individual in different environments, makes the understanding of the mechanisms affecting the diversity of ecological communities extremely difficult.
As a consequence, most theories of biodiversity are either limited to a single mechanism, or rely on highly simplified and possibly unrealistic assumptions. Thus, after more than a century of intensive research on species diversity, the world still lacks a solid, theoretical foundation that can effectively guide decision makers.
What enables different species to coexist in nature? Why do some areas, such as the tropics, host huge numbers of species, while others can accommodate only a few? How is climate change expected to affect the diversity of natural ecosystems? What level of habitat destruction can ecological communities suffer, and according to what rules should we design nature reserves?
Taking into account that preserving biological diversity (biodiversity) is crucial for the health of the environment, answering such questions is now recognized as one of the greatest challenges for the 21st century.
In his Ph.D. thesis in the Department of Evolution, Systematics and Ecology at the Hebrew University, Omri Allouche developed, under the supervision of Prof. Ronen Kadmon, a new theory of species diversity that attempts to provide a more effective basis for biodiversity conservation. The heart of the theory is a mathematical model that predicts the number of species expected in an ecological community from properties of the species (e.g., rates of birth, death, and migration) and the environment (e.g., resource availability, habitat loss, frequency of disturbances).
The generality of the model and its flexibility make it a highly effective tool for guiding conservation managers and policy makers. Interestingly, analyses of the model provide novel insights that often differ from common notions of conservationists. For example, in contrast to the intuition that improving habitat quality (e.g. by resource enrichment) should promote biodiversity, Allouche’s theory predicts that resource enrichment can actually reduce biodiversity, a result supported by empirical studies.
Another example is the response of ecological communities to habitat loss, which is recognized as the largest threat to biodiversity. Often the response of an ecosystem to mild habitat loss is used to forecast expected responses to large-scale habitat loss. The theory predicts that such forecasts may be misleading, and that ecological communities may show a sudden biodiversity collapse prior to some critical level of habitat loss.
One aspect of particular importance for conservation planning is the prediction of biodiversity responses to global climate change. Most current models of biodiversity responses to climate change make the assumption that dispersal ability of species is unlimited. In his work – which has earned him a Barenholz Prize at the Hebrew University -- Allouche shows that this assumption significantly reduces the predictive power of such models and can therefore lead to misleading conclusions.
Allouche believes that his contributions can improve the ability of conservation managers and policy makers to assess potential risks to biodiversity, to efficiently design nature reserves, to effectively identify and protect endangered species, and thus, to better conserve the diversity of ecological communities.
For further information: Jerry Barach, Dept. of Media Relations, the Hebrew University, Tel: 02-588-2904. Orit Sulitzeanu, Hebrew University spokesperson, Tel: 054-8820016.
Jerry Barach | Hebrew University of Jerusalem
Reducing household waste with less energy
18.01.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH
Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt
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...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
18.01.2017 | Materials Sciences
18.01.2017 | Information Technology
18.01.2017 | Ecology, The Environment and Conservation