Nirav Patel
2/22/11
Biogeography
1) Schlick-Steiner, Birgit C., Steiner, Florian M., Pautasso, Marco. 2008. Ants and people: a
test of two mechanisms potentially responsible for the large-scale human populationbiodiversity correlation for Formicidae in Europe. Journal of Biogeography (J.
Biogeogr.) (2008) 35, 2195-2206.
Brigit C. Schlick-Steiner and Florian M. Steiner are both with the School of Marine and
Tropical Biology, DB23, James Cook University in Townsville, Qld, Australia and
Marco Pautasso is with the Department of Biology at Imperial College London, Wye
Campus, Wye, Kent, UK.
2) Testing the correlation between ant species richness and the human population
size/density of European countries, and whether these two variables increase given the
plant species richness and mean annual temperature and precipitation. Ultimately, is there
a positive relationship between the biodiversity of invertebrates and the human
population?
3) There have been many recent studies that have documented positive relationships
between species diversity and human population size, recently the pattern has been
identified in certain plant species, but also with other vertebrates.
However, little is known about the generality of this pattern for invertebrates.
Invertebrates are species rich but are known to be understudied. So for these large scale
species-people correlations to be more complete and to apply to a more general pattern, it
is necessary that this pattern apply to invertebrates, as they compromise much of the
Earth’s biodiversity.
The authors chose data collected as a part of the Fauna Europaea to test for human
population-biodiversity correlation. As ants are often key components of ecosystems, the
play roles in predation, herbivory, decomposition, soil turnover, and seed dispersal. Ants
are often used as indicators of ecosystem health as well.
Europe is characterized biogeographically as a region with a relatively high human
population and low number of species in comparison to other continents. There are some
areas in Europe which high amounts of biodiversity in Europe which has correlated with
high ant species diversity as well. European biogeographical studies have been relatively
rare, most likely because of the political and linguistic fragmentation of the different
countries. But this situation has presented itself as an opportunity to test whether regions
with high human population size can contain a larger variety of habitats, correlating with
species richness, or whether regions with higher human density can also have a favorable
climate, for both people and species.
4)Utilizing data of the estimates of ant species richness for European countries provided
by Fauna Europaea project, the authors correlated this with human population size and
density data obtained from publicly accessible websites like EUROSTAT. The
Nirav Patel
2/22/11
Biogeography
correlation of ant species richness with human population size/density was analyzed on
its own and was controlled for variations among countries, in (1) area, (2) area and plant
species richness, and (3) area, plant species richness, and mean annual temperature and
precipitation.
5) The authors deduced that ant species richness significantly increased with increasing
human population size. Human population size explains more variance within ant
species richness rather than richness amongst European countries. The correlation can be
explained by a correlation of species richness and people with the factor of energy
availability, as temperature plays a big role for positive correlations. Variations in
temperature are concurrent with variations in human population size and in ant species
richness. Also, ant species richness could be correlated with plant species richness, as
was predicted.
Nirav Patel
2/22/11
Biogeography
6) The authors themselves state that they could not address with the available data the
issue of whether sampling effort might be positively related to human population size and
density. This sampling work is important in order to determine whether the correlation
persists due to this reason.
Nirav Patel
2/22/11
Biogeography
7.) Ultimately, this broad scale correlation of ant biodiversity and human population size
showed a positive finding, but the coexistence of high numbers of people and ant species
is a challenge in terms of a conservation perspective, as urbanization and human
disturbance results in problems with extinction and homogenization. The key is to
maintain biodiversity despite the need to live in our human modified landscapes.