Paul Jaccard
Encyclopedia
Paul Jaccard was a professor of botany and plant physiology
at the ETH Zurich
. He studied at the University of Lausanne
and ETH Zurich
(PhD 1894). He continued studies in Paris
with Gaston Bonnier
.
He developed the Jaccard index
of similarity (he called it coefficient de communauté) and published it in 1901.
He also introduced the use of the species-to-genus ratio (he called it generic coefficient) in biogeography
. In the 1920'es, Paul Jaccard engaged himself in a dispute with the Finnish
botanist and phytogeographer
Alvar Palmgren
over the interpretation of species-to-genus ratio, as evidence of competitive exclusion (as held by Jaccard) or attributable to random sampling (as held by Palmgren
).
Plant physiology
Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Closely related fields include plant morphology , plant ecology , phytochemistry , cell biology, and molecular biology.Fundamental processes such as photosynthesis, respiration, plant nutrition,...
at the ETH Zurich
ETH Zurich
The Swiss Federal Institute of Technology Zurich or ETH Zürich is an engineering, science, technology, mathematics and management university in the City of Zurich, Switzerland....
. He studied at the University of Lausanne
University of Lausanne
The University of Lausanne in Lausanne, Switzerland was founded in 1537 as a school of theology, before being made a university in 1890. Today about 12,000 students and 2200 researchers study and work at the university...
and ETH Zurich
ETH Zurich
The Swiss Federal Institute of Technology Zurich or ETH Zürich is an engineering, science, technology, mathematics and management university in the City of Zurich, Switzerland....
(PhD 1894). He continued studies in Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
with Gaston Bonnier
Gaston Bonnier
Gaston Eugène Marie Bonnier was a French botanist and plant ecologist. Bonnier first studied at École Normale Supérieure in Paris from 1873 to 1876. Together with Charles Flahault, he studied at Uppsala University in 1878...
.
He developed the Jaccard index
Jaccard index
The Jaccard index, also known as the Jaccard similarity coefficient , is a statistic used for comparing the similarity and diversity of sample sets....
of similarity (he called it coefficient de communauté) and published it in 1901.
He also introduced the use of the species-to-genus ratio (he called it generic coefficient) in biogeography
Biogeography
Biogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...
. In the 1920'es, Paul Jaccard engaged himself in a dispute with the Finnish
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...
botanist and phytogeographer
Phytogeography
Phytogeography , also called geobotany, is the branch of biogeography that is concerned with the geographic distribution of plant species...
Alvar Palmgren
Alvar Palmgren
Alvar Palmgren was a Finnish botanist and plant ecologist.Palmgren studied botany at the University of Helsinki under professor J.P. Norrlin. He graduated in 1906 and obtained his Ph.D. in 1914...
over the interpretation of species-to-genus ratio, as evidence of competitive exclusion (as held by Jaccard) or attributable to random sampling (as held by Palmgren
Alvar Palmgren
Alvar Palmgren was a Finnish botanist and plant ecologist.Palmgren studied botany at the University of Helsinki under professor J.P. Norrlin. He graduated in 1906 and obtained his Ph.D. in 1914...
).