Paul Jaccard

Paul Jaccard (born November 18, 1868 in Sainte-Croix VD ; † May 5, 1944 in Zurich ) was a Swiss high school teacher , botanist and plant physiologist .

Life

Origin, education and doctorate

Jaccard was born to Louis Samuel and Rose Elise Jaccard. At the age of 14 he lost his parents and was raised by an uncle who took care of his education. Jaccard attended college in Sainte-Croix. During his school days his natural history teacher and geologist Henri Golliez had a great influence on him. Already then he started a fossil collection . On a school trip in 1883 to the national exhibition in Zurich, he was enthusiastic about the geological collection of the Swiss Federal Polytechnic . He would have liked to study science , but had no money. From 1884 to 1887 he learned the teaching profession at the teacher training college in Lausanne and became a primary school teacher in Chexbres .

During his training Jaccard met the geologists Maurice Lugeon and Rittener and the botanist Louis Favrat (1827-1893) know. Together with Favrat he went on a botanical excursion to the Alps. Finally he managed to get a job as a preparator at the Botanical Museum of the Canton of Vaud in Lausanne. Now he was able to take his bachelor's degree alongside his full-time occupation at the museum . He overexerted himself and fell ill. After he recovered, he began studying at the University of Lausanne in 1889 . Just two years later, he obtained a degree in natural sciences. After graduating, he went to ETH Zurich, studied with Arnold Lang and Arnold Dodel-Port and received his doctorate in 1893 on the embryology of Ephedra helvetica .

job

After completing his studies and doctorate, Jaccard studied another semester in Paris with Gaston Bonnier . In 1894 he completed his habilitation in Lausanne on plant embryology and phytopalaeontology . Jaccard was then a natural history teacher at the secondary schools in Lausanne. As part of this activity, he wrote a natural science guide for elementary schools in Vaud and a “Manuel de Botanique” for secondary schools. In 1896 and 1897 he traveled to Munich for a short study visit to Karl von Goebel . He also went on a study trip to Sweden , Finland , Russia , the Caucasus and Turkestan with Émile Burnat . In 1903 Jaccard was appointed professor of general botany and plant physiology at the Swiss Federal Polytechnic in Zurich . He was the successor to Carl Eduard Cramer . His competitors were Carl Correns and Hans Conrad Schellenberg .

In Zurich, Jaccard mainly dealt with forestry. He founded an investigation center for microscopic wood assessment, put on a collection of wood samples and published on anatomical and physiological questions of the growth of trees. He received a prize from the Schnyder von Wartensee Foundation for his work on the growth of trees. During the semester break he went on botanical research trips to Egypt, Algeria, Morocco, England, USA, Sweden and Turkestan. In 1938 Jaccard retired.

research results

Jaccard tried from the amount of data and observations he had collected to derive laws about the growth and diversity of plant species depending on various factors such as location and climate. He defined various coefficients and formulated the observed relationships as laws. These laws and coefficients were repeatedly discussed controversially by later botanists and mathematicians, partly confirmed, partly refuted.

Set similarity

Jaccard defined a measure of the similarity between two sets. This measure of similarity ranges between 0, which is when the sets have no common elements, and 1, which is when the sets are identical. As a mathematical formula:

{\ displaystyle J (A, B) = {\ frac {| A \ cap B |} {| A \ cup B |}}}

.

This Jaccard coefficient was able to establish itself in mathematics and is used as a measure of similarity for sets, vectors and in general for objects. The Jaccard coefficient is used specifically for automatic text recognition and interpretation.

Jaccard himself developed this «Jaccard coefficient» in his paper Lois de distribution florale dans la zone alpine , published in 1902, on page 72. He called it «coefficient de communauté florale» (floristic community coefficient):

«The comparaison de deux associations déterminées par leur composition florale nous conduit à établir leur coefficient de communauté florale. Pour l'obtenir on procède de la façon suivante:

1. On commence par établir le nombre des espèces communes aux deux associations comparées,

2. on additionne le nombre des espèces de la première association avec le nombre des espèces de la seconde,

3. on soustrait de la somme obtenue le nombre des espèces communes aux deux associations et on obtient ainsi le nombre total des espèces existant sur les deux associations.

Pour obtenir le coefficient de communauté, il ne reste plus qu'a évaluer en% le rapport du nombre des espèces communes au nombre total des espèces.

Exemple: Deux prairies A et B possèdent, la première, 100 espèces, la seconde, 120 espèces; 60 espèces leur sont communes; elles possèdent ensemble 100 + 120 - 60 = 160 espèces distinctes: leur coefficient de communauté sera donc de

${\ displaystyle {\ frac {60} {160}} = 37 {\ tfrac {1} {2}} \%}$ »

“The comparison of two communities determined by their floral composition leads us to determine their floral community coefficient. To get it, do the following:

1. Determine the number of species in both communities,

2. the number of species in the first community is added to the number of species in the second community,

3. The number of species common to both communities is subtracted from this total, and the total number of species existing in both communities is obtained.

To obtain the community coefficient, calculate in% the ratio of the number of common species to the total number of species.

Example: Two meadows A and B, the first has 100 species, the second 120 species; They have 60 species in common; together they have 100 + 120 - 60 = 160 different species: their community coefficient is then

${\ displaystyle {\ frac {60} {160}} = 37 {\ tfrac {1} {2}} \%}$ "

- Paul Jaccard : Lois de distribution florale dans la zone alpine , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 38 (1902), p. 72, accessed online on November 23, 2018.

Generic coefficient

Jaccard defined the generic coefficient as a general measure of species diversity in an area: The generic coefficient of an area is the number of genera occurring in this area divided by the number of species occurring in this area.

{\ displaystyle generic coefficient = {\ frac {number of genera} {number of species}}}

.

If the generic coefficient is small, then the ecological diversity of the area is high; H. there is a variety of different types. Conversely, if the generic coefficient is large, then the biodiversity is low. In mathematical terms, one can also say: The generic coefficient is inversely proportional to species diversity.

In the literature, the species-to-genus ratio (S / G ratio) is also often used, which corresponds to the reciprocal of the generic coefficient:

{\ displaystyle types zuGattungenVerhaeltnis = {\ frac {1} {GenericCoefficient}} = {\ frac {number of types} {number of types}}}

.

If the species-to-genera ratio is high, then the ecological diversity of the area is high; H. there is a variety of different types. Conversely, if the species-to-genera ratio is small, then the species diversity is low. In mathematical terms, one can also say: The species-to-species ratio is proportional to species diversity.

Disputes

In Jaccard's time and later, there were repeated disputes about the generic coefficient, including with the Finnish botanist Alvar Palmgren and the Swiss botanist Arthur Maillefer . Maillefer claimed that the generic coefficient is by no means based on environmental factors, but rather arises from random effects ( null model ). He tried to prove this himself and with the help of the Hungarian mathematician George Pólya . Jaccard, in turn, cited various examples in which the statistical results of the null model did not agree with the generic coefficient.

Botanical laws

Jaccard postulated several laws with which he tried to express the influence of environmental factors on biodiversity:

1. The biodiversity of a given area is proportional to the diversity of its ecological conditions.
2. The similarity of the ecological conditions of two neighboring areas belonging to the same natural region is expressed by their community coefficient, but without any strict proportionality between the values of this coefficient and the ecological analogies observed .
3. Despite the physiognomic unity they show, the alpine pastures are composed of very different vegetation communities, even if the region is very small and shows great ecological uniformity.
4. The generic coefficient, i. H. the ratio of genera to species is inversely proportional to the diversity of ecological conditions in the region.
5. Given the same ecological conditions, the generic coefficient decreases with the extent of the region under consideration.
6. Under similar conditions, the islands' generic coefficient is greater than that of the closest mainland.
7. The generic coefficient increases with height.
8. The generic coefficient of dialypetals (= plants whose flowers have free-leaved, ungrown petals ) and that of gamopetals (= plants whose flowers have overgrown petals) as well as the generic coefficient of the compound family are very similar, often the same, to the generic Coefficients of the whole flora.
9. In the western regions of Europe, the generic coefficient increases with latitude and altitude.
10. In our regions, the number of common species decreases with altitude and the number of rare species increases, so that in the Alpine region the rare species are more numerous and the common species less common.

family

In 1899 Jaccard Adèle married Juliette Séchaud, daughter of Charles Henri.

Publications (selection)

Recherches embryologiques sur l'Ephédra helvetica CA Meyer , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 30 (1894), online
Un herbier de J.-J. Rousseau , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 30 (1894), online
Considérations critiques sur les bases du darwinisme appliquées au monde végétal , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 31 (1895), online
Note sur trois cas de tératologie végétale , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 32 (1896), online
Étude sur la flore du Vallon de Barberine , (with Amann, Jules), Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 32 (1896), online
Sur la présence des mêmes espèces végétales dans des stations dissemblables et sous des climats différents: étude critique de biologie végétale, spécialement des formations xérophiles des plantes , Bulletin de la Société Vaudoise des Sciences Naturelles, volume 33 (1897), online
La médecine végétale et les extraits végétaux dialysés , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 33 (1897), online
Les monstres dans le monde organique et les lois le la morphologie , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 34 (1898), online
Contribution auproblemème de l'immigration post-glaciaire de la flore alpine: étude comparative de la flore alpine du massif de Wildhorn, du haut bassin du Trient et de la haute vallée de Bagnes , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 36 (1900), online
Distribution de la flore alpine dans le Bassin des Dranses et dans quelques régions voisines , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 37 (1901), online
Plantae turkestanicae: herborisation dans le turkestan russe , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 37 (1901), online
Étude comparative de la distribution florale dans une portion des Alpes et du Jura , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 37 (1901), online
Lois de distribution florale dans la zone alpine , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 38 (1902), online
Nouvelles recherches sur la distribution florale , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 44 (1908), online
Anatomy and physiology: geotropisme, poids spécifique et structure anatomique des branches d'un frêne pleureur ("Fraxinus excelsior var. Pendula") , publications of the Geobotanical Institute Rübel in Zurich, volume 3 (1925), online
Comparative studies on the distribution of alpine flora in some regions of the western and eastern Alps , annual report of the Naturforschenden Gesellschaft Graubünden, volume 45 (1901–1902), online
Comment expliquer l'assimilation prématinale du carbone atmérique par les plantes vertes , reports of the Swiss Botanical Society = Bulletin de la Société Botanique Suisse, Volume 52 (1942), online
Distribution de la flore culminale dans le Jura méridional (communication préliminaire) , (with Aubert, Samuel), reports of the Swiss Botanical Society = Bulletin de la Société Botanique Suisse, Volume 12 (1902), online
Observations critiques concernant la théorie mécanique de l'accroissement en épaisseur des arbres , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 51 (1916-1917), online
Que pouvons-nous attendre de l'électroculture? , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 56 (1925-1929), online
Phytosociologie et phytodémographie , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 56 (1925-1929), online
Evolution morphologique de la flore et structure anatomique du bois , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 62 (1942-1945), online
Influence de la courbure des tiges sur leur croissance en épaisseur , Mémoires de la Société Vaudoise des Sciences Naturelles, Volume 2 (1924–1928), online
Le coefficient générique et le coefficient de communauté dans la flore marocaine , Mémoires de la Société Vaudoise des Sciences Naturelles, Volume 2 (1924–1928), online
La chorologie sélective et sa signification pour la sociologie végétale , Mémoires de la Société Vaudoise des Sciences Naturelles, Volume 1 (1922–1924), online
Coefficient générique réel et coefficient générique probable , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 61 (1940-1941), online
Cas particulier concernant le coefficient générique , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 60 (1937-1939), online
Influence réciproque du sol et de la végétation sur les variations de la flore , report on the Geobotanical Research Institute Rübel in Zurich, volume - (1938), online
Something about the Moroccan iron tree (Argania Sideroxylon) , Schweizerische Zeitschrift für Forstwesen = Swiss foresty journal = Journal forestier suisse, Volume 77 (1926), online
Effect of frost on leaf waste , Schweizerische Zeitschrift für Forstwesen = Swiss foresty journal = Journal forestier suisse, Volume 60 (1909), online
A fertile witch's broom on larch , Schweizerische Zeitschrift für Forstwesen = Swiss foresty journal = Journal forestier suisse, Volume 66 (1915), online
The mycorrhizas and their role in nourishing forest trees , Swiss journal for forestry = Swiss foresty journal = Journal forestier suisse, Volume 55 (1904), online
Fonctions physiologiques des éléments constitutifs du bois , Journal forestier suisse: organe de la Société Forestière Suisse, Volume 94 (1943), online
Sur le géotropisme du frêne pleureur , Journal forestier suisse: organe de la Société Forestière Suisse, Volume 76 (1925), online
Les dunes de Mogador et leur fixation , Journal forestier suisse: organe de la Société Forestière Suisse, Volume 77 (1926), online
De la représentation proportionnelle chez les plantes , Journal forestier suisse: organe de la Société Forestière Suisse, Volume 73 (1922), online
On the subject of parc national suisse du val Cluoza , Journal forestier suisse: organe de la Société Forestière Suisse, volume 61 (1910), online
Absorption radiculaire provoquée par le gel , Journal forestier suisse: organe de la Société Forestière Suisse, Volume 57 (1906), online
Des journées désastreuses , Journal forestier suisse: organe de la Société Forestière Suisse, Volume 59 (1908), online

Web links

Literature by and about Paul Jaccard in the catalog of the German National Library
obituary
Paul Jaccard: Comparative studies on the distribution of alpine flora in some regions of the western and eastern Alps , annual report of the Naturforschenden Gesellschaft Graubünden, volume 45 (1901-1902), online
George Pólya: A Probability Problem in Plant Sociology . Quarterly publication of the Natural Research Society in Zurich. 75, 1930, pp. 211-219. on-line
Arthur Maillefer: Les lois de Paul Jaccard , Mémoires de la Société Vaudoise des Sciences Naturelles, Volume 3 (1929-1930), online

Individual evidence

↑ ^a ^b ^c ^d ^e Martin Kurz: Paul Jaccard. In: Historical Lexicon of Switzerland . September 1, 2005 , accessed November 21, 2018 .
↑ ^a ^b ^c ^d ^e ^f ^g ^h Obituary during negotiations of the Swiss Natural Research Society. Volume 124 (1944). Retrieved November 21, 2018.
↑ Similarity measures for vectors at Fraunhofer. Retrieved November 23, 2018.
^ Jaccard coefficient in Hans Friedrich Eckey, Reinhold Kosfeld, Martina Rengers: Multivariate Statistics , Betriebswirtschaftlicher Verlag Dr. Th. Gabler GmbH, Wiesbaden, 2002, ISBN 3-409-11969-8 , p. 219. Accessed November 23, 2018.
↑ Jaccard coefficient in seo-suedwes. Retrieved November 23, 2018.
↑ Paul Jaccard: Comparative studies on the distribution of alpine flora in some regions of the western and eastern Alps , annual report of the Naturforschenden Gesellschaft Graubünden, volume 45 (1901–1902), p. 129, online
^ Paul Jaccard: Lois de distribution florale dans la zone alpine , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 38 (1902), p. 72, accessed online on November 23, 2018.
^ Paul Jaccard: The statistical-floristic method as the basis of plant sociology in the manual of biological working methods by E. Abderhalden, pp. 165–232, Berlin 1928.
^ Paul Jaccard: Le coefficient générique et le coefficient de communauté dans la flore marocaine , Mémoires de la Société Vaudoise des Sciences Naturelles, Volume 2 (1924–1928), accessed online on November 22, 2018.
↑ Alvar Palmgren: Chance and secular land elevation as plant-geographic factors in Societas pro Fauna er Flora Fennica, Acta Botanica Fennica, Helsingforsia, 1925, online
^ Pólya, G .: A probability problem in plant sociology . Quarterly publication of the Natural Research Society in Zurich. 75 (1930): pp. 211-219. Retrieved online on November 17, 2018.
↑ Arthur Maillefer: Le coefficient générique de P. Jaccard et sa signification , in Mémoires de la Société vaudoise des sciences naturelles, Société vaudoise des sciences naturelles, 1929, Volume 3, Issue 4 doi : 10.5169 / seals-249679
↑ Paul Jaccard: Coefficient générique réel et coefficient générique probable , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 61 (1940-1941), online Accessed November 22, 2018th
^ Paul Jaccard: Cas particulier concernant le coefficient générique , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 60 (1937–1939), accessed online on November 22, 2018.
^ Arthur Maillefer: Les lois de Paul Jaccard , Mémoires de la Société Vaudoise des Sciences Naturelles, Volume 3 (1929–1930), accessed online on November 22, 2018.
^ Paul Jaccard: Lois de distribution florale dans la zone alpine , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 38 (1902), accessed online on November 22, 2018.
^ Paul Jaccard: Influence réciproque du sol et de la végétation sur les variations de la flore , report on the Geobotanical Research Institute Rübel in Zurich, volume - (1938), accessed online on November 22, 2018.
^ Paul Jaccard: Les monstres dans le monde organique et les lois le la morphologie , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 34 (1898), accessed online on November 22, 2018.

personal data
SURNAME	Jaccard, Paul
BRIEF DESCRIPTION	Swiss high school teacher, botanist and plant physiologist
DATE OF BIRTH	November 18, 1868
PLACE OF BIRTH	Sainte-Croix VD
DATE OF DEATH	May 5, 1944
Place of death	Zurich

[VitaHLS-1] Martin Kurz: Paul Jaccard. In: Historical Lexicon of Switzerland . September 1, 2005 , accessed November 21, 2018 .

[Nachruf-2] ↑ ^a ^b ^c ^d ^e ^f ^g ^h Obituary during negotiations of the Swiss Natural Research Society. Volume 124 (1944). Retrieved November 21, 2018.

[3] Similarity measures for vectors at Fraunhofer. Retrieved November 23, 2018.

[4] Jaccard coefficient in Hans Friedrich Eckey, Reinhold Kosfeld, Martina Rengers: Multivariate Statistics , Betriebswirtschaftlicher Verlag Dr. Th. Gabler GmbH, Wiesbaden, 2002, ISBN 3-409-11969-8 , p. 219. Accessed November 23, 2018.

[5] Jaccard coefficient in seo-suedwes. Retrieved November 23, 2018.

[6] Paul Jaccard: Comparative studies on the distribution of alpine flora in some regions of the western and eastern Alps , annual report of the Naturforschenden Gesellschaft Graubünden, volume 45 (1901–1902), p. 129, online

[7] Paul Jaccard: Lois de distribution florale dans la zone alpine , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 38 (1902), p. 72, accessed online on November 23, 2018.

[8] Paul Jaccard: The statistical-floristic method as the basis of plant sociology in the manual of biological working methods by E. Abderhalden, pp. 165–232, Berlin 1928.

[9] Paul Jaccard: Le coefficient générique et le coefficient de communauté dans la flore marocaine , Mémoires de la Société Vaudoise des Sciences Naturelles, Volume 2 (1924–1928), accessed online on November 22, 2018.

[10] Alvar Palmgren: Chance and secular land elevation as plant-geographic factors in Societas pro Fauna er Flora Fennica, Acta Botanica Fennica, Helsingforsia, 1925, online

[11] Pólya, G .: A probability problem in plant sociology . Quarterly publication of the Natural Research Society in Zurich. 75 (1930): pp. 211-219. Retrieved online on November 17, 2018.

[12] Arthur Maillefer: Le coefficient générique de P. Jaccard et sa signification , in Mémoires de la Société vaudoise des sciences naturelles, Société vaudoise des sciences naturelles, 1929, Volume 3, Issue 4 doi : 10.5169 / seals-249679

[13] Paul Jaccard: Coefficient générique réel et coefficient générique probable , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 61 (1940-1941), online Accessed November 22, 2018th

[14] Paul Jaccard: Cas particulier concernant le coefficient générique , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 60 (1937–1939), accessed online on November 22, 2018.

[15] Arthur Maillefer: Les lois de Paul Jaccard , Mémoires de la Société Vaudoise des Sciences Naturelles, Volume 3 (1929–1930), accessed online on November 22, 2018.

[16] Paul Jaccard: Lois de distribution florale dans la zone alpine , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 38 (1902), accessed online on November 22, 2018.

[17] Paul Jaccard: Influence réciproque du sol et de la végétation sur les variations de la flore , report on the Geobotanical Research Institute Rübel in Zurich, volume - (1938), accessed online on November 22, 2018.

[18] Paul Jaccard: Les monstres dans le monde organique et les lois le la morphologie , Bulletin de la Société Vaudoise des Sciences Naturelles, Volume 34 (1898), accessed online on November 22, 2018.