Areas of endemism of Patagonian steppes: An approach based on insect distributional patterns.

M.C. DOMÍNGUEZ; ROIG JUÑENT, SERGIO; TASSIN, J.; OCAMPO, F.

Utha

Congreso; Entomological Society Annual Meetings; 2004

Entomological Society of America

<!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:1; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:0 0 0 0 0 0;} @font-face {font-family:Times; panose-1:2 2 6 3 5 4 5 2 3 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:536881799 0 0 0 511 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; text-autospace:none; font-size:12.0pt; font-family:"Times","serif"; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-ansi-language:EN-US;} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} .MsoPapDefault {mso-style-type:export-only; margin-bottom:10.0pt; line-height:115%;} @page WordSection1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.WordSection1 {page:WordSection1;} --> One of the most debated aspects in historical biogeography at the moment is the identification and delimitation of areas of endemism. The Patagonian Steppe constitutes the arid environment of the subantartic region, two other environments are present in this region: the Subantartic Woods and the Antartic Moorlands.  In this contribution, the Endemicity Analisys (EA), which evaluates areas of endemism by means of an endemicity index (ei) as performed with the NDM program (v.1.6), was applied in order to determine areas of endemism in the Patagonian Steppe. The distribution data of 159 species of insects collected in the Patagonian Steppe was used to identify areas of endemism. A matrix based on 1317 georeferenced data entries was constructed, for the presence or absence of the different taxa in a 1º x 1º quadrat grid of the region. Initially, two different types of Endemicity Analysis (EA) were performed seeking for areas defined by “four o more” species. The first of analysis was performed without taking into consideration those quadrats where no species have been recorded (empty quadrats) which in many cases meant a discontinuous distribution. The second analysis was performed assuming a continuous distribution for each species. In both analyses, EA recognized in the same five areas of endemism: Western, southwestern Payunia, northern Suabandean, southern Subandean, and Austral. A third analysis, assuming continuous distributions, was performed using “three” as the number of species necessary for an area to be identified as an area of endemism. The results of the third analysis allowed the identification of three more areas of endemism: northen Payunia, Chubutian, and Santacrucian. Some of these areas identified as a result of these analyses were defined in previous contributions. The areas known as Payunia and Subandean could be composed in fact by two different areas respectively.