Dutch elm disease (DED) spread throughout the United States in the 20th century and resulted in mortality of many elm trees. In this study, bearing trees from Indiana's historical Public Land Survey (PLS) records were used to reconstruct species mingling, diameter differentiation, and competition indices of elm prior to the introduction of DED. Prior to DED spread, elm had an average species mingling index of 0.77, a diameter differentiation index of 0.36, and a competition index of 1.22. Forests where elm had significantly lower mingling indices occurred along rivers. Forests where elm had significantly lower diameter differentiation indices were located near the homeland of the Piankashaw Tribe, which later became the French settlement of Vincennes. Forests where elm had significantly higher diameter differentiation indices were in areas that experienced later settlement by Europeans. Competition indices for elm were regularly dispersed across the state with no significant spatial clustering. This study demonstrated the impact of physiography and human activities on the structure of elm prior to the spread of DED and documented the successful application of PLS records to provide an ecological baseline of elm prior to the introduction of a non-native pathogen. La maladie hollandaise de l'orme (MHO) s'est r & eacute;pandue aux & Eacute;tats-Unis au XXe si & eacute;cle, entra & icirc;nant la mortalit & eacute; de nombreux ormes. Dans cette & eacute;tude, des arbres rep & eacute;res des archives d'arpentage des terres publiques de l'Indiana ont & eacute;t & eacute; utilis & eacute;s pour reconstituer des indices de mixit & eacute; d'esp & eacute;ces, de diff & eacute;renciation des diam & eacute;tres et de comp & eacute;tition pour l'orme. Avant l'introduction de la MHO, l'orme avait un indice de mixit & eacute; moyen de 0,77, un indice de diff & eacute;renciation des diam & eacute;tres de 0,36 et un indice de comp & eacute;tition de 1,22. L'indice de mixit & eacute; & eacute;tait significativement plus faible dans les for & ecirc;ts ripariennes. L'indice de diff & eacute;renciation des diam & eacute;tres & eacute;tait significativement plus faible dans les for & ecirc;ts du territoire de la Nation Piankashaw, qui est plus tard devenu l'& eacute;tablissement fran & ccedil;ais de Vincennes. L'indice de diff & eacute;renciation des diam & eacute;tres & eacute;tait significativement plus & eacute;lev & eacute; dans les zones colonis & eacute;es plus tardivement par les Europ & eacute;ens. Aucun patron spatial particulier n'a & eacute;t & eacute; not & eacute; en ce qui concerne l'indice de comp & eacute;tition. Cette & eacute;tude a montr & eacute; les effets de la physiographie et des activit & eacute;s humaines sur la structure des peuplements d'orme avant l'introduction de la MHO, en plus de fournir un exemple d'utilisation des archives d'arpentage comme base de comparaison historique avant l'introduction d'un pathog & eacute;ne exotique.
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