Jenny, The Rucker Index is the numerical average of the tallest specimen of each of the top ten tallest species of tree on a site. Since this initial definition the term has been expanded to include a series of girth measurements made in the same way and an index of varying numbers of trees. Thus a RI5 has only five heights included, a RI20 has the heights of twenty trees included and so forth. There is an article in the Rucker Index published in: Bulletin of the Eastern Native Tree Society, Volume 3, Number 4, Fall 2008 http://www.nativetreesociety.org/bulletin/b3_4/B_ENTS_v03_04.pdf On the ENTS site is an entire section devoted to the Rucker Index: http://www.nativetreesociety.org/measure/index_measure.html There are discussions of other types of Rucker Indexes in the various individual posts. In May 2006 http://www.nativetreesociety.org/measure/rucker/to_rucker_or_not_to_rucker.htm I proposed a more formal structure for the notation of various types of indexes and this was again presented and updated in October 2008 http://www.nativetreesociety.org/measure/rucker/historical_rucker_index.htm These discussions should enable you to understand the ideas.
Ed Frank --~--~---------~--~----~------------~-------~--~----~ Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected] -~----------~----~----~----~------~----~------~--~---
