In: New Research on Forest Ecology ISBN 1-60021-434-7 Editor: Archibald K. Scaggs, pp. 129-140 © 2007 Nova Science Publishers, Inc. Chapter 7 RELATIONSHIPS BETWEEN METABOLIZABLE ENERGY AND CHEMICAL P ARAMETERS FROM FOREST FRUITS USING A P ARALLEL GENETIC ALGORITHM WORLDWIDE MODEL D. Patón ∗ , A. Salvado and F. Venegas Ecology Unit. Faculty of Science. University of Extremadura. Avda. de Elvas s/n Badajoz, Spain ABSTRACT Metabolizable energy (ME) is a basic parameter in the analysis of the carrying capacity of forage resources. Nevertheless, its determination its costly in time in comparison to other chemical parameters usually used in Range Management studies, such as Crude Protein (CP), Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF), Acid Detergent Lignin (ADL), Crude Fat (CF), Carbohydrates (C) or Ashes (A). We propose a model based on Parallel Genetic Algorithms (PGAM) on worldwide data obtained in different media such as Internet, scientific data bases or different publications (journals, proceedings...). The PGAM model to determine ME is based on two parameters: C and CF with good estimations (r= 0.835, p < 0.001). This mathematical model can be used in carrying capacity studies to reduce the high cost of ME analysis in comparison to the cheaper cost of CF and C analysis. The fact that this model is based on a worldwide series of data demonstrates its applicability in a very wide context. Keywords: Parallel Genetic Algorithm; forest; fruits; energy.  E-mail: dpaton@unex.es. No part of this digital document may be reproduced, stored in a retrieval system or transmitted in any form or by any means. The publisher has taken reasonable care in the preparation of this digital document, but makes no expressed or implied warranty of any kind and assumes no responsibility for any errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of information contained herein. This digital document is sold with the clear understanding that the publisher is not engaged in rendering legal, medical or any other professional services.