<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0188-4611</journal-id>
<journal-title><![CDATA[Investigaciones geográficas]]></journal-title>
<abbrev-journal-title><![CDATA[Invest. Geog]]></abbrev-journal-title>
<issn>0188-4611</issn>
<publisher>
<publisher-name><![CDATA[Universidad Nacional Autónoma de México, Instituto de Geografía]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0188-46111999000100006</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Un método gráfico para la regionalización agroecológica de recursos naturales]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Ritter Ortiz]]></surname>
<given-names><![CDATA[Walter]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Guzmán Ruiz]]></surname>
<given-names><![CDATA[Sergio Antonio]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Estrada Betancourt]]></surname>
<given-names><![CDATA[Alfonso]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Universidad Nacional Autónoma de México Centro de Ciencias de la Atmósfera ]]></institution>
<addr-line><![CDATA[México D. F.]]></addr-line>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>04</month>
<year>1999</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>04</month>
<year>1999</year>
</pub-date>
<numero>38</numero>
<fpage>57</fpage>
<lpage>68</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S0188-46111999000100006&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S0188-46111999000100006&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S0188-46111999000100006&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[En este trabajo se usaron modelos empíricos de la productividad natural neta (B NN) anual para los diferentes ecosistemas, a partir de parámetros climáticos como temperatura, precipitación, evapotranspiración y los índices de aridez, Se calcula la estabilidad de la B NN anual de las diferentes zonas ecológicas, comparando los autovalores de la matriz comunitaria resultante de la interacción biológica con la varianza de la aleatoriedad ambiental climática (precipitación), lo cual permite establecer zonas agroecológicas de igual comportamiento. La sensibilidad de respuesta de los ecosistemas se deduce con un modelo teórico hamiltoniano, transformado a un problema estadístico.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[In order to acquire a practical methodology of great use for the B NN computation and its involved dynamics, that contains a large potentiality in the use of decisions for the continuity and optimization of natural resources as well as for the acquisition of the maximum sustained yield (MSY), we use the B NN annual empirical models for the different ecosystems from climatic parameters like: temperature, rainfall, evapotranspiration and aridity indexes. The stability of the annual B NN for different ecological environments by comparing the eigenvalues of the communitary matrix resultant from biological interaction with the variance of the climatic environmental randomness (precipitation) is also computed. The sensibility response of ecosystems is derived by a theoretical Hamiltonian model transformed to a statistical problem.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[Clasificación agroecológica]]></kwd>
<kwd lng="es"><![CDATA[productividad]]></kwd>
<kwd lng="es"><![CDATA[ecología geográfica]]></kwd>
<kwd lng="en"><![CDATA[Agroecological typology]]></kwd>
<kwd lng="en"><![CDATA[productivity]]></kwd>
<kwd lng="en"><![CDATA[ecological geography]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[  	    <p align="center"><font face="verdana" size="4"><b>Un m&eacute;todo gr&aacute;fico para la regionalizaci&oacute;n agroecol&oacute;gica de recursos naturales</b></font></p> 	    <p align="center">&nbsp;</p> 	    <p align="center"><font face="verdana" size="2"><b>Walter Ritter Ortiz* Sergio Antonio Guzm&aacute;n Ruiz** Alfonso Estrada Betancourt**</b></font></p>     <p align="justify">&nbsp;</p>     <p align="justify"><font face="verdana" size="2"><i>* Centro de Ciencias de la Atm&oacute;sfera, UNAM, Ciudad Universitaria, Coyoac&aacute;n 04510 M&eacute;xico, D. F. profesor visitante en la BUAP (Biolog&iacute;a) y UMAR (Posgrado). </i></font></p>     <p align="justify"><font face="verdana" size="2"><i>** Centro de Ciencias de la Atm&oacute;sfera, UNAM, Ciudad Universitaria, Coyoac&aacute;n 04510 M&eacute;xico, D. F. M&eacute;xico.</i></font></p>     <p align="justify">&nbsp;</p>     <p align="justify"><font face="verdana" size="2">Recibido: mayo 18, 1998    <br> </font><font face="verdana" size="2">Aceptado versi&oacute;n final: noviembre 23, 1998</font></p>     ]]></body>
<body><![CDATA[<p align="justify">&nbsp;</p>     <p align="justify"><font face="verdana" size="2"><b>Resumen</b></font></p>     <p align="justify"><font face="verdana" size="2">En este trabajo se usaron modelos emp&iacute;ricos de la productividad natural neta (B<sub>NN</sub>) anual para los diferentes ecosistemas, a partir de par&aacute;metros clim&aacute;ticos como temperatura, precipitaci&oacute;n, evapotranspiraci&oacute;n y los &iacute;ndices de aridez, Se calcula la estabilidad de la B<sub>NN </sub>anual de las diferentes zonas ecol&oacute;gicas, comparando los autovalores de la matriz comunitaria resultante de la interacci&oacute;n biol&oacute;gica con la varianza de la aleatoriedad ambiental clim&aacute;tica (precipitaci&oacute;n), lo cual permite establecer zonas agroecol&oacute;gicas de igual comportamiento. La sensibilidad de respuesta de los ecosistemas se deduce con un modelo te&oacute;rico hamiltoniano, transformado a un problema estad&iacute;stico.</font></p>      <p align="justify"><font face="verdana" size="2"><b>Palabras clave:</b> Clasificaci&oacute;n agroecol&oacute;gica, productividad, ecolog&iacute;a geogr&aacute;fica.</font></p>  	    <p align="justify">&nbsp;</p> 	    <p align="justify"><font face="verdana" size="2"><b>Abstract</b></font></p> 	    <p align="justify"><font face="verdana" size="2">In order to acquire a practical methodology ot great use for the B<sub>NN</sub> computation and its involved dynamics, that contains a large potentiality in the use of decisions for the continuity and optimization of natural resources as well as for the acquisition of the maximum sustained yield (MSY), we use the <i>B</i><sub>NN</sub> annual empirical models for the different ecosystems from climatic parameters like: temperature, rainfall, evapotranspiration and aridity indexes. The stability of the annual B<sub>NN</sub> for different ecological environments by comparing the eigenvalues of the communitary matrix resultant from biological interaction with the variance of the climatic environmental randomness (precipitation) is also computed. The sensibility response of ecosystems is derived by a theoretical Hamiltonian model transformed to a statistical problem.</font></p>      <p align="justify"><font face="verdana" size="2"><b>Key words:</b> Agroecological typology, productivity, ecological geography.</font></p>  	    <p align="justify">&nbsp;</p>     <p align="justify"><font face="verdana" size="2"><a href="/pdf/igeo/n38/n38a6.pdf" target="_blank">DESCARGAR ART&Iacute;CULO EN FORMATO PDF</a></font></p>     ]]></body>
<body><![CDATA[<p align="justify">&nbsp;</p>     <p align="justify"><b><font face="verdana" size="2">REFERENCIAS</font></b></p>     <!-- ref --><p align="justify"><font face="verdana" size="2">Budyko, J. I. (1974), <i>Climate and Life,</i> Academic Press, 508 p.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629444&pid=S0188-4611199900010000600001&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Cooper, J. P. (1975), <i>Photosynthesis and Productivity on different environments,</i> Cambridge University Press, London, 353 p.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629446&pid=S0188-4611199900010000600002&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Flores J., J. P. (1988). Determinaci&oacute;n de dosis de fertilizaci&oacute;n nitrogenada para ma&iacute;z y cebada en el estado de Tlaxcala mediante un modelo lineal simplificado, tesis de Maestr&iacute;a en Ciencias, Colegio de Posgraduados, Montecillos, Estado, de M&eacute;xico, 123 p.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629448&pid=S0188-4611199900010000600003&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Gell&#45;Mann, M. (1994), "The Quark and the Jaguar. Adventures in the Simple and the Complex", <i>Metatemas</i> 38, 413 p.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629450&pid=S0188-4611199900010000600004&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    ]]></body>
<body><![CDATA[<!-- ref --><p align="justify"><font face="verdana" size="2">Giorgi, F., y L. O. Mearns (1991), "Approaches to the simulation of regional climate change: A review", <i>Reviews of Geophysics,</i> 29(2):191&#45;216.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629452&pid=S0188-4611199900010000600005&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Kerner, E. H. (1957), "A statistical mechanics of interacting biological species", <i>Bull. Math. Biophys.,</i> 19, pp. 121&#45;146.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629454&pid=S0188-4611199900010000600006&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Kerner, E. H. (1959), "Further considerations on the statistical mechanics of biological associations", <i>Bull. Math. Biophys.,</i> 21, pp. 217&#45;225.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629456&pid=S0188-4611199900010000600007&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">03 Krebs, J. (1985), <i>Ecolog&iacute;a. Estudio de la distribuci&oacute;n y la abundancia,</i> Ed. Harla, M&eacute;xico, 753 p.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629458&pid=S0188-4611199900010000600008&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Kulshreshtha, S. N., (1993), "World Water Resourses and Regional Vulnerability: Impact of Future Changes, RR&#45;93&#45;10", International Institute for Applied Systems Analysis, Laxenburg, Austria.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629460&pid=S0188-4611199900010000600009&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    ]]></body>
<body><![CDATA[<!-- ref --><p align="justify"><font face="verdana" size="2">Leigh, E. G. (1965), "On the relation between the productivity, biomass, diversity, and stability of a community", <i>Zoology,</i> vol, 53, pp. 777&#45;783.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629462&pid=S0188-4611199900010000600010&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Leith, H. y E. Box (1972), "Evapotranspiration and Primary Productivity, C, W. Thornthwaite Memorial Model", in <i>Papers on Selected Topics in Climatology,</i> J. R. Mather, ed., Elmer, New York, 2:37&#45;44.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629464&pid=S0188-4611199900010000600011&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Leith, H. (1973), Primary Productivity in Ecosystems: Comparative Analysis of Global Patterns, <i>Unifying Concepts in Ecology,</i> pp. 67&#45;68,    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629466&pid=S0188-4611199900010000600012&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">May, R. M. (1973), <i>Stability and Complexity in Model Ecosystems,</i> Princeton, N. J., 235 p.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629468&pid=S0188-4611199900010000600013&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Ritter O., W., M. E. de Garay, y R. S. Guzm&aacute;n (1986), "Balance de radiaci&oacute;n y potenciales de productividad primarla en algunos ecosistemas terrestres de la Rep&uacute;blica Mexicana", <i>Geof. Int,.</i> vol. 25, n&uacute;m. 2, pp. 285&#45;314.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629470&pid=S0188-4611199900010000600014&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    ]]></body>
<body><![CDATA[<!-- ref --><p align="justify"><font face="verdana" size="2">Ritter O., W., A. Noguez e I. Rosas (1988), "Evaluaci&oacute;n del potencial de la estabilidad de la producci&oacute;n agr&iacute;cola con base en &iacute;ndices clim&aacute;ticos para algunas localidades de ia Rep&uacute;blica Mexicana", <i>Geof. Int.,</i> vol. 7, n&uacute;m. 2, pp. 263&#45;278.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629472&pid=S0188-4611199900010000600015&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Ritter O., W., R. S. Guzm&aacute;n y S. Zempoaltecatl (1991), "Duraci&oacute;n e intensidad de sequ&iacute;as en el estado de Tlaxcala y sus posibilidades de pron&oacute;stico", <i>V Congreso Nacional de Meteorolog&iacute;a,</i> 2&#45;4 oct./1991. Ciudad Ju&aacute;rez, Chihuahua.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629474&pid=S0188-4611199900010000600016&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Ritter O., W., A. P. Mosi&ntilde;o y  E. Buend&iacute;a (1995), Rainfall variability and predictability for agricultural purposes in Central Mexico.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629476&pid=S0188-4611199900010000600017&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Ritter O., W. (1996), Un modelo integral clima&#45;producci&oacute;n (aplicaciones en la optimizaci&oacute;n de ecosistemas naturales y agr&iacute;colas del estado de Tlaxcala), tesis de Doctorado en Biolog&iacute;a, Facultad de Ciencias, UNAM, M&eacute;xico, 159 p.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629478&pid=S0188-4611199900010000600018&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Rosenzweig, M. L. (1968), "Net Primary Productivity of Terrestrial Communities: Prediction from Climatological Data", <i>Am Nat.,</i> 102 (1923), pp. 67&#45;74.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629480&pid=S0188-4611199900010000600019&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    ]]></body>
<body><![CDATA[<!-- ref --><p align="justify"><font face="verdana" size="2">Stakhiv, E., (1993), "Water resources planning and management under climate uncertainty", in Ballentine, T. and E. Stakhiv (eds.). <i>Proceedings of conference on Climate Change and Water Resources Management,</i> US Army Institute for Water Resources, Fort Belvoir, VA, USA: IV/20&#45;IV/36.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629482&pid=S0188-4611199900010000600020&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Vander Meer, H. (1981), <i>Elementary mathematical ecology,</i> John Wiley &amp; Sons, 287 p.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629484&pid=S0188-4611199900010000600021&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>  	    <!-- ref --><p align="justify"><font face="verdana" size="2">Whittaker, R. H. (1975), <i>Communities and Ecosystems,</i> 2nd ed. MacMillan, New York, 162 p.    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=4629486&pid=S0188-4611199900010000600022&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --></font></p>      ]]></body><back>
<ref-list>
<ref id="B1">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Budyko]]></surname>
<given-names><![CDATA[J. I.]]></given-names>
</name>
</person-group>
<source><![CDATA[Climate and Life]]></source>
<year>1974</year>
<page-range>508</page-range><publisher-name><![CDATA[Academic Press]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B2">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Cooper]]></surname>
<given-names><![CDATA[J. P.]]></given-names>
</name>
</person-group>
<source><![CDATA[Photosynthesis and Productivity on different environments]]></source>
<year>1975</year>
<page-range>353</page-range><publisher-loc><![CDATA[London ]]></publisher-loc>
<publisher-name><![CDATA[Cambridge University Press]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B3">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Flores J.]]></surname>
<given-names><![CDATA[J. P.]]></given-names>
</name>
</person-group>
<source><![CDATA[Determinación de dosis de fertilización nitrogenada para maíz y cebada en el estado de Tlaxcala mediante un modelo lineal simplificado]]></source>
<year>1988</year>
<page-range>123</page-range></nlm-citation>
</ref>
<ref id="B4">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Gell-Mann]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
</person-group>
<article-title xml:lang="en"><![CDATA[The Quark and the Jaguar. Adventures in the Simple and the Complex]]></article-title>
<source><![CDATA[Metatemas]]></source>
<year>1994</year>
<volume>38</volume>
<page-range>413</page-range></nlm-citation>
</ref>
<ref id="B5">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Giorgi]]></surname>
<given-names><![CDATA[F.]]></given-names>
</name>
<name>
<surname><![CDATA[Mearns]]></surname>
<given-names><![CDATA[L. O.]]></given-names>
</name>
</person-group>
<article-title xml:lang="en"><![CDATA[Approaches to the simulation of regional climate change: A review]]></article-title>
<source><![CDATA[Reviews of Geophysics]]></source>
<year>1991</year>
<volume>29</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>191-216</page-range></nlm-citation>
</ref>
<ref id="B6">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Kerner]]></surname>
<given-names><![CDATA[E. H.]]></given-names>
</name>
</person-group>
<article-title xml:lang="en"><![CDATA[A statistical mechanics of interacting biological species]]></article-title>
<source><![CDATA[Bull. Math. Biophys]]></source>
<year>1957</year>
<volume>19</volume>
<page-range>121-146</page-range></nlm-citation>
</ref>
<ref id="B7">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Kerner]]></surname>
<given-names><![CDATA[E. H.]]></given-names>
</name>
</person-group>
<article-title xml:lang="en"><![CDATA[Further considerations on the statistical mechanics of biological associations]]></article-title>
<source><![CDATA[Bull. Math. Biophys.]]></source>
<year>1959</year>
<volume>21</volume>
<page-range>217-225</page-range></nlm-citation>
</ref>
<ref id="B8">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Krebs]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
</person-group>
<source><![CDATA[Ecología. Estudio de la distribución y la abundancia]]></source>
<year>1985</year>
<page-range>753</page-range><publisher-loc><![CDATA[México ]]></publisher-loc>
<publisher-name><![CDATA[Harla]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B9">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Kulshreshtha]]></surname>
<given-names><![CDATA[S. N.]]></given-names>
</name>
</person-group>
<source><![CDATA[World Water Resourses and Regional Vulnerability: Impact of Future Changes, RR-93-10]]></source>
<year>1993</year>
<publisher-loc><![CDATA[Laxenburg ]]></publisher-loc>
<publisher-name><![CDATA[International Institute for Applied Systems Analysis]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B10">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Leigh]]></surname>
<given-names><![CDATA[E. G.]]></given-names>
</name>
</person-group>
<article-title xml:lang="en"><![CDATA[On the relation between the productivity, biomass, diversity, and stability of a community]]></article-title>
<source><![CDATA[Zoology]]></source>
<year>1965</year>
<volume>53</volume>
<page-range>777-783</page-range></nlm-citation>
</ref>
<ref id="B11">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Leith]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
<name>
<surname><![CDATA[Box]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
</person-group>
<article-title xml:lang="en"><![CDATA[Evapotranspiration and Primary Productivity, C, W. Thornthwaite Memorial Model]]></article-title>
<person-group person-group-type="editor">
<name>
<surname><![CDATA[Mather]]></surname>
<given-names><![CDATA[J. R.]]></given-names>
</name>
</person-group>
<source><![CDATA[Papers on Selected Topics in Climatology]]></source>
<year>1972</year>
<volume>2</volume>
<page-range>37-44</page-range><publisher-loc><![CDATA[New York ]]></publisher-loc>
<publisher-name><![CDATA[Elmer]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B12">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Leith]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
</person-group>
<article-title xml:lang="en"><![CDATA[Primary Productivity in Ecosystems: Comparative Analysis of Global Patterns]]></article-title>
<source><![CDATA[Unifying Concepts in Ecology]]></source>
<year>1973</year>
<page-range>67-68</page-range></nlm-citation>
</ref>
<ref id="B13">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[May]]></surname>
<given-names><![CDATA[R. M.]]></given-names>
</name>
</person-group>
<source><![CDATA[Stability and Complexity in Model Ecosystems]]></source>
<year>1973</year>
<page-range>235</page-range><publisher-loc><![CDATA[Princeton^eN. J. N. J.]]></publisher-loc>
</nlm-citation>
</ref>
<ref id="B14">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ritter O.]]></surname>
<given-names><![CDATA[W.]]></given-names>
</name>
<name>
<surname><![CDATA[de Garay]]></surname>
<given-names><![CDATA[M. E.]]></given-names>
</name>
<name>
<surname><![CDATA[Guzmán]]></surname>
<given-names><![CDATA[R. S.]]></given-names>
</name>
</person-group>
<article-title xml:lang="es"><![CDATA[Balance de radiación y potenciales de productividad primarla en algunos ecosistemas terrestres de la República Mexicana]]></article-title>
<source><![CDATA[Geof. Int]]></source>
<year>1986</year>
<volume>25</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>285-314</page-range></nlm-citation>
</ref>
<ref id="B15">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ritter O.]]></surname>
<given-names><![CDATA[W.]]></given-names>
</name>
<name>
<surname><![CDATA[Noguez]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Rosas]]></surname>
<given-names><![CDATA[I.]]></given-names>
</name>
</person-group>
<article-title xml:lang="es"><![CDATA[Evaluación del potencial de la estabilidad de la producción agrícola con base en índices climáticos para algunas localidades de ia República Mexicana]]></article-title>
<source><![CDATA[Geof. Int.]]></source>
<year>1988</year>
<volume>7</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>263-278</page-range></nlm-citation>
</ref>
<ref id="B16">
<nlm-citation citation-type="confpro">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ritter O.]]></surname>
<given-names><![CDATA[W.]]></given-names>
</name>
<name>
<surname><![CDATA[Guzmán]]></surname>
<given-names><![CDATA[R. S.]]></given-names>
</name>
<name>
<surname><![CDATA[Zempoaltecatl]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
</person-group>
<article-title xml:lang="es"><![CDATA[Duración e intensidad de sequías en el estado de Tlaxcala y sus posibilidades de pronóstico]]></article-title>
<source><![CDATA[]]></source>
<year>1991</year>
<conf-name><![CDATA[V Congreso Nacional de Meteorología]]></conf-name>
<conf-date>2-4 oct./1991</conf-date>
<conf-loc>Ciudad Juárez Chihuahua</conf-loc>
</nlm-citation>
</ref>
<ref id="B17">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ritter O.]]></surname>
<given-names><![CDATA[W.]]></given-names>
</name>
<name>
<surname><![CDATA[Mosiño]]></surname>
<given-names><![CDATA[A. P.]]></given-names>
</name>
<name>
<surname><![CDATA[Buendía]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
</person-group>
<source><![CDATA[Rainfall variability and predictability for agricultural purposes in Central Mexico]]></source>
<year>1995</year>
</nlm-citation>
</ref>
<ref id="B18">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ritter O.]]></surname>
<given-names><![CDATA[W.]]></given-names>
</name>
</person-group>
<source><![CDATA[Un modelo integral clima-producción (aplicaciones en la optimización de ecosistemas naturales y agrícolas del estado de Tlaxcala)]]></source>
<year>1996</year>
<page-range>159</page-range></nlm-citation>
</ref>
<ref id="B19">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Rosenzweig]]></surname>
<given-names><![CDATA[M. L.]]></given-names>
</name>
</person-group>
<article-title xml:lang="en"><![CDATA[Net Primary Productivity of Terrestrial Communities: Prediction from Climatological Data]]></article-title>
<source><![CDATA[Am Nat.]]></source>
<year>1968</year>
<volume>102</volume>
<numero>1923</numero>
<issue>1923</issue>
<page-range>67-74</page-range></nlm-citation>
</ref>
<ref id="B20">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Stakhiv]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
</person-group>
<article-title xml:lang="en"><![CDATA[Water resources planning and management under climate uncertainty]]></article-title>
<person-group person-group-type="editor">
<name>
<surname><![CDATA[Ballentine]]></surname>
<given-names><![CDATA[T.]]></given-names>
</name>
<name>
<surname><![CDATA[Stakhiv]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
</person-group>
<source><![CDATA[Proceedings of conference on Climate Change and Water Resources Management]]></source>
<year>1993</year>
<publisher-loc><![CDATA[Fort Belvoir^eVA VA]]></publisher-loc>
<publisher-name><![CDATA[US Army Institute for Water Resources]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B21">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Vander Meer]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
</person-group>
<source><![CDATA[Elementary mathematical ecology]]></source>
<year>1981</year>
<page-range>287</page-range><publisher-name><![CDATA[Wiley]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B22">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Whittaker]]></surname>
<given-names><![CDATA[R. H.]]></given-names>
</name>
</person-group>
<source><![CDATA[Communities and Ecosystems]]></source>
<year>1975</year>
<edition>2</edition>
<page-range>162</page-range><publisher-loc><![CDATA[New York ]]></publisher-loc>
<publisher-name><![CDATA[MacMillan]]></publisher-name>
</nlm-citation>
</ref>
</ref-list>
</back>
</article>
