<?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>0187-5779</journal-id>
<journal-title><![CDATA[Terra Latinoamericana]]></journal-title>
<abbrev-journal-title><![CDATA[Terra Latinoam]]></abbrev-journal-title>
<issn>0187-5779</issn>
<publisher>
<publisher-name><![CDATA[Sociedad Mexicana de la Ciencia del Suelo A.C.]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0187-57792019000400459</article-id>
<article-id pub-id-type="doi">10.28940/terra.v37i4.548</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Gas exchange and fluorescence of Brosimum alicastrum]]></article-title>
<article-title xml:lang="es"><![CDATA[El intercambio de gases y fluorescencia de Brosimum alicastrum]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Hernández-González]]></surname>
<given-names><![CDATA[Olivia]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Vergara-Yoisura]]></surname>
<given-names><![CDATA[Silvia]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Sulub-Tun]]></surname>
<given-names><![CDATA[Roger]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Castillo-Chuc]]></surname>
<given-names><![CDATA[José]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Larqué-Saavedra]]></surname>
<given-names><![CDATA[Alfonso]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad Intercultural Maya de Quintana Roo Departamento de Desarrollo Sostenible ]]></institution>
<addr-line><![CDATA[ Quintana Roo]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Centro de Investigación Científica de Yucatán, A. C. Banco de Germoplasma Unidad de Recursos Naturales]]></institution>
<addr-line><![CDATA[Mérida Yucatán]]></addr-line>
<country>México</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>12</month>
<year>2019</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>12</month>
<year>2019</year>
</pub-date>
<volume>37</volume>
<numero>4</numero>
<fpage>459</fpage>
<lpage>467</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S0187-57792019000400459&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S0187-57792019000400459&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S0187-57792019000400459&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[SUMMARY: Gas exchange measurements were taken with an infrared gas analyzer (IRGA) and chlorophyll fluorescence with a modulated amplitude pulse fluorimeter (Mini-PAM) on fully developed leaves of ramon (Brosimum alicastrum Swartz) a tropical rainforest tree, grown in its natural habitat as to collect basic information of its physiological behavior. Data showed that maximum fixation of CO2 was 5 µmol m-2 s-1, photosynthetic efficiency was 0.67 while the photosystem II was found to saturate at a photonic flux density (PFD) of 500 µmol at 15 h. A high correlation was found between photosynthesis and transpiration. Highest water use efficiency occurred after 15 hours at a temperature of 30 °C, while chlorophyll levels remained constant. This is a shade tolerant, plant species thus it was found that initiates the photosynthetic process with low levels of light, presenting a light compensation point of 24 µmol m-2 s-1. In a parallel study, the same variables were measured in two sets of individuals of the same specie collected from two distant localities but growth in pots in the open. Photosynthetic variables of this plant species data showed very similar patterns. The results obtained suggest that, during the daylight hours and at higher temperatures, this species can carry out photosynthesis with high water use efficiency. Based on the results, the conclusion is that this plant species can adapt to a diversity of environmental conditions.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[RESUMEN: Se realizaron mediciones de intercambio de gases con la ayuda de un analizador de gases en el infrarrojo (IRGA) y de fluorescencia de clorofilas con un fluorímetro de pulso de amplitud modulada (Mini-PAM) en hojas completamente desarrolladas del árbol del ramón (Brosimum alicastrum Swartz) en su hábitat natural para obtener información básica sobre su comportamiento fisiológico. Los resultados señalan que la máxima fijación de CO2 es de 5 µmol m-2 s-1, con una eficiencia fotosintética de 0.67 en tanto que el fotosistema II se satura con un flujo fotónico de 500 µmol a las 15 h. Se encontró una alta correlación entre fotosíntesis y transpiración. La máxima eficiencia fotosintética se detectó después de las 15 h a una temperatura de 30 °C, en tanto que los niveles de clorofila permanecieron constantes. Este árbol es una especie tolerante a la sombra por lo que el proceso de fotosíntesis se inicia a bajos niveles de luz, con un punto de compensación de luz a los 24 µmol m-2 s-1. En un estudio paralelo, las mismas variables fueron medidas en dos conjuntos de individuos de localidades muy distantes. Los patrones fotosintéticos fueron muy similares. Los resultados obtenidos sugieren que, durante el día a altas temperaturas, estos conjuntos desarrollan fotosíntesis con alta eficiencia de uso del agua. Basados en estos resultados se propone que esta especie puede adaptarse a diversas condiciones ambientales.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[photosynthesis]]></kwd>
<kwd lng="en"><![CDATA[ramon tree]]></kwd>
<kwd lng="en"><![CDATA[stomatal conductance]]></kwd>
<kwd lng="en"><![CDATA[tropical dry forest]]></kwd>
<kwd lng="en"><![CDATA[water use efficiency]]></kwd>
<kwd lng="es"><![CDATA[fotosíntesis]]></kwd>
<kwd lng="es"><![CDATA[árbol de ramón]]></kwd>
<kwd lng="es"><![CDATA[conductancia estomática]]></kwd>
<kwd lng="es"><![CDATA[bosque tropical húmedo]]></kwd>
<kwd lng="es"><![CDATA[uso eficiente del agua]]></kwd>
</kwd-group>
</article-meta>
</front><back>
<ref-list>
<ref id="B1">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ayala]]></surname>
<given-names><![CDATA[S. A.]]></given-names>
</name>
<name>
<surname><![CDATA[Krihnamurthy]]></surname>
<given-names><![CDATA[L.]]></given-names>
</name>
<name>
<surname><![CDATA[Basulto]]></surname>
<given-names><![CDATA[G. J. A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Leguminosas de cobertera para mejorar y sostener la productividad de maíz en el sur de Yucatán]]></article-title>
<source><![CDATA[Terra Latinoamericana]]></source>
<year>2008</year>
<numero>27</numero>
<issue>27</issue>
<page-range>63-9</page-range></nlm-citation>
</ref>
<ref id="B2">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Björkman]]></surname>
<given-names><![CDATA[O.]]></given-names>
</name>
<name>
<surname><![CDATA[Demming]]></surname>
<given-names><![CDATA[B.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Photon yield of O2 evolution and chlorophyll fluorescence characteristics at 77 K among vascular plants of diverse origins]]></article-title>
<source><![CDATA[Planta]]></source>
<year>1987</year>
<numero>170</numero>
<issue>170</issue>
<page-range>489-504</page-range></nlm-citation>
</ref>
<ref id="B3">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Calderón A.]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
</person-group>
<source><![CDATA[La poda de árboles frutales]]></source>
<year>1975</year>
<publisher-loc><![CDATA[México, D. F. ]]></publisher-loc>
<publisher-name><![CDATA[Limusa]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B4">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Dang]]></surname>
<given-names><![CDATA[Q. L.]]></given-names>
</name>
<name>
<surname><![CDATA[Lieffers]]></surname>
<given-names><![CDATA[V. J.]]></given-names>
</name>
<name>
<surname><![CDATA[Rothwell]]></surname>
<given-names><![CDATA[R. L.]]></given-names>
</name>
<name>
<surname><![CDATA[Macdonald]]></surname>
<given-names><![CDATA[S. E.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Diurnal variation and interrelations of ecophysiological parameters in three peatland woody species under different weather and soil moisture conditions]]></article-title>
<source><![CDATA[Oecologia]]></source>
<year>1991</year>
<numero>88</numero>
<issue>88</issue>
<page-range>317-24</page-range></nlm-citation>
</ref>
<ref id="B5">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Donovan]]></surname>
<given-names><![CDATA[L. A.]]></given-names>
</name>
<name>
<surname><![CDATA[Ehleringer]]></surname>
<given-names><![CDATA[J. R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Ecophysiological differences among juvenile and reproductive plants of several woody species]]></article-title>
<source><![CDATA[Oecologia]]></source>
<year>1991</year>
<numero>86</numero>
<issue>86</issue>
<page-range>594-7</page-range></nlm-citation>
</ref>
<ref id="B6">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hernández-González]]></surname>
<given-names><![CDATA[O.]]></given-names>
</name>
<name>
<surname><![CDATA[Vergara-Yoisura]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
<name>
<surname><![CDATA[Larqué-Saavedra]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Primeras etapas de crecimiento de Brosimum alicastrum Sw. en Yucatán]]></article-title>
<source><![CDATA[Rev. Mex. Cienc. For.]]></source>
<year>2014</year>
<numero>6</numero>
<issue>6</issue>
<page-range>38-48</page-range></nlm-citation>
</ref>
<ref id="B7">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hoel]]></surname>
<given-names><![CDATA[B. O.]]></given-names>
</name>
<name>
<surname><![CDATA[Solhaug]]></surname>
<given-names><![CDATA[K. A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effect of irradiance on chlorophyll estimation with the Minolta SPAD-502 leaf Chlorophyll Meter]]></article-title>
<source><![CDATA[Ann. Bo.]]></source>
<year>1998</year>
<numero>82</numero>
<issue>82</issue>
<page-range>389-92</page-range></nlm-citation>
</ref>
<ref id="B8">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Koch]]></surname>
<given-names><![CDATA[G. W.]]></given-names>
</name>
<name>
<surname><![CDATA[Amthor]]></surname>
<given-names><![CDATA[J. S.]]></given-names>
</name>
<name>
<surname><![CDATA[Goulden]]></surname>
<given-names><![CDATA[M. L]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Diurnal patterns of leaf photosynthesis, conductance and water potential at the top of a lowland rain forest canopy in Cameroon: Measurements from the Radeau des Cimes]]></article-title>
<source><![CDATA[Tree Physiol.]]></source>
<year>1994</year>
<numero>14</numero>
<issue>14</issue>
<page-range>347-60</page-range></nlm-citation>
</ref>
<ref id="B9">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Langenheim]]></surname>
<given-names><![CDATA[J. H.]]></given-names>
</name>
<name>
<surname><![CDATA[Osmond]]></surname>
<given-names><![CDATA[C. B.]]></given-names>
</name>
<name>
<surname><![CDATA[Brooks]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Ferrar]]></surname>
<given-names><![CDATA[P. J.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Photosynthetic responses to light in seedlings of selected Amazonian and Australian rainforest tree species]]></article-title>
<source><![CDATA[Oecologia]]></source>
<year>1984</year>
<numero>63</numero>
<issue>63</issue>
<page-range>215-24</page-range></nlm-citation>
</ref>
<ref id="B10">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Montgomery]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Relative importance of photosynthetic physiology and biomass allocation for tree seedling growth across a broad light gradient]]></article-title>
<source><![CDATA[Tree Physiol.]]></source>
<year>2004</year>
<numero>24</numero>
<issue>24</issue>
<page-range>155-67</page-range></nlm-citation>
</ref>
<ref id="B11">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Montgomery]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
<name>
<surname><![CDATA[Chazdon]]></surname>
<given-names><![CDATA[R. L.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Light gradient partitioning by tropical tree seedlings in the absence of canopy gaps]]></article-title>
<source><![CDATA[Oecologia]]></source>
<year>2002</year>
<numero>131</numero>
<issue>131</issue>
<page-range>165-74</page-range></nlm-citation>
</ref>
<ref id="B12">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Mooney]]></surname>
<given-names><![CDATA[H. A.]]></given-names>
</name>
<name>
<surname><![CDATA[Gulmon]]></surname>
<given-names><![CDATA[S. L.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Constraints on leaf structure and function in reference to herbivory]]></article-title>
<source><![CDATA[Bioscience]]></source>
<year>1982</year>
<numero>32</numero>
<issue>32</issue>
<page-range>198-206</page-range></nlm-citation>
</ref>
<ref id="B13">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Navarro]]></surname>
<given-names><![CDATA[R. M.]]></given-names>
</name>
<name>
<surname><![CDATA[Maldonado-Rodríguez]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
<name>
<surname><![CDATA[Ariza]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Fluorescencia de la clorof ila en cinco procedencias de Pinus halepensis Mill y su respuesta a estrés hídrico]]></article-title>
<source><![CDATA[Cuad. Soc. Esp. Cien. For.]]></source>
<year>2004</year>
<numero>17</numero>
<issue>17</issue>
<page-range>69-74</page-range></nlm-citation>
</ref>
<ref id="B14">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Niinemets]]></surname>
<given-names><![CDATA[U.]]></given-names>
</name>
<name>
<surname><![CDATA[Cescatti]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Rodeghiero]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Tosens]]></surname>
<given-names><![CDATA[T.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Leaf internal diffusion conductance limits photosynthesis more strongly in older leaves of Mediterranean evergreen broad-leaved species]]></article-title>
<source><![CDATA[Plant, Cell Environ.]]></source>
<year>2005</year>
<numero>28</numero>
<issue>28</issue>
<page-range>1552-66</page-range></nlm-citation>
</ref>
<ref id="B15">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Oberbauer]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Plant water relations of selected species in wet and dry tropical lowland forests in Costa Rica]]></article-title>
<source><![CDATA[Rev. Biol. Trop.]]></source>
<year>1985</year>
<numero>33</numero>
<issue>33</issue>
<page-range>137-42</page-range></nlm-citation>
</ref>
<ref id="B16">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ögren]]></surname>
<given-names><![CDATA[E.]]></given-names>
</name>
<name>
<surname><![CDATA[Sundin]]></surname>
<given-names><![CDATA[U.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Photosynthetic responses to variable light: a comparison of species from contrasting habitats]]></article-title>
<source><![CDATA[Oecologia]]></source>
<year>1996</year>
<numero>106</numero>
<issue>106</issue>
<page-range>18-27</page-range></nlm-citation>
</ref>
<ref id="B17">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Querejeta]]></surname>
<given-names><![CDATA[J. I.]]></given-names>
</name>
<name>
<surname><![CDATA[Estrada-Medina]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
<name>
<surname><![CDATA[Allen]]></surname>
<given-names><![CDATA[M. F.]]></given-names>
</name>
<name>
<surname><![CDATA[Jiménez-Osornio]]></surname>
<given-names><![CDATA[J. J.]]></given-names>
</name>
<name>
<surname><![CDATA[Ruenes]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Utilization of bedrock water by Brosimum alicastrum trees growing on shallow soil atop limestone in a dry tropical climate]]></article-title>
<source><![CDATA[Plant Soil]]></source>
<year>2006</year>
<numero>287</numero>
<issue>287</issue>
<page-range>187-97</page-range></nlm-citation>
</ref>
<ref id="B18">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ramos]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
<name>
<surname><![CDATA[Grace]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The effects of shade on the gas exchange of seedlings of four tropical trees from Mexico]]></article-title>
<source><![CDATA[Funct. Ecol.]]></source>
<year>1990</year>
<page-range>667-77</page-range></nlm-citation>
</ref>
<ref id="B19">
<nlm-citation citation-type="">
<collab>StatSoft, Inc.</collab>
<source><![CDATA[Statistica]]></source>
<year>2004</year>
<publisher-loc><![CDATA[Tulsa, OK, USA ]]></publisher-loc>
</nlm-citation>
</ref>
<ref id="B20">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Strauss-Debenedetti]]></surname>
<given-names><![CDATA[S. I.]]></given-names>
</name>
<name>
<surname><![CDATA[Bazzaz]]></surname>
<given-names><![CDATA[F. A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Plasticity and acclimation to light in tropical Moraceae of different successional positions]]></article-title>
<source><![CDATA[Oecologia]]></source>
<year>1991</year>
<numero>87</numero>
<issue>87</issue>
<page-range>377-87</page-range></nlm-citation>
</ref>
<ref id="B21">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Thiele]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Krause]]></surname>
<given-names><![CDATA[G. H.]]></given-names>
</name>
<name>
<surname><![CDATA[Winter]]></surname>
<given-names><![CDATA[K.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[In situ study of photoinhibition of photosynthesis and xanthophyll cycle activity in plants growing in natural gaps of the tropical forest]]></article-title>
<source><![CDATA[Aust. J. Plant Physiol.]]></source>
<year>1998</year>
<numero>25</numero>
<issue>25</issue>
<page-range>189-95</page-range></nlm-citation>
</ref>
<ref id="B22">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Walters]]></surname>
<given-names><![CDATA[M. B.]]></given-names>
</name>
<name>
<surname><![CDATA[Reich]]></surname>
<given-names><![CDATA[P. B.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Low-light carbon balance and shade tolerance in the seedlings of woody plants: do winter deciduous and broad-leaved evergreen species differ?]]></article-title>
<source><![CDATA[New Phytol.]]></source>
<year>1999</year>
<numero>143</numero>
<issue>143</issue>
<page-range>143-54</page-range></nlm-citation>
</ref>
</ref-list>
</back>
</article>
