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No. de sistema: 000022321

LDR _ _ 00000nam^^22^^^^^za^4500
008 _ _ 010111s2000^^^^mx^^^^^f^m^^^z000^0^spa^d
040 _ _ a| ECO
c| ECO
043 _ _ a| n-mx-cp
044 _ _ a| mx
084 _ _ a| TE/634.97
b| M4
100 1 _ a| Méndez Dewar, Guadalupe
c| Dra.
245 1 0 a| Contrastes espaciales de luz en claros, bordes y hábitats perturbados en Los Altos de Chiapas, México
c| Guadalupe Méndez Dewar
260 _ _ a| San Cristóbal de Las Casas, Chiapas, México
b| El Colegio de la Frontera Sur
c| 2000
300 _ _ a| 29 hojas
c| 28 centímetros
502 _ _ a| Tesis (Maestría en Ciencias en Recursos Naturales y Desarrollo Rural)--El Colegio de la Frontera Sur, 2000
504 _ _ a| Bibliografía (hojas 19-25)
520 1 _ a| We evaluated the light conditions of points in small gaps (64-175 m2) and in surrounding forested areas with hemispheric photographs, and its relationship with growth variables in 605 transplanted individuals (2.5 x 3.0 m from each other) of five native tree species: Almis acuminata, Cornus excelsa, Liquidambar styraciflua, Persea americana and Ouercus laurina. We assumed that spatial light contrasts between open and forested habitats have decreased with recent rising of disturbance levels. Plant performance variables were related (after 15 months) to direct sunlight (RDS) al the transplant point, and with spatial light contrast indices (LCl) constructed with RDS values in neighboring points. Positive contrasts included relatively highlight points surrounded by shaded areas; negative constrasts represented shaded points in the middle of more illuminated spots. Study plots showed a large heterogeneity of light enviromiients. Highest negative contrasts occurred when RDS < 15%; an asymptote (LCl = 0) was associated to canopy openings with RDS> 35%. Multiple linear regression indicated that RDS was related to shoot height of Liquidambar (P < 0.007) after removing the effect of their initial measurements. With only negative contrast points in the regression, height was related to RDS in Alnus (P < 0.05), Cornus (P < 0.045), and Liquidambar (P < 0.009), and stem diameter in Persea (P < 0.041). Basal stem diameter in Liquidambar (P < 0.039) and leaf size in Ouercus (P < 0.002) were explained by RDS under positive contrasts. Taller and thicker plants of Ouercus (P < 0.016) were related to high contrasts under high-light conditions.
520 1 _ a| The results indicate that plant performance may depend on relative conditions of the light environment in addition to point-level values. Further criteria and indicators of forest sustainability and functional classification of tree species may consider the heterogeneity of light environments as represented by spatial light contrasts.
538 _ _ a| Adobe Acrobat profesional 6.0 o superior
650 _ 4 a| Luz
650 _ 4 a| Árboles forestales
651 _ 4 a| Huixtán (Chiapas, México)
700 1 _ a| González Espinosa, Mario
d| 1950-
e| tutor
700 1 _ a| Quintana Ascencio, Pedro F.
d| 1959-
e| asesor
700 1 _ a| Castellanos Albores, Jorge
e| asesor
901 _ _ a| Maestría
905 _ _ a| Ecosur
905 _ _ a| CRIIS
905 _ _ a| Frosur
905 _ _ a| Biblioelectrónica
LNG spa
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Contrastes espaciales de luz en claros, bordes y hábitats perturbados en Los Altos de Chiapas, México / Guadalupe Méndez Dewar
Méndez Dewar, Guadalupe (autor)
González Espinosa, Mario, 1950- (tutor)
Quintana Ascencio, Pedro F., 1959- (asesor)
Castellanos Albores, Jorge (asesor)
Editor: San Cristóbal de Las Casas, Chiapas, México : El Colegio de la Frontera Sur, 2000
Descripción: 29 hojas ; 28 centímetros
Tesis: Tesis (Maestría en Ciencias en Recursos Naturales y Desarrollo Rural)--El Colegio de la Frontera Sur, 2000
Clasificación: TE/634.97/M4
Bibliotecas:
Campeche , Chetumal , San Cristóbal , Tapachula , Villahermosa
Nota: Bibliografía (hojas 19-25)
No. de sistema: 22321
Tipo: Tesis - Maestría
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Inglés

"We evaluated the light conditions of points in small gaps (64-175 m2) and in surrounding forested areas with hemispheric photographs, and its relationship with growth variables in 605 transplanted individuals (2.5 x 3.0 m from each other) of five native tree species: Almis acuminata, Cornus excelsa, Liquidambar styraciflua, Persea americana and Ouercus laurina. We assumed that spatial light contrasts between open and forested habitats have decreased with recent rising of disturbance levels. Plant performance variables were related (after 15 months) to direct sunlight (RDS) al the transplant point, and with spatial light contrast indices (LCl) constructed with RDS values in neighboring points. Positive contrasts included relatively highlight points surrounded by shaded areas; negative constrasts represented shaded points in the middle of more illuminated spots. Study plots showed a large heterogeneity of light enviromiients. Highest negative contrasts occurred when RDS < 15%; an asymptote (LCl = 0) was associated to canopy openings with RDS> 35%. Multiple linear regression indicated that RDS was related to shoot height of Liquidambar (P < 0.007) after removing the effect of their initial measurements. With only negative contrast points in the regression, height was related to RDS in Alnus (P < 0.05), Cornus (P < 0.045), and Liquidambar (P < 0.009), and stem diameter in Persea (P < 0.041). Basal stem diameter in Liquidambar (P < 0.039) and leaf size in Ouercus (P < 0.002) were explained by RDS under positive contrasts. Taller and thicker plants of Ouercus (P < 0.016) were related to high contrasts under high-light conditions."

"The results indicate that plant performance may depend on relative conditions of the light environment in addition to point-level values. Further criteria and indicators of forest sustainability and functional classification of tree species may consider the heterogeneity of light environments as represented by spatial light contrasts."

SIBE Campeche
Codigo de barra
Estado
Colección
ECO040001030
(Disponible)
Publicaciones ECOSUR
SIBE Chetumal
Codigo de barra
Estado
Colección
ECO030000378
(Disponible)
Publicaciones ECOSUR
SIBE San Cristóbal
Codigo de barra
Estado
Colección
ECO010016428
(Disponible)
Publicaciones ECOSUR
SIBE Tapachula
Codigo de barra
Estado
Colección
ECO020003065
(Disponible)
Publicaciones ECOSUR
SIBE Villahermosa
Codigo de barra
Estado
Colección
ECO050001402
(Disponible)
Publicaciones ECOSUR

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