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'''Michael C. Wiemann y G. Bruce Williamson. 1988.''' Extreme radial changes in wood specific gravity in some tropical pioneers. Wood and Fiber Science, '''20'''(3), 1988, pp. 344-349{{ref|bruce}})<br> | '''Michael C. Wiemann y G. Bruce Williamson. 1988.''' Extreme radial changes in wood specific gravity in some tropical pioneers. Wood and Fiber Science, '''20'''(3), 1988, pp. 344-349{{ref|bruce}})<br> | ||
===Abstract=== | ===Abstract=== | ||
<small>(tomado del artículo)</small> | <small>(tomado del artículo)</small> | ||
Twelve ''[[Hampea appendiculata]]'', six ''[[Heliocarpus appendiculatus]]'', and twelve ''[[Ochroma pyramidale]]'' trees from tropical wet forest in Costa Rica were sampled across their radii. Wood from all three species increased linearly in specific gravity{{ref|density}},{{ref|valores}} from pith to bark. The magnitude of the increase was about 0.1 units of specific gravity per 10 cm of radius, although there were differences between the species and between trees within each species. All three species colonize clearings and disturbed sites, and these extreme changes in specific gravity may be associated with the pioneer habit in the wet forest.{{ref|referencias}} | Twelve ''[[Hampea appendiculata]]'', six ''[[Heliocarpus appendiculatus]]'', and twelve ''[[Ochroma pyramidale]]'' trees from tropical wet forest in Costa Rica were sampled across their radii. Wood from all three species increased linearly in specific gravity{{ref|density}},{{ref|valores}} from pith to bark. The magnitude of the increase was about 0.1 units of specific gravity per 10 cm of radius, although there were differences between the species and between trees within each species. All three species colonize clearings and disturbed sites, and these extreme changes in specific gravity may be associated with the pioneer habit in the wet forest.{{ref|referencias}} | ||
Véase también: | |||
# [[Richards, P. y G. B. Williamson. 1975.]] Treefalls and Patterns of Understory Species in a Wet Lowland Tropical Forest. Ecology | |||
# [[Cramer, J. M.; R. C. G. Mesquita; G. Bruce Williamson. 2007.]] Forest fragmentation differentially affects seed dispersal of large and small-seeded tropical trees. Biological Conservation. | |||
#[[Mesquita, R. C. G.; K. Ickes; G. Ganade; G. Bruce Williamson. 2001.]] Alternative successional pathways in the Amazon Basin. Journal of Ecology | |||
#[[Laurance, W. F.; G. Bruce Williamson, G. 2001.]] Positive feedbacks among forest fragmentation, drought, and climate change in the Amazon. | |||
#[[Laurance, William F.; G. Bruce Williamson; et al. 2011.]] The fate of Amazonian forest fragments: A 32-year investigation. Biological Conservation. | |||
#[[Wiemann, M.C.; G. Bruce Williamson. 2012.]] Testing a novel method to approximate wood specific gravity of trees. Forest Science. | |||
#[[Oyomoare Osazuwa-Peters; Amy E. Zanne. 2011.]] [http://prometheuswiki.org/tiki-index.php?page=Wood+density+protocol Wood density protocol.] Wood density is defined as mass of wood per unit volume. It is an important trait for understanding the function and ecology of woody species, as well as estimating stored biomass and carbon content (Chave et al. 2009). It is used as an indicator of wood quality and tissue allocation patterns and a predictor of plant performance. | |||
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<small> | <small> | ||
===Apostillas=== | ===Apostillas=== | ||
#{{notas|bruce}}. G.B. Williamson (PhD Indiana U, post doc en UofMichigan y Assistant Prof. at USFlorida) developed his doctoral diss. about the ecological significance of '''specific gravity of wood''' (or ''wood density'' expressed in g/cm<sup>3</sup>). The central points are:<br>– slow-growing spp accumulate more wood/unit time than fast-growing spp, thereby, have a higher wood density<br>– the ''average wood density of a forest'' (mean of spp abundance times wood density of each spp) reflects the age of the forest (if there is no selective logging). The higher the mean wood density the older the forest. <br>''∂<sub>k</sub>'' = (∑ ''∂<sub>i</sub>n<sub>i</sub>)/∑n<sub>i</sub>''<br>Where:<br>''∂<sub>k</sub>'' = mean density of the ''k<sub>th</sub>'' forest<br>''∂<sub>i</sub>'' = wood density of the ''i<sub>th</sub>'' species<br>''n<sub>i</sub>'' = abundance of the ''i<sub>th</sub>'' species<br>[[usuario:Lcgarcia|Luis Carlos García Lozano]] has a copy (paper) of Williamson's dissertation. It can be scanned or photocopied upon request. | #{{notas|bruce}}. G.B. Williamson (PhD Indiana U, post doc en UofMichigan y Assistant Prof. at USFlorida; currently Associate Professor, Louisiana State University) developed his doctoral diss. about the ecological significance of '''specific gravity of wood''' (or ''wood density'' expressed in g/cm<sup>3</sup>). The central points are:<br>– slow-growing spp accumulate more wood/unit time than fast-growing spp, thereby, have a higher wood density<br>– the ''average wood density of a forest'' (mean of spp abundance times wood density of each spp) reflects the age of the forest (if there is no selective logging). The higher the mean wood density the older the forest. <br>''∂<sub>k</sub>'' = (∑ ''∂<sub>i</sub>n<sub>i</sub>)/∑n<sub>i</sub>''<br>Where:<br>''∂<sub>k</sub>'' = mean density of the ''k<sub>th</sub>'' forest<br>''∂<sub>i</sub>'' = wood density of the ''i<sub>th</sub>'' species<br>''n<sub>i</sub>'' = abundance of the ''i<sub>th</sub>'' species<br>[[usuario:Lcgarcia|Luis Carlos García Lozano]] has a copy (paper) of Williamson's dissertation. It can be scanned or photocopied upon request. | ||
#{{notas|valores}}. Rather ample lists of wood density values compliled from the ecological lierature, can be seen in:<br>– [http://db.worldagroforestry.org ICRAF Database - Wood Density]<br>– [http://www.fao.org/docrep/w4095e/w4095e0c.htm Estimating Biomass and Biomass Change of Tropical Forests: a Primer. (FAO Forestry Paper - 134, 1997)]<br>– [https://www.google.com.co/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&ved=0ahUKEwi17pvL28PMAhWBmh4KHbvLDmwQFghLMAY&url=http%3A%2F%2Fwww.fs.fed.us%2Fglobal%2Fiitf%2Fpubs%2Fgtr_so088_1992.pdf&usg=AFQjCNHDGZ5X5wBavWHcaS9pAr-63b3DhA&sig2=b_eLfkiZ6wiZtgX2Wj0ajw&bvm=bv.121421273,d.dmo Wood Densities of Tropical Tree Species] | #{{notas|valores}}. Rather ample lists of wood density values compliled from the ecological lierature, can be seen in:<br>– [http://db.worldagroforestry.org ICRAF Database - Wood Density]<br>– [http://www.fao.org/docrep/w4095e/w4095e0c.htm Estimating Biomass and Biomass Change of Tropical Forests: a Primer. (FAO Forestry Paper - 134, 1997)]<br>– [https://www.google.com.co/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&ved=0ahUKEwi17pvL28PMAhWBmh4KHbvLDmwQFghLMAY&url=http%3A%2F%2Fwww.fs.fed.us%2Fglobal%2Fiitf%2Fpubs%2Fgtr_so088_1992.pdf&usg=AFQjCNHDGZ5X5wBavWHcaS9pAr-63b3DhA&sig2=b_eLfkiZ6wiZtgX2Wj0ajw&bvm=bv.121421273,d.dmo Wood Densities of Tropical Tree Species] | ||
#{{notas|density}}. Wood density is a specific property (a given sp of tree has a wood density value relatively constant accross the natural range of the sp); however, there is variance to this value: | #{{notas|density}}. Wood density is a specific property (a given sp of tree has a wood density value relatively constant accross the natural range of the sp); however, there is variance to this value: some of it is phenotypic (incomplete expression of genetically determined density), some ontogenic (younger individuals differ from older ones in terms of density) and also, in the case of the paper here cited, young wood differs from older wood (within the same individual). | ||
#{{notas|referencias}}. Besides the present paper, the basic references to Williamson's work are:<br>– Williamson, G. B. 1975. Pattern and | #{{notas|referencias}}. Besides the present paper, the basic references to Williamson's work are:<br>– Williamson, G. B. 1975. Pattern and seral composition in an old-growth beech-maple forest. Ecology '''56'''(3):727-731.<br>– Williamson, G. B. 1984. Gradients in wood specific gravity of trees. Bull. Torrey Bot. Club '''111'''(1):51-55. | ||
</small> | </small> | ||
Línea 17: | Línea 29: | ||
Department of Botany, Louisiana State University | Department of Botany, Louisiana State University | ||
Baton Rouge, LA 70803-1705 | Baton Rouge, LA 70803-1705 | ||
(Received July 1987)--> | (Received July 1987) | ||
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Year | |||
G. B. Williamson, M. C. Wiemann | |||
Journal: American Journal of Botany - AMER J BOT , vol. 97, no. 3, pp. 519-524, '''2010''' | |||
Age-Dependent Radial Increases in Wood Specific Gravity of Tropical Pioneers in Costa Rica (Citations: 2) | |||
G. Bruce Williamson, Michael C. Wiemann | |||
Journal: Biotropica , 2010 | |||
A note on amphibian decline in a central Amazonian lowland forest | |||
Jessica L. DeichmannG, G. Bruce Williamson, Albertina P. Lima, Warren D. Allmon | |||
The massive reductions in amphibian populations taking place across the globe are unprecedented in modern times. Within the Neotropics, the enigmatic decline of amphibians has been considered predominantly a montane phenomenon; however, recent evidence suggests amphibian and reptile populations in lowland forests in Central America are waning as well. Unfortunately, very little baseline data are available for conducting large scale ... | |||
Journal: Biodiversity and Conservation - BIODIVERS CONSERV , vol. 19, no. 12, pp. 3619-3627, 2010 | |||
Effects of Geomorphology and Primary Productivity on Amazonian Leaf Litter Herpetofauna: Effects of Productivity on Amazonian Herpetofauna | |||
Jessica L. Deichmann, Albertina P. Lima, G. Bruce Williamson | |||
Journal: Biotropica , pp. no-no, 2010 | |||
Anuran artifacts of preservation: 27 years later | |||
Jessica L. Deichmann, Jeff Boundy, G. Bruce Williamson | |||
Anuran artifacts of preservation: 27 years later. Measurements made on preserved anuran specimens are often used in studies of systematics, ecology and evolution. Here, we examine the effect of preservation on one of the most common measurement of frogs, snout-urostyle length (SUL). Preservation had significant effects on the SUL of 13 of the 14 species of North American frogs ... | |||
Published in 2009. | |||
Predicting Biomass from Snout–Vent Length in New World Frogs (Citations: 3) | |||
Jessica L. Deichmann, William E. Duellman, G. Bruce Williamson | |||
Journal: Journal of Herpetology - J HERPETOL , vol. 42, no. 2, pp. 238-245, 2008 | |||
A Dung Beetle Assemblage in an Urban Park in Louisiana (Citations: 1) | |||
Meghan G. Radtke, Chris E. Carlton, G. Bruce Williamson | |||
We examined the dynamics of a dung beetle community over the course of a year in a forested urban park in Baton Rouge, LA. Dung beetle volume per trap-day and abundance peaked during March and the months of August through November, with species richness highest during March. The subfamily Aphodiinae dominated the community during the cold months, and Scarabaeinae ... | |||
Journal: Southeastern Naturalist - SOUTHEAST NAT , vol. 7, no. 1, pp. 101-110, 2008 | |||
Forest fragment size effects on dung beetle communities? (Citations: 1) | |||
M. G. Radtke, C. R. V. da Fonseca, G. B. Williamson | |||
Journal: Biological Conservation - BIOL CONSERV , vol. 141, no. 3, pp. 613-614, 2008 | |||
Forest fragmentation differentially affects seed dispersal of large and small-seeded tropical trees (Citations: 19) | |||
Jennifer M. Cramer, Rita C. G. Mesquita, G. Bruce Williamson | |||
The responses of plant–animal interactions to forest fragmentation can vary. We hypothesized that large-seeded plant species would be more susceptible to forest fragmentation than small-seeded species because large-seeded species rely on a few, extinction prone dispersers. We compared seed dispersal of the large-seeded, mammal dispersed Duckeodendron cestroides and the small-seeded, avian dispersed Bocageopsis multiflora. ... | |||
Journal: Biological Conservation - BIOL CONSERV , vol. 137, no. 3, pp. 415-423, 2007 | |||
Forest Fragmentation Reduces Seed Dispersal of Duckeodendron cestroides, a Central Amazon Endemic (Citations: 9) | |||
Jennifer M. Cramer, Rita C. G. Mesquita, Tony Vizcarra Bentos, Barry Moser, G. Bruce Williamson | |||
Journal: Biotropica , vol. 39, no. 6, pp. 709-718, 2007 | |||
The Old and Young Amazon: Dung Beetle Biomass, Abundance, and Species Diversity (Citations: 2) | |||
M. G. Radtke, C. R. V. da Fonseca, G. B. Williamson | |||
Journal: Biotropica , vol. 39, no. 6, pp. 725-730, 2007 | |||
The distributions of howling monkeys ( Alouatta pigra and A. palliata ) in southeastern Mexico and Central America | |||
Amrei Baumgarten, G. Bruce Williamson | |||
We compared the distributions of Alouatta palliata and A. pigra in southeastern Mexico and Central America with geographic and ecological features to infer current barriers and ecological preferences. Distribution data were obtained from museum specimen localities, study sites, historic records and field surveys and integrated into digital elevation and ecosystem maps using GIS. A. pigra evidently occurs at a number ... | |||
Journal: Primates , vol. 48, no. 4, pp. 310-315, 2007 | |||
Distribution of the Black Howler Monkey ( Alouatta pigra ) and the Mantled Howler Monkey ( A . palliata ) in Their Contact Zone in Eastern Guatemala | |||
Amrei Baumgarten, G. Bruce Williamson | |||
Journal: Neotropical Primates , vol. 14, no. 1, pp. 11-18, 2007 | |||
Volume as a Predictor for Biomass: Equations for Neotropical Scarabaeidae (Citations: 1) | |||
M. G. Radtke, C. R. V. Da Fonseca, G. B. Williamson | |||
Journal: Annals of The Entomological Society of America - ANN ENTOMOL SOC AMER , vol. 99, no. 5, pp. 831-836, 2006 | |||
Environmental Correlates of Tree and Seedling–Sapling Distributions in a Mexican Tropical Dry Forest (Citations: 8) | |||
Yalma Luisa Vargas-Rodriguez, J. Antonio Vázquez-García, G. Bruce Williamson | |||
Bray and Curtis ordination was used to explore which environmental variables explained importance values and the presence–absence of tropical tree seedlings, saplings and adults in La Escondida-La Cabaña, Sierra de Manantlán, Jalisco, Mexico. The diameters of trees ≥2.5 cm DBH and the presence and height of seedlings and saplings were measured in nine 0.1 ha sites. Four matrice... | |||
Journal: Plant Ecology - PLANT ECOL , vol. 180, no. 1, pp. 117-134, 2005 | |||
Volume and Linear Measurements as Predictors of Dung Beetle (Coleoptera: Scarabaeidae) Biomass (Citations: 3) | |||
M. G. Radtke, G. B. Williamson | |||
Journal: Annals of The Entomological Society of America - ANN ENTOMOL SOC AMER , vol. 98, no. 4, pp. 548-551, 2005 | |||
Biotropica: Two for One... Join ATBC in 2003 for Two Years | |||
G. Bruce Williamson, Biotropica Curator | |||
Journal: Biotropica , vol. 35, no. 1, pp. 132-132, 2003 | |||
Biotropica: Two for One…Join ATBC in 2003 for Two Years | |||
G. Bruce Williamson | |||
Journal: Biotropica , vol. 35, no. 1, 2003 | |||
Mast fruiting and ENSO cycles - does the cue betray a cause? (Citations: 16) | |||
G. Bruce Williamson, Kalan Ickes | |||
Journal: Oikos , vol. 97, no. 3, pp. 459-461, 2002 | |||
Biotropica, A New Deal on Old Issues | |||
G. Bruce Williamson, Biotropica Curator | |||
Journal: Biotropica , vol. 34, no. 2, pp. 331-331, 2002 | |||
Biotropica, A New Deal on Old Issues | |||
G. Bruce Williamson | |||
Journal: Biotropica , vol. 34, no. 2, 2002 | |||
Positive Feedbacks among Forest Fragmentation, Drought, and Climate Change in the Amazon (Citations: 113) | |||
William F. Laurance, G. Bruce Williamson | |||
The Amazon basin is experiencing rapid forest loss and fragmentation. Fragmented forests are more prone than intact forests to periodic damage from El Niño-Southern Oscillation (ENSO) droughts, which cause elevated tree mortality, increased litterfall, shifts in plant phenology, and other ecological changes, especially near forest edges. Moreover, positive feedbacks among forest loss, fragmentation, fire, and regional climate change appear... | |||
Journal: Conservation Biology - CONSERV BIOL , vol. 15, no. 6, pp. 1529-1535, 2001 | |||
Alternative successional pathways in the Amazon Basin (Citations: 67) | |||
Rita C. G. Mesquita, Kalan Ickes, Gislene Ganade, G. Bruce Williamson | |||
Journal: Journal of Ecology - J ECOL , vol. 89, no. 4, pp. 528-537, 2001 | |||
Effects of a strong drought on Amazonian forest fragments and edges (Citations: 33) | |||
WILLIAM F. LAURANCE, G. BRUCE WILLIAMSON, PATRICIA DELAMÔNICA, ALEXANDRE OLIVEIRA, THOMAS E. LOVEJOY, CLAUDE GASCON, LUCIANO POHL | |||
Journal: Journal of Tropical Ecology - J TROP ECOL , vol. 17, no. 06, 2001 | |||
Amazonian Tree Mortality during the 1997 El Nino Drought (Citations: 70) | |||
G. Bruce Williamson, William F. Laurance, Alexandre A. Oliveira, Patricia Delamonica, Claude Gascon, Thomas E. Lovejoy, Luciano Pohl | |||
Abstract: In1997, the Amazon Basin experienced an exceptionally severe El Niño drought. We assessed ef- | |||
Journal: Conservation Biology - CONSERV BIOL , vol. 14, no. 5, pp. 1538-1542, 2000 | |||
Dispersal of Amazonian Trees: Hydrochory in Pentaclethra macroloda1 (Citations: 6) | |||
G. Bruce Williamson, Flivia Costa | |||
Journal: Biotropica , vol. 32, no. 3, pp. 548-552, 2000 | |||
Dispersal of Amazonian Trees: Hydrochory in Pentaclethra macroloba1 | |||
G. Bruce Williamson, Flávia Costa | |||
Journal: Biotropica , vol. 32, no. 3, 2000 | |||
Dispersal of Amazonian Trees: Hydrochory in Swartzia polyphylla1 (Citations: 11) | |||
G. Bruce Williamson, Flavia Costa, Carolina V. Minte Vera | |||
Journal: Biotropica , vol. 31, no. 3, pp. 460-465, 1999 | |||
How many millenarians in Amazonia? Sizing the ages of large trees (Citations: 4) | |||
G. Bruce Williamson, Tim Van Eldik, Patricia Delamônica, William F Laurance | |||
Journal: Trends in Plant Science - TRENDS PLANT SCI , vol. 4, no. 10, pp. 387-387, 1999 | |||
Wood Specific Gravity and Anatomy in Heliocarpus appendiculatus (Tiliaceae) (Citations: 9) | |||
Suzanne S. McDonald, G. Bruce Williamson, Michael C. Wiemann | |||
Journal: American Journal of Botany - AMER J BOT , vol. 82, no. 7, 1995 | |||
Phylogenetic community structure during succession: Evidence from three Neotropical forest sites | |||
Susan G. Letcher, Robin L. Chazdon, Ana C. S. Andrade, Frans Bongers, Michiel van Breugel, Bryan Finegan, Susan G. Laurance, Rita C. G. Mesquita, Miguel Martínez-Ramos, G. Bruce Williamson | |||
The phylogenetic structure of communities can reveal forces shaping community assembly, but the vast majority of work on phylogenetic community structure has been conducted in mature ecosystems. Here, we present an analysis of the phylogenetic structure of three Neotropical rain forest communities undergoing succession. In each site, the net relatedness of the community is initially high and consistently declines during ... | |||
Journal: Perspectives in Plant Ecology Evolution and Systematics - PERSPECT PLANT ECOL EVOL SYST | |||
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Environmental gradients and the evolution of successional habitat specialization: a test case with 14 Neotropical forest sites. Journal of Ecology. Volume 103, Issue 5. September 2015, pp 1276–1290 | |||
Susan G. Letcher, Jesse R. Lasky, | |||
Robin L. Chazdon, | |||
Natalia Norden, | |||
S. Joseph Wright, | |||
Jorge A. Meave, | |||
Eduardo A. Pérez-García, | |||
Rodrigo Muñoz, | |||
Eunice Romero-Pérez, | |||
Ana Andrade, | |||
José Luis Andrade, | |||
Patricia Balvanera, | |||
Justin M. Becknell, | |||
Tony V. Bentos, | |||
Radika Bhaskar, | |||
Frans Bongers, | |||
Vanessa Boukili, | |||
Pedro H. S. Brancalion, | |||
Ricardo G. César, | |||
Deborah A. Clark, | |||
David B. Clark, | |||
Dylan Craven, | |||
Alexander DeFrancesco, | |||
Juan M. Dupuy, | |||
Bryan Finegan, | |||
Eugenio González-Jiménez, | |||
Jefferson S. Hall, | |||
Kyle E. Harms, | |||
José Luis Hernández-Stefanoni, | |||
Peter Hietz, | |||
Deborah Kennard, | |||
Timothy J. Killeen, | |||
Susan G. Laurance, | |||
Edwin E. Lebrija-Trejos, | |||
Madelon Lohbeck, | |||
Miguel Martínez-Ramos, | |||
Paulo E. S. Massoca, | |||
Rita C. G. Mesquita, | |||
Francisco Mora, | |||
Robert Muscarella, | |||
Horacio Paz, | |||
Fernando Pineda-García, | |||
Jennifer S. Powers, | |||
Ruperto Quesada-Monge, | |||
Ricardo R. Rodrigues, | |||
Manette E. Sandor, | |||
Lucía Sanaphre-Villanueva, | |||
Elisabeth Schüller, | |||
Nathan G. Swenson, | |||
Alejandra Tauro, | |||
María Uriarte, | |||
Michiel van Breugel, | |||
Orlando Vargas-Ramírez, | |||
Ricardo A. G. Viani, | |||
Amanda L. Wendt, | |||
G. Bruce Williamson | |||
First published: 29 June 2015Full publication history | |||
DOI: 10.1111/1365-2745.12435View/save citation | |||
Cited by: 2 articlesRefresh citation countCiting literature | |||
Article has an altmetric score of 9 | |||
Funding Information | |||
Summary | |||
Successional gradients are ubiquitous in nature, yet few studies have systematically examined the evolutionary origins of taxa that specialize at different successional stages. Here we quantify successional habitat specialization in Neotropical forest trees and evaluate its evolutionary lability along a precipitation gradient. Theoretically, successional habitat specialization should be more evolutionarily conserved in wet forests than in dry forests due to more extreme microenvironmental differentiation between early and late-successional stages in wet forest. | |||
We applied a robust multinomial classification model to samples of primary and secondary forest trees from 14 Neotropical lowland forest sites spanning a precipitation gradient from 788 to 4000 mm annual rainfall, identifying species that are old-growth specialists and secondary forest specialists in each site. We constructed phylogenies for the classified taxa at each site and for the entire set of classified taxa and tested whether successional habitat specialization is phylogenetically conserved. We further investigated differences in the functional traits of species specializing in secondary vs. old-growth forest along the precipitation gradient, expecting different trait associations with secondary forest specialists in wet vs. dry forests since water availability is more limiting in dry forests and light availability more limiting in wet forests. | |||
Successional habitat specialization is non-randomly distributed in the angiosperm phylogeny, with a tendency towards phylogenetic conservatism overall and a trend towards stronger conservatism in wet forests than in dry forests. However, the specialists come from all the major branches of the angiosperm phylogeny, and very few functional traits showed any consistent relationships with successional habitat specialization in either wet or dry forests. | |||
Synthesis. The niche conservatism evident in the habitat specialization of Neotropical trees suggests a role for radiation into different successional habitats in the evolution of species-rich genera, though the diversity of functional traits that lead to success in different successional habitats complicates analyses at the community scale. Examining the distribution of particular lineages with respect to successional gradients may provide more insight into the role of successional habitat specialization in the evolution of species-rich taxa. | |||
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Revisión actual - 06:41 25 abr 2018
Michael C. Wiemann y G. Bruce Williamson. 1988. Extreme radial changes in wood specific gravity in some tropical pioneers. Wood and Fiber Science, 20(3), 1988, pp. 344-349[1] )
Abstract
(tomado del artículo)
Twelve Hampea appendiculata, six Heliocarpus appendiculatus, and twelve Ochroma pyramidale trees from tropical wet forest in Costa Rica were sampled across their radii. Wood from all three species increased linearly in specific gravity[2] ,[3] from pith to bark. The magnitude of the increase was about 0.1 units of specific gravity per 10 cm of radius, although there were differences between the species and between trees within each species. All three species colonize clearings and disturbed sites, and these extreme changes in specific gravity may be associated with the pioneer habit in the wet forest.[4]
Véase también:
- Richards, P. y G. B. Williamson. 1975. Treefalls and Patterns of Understory Species in a Wet Lowland Tropical Forest. Ecology
- Cramer, J. M.; R. C. G. Mesquita; G. Bruce Williamson. 2007. Forest fragmentation differentially affects seed dispersal of large and small-seeded tropical trees. Biological Conservation.
- Mesquita, R. C. G.; K. Ickes; G. Ganade; G. Bruce Williamson. 2001. Alternative successional pathways in the Amazon Basin. Journal of Ecology
- Laurance, W. F.; G. Bruce Williamson, G. 2001. Positive feedbacks among forest fragmentation, drought, and climate change in the Amazon.
- Laurance, William F.; G. Bruce Williamson; et al. 2011. The fate of Amazonian forest fragments: A 32-year investigation. Biological Conservation.
- Wiemann, M.C.; G. Bruce Williamson. 2012. Testing a novel method to approximate wood specific gravity of trees. Forest Science.
- Oyomoare Osazuwa-Peters; Amy E. Zanne. 2011. Wood density protocol. Wood density is defined as mass of wood per unit volume. It is an important trait for understanding the function and ecology of woody species, as well as estimating stored biomass and carbon content (Chave et al. 2009). It is used as an indicator of wood quality and tissue allocation patterns and a predictor of plant performance.
Apostillas
- ^ . G.B. Williamson (PhD Indiana U, post doc en UofMichigan y Assistant Prof. at USFlorida; currently Associate Professor, Louisiana State University) developed his doctoral diss. about the ecological significance of specific gravity of wood (or wood density expressed in g/cm3). The central points are:
– slow-growing spp accumulate more wood/unit time than fast-growing spp, thereby, have a higher wood density
– the average wood density of a forest (mean of spp abundance times wood density of each spp) reflects the age of the forest (if there is no selective logging). The higher the mean wood density the older the forest.
∂k = (∑ ∂ini)/∑ni
Where:
∂k = mean density of the kth forest
∂i = wood density of the ith species
ni = abundance of the ith species
Luis Carlos García Lozano has a copy (paper) of Williamson's dissertation. It can be scanned or photocopied upon request. - ^ . Rather ample lists of wood density values compliled from the ecological lierature, can be seen in:
– ICRAF Database - Wood Density
– Estimating Biomass and Biomass Change of Tropical Forests: a Primer. (FAO Forestry Paper - 134, 1997)
– Wood Densities of Tropical Tree Species - ^ . Wood density is a specific property (a given sp of tree has a wood density value relatively constant accross the natural range of the sp); however, there is variance to this value: some of it is phenotypic (incomplete expression of genetically determined density), some ontogenic (younger individuals differ from older ones in terms of density) and also, in the case of the paper here cited, young wood differs from older wood (within the same individual).
- ^ . Besides the present paper, the basic references to Williamson's work are:
– Williamson, G. B. 1975. Pattern and seral composition in an old-growth beech-maple forest. Ecology 56(3):727-731.
– Williamson, G. B. 1984. Gradients in wood specific gravity of trees. Bull. Torrey Bot. Club 111(1):51-55.