Browsing by Autor "Todd S. Fredericksen"

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Alternative tree girdling and herbicide treatments for liberation and timber stand improvement in Bolivian tropical forests
(Elsevier BV, 2006) Calvin Ohlson-Kiehn; William Pariona; Todd S. Fredericksen
Beyond reduced-impact logging: Silvicultural treatments to increase growth rates of tropical trees
(Elsevier BV, 2008) Marielos Peña‐Claros; Todd S. Fredericksen; Alejandro Alarcón; Geoffrey M. Blate; U. Choque; Claudio Leaño; Juan Carlos Licona; Bonifacio Mostacedo; William Pariona; Z. Villegas
Comparative regeneration ecology of three leguminous timber species in a Bolivian tropical dry forest
(Springer Science+Business Media, 2000) Todd S. Fredericksen; Marcos Joaquín Justiniano; B. Mostacedo; Deborah Kennard; L. McDonald
Contributions of root and stump sprouts to natural regeneration of a logged tropical dry forest in Bolivia
(Elsevier BV, 2008) Bonifacio Mostacedo; Francis E. Putz; Todd S. Fredericksen; Armando Villca; Turian Palacios
Corrigendum to “Sustainability of timber harvesting in Bolivian tropical forests” [For. Ecol. Manage. 214 (2005) 294–304]
(Elsevier BV, 2006) Erhard Dauber; Todd S. Fredericksen; Marielos Peña‐Claros
Effect of skidder disturbance on commercial tree regeneration in logging gaps in a Bolivian tropical forest
(Elsevier BV, 2002) Todd S. Fredericksen; William Pariona
El uso de claros de aprovechamiento forestal por la avifauna de un bosque semideciduo chiquitano de Santa Cruz, Bolivia
(2002) Betty Flores; Damián I. Rumiz; Todd S. Fredericksen; Nell J. Fredericksen
Se realizó un estudio en un bosque seco o semideciduo chiquitano de la región de Lomerío, a un año de una extracción forestal selectiva de baja intensidad. Evaluamos la riqueza, diversidad, abundancia relativa y representación de gremios de aves (126 individuos de 32 especies) capturadas con redes de niebla en claros de extracción de dos tamaños y en sitios adyacentes sin extracción. La riqueza, abundancia y diversidad de especies mostraron una disminución consistente desde los claros grandes, a claros chicos y a sitios sin extracción, aunque las diferencias entre tratamientos no siempre fueron significativas. Los insectívoros Thamnophilus sticturus, Cnemotriccus fuscatus y Thryothorus guarayanus fueron las aves más frecuentes en los claros grandes, mientras que Thamnophilus sticturus, Sittasomus griseicapillus, Thryothorus guarayanus y Basileuterus culicivorus fueron las especies más capturadas en los claros chicos y en los sitios sin extracción. De ocho gremios examinados, sólo la abundancia de los insectívoros que capturan su presa en el aire fue mayor en los claros; los restantes gremios no presentaron diferencias significativas entre tratamientos. Las actividades de aprovechamiento forestal aparentemente no causaron fuertes impactos en la comunidad de aves en el área de estudio después de un año. Sin embargo, los cambios cualitativos podrían ser sutiles y pasar desapercibidos en este plazo, y ser notables solo después de muchos años.
Harvesting free-standing fig trees for timber in Bolivia: potential implications for forest management
(Elsevier BV, 1999) Todd S. Fredericksen; Damián I. Rumiz; Marcos Joaquı́n Justiniano Bravo; Rafael Agaupe Abacay
Invasion of Non-Commercial Tree Species After Selection Logging in a Bolivian Tropical Forest
(Taylor & Francis, 2000) Todd S. Fredericksen; Juan Carlos Licona
Abstract Single-tree selection logging will likely result in a 4.3% loss in the relative abundance and a 4.1% loss in basal area of trees of commercial species in one cutting cycle due to their removal by harvesting combined with their potential recolonization of only 31% of logging gaps in a Bolivian tropical dry forest. Densities of the most valuable species, Amburana cearensis and Cedrela fissilis, were particularly reduced by logging. To sustain the current harvesting rate, uses need to be developed for more non-commercial species and/or silvicul-tural treatments employed that increase regeneration of commercial species and remove non-commercial species using timber stand improvement techniques.
Natural regeneration and environmental relationships of tree species in logging gaps in a Bolivian tropical forest
(Elsevier BV, 2005) Andrew Park; M. Joaquin Justiniano; Todd S. Fredericksen
Natural regeneration and liberation of timber species in logging gaps in two Bolivian tropical forests
(Elsevier BV, 2003) William Pariona; Todd S. Fredericksen; Juan Carlos Licona
Phenology of Tree Species in Bolivian Dry Forests
(Wiley, 2000) Marcos Joaquín Justiniano; Todd S. Fredericksen
ABSTRACT Phenological characteristics of 453 individuals representing 39 tree species were investigated in two dry forests of the Lomerío region, Department of Santa Cruz, Bolivia. The leaf, flower, and fruit production of canopy and sub–canopy forest tree species were recorded monthly over a two–year period. Most canopy species lost their leaves during the dry season, whereas nearly all sub–canopy species retained their leaves. Peak leaf fall for canopy trees coincided with the peak of the dry season in July and August. Flushing of new leaves was complete by November in the early rainy season. Flowering and fruiting were bimodal, with a major peak occurring at the end of the dry season (August–October) and a minor peak during the rainy season (January). Fruit development was sufficiently long in this forest that fruiting peaks actually tended to precede flowering peaks by one month. A scarcity of fruit was observed in May, corresponding to the end of the rainy season. With the exception of figs ( Ficus ), most species had fairly synchronous fruit production. Most canopy trees had small, wind dispersed seeds or fruits that matured during the latter part of the dry season, whereas many sub–canopy tree species produced larger animal– or gravity–dispersed fruits that matured during the peak of the rainy season. Most species produced fruit annually. Lomerio received less rainfall than other tropical dry forests in which phenological studies have been conducted, but rainfall can be plentiful during the dry season in association with the passage of Antarctic cold fronts. Still, phenological patterns in Bolivian dry forests appear to be similar to those of other Neotropical dry forests.
Phenology of Tree Species in Bolivian Dry Forests1
(Wiley, 2000) Marcos Joaquín Justiniano; Todd S. Fredericksen
Phenological characteristics of 453 individuals representing 39 tree species were investigated in two dry forests of the Lomerío region, Department of Santa Cruz, Bolivia. The leaf, flower, and fruit production of canopy and sub-canopy forest tree species were recorded monthly over a two-year period. Most canopy species lost their leaves during the dry season, whereas nearly all sub-canopy species retained their leaves. Peak leaf fall for canopy trees coincided with the peak of the dry season in July and August. Flushing of new leaves was complete by November in the early rainy season. Flowering and fruiting were bimodal, with a major peak occurring at the end of the dry season (August–October) and a minor peak during the rainy season (January). Fruit development was sufficiently long in this forest that fruiting peaks actually tended to precede flowering peaks by one month. A scarcity of fruit was observed in May, corresponding to the end of the rainy season. With the exception of figs (Ficus), most species had fairly synchronous fruit production. Most canopy trees had small, wind dispersed seeds or fruits that matured during the latter part of the dry season, whereas many sub-canopy tree species produced larger animal- or gravity-dispersed fruits that matured during the peak of the rainy season. Most species produced fruit annually. Lomerío received less rainfall than other tropical dry forests in which phenological studies have been conducted, but rainfall can be plentiful during the dry season in association with the passage of Antarctic cold fronts. Still, phenological patterns in Bolivian dry forests appear to be similar to those of other Neotropical dry forests.
Post-fire tree regeneration in lowland Bolivia: implications for fire management
(Elsevier BV, 2002) Kevin Gould; Todd S. Fredericksen; F. J. Morales; Deborah Kennard; Francis E. Putz; Bonifacio Mostacedo; Marisol Toledo
Regeneration of commercial tree species following silvicultural treatments in a moist tropical forest
(Elsevier BV, 2007) Marielos Peña‐Claros; Edward M. Peters; M. Joaquin Justiniano; Frans Bongers; Geoffrey M. Blate; Todd S. Fredericksen; Francis E. Putz
Regeneration of timber species following selection logging in a Bolivian tropical dry forest
(Elsevier BV, 2000) Todd S. Fredericksen; Bonifacio Mostacedo
Regeneration status of important tropical forest tree species in Bolivia: assessment and recommendations
(Elsevier BV, 1999) Bonifacio Mostacedo C; Todd S. Fredericksen
Silvicultural intensification for tropical forest conservation
(Springer Science+Business Media, 2003) Todd S. Fredericksen; Francis E. Putz
Soil Effects on Forest Structure and Diversity in a Moist and a Dry Tropical Forest
(Wiley, 2011) Marielos Peña‐Claros; Lourens Poorter; Alfredo Alarcón; Geoffrey M. Blate; U. Choque; Todd S. Fredericksen; M. Joaquin Justiniano; Claudio Leaño; Juan Carlos Licona; William Pariona
ABSTRACT Soil characteristics are important drivers of variation in wet tropical forest structure and diversity, but few studies have evaluated these relationships in drier forest types. Using tree and soil data from 48 and 32 1 ha plots, respectively, in a Bolivian moist and dry forest, we asked how soil conditions affect forest structure and diversity within each of the two forest types. After correcting for spatial effects, soil‐vegetation relationships differed between the dry and the moist forest, being strongest in the dry forest. Furthermore, we hypothesized that soil nutrients would play a more important role in the moist forest than in the dry forest because vegetation in the moist forest is less constrained by water availability and thus can show its full potential response to soil fertility. However, contrary to our expectations, we found that soil fertility explained a larger number of forest variables in the dry forest (50 percent) than in the moist forest (17 percent). Shannon diversity declined with soil fertility at both sites, probably because the most dominant, shade‐tolerant species strongly increased in abundance as soil fertility increased.
Sustainability of timber harvesting in Bolivian tropical forests
(Elsevier BV, 2005) Erhard Dauber; Todd S. Fredericksen; M C Leiros de la Pena