Tropical rainforests are among the most complex and diverse ecosystems, composed of a mosaic of shady understory under the closed canopy and tree-fall gaps of varying sizes and age. The light reaching the forest floor favors the recruitment of fast growing plant species and provide food resources for other animal species including butterflies. The Nymphalidae are the most species rich butterfly family in the tropics, and are ideal bioindicators. We investigated the effect of the tree-fall gaps on the assemblages of fruit feeding Nymphalidae. We used fruit-bait traps in 15 tree-fall gaps from 100 to 1000 m2 and 15 in undisturbed understory, from July until November, in a lowland tropical rainforest in southeastern Peru. We found distinct differences in butterfly assemblages between tree-fall gaps and understory, with a higher number of species in gaps, associated with a higher level light. We identified several species mostly found in one of the habitats, and generalist species. The heterogeneity was large within the same site both in gaps and in the understory. The difference between butterfly assemblages increased with gap size. Butterfly species were mainly associated with the absence of vines in the gaps, and found in large and light gaps. We distinguished several species according to their preferences for the vegetation structure, light level and size of gaps. We concluded that one example that maintains the biodiversity in the tropical rainforest is the formation of tree fall gaps of different sizes resulting in different species assemblages.

A Baixada Santista encontra-se na região central do litoral de São Paulo (23o55\'S). É um típico ambiente costeiro tropical dominado por extensos manguezais. Entretanto, o sistema vem sofrendo intenso processo de alteração ambiental devido a atividades industriais e portuárias, além da ausência de planejamento urbano. O presente estudo foi realizado em bosques de mangue na Ilha Barnabé, onde ocorreu derramamento e combustão de produto químico (diciclopentadieno - DCPD), em 1998. A fim de avaliar o grau de perturbação e os processos regenerativos dos bosques de mangue foram caracterizadas a estrutural vegetal, área foliar, microtopografia e produção de serapilheira, durante 25 meses, entre fevereiro de 2002 e a fevereiro de 2004. As características estruturais mostraram mortalidade e formação de clareiras seguidas de regeneração. Também foram observadas deformidades foliares e erosão como conseqüência do evento. A produção de serapilheira sugere certa desordem funcional no sistema. A metodologia utilizada mostrou-se adequada como ferramenta para avaliação de impactos em bosques de mangue. Sugere-se monitoramento de longo prazo nas áreas de manguezal impactadas para melhor compreensão dos efeitos de tensores naturais e/ou induzidos pelo homem. / The Baixada Santista and Santos Estuary are located in the central portion of the São Paulo State coastline (23º55\'S). It is a typical tropical coastal environment dominated by extensive mangroves areas despite the intensive harbor and heavy industrial activities, and their location within a continually evolving human landscape. The present study was developed in a mangrove area at Barnabé Island (Santos Estuary), a site impacted in 1998 by a DCPD (dicyclopentadiene) spill that was followed by a fire. In order to assess residual impacts, and to describe natural restoration processes, leaf area, microtopography, and litter fall during the 25 months period from February 2002 to February 2004 was monitored. Structural changes included gap formation due to mangrove tree mortality and partial regeneration. Leaf deformities were observed as well as accelerated coastal erosion due to the loss of the mangrove fringe. Litter fall production suggests a systemic level functional impairment. The methodology used appears adequate to describe and assess the level of impact and recovery pattern of a mangrove stand affected by a chemical spill. It is suggested that more extensive (long-term) monitoring studies on impacted mangroves must be developed as effective tools helping to understand the response of systems exposed to natural or human-induced stressors.

A Baixada Santista encontra-se na região central do litoral de São Paulo (23o55\'S). É um típico ambiente costeiro tropical dominado por extensos manguezais. Entretanto, o sistema vem sofrendo intenso processo de alteração ambiental devido a atividades industriais e portuárias, além da ausência de planejamento urbano. O presente estudo foi realizado em bosques de mangue na Ilha Barnabé, onde ocorreu derramamento e combustão de produto químico (diciclopentadieno - DCPD), em 1998. A fim de avaliar o grau de perturbação e os processos regenerativos dos bosques de mangue foram caracterizadas a estrutural vegetal, área foliar, microtopografia e produção de serapilheira, durante 25 meses, entre fevereiro de 2002 e a fevereiro de 2004. As características estruturais mostraram mortalidade e formação de clareiras seguidas de regeneração. Também foram observadas deformidades foliares e erosão como conseqüência do evento. A produção de serapilheira sugere certa desordem funcional no sistema. A metodologia utilizada mostrou-se adequada como ferramenta para avaliação de impactos em bosques de mangue. Sugere-se monitoramento de longo prazo nas áreas de manguezal impactadas para melhor compreensão dos efeitos de tensores naturais e/ou induzidos pelo homem. / The Baixada Santista and Santos Estuary are located in the central portion of the São Paulo State coastline (23º55\'S). It is a typical tropical coastal environment dominated by extensive mangroves areas despite the intensive harbor and heavy industrial activities, and their location within a continually evolving human landscape. The present study was developed in a mangrove area at Barnabé Island (Santos Estuary), a site impacted in 1998 by a DCPD (dicyclopentadiene) spill that was followed by a fire. In order to assess residual impacts, and to describe natural restoration processes, leaf area, microtopography, and litter fall during the 25 months period from February 2002 to February 2004 was monitored. Structural changes included gap formation due to mangrove tree mortality and partial regeneration. Leaf deformities were observed as well as accelerated coastal erosion due to the loss of the mangrove fringe. Litter fall production suggests a systemic level functional impairment. The methodology used appears adequate to describe and assess the level of impact and recovery pattern of a mangrove stand affected by a chemical spill. It is suggested that more extensive (long-term) monitoring studies on impacted mangroves must be developed as effective tools helping to understand the response of systems exposed to natural or human-induced stressors.

Gap dynamics theory proposes that forest canopy gaps provide the high light levels needed for regeneration. Little attention has been given to more gradual alternatives; however, recent studies have demonstrated declines in within-crown leaf area index with tree size in temperate forest trees. Our project builds on this previous research by assessing the prevalence of this age-related crown thinning phenomenon. We quantified crown openness for 18 dominant tree species in temperate and tropical forests (n = 1786 trees). Separate pooled groupings of tropical and temperate species showed significantly positive relationships between openness and DBH (p<0.001). Of the 9 sampled species showing positive relationships, significance (p< 0.05) was detected in 3 out of 10 tropical species and 1 out of 8 temperate species. Two temperate species showed significantly reduced canopy openness with size. These trends highlight the role that very large trees play in influencing light availability for understorey regeneration.

Gap dynamics theory proposes that forest canopy gaps provide the high light levels needed for regeneration. Little attention has been given to more gradual alternatives; however, recent studies have demonstrated declines in within-crown leaf area index with tree size in temperate forest trees. Our project builds on this previous research by assessing the prevalence of this age-related crown thinning phenomenon. We quantified crown openness for 18 dominant tree species in temperate and tropical forests (n = 1786 trees). Separate pooled groupings of tropical and temperate species showed significantly positive relationships between openness and DBH (p<0.001). Of the 9 sampled species showing positive relationships, significance (p< 0.05) was detected in 3 out of 10 tropical species and 1 out of 8 temperate species. Two temperate species showed significantly reduced canopy openness with size. These trends highlight the role that very large trees play in influencing light availability for understorey regeneration.

Rainforest is a dynamic ecosystem where species are affected by numerous biotic and abiotic factors. One important abiotic factor for many species is the availability of sunlight. The understory habitat under the closed undisturbed canopy is comparably constant with regard to sunlight and therefore also humidity and temperature. The canopy regulates the amount of sunlight that will reach the ground, which means that changes in canopy cover will change the understory environment. The main natural disturbances that affect the structure of rainforest are tree falls, that resulting in tree-fall gaps. The aim of this study was to compare the vertical stratification and species composition of fruit-feeding Nymphalidae butterflies between tree-fall gaps of different sizes and undisturbed understory in a primary rainforest in Madidi National Park, Bolivia. Fruit-baited traps were suspended at ground level (2 m) and in canopy (10-15 m) in 5 tree-fall gaps and adjacent undisturbed understory, a total of 40 traps. There were more species rich assemblages in gaps both at ground level and in canopy, compared to understory. The data show that there are different species assemblages in tree-fall gaps, undisturbed understory, canopy and at ground level. The vegetation structure affected by the amount of sun light was an important factor affecting butterfly assemblages. There was a tendency that differences among gap assemblages increased with gap size. These results indicate the importance of the mosaic pattern caused by natural tree-fall gaps, they contain specific resources that favor different butterfly assemblages.

Made available in DSpace on 2014-06-11T19:23:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-10-27Bitstream added on 2014-06-13T20:10:55Z : No. of bitstreams: 1 martins_la_me_botfca.pdf: 9668913 bytes, checksum: 69b87662a1dd037524113f277bfdba4c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A Mata Atlântica é um dos biomas de maior biodiversidade do planeta, que há séculos tem sido sistematicamente destruída pelo desmatamento e fragmentação florestal, principalmente no domínio da Floresta Estacional Semidecidual. Os fragmentos remanescentes frequentemente têm sofrido distúrbios adicionais, tanto antrópicos quanto naturais. Deste modo, para a sua conservação e restauração é fundamental o conhecimento da resposta desses ecossistemas aos distúrbios. Este trabalho teve como objetivo geral caracterizar a estrutura da vegetação e a regeneração natural de um fragmento de floresta estacional semidecidual com diferentes históricos de perturbações e conhecer o papel das clareiras na regeneração de algumas das suas espécies arbóreas mais representativas. A pesquisa foi realizada em um fragmento de floresta estacional semidecidual com aproximadamente 615 ha (Reserva Particular do Patrimônio Natural (RPPN) Olavo Egydio Setúbal), no município de Lençóis Paulista (22. 27’S, 48.57W), SP. A amostragem foi feita através da demarcação de parcelas permanentes contíguas (10 x 10 m), totalizando um hectare em cada uma de três área na floresta( três hectares no total), sendo: área A , local que sofreu efeitos de um tornado ocorrido há cinco anos atrás; área B: área mais bem conservada, sem histórico recente de perturbações antrópicas e, área C, com registros de extração seletiva de madeira até meados da década de 70. Em cada área foram sorteadas 50 parcelas de 10 x 10 m para o levantamento fitossociológico do estrato arbóreo (indivíduos com altura 1,30 m) e regenerante (altura 0,50 e <1,30 m, levantado em 3 sub-parcelas de 10 x 1 m). Para a regeneração natural, cada subparcela amostrada foi categorizada como sendo de clareira (definição de Brokaw, 1982) ou de dossel fechado. O monitoramento do microclima foi feito quatro vezes... / The Atlantic Forest is one of the richest planest’s biomes in biodiversity, which has been systematically destroyed by deforestation and forest fragmentation., mainly at the Seasonal Semideciduous Forest domain. The remaining forest fragments have often suffered further disturbances , be natural or anthropogenic. To conserve or restore these ecosystems is fundamental to know how do they respond to the disturbances. This paper has the objective of characterizing the vegetation structure and the natural regeneration of a forest fragment with different disturbances histories, assessing the role of gaps in the regeneration of its most representatives tree species..The research was realized in a 615 ha seasonal semideciduous forest fragment (Private Natural Patrimony Reserve-RPPN “Olavo Egydio Setúbal”), at Lençóis Paulista Municipality (22. 27’S, 48.57W), SP. Sampling method was by contiguous permanent plots (10 x 10m), totalizing one hectare in each of three study sites within the forest (three ha in the total: Area A: site subjected to a tornado disturbance five years ago; Area B: site well conserved, with no recent anthropogenic disturbances events and, Area C: site were selective logging was registered until meddle 70’s. In each site 50 plots (10 x 10 m) were randomly assorted for the phytosociological (stems 1.30 height) and natural regeneration (1.30 < height 0.50 m, surveyed in three 1 x 10 m sub-plots within each plot) assessment. Each sub-plot established for natural regeneration survey was categorized as gap (Brokaw´s definition, 1982) or closed canopy. Microclimate was monitored four times in the year, within three consecutive days, in pairs of gap and closed canopy plots, in each of the three study sites. The preference of some tree species for regenerating in gap or closed canopy habitats was also tested. Within the three samples sites we sampled 10.570 individuals... (Complete abstract click electronic access below)

Orientador: Vera Lex Engel / Banca: Sebastião Venâncio Martins / Banca: Renata Cristina Batista Fonseca / Resumo: A Mata Atlântica é um dos biomas de maior biodiversidade do planeta, que há séculos tem sido sistematicamente destruída pelo desmatamento e fragmentação florestal, principalmente no domínio da Floresta Estacional Semidecidual. Os fragmentos remanescentes frequentemente têm sofrido distúrbios adicionais, tanto antrópicos quanto naturais. Deste modo, para a sua conservação e restauração é fundamental o conhecimento da resposta desses ecossistemas aos distúrbios. Este trabalho teve como objetivo geral caracterizar a estrutura da vegetação e a regeneração natural de um fragmento de floresta estacional semidecidual com diferentes históricos de perturbações e conhecer o papel das clareiras na regeneração de algumas das suas espécies arbóreas mais representativas. A pesquisa foi realizada em um fragmento de floresta estacional semidecidual com aproximadamente 615 ha (Reserva Particular do Patrimônio Natural (RPPN) Olavo Egydio Setúbal), no município de Lençóis Paulista (22. 27'S, 48.57W), SP. A amostragem foi feita através da demarcação de parcelas permanentes contíguas (10 x 10 m), totalizando um hectare em cada uma de três área na floresta( três hectares no total), sendo: área A, local que sofreu efeitos de um tornado ocorrido há cinco anos atrás; área B: área mais bem conservada, sem histórico recente de perturbações antrópicas e, área C, com registros de extração seletiva de madeira até meados da década de 70. Em cada área foram sorteadas 50 parcelas de 10 x 10 m para o levantamento fitossociológico do estrato arbóreo (indivíduos com altura 1,30 m) e regenerante (altura 0,50 e <1,30 m, levantado em 3 sub-parcelas de 10 x 1 m). Para a regeneração natural, cada subparcela amostrada foi categorizada como sendo de clareira (definição de Brokaw, 1982) ou de dossel fechado. O monitoramento do microclima foi feito quatro vezes... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Atlantic Forest is one of the richest planest's biomes in biodiversity, which has been systematically destroyed by deforestation and forest fragmentation., mainly at the Seasonal Semideciduous Forest domain. The remaining forest fragments have often suffered further disturbances, be natural or anthropogenic. To conserve or restore these ecosystems is fundamental to know how do they respond to the disturbances. This paper has the objective of characterizing the vegetation structure and the natural regeneration of a forest fragment with different disturbances histories, assessing the role of gaps in the regeneration of its most representatives tree species..The research was realized in a 615 ha seasonal semideciduous forest fragment (Private Natural Patrimony Reserve-RPPN "Olavo Egydio Setúbal"), at Lençóis Paulista Municipality (22. 27'S, 48.57W), SP. Sampling method was by contiguous permanent plots (10 x 10m), totalizing one hectare in each of three study sites within the forest (three ha in the total: Area A: site subjected to a tornado disturbance five years ago; Area B: site well conserved, with no recent anthropogenic disturbances events and, Area C: site were selective logging was registered until meddle 70's. In each site 50 plots (10 x 10 m) were randomly assorted for the phytosociological (stems 1.30 height) and natural regeneration (1.30 < height 0.50 m, surveyed in three 1 x 10 m sub-plots within each plot) assessment. Each sub-plot established for natural regeneration survey was categorized as gap (Brokaw's definition, 1982) or closed canopy. Microclimate was monitored four times in the year, within three consecutive days, in pairs of gap and closed canopy plots, in each of the three study sites. The preference of some tree species for regenerating in gap or closed canopy habitats was also tested. Within the three samples sites we sampled 10.570 individuals... (Complete abstract click electronic access below) / Mestre

Central to the issue of harvest feasibility on the outer BC coast (CWHvh) is the question of whether sites, once harvested, can be regenerated, and whether the time period for replacement and subsequent growth is economically and environmentally acceptable. Since low productivity sites have not been harvested in the past, there is a lack of data to answer this question. We tried to provide an answer by assessing regeneration following natural disturbances. Small scale gap disturbances are the norm within old-growth stands. If regeneration is not a problem in gaps, then we have some evidence that regeneration should not be a problem upon implementation of our management practices. The objectives of this study were: (1) to develop baseline information on the mechanisms and the patterns of regeneration across a sequence of forest types; (2) to assess regeneration success with respect to productivity; and (3) to estimate future growth and productivity.

The Mountain Hemlock (MH) zone includes all subalpine forests along British Columbia’s coast. It occurs at elevations where most precipitation falls as snow and the growing season is less than 4 months long. The zone includes the continuous forest of the forested subzones and the tree islands of the parkland subzones (Figure 1). Old-growth stands are populated by mountain hemlock, Pacific silver fir, and Alaska yellow-cedar, and are among the least-disturbed ecosystems in the world. Canopy trees grow slowly and are commonly older than 600 years, while some Alaska yellow-cedars may be up to 2000 years old. Understanding regeneration patterns in the MH zone has become increasingly important as logging continues towards higher elevations of the zone where snowpacks are deeper.