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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The Effects of Prescribed Fire on the Herbaceous Layer in the Southern Appalachian Mountains.

Zimmerman, Michael Lee 15 August 2006 (has links) (PDF)
Prescribed fire in the southern Appalachians is a frequently used and controversial forest management practice. Research is limited on the effects of prescribed fire in the mesic southern Appalachians, where many of Tennessee's rare and regionally endemic plant species occur. This study examined the effects of prescribed fire on the herbaceous layer. Field work was conducted on six previously burned sites within the Cherokee National Forest in northeast Tennessee. Complimentary non-burned sites were selected based on similarity of physical characteristics and forest structure. The numbers of herbaceous species and individuals and the total numbers of species and individuals were determined and used to compare burned and unburned forest. Following prescribed fires there were significant reductions in the number of herbaceous species and individuals. Species with myrmecochorous (ant-dispersed) seeds were markedly reduced on burned sites. Despite considerable variation among sites, the negative impact of fire on forest herbs was clearly evident.
2

Tree Regeneration Ecology and Herbaceous Layer Dynamics of an Old-growth Central Appalachian Forest

Chapman, Julia I. 21 August 2012 (has links)
No description available.
3

Restauração da vegetação de Cerrado após silvicultura de Pinus spp. / Cerrado restoration after Pinus spp. silviculture

Haddad, Thaís Mazzafera 07 June 2019 (has links)
Em todo o mundo, a conservação de savanas é menos valorizada que a de florestas. No Cerrado Brasileiro, majoritariamente composto por savanas, a expansão de plantações florestais é uma ameaça à biodiversidade. Entender o impacto dessas plantações na comunidade nativa e como restaurá-las quando os plantios são abandonados é uma demanda relevante. O principal objetivo do estudo foi avaliar se, em plantações florestais de pinus abandonadas, é possível restaurar a vegetação nativa de savanas ou se há necessidade de manejo após o abandono. Foram avaliadas três práticas recorrentes de restauração em plantações florestais: áreas abandonadas em que as árvores de pinus são mantidas em pé (pinus abandonado), áreas com corte raso de pinus seguido de abandono (restauração passiva) e áreas em que, após o corte raso do pinus, foram plantadas árvores nativas e controladas as gramíneas exóticas (restauração ativa). As práticas foram comparadas entre si e com cerrado típico (savana natural primária) e cerradão (savana adensada pela exclusão do fogo), em duas regiões (Assis e Mogi-Guaçu - SP). Foram avaliados o estrato arbóreo (DAP &#8805; 5 cm) e o arbustivo e arbóreo regenerante (DAP < 5 cm e H &#8805; 50 cm). A densidade de ervas não graminides, a riqueza de ervas graminóides e não graminóides, a cobertura do solo por vegetação nativa e por gramíneas exóticas e a cobertura de dossel foram avaliadas em Assis - SP. As espécies foram classificadas em típicas de savana, florestais e generalistas. O pinus abandonado apresentou menores valores de densidade, área basal e riqueza geral e de espécies típicas de savana para o estrato arbóreo. O estrato arbustivo e arbóreo regenerante não variou em densidade e riqueza em função das técnicas de restauração, embora a densidade tenha sido sempre menor do que a de savanas primárias. Restauração passiva e ativa apresentaram riqueza de espécies típicas de savana, no estrato arbóreo, semelhantes à savana primária. Entretanto, apenas a restauração passiva apresentou densidade semelhante à referência para espécies típicas de savana. Nenhuma prática de restauração foi eficaz para restaurar a comunidade herbácea e todas tiveram alta cobertura de dossel e presença de espécies florestais e generalistas. No decorrer do estudo, o pinus abandonado e a restauração passiva em Mogi-Guaçu - SP sofreram um incêndio e avaliamos o papel do fogo para a restauração do estrato herbáceo, comparando as duas práticas com savanas primárias e com a restauração ativa, que não queimou. Foram avaliadas a riqueza e a similaridade florística do estrato herbáceo e a cobertura do solo por herbáceas nativas e por gramíneas exóticas. Savanas primárias apresentaram composição florística diferente e maior riqueza que as áreas em restauração. A restauração passiva associada à queima resultou em maior cobertura por herbáceas nativas e mais espécies em comum com as savanas primárias do que a restauração ativa sem fogo. Entretanto, ambas as práticas de restauração resultaram em maior cobertura por gramíneas exóticas do que nas savanas primárias. Conclui-se que o corte do pinus seguido de abandono é mais eficaz à restauração da comunidade lenhosa típica de cerrado do que as demais técnicas comparadas. Porém, devido à ausência do fogo, as áreas tenderão a formar fisionomias florestais no futuro, sem a presença da comunidade herbácea nativa. A ocorrência do fogo nas áreas de Mogi-Guaçu reforça a importância das queimas para a restauração da comunidade herbácea típica do Cerrado. / Throughout the world, savanna conservation is less valued than is forest conservation. The Brazilian Cerrado, which is mostly composed by savannas, is having its biodiversity threatened by the expansion of forest plantations. Thus, it is relevant to understand how those plantations affects native communities and how to restore those areas when plantations are abandoned. The main objective of the study was to evaluate whether abandoned pine plantations can restore the native savannas or if there is a need for management for the restoration to take place. Three recurrent restoration practices in forest plantations were evaluated: abandoned pine plantations where pine trees are kept standing (abandoned pine plantation), areas abandoned after pinus harvesting (passive restoration) and areas with native tree seedling plantation and grasses control after pinus harvesting (active restoration). The practices were compared among themselves and to old-growth savanna and cerradão (encroached savanna), in two regions (Assis - SP and Mogi-Guaçu - SP). We evaluated trees (DBH &#8805; 5 cm) and woody natural regeneration (DBH < 5 cm and H &#8805; 50). Nongraminoid species density, richness of grasses and nongraminoid species, ground cover by native vegetation and by exotic grasses, and canopy cover were evaluated in Assis - SP. Surveyed individuals were classified as savanna, forest and generalist species. Abandoned pine plantation had the lowest tree density and general basal area and richness, as well as the lowest richness for savanna tree species. Woody natural regeneration did not vary in density and richness among restoration practices, although density was lower compared to the old-growth savanna. Community richness for savanna tree species was similar among passive and active restorations and old-growth savanna. However, only the passive restoration presented tree density similar to the reference for savanna species. No restoration practice was effective for the restoration of the native herbaceous community, and all practices had high canopy cover and presence of forest and generalist species. During the study, abandoned pine plantation and passive restoration in Mogi-Guaçu - SP burned and we evaluated the role of fire for the restoration of the native herbaceous community. We compared the herbaceous community richness and floristic similarity of the two restoration practices to old-growth savannas and to the active restoration, which did not burn. Ground cover by native herbs and by exotic grasses were also evaluated. The old-growth savannas are floristically different and have a greater richness than restoration sites. The burned passive restoration had more species in common with the old-growth savannas and a higher ground cover by native herbs than active restoration without fire. However, both restoration practices had higher ground cover by exotic grasses than old-growth savannas. We conclude that pine harvesting followed by passive restoration was the most effective practice for the restoration of the Cerrado native woody community. However, due to the lack of fire, areas tend to become forest physiognomies without native herbs in the future. The fire in the Mogi-Guaçu highlighted the importance of fire for the Cerrado native herbaceous community restoration.
4

Estrutura da vegetação da floresta paludosa da restinga no sul do Brasil

Mancino, Luciana Carla January 2014 (has links)
As florestas que ocorrem na planície costeira brasileira podem ser classificadas em Florestas Arenosas (FAR) e Paludosas da Restinga (FPR). A inundação constante nos solos das FPR sustentam comunidades pobres em espécies. Mas, nos locais com inundações curtas, a riqueza de espécies pode ser ainda maior do que florestas adjacentes bem drenadas. O objetivo geral foi determinar o padrão florístico-estrutural do componente arbóreo e herbáceo da FPR em três áreas localizadas em Içara (IÇA) e Balneário Arroio do Silva (BAS), em Santa Catarina e Morrinhos do Sul (MDS), no Rio Grande do Sul, determinar os fatores ambientais que influenciam esses componentes, mostrar as diferenças nos padrões do componente arbóreo entre FPR e FAR e propor o seu reconhecimento como distintas fisionomias da Restinga. Esta tese compreende três capítulos (artigos). No primeiro capítulo, analisamos variações no padrão florístico-estrutural do componente arbóreo em três áreas da FPR no nordeste do Rio Grande do Sul e Sul de Santa Catarina. Hipotetizamos que locais com condições ambientais mais estressantes tivesse menor diversidade e que a grande variação no regime hidrológico e condições físico-químicas do solo deveria resultar em diferenças na estrutura e composição de espécies. No segundo capítulo, avaliamos a estrutura do componente herbáceo-terrícola e e sua correlação com a luminosidade, fertilidade edáfica, microtopografia e a cobertura de palmeiras. O terceiro capítulo buscou determinar se havia diferenças no padrão florístico-estrutural do componente arbóreo das FPR e FAR, seus hábitats e suas relações com fatores de solo, latitude, com base neste e em outros levantamentos no Sul do Brasil. Foram instaladas 13 parcelas de 100 m² (20 x 50 m) para o levantamento das árvores e de 13 parcelas de 5 m² (1 x 5 m contíguas) para as espécies herbáceas em cada uma das áreas. Os fatores ambientais analisados foram os parâmetros químicos e físico-hídricos do solo (0-15 cm de profundidade), a microtopografia, a abertura do dossel (luz) e a cobertura de palmeiras. As espécies arbóreas (capítulo 1) com CAP ≥ 12 cm (ou DAP ≥ 3,8 cm) e altura ≥ 3 m foram registradas e avaliadas pela densidade, frequência, altura e diversidade. As espécies herbáceas terrícolas (capítulo 2) foram avaliadas pela riqueza e cobertura, e através de análises multivariadas (Análise de Correspondência Canônica - CCA) com a matriz das espécies e das variáveis ambientais com alta correlação. A luminosidade foi determinada a partir de fotografias hemisféricas do dossel. No capítulo 3, utilizamos as espécies arbóreas de estudos científicos com DAP ≥ 5 cm e realizamos uma NPManova para mostrar as diferenças florístico-estruturais entre FPR e FAR e uma CCA com a matriz das espécies e com o tipo de solo, precipitação, altitude e latitude. As FPR apresentaram abertura do dossel, características de solo e microtopografia muito variáveis, baixa similaridade florística entre as áreas e elevada riqueza de espécies herbáceas terrícolas e arbóreas. No primeiro capítulo, encontramos nas três áreas 111 espécies arbóreas e 40 famílias com muito baixa similaridade florística entre as áreas. As três áreas apresentaram diferenças na composicão e estrutura devido a presença de muitas espécies com baixa frequência e ampla distribuição (Mata Atlântica) em locais sem inundação constante, contribuindo para a manutenção da diversidade regional no Sul do Brasil. No segundo capítulo, registramos 41 espécies herbáceas terrícolas pertencentes à 20 famílias. A média de riqueza e cobertura de ervas foi significativamente diferente entre as áreas, como também a variação do regime de luz, cobertura de palmeiras e vários parâmetros do solo. Monilófitas se destacaram em riqueza e monocotiledôneas em cobertura. Mostramos a influência da luminosidade e alguns parâmetros do solo sobre a cobertura vegetal, explicando a separação de grupos de espécies, em termos de preferência de habitat. No terceiro capítulo, os estudos compilados continham 265 espécies arbóreas da FPR e 109 na FAR e as claras diferenças florístico-estruturais entre essas fisionomias tornaram-se óbvias. A CCA indicou que as espécies foram influenciadas principalmente pelas características dos solos e microtopográficas, ligadas à frequência de inundação. Os resultados obtidos neste estudo em termos de riqueza de espécies arbóreas e herbáceas foram um tanto surpreendentes. Nossas análises confirmaram as diferenças de solo e florístico-estruturais entre as FPR e as FAR. Essas diferenças florístico-estruturais são suficientemente claras para permitir a consideração dessas fisionomias tão distintas da Restinga, essenciais para sua devida conservação. / The forests that occur in the brazilian coastal plain can be classified into Sandy Restinga Forests (SARF) and Swamp Restinga Forest (SWRF). The constant flooding of soils in SWRF support species poor communities. However, at sties where only short periods of flooding occur, richness may be even larger than that of adjacent well-drained forests. The overall goals of this work were (1) to determine the floristic- structural pattern of tree and terricolous herbaceous species of SWRF in three areas located in Içara (IÇA) and Balneário Arroio do Silva (BAS), Santa Catarina, and Morrinhos do Sul (MDS), Rio Grande do Sul, (2) to determine some of the environmental factors that influence these components, and (3) to show differences in the tree component between SWRF and SARF. This work comprises three chapters (articles). In the first chapter we examine variations in floristic-structural pattern of the tree component in three areas of the SWRF in northeastern Rio Grande do Sul and southern Santa Catarina. We expected that sites with more stressful environmental conditions had lower diversity and that the wide variation in the hydrological regime and physico-chemical soil conditions should result in differences in structure and species composition. In chapter two, we evaluate the structure of terricolous herbaceous component and its correlation with luminosity, soil fertility, microtopography and palm cover. In the third chapter, we analyze differences in floristic-structural pattern of the tree component of the SWRF and SARF, their habitats and their relations with edaphic and biogeographic factors, based on our own data and on that from other surveys in southern Brazil. Thirteen plots of 100 m² (20 x 50 m) were installed for the survey of trees and 13 plots of 5 m² for terrestrial herbaceous species in each of the three SWRF areas. Environmental factors were analyzed, including chemical and physical-hydric soil parameters (0-15 cm depth), microtopography, canopy openness (light) and palm cover. Tree species (Chapter 1) with diameter at breast height ≥ 3.8 cm and height ≥ 3 m were recorded and evaluated with respect to density, frequency, height and diversity. Terricolous herbaceous species (Chapter 2) were evaluated regarding richness and cover, and by help of multivariate analysis (Canonical Correspondence Analysis - CCA), using the matrices of species and of environmental variables. Luminosity was determined by help of hemispherical canopy photographs. In Chapter 3, we use tree species with diameter at breast height ≥ 5 cm of scientific studies. We performed a NPManova to show the floristic-structural differences between SWRF and SARF and a CCA of species matrix with soil type, rainfall, altitude and latitude. In general, the three SWRF areas showed highly variable canopy openness, soil characteristics and microtopography, very low floristic similarity between areas and high richness of terricolous herbaceous and trees species. The data from the first chapter showed a total of 111 tree species belonging to 40 families. The three areas showed differences in composition and structure due to the presence of many species with low frequency and wide distribution (Atlantic Rain Forest) in places without constant flooding, contributing to the maintenance of regional diversity in southern Brazil. In the second chapter, we recorded 41 terricolous herbaceous species belong to 20 families. Mean richness and cover of herbs differed significantly between areas, as well as the variation of luminosity, palm cover and many soil parameters. Monilophytes were characteristic in terms of richness and monocots in terms of cover value. We showed the influence of light and some soil parameters on vegetation cover, explaining the separation of groups of species in terms of habitat preference. In the third chapter, the compiled studies contained a total of 265 tree species in SWRF and 109 in SARF and clear floristic-phytosociological differences between SWRF and SARF became obvious. CCA indicated that the species were mainly influenced by microtopography and soil characteristics related to the frequency of flooding. Results obtained in this study regarding richness of tree and herbaceous species were somewhat surprising. Our analyses confirmed the soil and floristic-structural differences between the SWRF and the SARF. These floristic-structural differences are clear enough to allow for consideration as distinct physiognomies of Restinga, essential for their proper consideration in conservation.
5

Estrutura da vegetação da floresta paludosa da restinga no sul do Brasil

Mancino, Luciana Carla January 2014 (has links)
As florestas que ocorrem na planície costeira brasileira podem ser classificadas em Florestas Arenosas (FAR) e Paludosas da Restinga (FPR). A inundação constante nos solos das FPR sustentam comunidades pobres em espécies. Mas, nos locais com inundações curtas, a riqueza de espécies pode ser ainda maior do que florestas adjacentes bem drenadas. O objetivo geral foi determinar o padrão florístico-estrutural do componente arbóreo e herbáceo da FPR em três áreas localizadas em Içara (IÇA) e Balneário Arroio do Silva (BAS), em Santa Catarina e Morrinhos do Sul (MDS), no Rio Grande do Sul, determinar os fatores ambientais que influenciam esses componentes, mostrar as diferenças nos padrões do componente arbóreo entre FPR e FAR e propor o seu reconhecimento como distintas fisionomias da Restinga. Esta tese compreende três capítulos (artigos). No primeiro capítulo, analisamos variações no padrão florístico-estrutural do componente arbóreo em três áreas da FPR no nordeste do Rio Grande do Sul e Sul de Santa Catarina. Hipotetizamos que locais com condições ambientais mais estressantes tivesse menor diversidade e que a grande variação no regime hidrológico e condições físico-químicas do solo deveria resultar em diferenças na estrutura e composição de espécies. No segundo capítulo, avaliamos a estrutura do componente herbáceo-terrícola e e sua correlação com a luminosidade, fertilidade edáfica, microtopografia e a cobertura de palmeiras. O terceiro capítulo buscou determinar se havia diferenças no padrão florístico-estrutural do componente arbóreo das FPR e FAR, seus hábitats e suas relações com fatores de solo, latitude, com base neste e em outros levantamentos no Sul do Brasil. Foram instaladas 13 parcelas de 100 m² (20 x 50 m) para o levantamento das árvores e de 13 parcelas de 5 m² (1 x 5 m contíguas) para as espécies herbáceas em cada uma das áreas. Os fatores ambientais analisados foram os parâmetros químicos e físico-hídricos do solo (0-15 cm de profundidade), a microtopografia, a abertura do dossel (luz) e a cobertura de palmeiras. As espécies arbóreas (capítulo 1) com CAP ≥ 12 cm (ou DAP ≥ 3,8 cm) e altura ≥ 3 m foram registradas e avaliadas pela densidade, frequência, altura e diversidade. As espécies herbáceas terrícolas (capítulo 2) foram avaliadas pela riqueza e cobertura, e através de análises multivariadas (Análise de Correspondência Canônica - CCA) com a matriz das espécies e das variáveis ambientais com alta correlação. A luminosidade foi determinada a partir de fotografias hemisféricas do dossel. No capítulo 3, utilizamos as espécies arbóreas de estudos científicos com DAP ≥ 5 cm e realizamos uma NPManova para mostrar as diferenças florístico-estruturais entre FPR e FAR e uma CCA com a matriz das espécies e com o tipo de solo, precipitação, altitude e latitude. As FPR apresentaram abertura do dossel, características de solo e microtopografia muito variáveis, baixa similaridade florística entre as áreas e elevada riqueza de espécies herbáceas terrícolas e arbóreas. No primeiro capítulo, encontramos nas três áreas 111 espécies arbóreas e 40 famílias com muito baixa similaridade florística entre as áreas. As três áreas apresentaram diferenças na composicão e estrutura devido a presença de muitas espécies com baixa frequência e ampla distribuição (Mata Atlântica) em locais sem inundação constante, contribuindo para a manutenção da diversidade regional no Sul do Brasil. No segundo capítulo, registramos 41 espécies herbáceas terrícolas pertencentes à 20 famílias. A média de riqueza e cobertura de ervas foi significativamente diferente entre as áreas, como também a variação do regime de luz, cobertura de palmeiras e vários parâmetros do solo. Monilófitas se destacaram em riqueza e monocotiledôneas em cobertura. Mostramos a influência da luminosidade e alguns parâmetros do solo sobre a cobertura vegetal, explicando a separação de grupos de espécies, em termos de preferência de habitat. No terceiro capítulo, os estudos compilados continham 265 espécies arbóreas da FPR e 109 na FAR e as claras diferenças florístico-estruturais entre essas fisionomias tornaram-se óbvias. A CCA indicou que as espécies foram influenciadas principalmente pelas características dos solos e microtopográficas, ligadas à frequência de inundação. Os resultados obtidos neste estudo em termos de riqueza de espécies arbóreas e herbáceas foram um tanto surpreendentes. Nossas análises confirmaram as diferenças de solo e florístico-estruturais entre as FPR e as FAR. Essas diferenças florístico-estruturais são suficientemente claras para permitir a consideração dessas fisionomias tão distintas da Restinga, essenciais para sua devida conservação. / The forests that occur in the brazilian coastal plain can be classified into Sandy Restinga Forests (SARF) and Swamp Restinga Forest (SWRF). The constant flooding of soils in SWRF support species poor communities. However, at sties where only short periods of flooding occur, richness may be even larger than that of adjacent well-drained forests. The overall goals of this work were (1) to determine the floristic- structural pattern of tree and terricolous herbaceous species of SWRF in three areas located in Içara (IÇA) and Balneário Arroio do Silva (BAS), Santa Catarina, and Morrinhos do Sul (MDS), Rio Grande do Sul, (2) to determine some of the environmental factors that influence these components, and (3) to show differences in the tree component between SWRF and SARF. This work comprises three chapters (articles). In the first chapter we examine variations in floristic-structural pattern of the tree component in three areas of the SWRF in northeastern Rio Grande do Sul and southern Santa Catarina. We expected that sites with more stressful environmental conditions had lower diversity and that the wide variation in the hydrological regime and physico-chemical soil conditions should result in differences in structure and species composition. In chapter two, we evaluate the structure of terricolous herbaceous component and its correlation with luminosity, soil fertility, microtopography and palm cover. In the third chapter, we analyze differences in floristic-structural pattern of the tree component of the SWRF and SARF, their habitats and their relations with edaphic and biogeographic factors, based on our own data and on that from other surveys in southern Brazil. Thirteen plots of 100 m² (20 x 50 m) were installed for the survey of trees and 13 plots of 5 m² for terrestrial herbaceous species in each of the three SWRF areas. Environmental factors were analyzed, including chemical and physical-hydric soil parameters (0-15 cm depth), microtopography, canopy openness (light) and palm cover. Tree species (Chapter 1) with diameter at breast height ≥ 3.8 cm and height ≥ 3 m were recorded and evaluated with respect to density, frequency, height and diversity. Terricolous herbaceous species (Chapter 2) were evaluated regarding richness and cover, and by help of multivariate analysis (Canonical Correspondence Analysis - CCA), using the matrices of species and of environmental variables. Luminosity was determined by help of hemispherical canopy photographs. In Chapter 3, we use tree species with diameter at breast height ≥ 5 cm of scientific studies. We performed a NPManova to show the floristic-structural differences between SWRF and SARF and a CCA of species matrix with soil type, rainfall, altitude and latitude. In general, the three SWRF areas showed highly variable canopy openness, soil characteristics and microtopography, very low floristic similarity between areas and high richness of terricolous herbaceous and trees species. The data from the first chapter showed a total of 111 tree species belonging to 40 families. The three areas showed differences in composition and structure due to the presence of many species with low frequency and wide distribution (Atlantic Rain Forest) in places without constant flooding, contributing to the maintenance of regional diversity in southern Brazil. In the second chapter, we recorded 41 terricolous herbaceous species belong to 20 families. Mean richness and cover of herbs differed significantly between areas, as well as the variation of luminosity, palm cover and many soil parameters. Monilophytes were characteristic in terms of richness and monocots in terms of cover value. We showed the influence of light and some soil parameters on vegetation cover, explaining the separation of groups of species in terms of habitat preference. In the third chapter, the compiled studies contained a total of 265 tree species in SWRF and 109 in SARF and clear floristic-phytosociological differences between SWRF and SARF became obvious. CCA indicated that the species were mainly influenced by microtopography and soil characteristics related to the frequency of flooding. Results obtained in this study regarding richness of tree and herbaceous species were somewhat surprising. Our analyses confirmed the soil and floristic-structural differences between the SWRF and the SARF. These floristic-structural differences are clear enough to allow for consideration as distinct physiognomies of Restinga, essential for their proper consideration in conservation.
6

Estrutura da vegetação da floresta paludosa da restinga no sul do Brasil

Mancino, Luciana Carla January 2014 (has links)
As florestas que ocorrem na planície costeira brasileira podem ser classificadas em Florestas Arenosas (FAR) e Paludosas da Restinga (FPR). A inundação constante nos solos das FPR sustentam comunidades pobres em espécies. Mas, nos locais com inundações curtas, a riqueza de espécies pode ser ainda maior do que florestas adjacentes bem drenadas. O objetivo geral foi determinar o padrão florístico-estrutural do componente arbóreo e herbáceo da FPR em três áreas localizadas em Içara (IÇA) e Balneário Arroio do Silva (BAS), em Santa Catarina e Morrinhos do Sul (MDS), no Rio Grande do Sul, determinar os fatores ambientais que influenciam esses componentes, mostrar as diferenças nos padrões do componente arbóreo entre FPR e FAR e propor o seu reconhecimento como distintas fisionomias da Restinga. Esta tese compreende três capítulos (artigos). No primeiro capítulo, analisamos variações no padrão florístico-estrutural do componente arbóreo em três áreas da FPR no nordeste do Rio Grande do Sul e Sul de Santa Catarina. Hipotetizamos que locais com condições ambientais mais estressantes tivesse menor diversidade e que a grande variação no regime hidrológico e condições físico-químicas do solo deveria resultar em diferenças na estrutura e composição de espécies. No segundo capítulo, avaliamos a estrutura do componente herbáceo-terrícola e e sua correlação com a luminosidade, fertilidade edáfica, microtopografia e a cobertura de palmeiras. O terceiro capítulo buscou determinar se havia diferenças no padrão florístico-estrutural do componente arbóreo das FPR e FAR, seus hábitats e suas relações com fatores de solo, latitude, com base neste e em outros levantamentos no Sul do Brasil. Foram instaladas 13 parcelas de 100 m² (20 x 50 m) para o levantamento das árvores e de 13 parcelas de 5 m² (1 x 5 m contíguas) para as espécies herbáceas em cada uma das áreas. Os fatores ambientais analisados foram os parâmetros químicos e físico-hídricos do solo (0-15 cm de profundidade), a microtopografia, a abertura do dossel (luz) e a cobertura de palmeiras. As espécies arbóreas (capítulo 1) com CAP ≥ 12 cm (ou DAP ≥ 3,8 cm) e altura ≥ 3 m foram registradas e avaliadas pela densidade, frequência, altura e diversidade. As espécies herbáceas terrícolas (capítulo 2) foram avaliadas pela riqueza e cobertura, e através de análises multivariadas (Análise de Correspondência Canônica - CCA) com a matriz das espécies e das variáveis ambientais com alta correlação. A luminosidade foi determinada a partir de fotografias hemisféricas do dossel. No capítulo 3, utilizamos as espécies arbóreas de estudos científicos com DAP ≥ 5 cm e realizamos uma NPManova para mostrar as diferenças florístico-estruturais entre FPR e FAR e uma CCA com a matriz das espécies e com o tipo de solo, precipitação, altitude e latitude. As FPR apresentaram abertura do dossel, características de solo e microtopografia muito variáveis, baixa similaridade florística entre as áreas e elevada riqueza de espécies herbáceas terrícolas e arbóreas. No primeiro capítulo, encontramos nas três áreas 111 espécies arbóreas e 40 famílias com muito baixa similaridade florística entre as áreas. As três áreas apresentaram diferenças na composicão e estrutura devido a presença de muitas espécies com baixa frequência e ampla distribuição (Mata Atlântica) em locais sem inundação constante, contribuindo para a manutenção da diversidade regional no Sul do Brasil. No segundo capítulo, registramos 41 espécies herbáceas terrícolas pertencentes à 20 famílias. A média de riqueza e cobertura de ervas foi significativamente diferente entre as áreas, como também a variação do regime de luz, cobertura de palmeiras e vários parâmetros do solo. Monilófitas se destacaram em riqueza e monocotiledôneas em cobertura. Mostramos a influência da luminosidade e alguns parâmetros do solo sobre a cobertura vegetal, explicando a separação de grupos de espécies, em termos de preferência de habitat. No terceiro capítulo, os estudos compilados continham 265 espécies arbóreas da FPR e 109 na FAR e as claras diferenças florístico-estruturais entre essas fisionomias tornaram-se óbvias. A CCA indicou que as espécies foram influenciadas principalmente pelas características dos solos e microtopográficas, ligadas à frequência de inundação. Os resultados obtidos neste estudo em termos de riqueza de espécies arbóreas e herbáceas foram um tanto surpreendentes. Nossas análises confirmaram as diferenças de solo e florístico-estruturais entre as FPR e as FAR. Essas diferenças florístico-estruturais são suficientemente claras para permitir a consideração dessas fisionomias tão distintas da Restinga, essenciais para sua devida conservação. / The forests that occur in the brazilian coastal plain can be classified into Sandy Restinga Forests (SARF) and Swamp Restinga Forest (SWRF). The constant flooding of soils in SWRF support species poor communities. However, at sties where only short periods of flooding occur, richness may be even larger than that of adjacent well-drained forests. The overall goals of this work were (1) to determine the floristic- structural pattern of tree and terricolous herbaceous species of SWRF in three areas located in Içara (IÇA) and Balneário Arroio do Silva (BAS), Santa Catarina, and Morrinhos do Sul (MDS), Rio Grande do Sul, (2) to determine some of the environmental factors that influence these components, and (3) to show differences in the tree component between SWRF and SARF. This work comprises three chapters (articles). In the first chapter we examine variations in floristic-structural pattern of the tree component in three areas of the SWRF in northeastern Rio Grande do Sul and southern Santa Catarina. We expected that sites with more stressful environmental conditions had lower diversity and that the wide variation in the hydrological regime and physico-chemical soil conditions should result in differences in structure and species composition. In chapter two, we evaluate the structure of terricolous herbaceous component and its correlation with luminosity, soil fertility, microtopography and palm cover. In the third chapter, we analyze differences in floristic-structural pattern of the tree component of the SWRF and SARF, their habitats and their relations with edaphic and biogeographic factors, based on our own data and on that from other surveys in southern Brazil. Thirteen plots of 100 m² (20 x 50 m) were installed for the survey of trees and 13 plots of 5 m² for terrestrial herbaceous species in each of the three SWRF areas. Environmental factors were analyzed, including chemical and physical-hydric soil parameters (0-15 cm depth), microtopography, canopy openness (light) and palm cover. Tree species (Chapter 1) with diameter at breast height ≥ 3.8 cm and height ≥ 3 m were recorded and evaluated with respect to density, frequency, height and diversity. Terricolous herbaceous species (Chapter 2) were evaluated regarding richness and cover, and by help of multivariate analysis (Canonical Correspondence Analysis - CCA), using the matrices of species and of environmental variables. Luminosity was determined by help of hemispherical canopy photographs. In Chapter 3, we use tree species with diameter at breast height ≥ 5 cm of scientific studies. We performed a NPManova to show the floristic-structural differences between SWRF and SARF and a CCA of species matrix with soil type, rainfall, altitude and latitude. In general, the three SWRF areas showed highly variable canopy openness, soil characteristics and microtopography, very low floristic similarity between areas and high richness of terricolous herbaceous and trees species. The data from the first chapter showed a total of 111 tree species belonging to 40 families. The three areas showed differences in composition and structure due to the presence of many species with low frequency and wide distribution (Atlantic Rain Forest) in places without constant flooding, contributing to the maintenance of regional diversity in southern Brazil. In the second chapter, we recorded 41 terricolous herbaceous species belong to 20 families. Mean richness and cover of herbs differed significantly between areas, as well as the variation of luminosity, palm cover and many soil parameters. Monilophytes were characteristic in terms of richness and monocots in terms of cover value. We showed the influence of light and some soil parameters on vegetation cover, explaining the separation of groups of species in terms of habitat preference. In the third chapter, the compiled studies contained a total of 265 tree species in SWRF and 109 in SARF and clear floristic-phytosociological differences between SWRF and SARF became obvious. CCA indicated that the species were mainly influenced by microtopography and soil characteristics related to the frequency of flooding. Results obtained in this study regarding richness of tree and herbaceous species were somewhat surprising. Our analyses confirmed the soil and floristic-structural differences between the SWRF and the SARF. These floristic-structural differences are clear enough to allow for consideration as distinct physiognomies of Restinga, essential for their proper consideration in conservation.
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Herb Layer Dynamics and Disturbance Response in the Mixed Mesophytic Forest Region of Southeastern Ohio

Small, Christine Jodie 11 October 2001 (has links)
No description available.
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Vliv světelných poměrů na vegetaci bylinného patra v horských smrčinách Krkonoš s využitím GIS / Influence of the light conditions on herbaceous layer in mountain spruce forests in the Giant Mountains using GIS

ČIHÁK, Jan January 2010 (has links)
Mountain forests are an important part of the landscape in our country. In the last three decades they have been seriously damaged by anthropogenic influence, especially immissions. The immissions make worse the health status of Norway spruce (Picea abies) forests, which cause changes in a structure of herbaceous layer, in which the health status of forest stand is reflected. The main goals of my work were to map the cover of herbaceous and mossy layers in two permanent research plots in the Giant Mountains ( Alžbětinka, Modrý důl), to create maps of herbaceous cover, to digitize them and to compare these maps with the extent in years 1993-1994 using a developing analysis in GIS and to detect influence of light conditions on herbaceous layer. Using digitizing and static evaluation of prepared detailed vegetation maps of the both permanent research plots, some important changes were found out in dominant soil cover categories. In the first research plot Alžbětinka, decline of the grass Calamagrostis villosa and increasing of Vaccinium myrtillus cover were evident. In the second research plot Modrý důl, decline of both investigated species, Avenella flexuosa and Calamagrostis villosa, was observed. Another goal of my research was to detect influence of the light conditions on herbaceous layer and nature regeneration of the Norway spruce on permanent research plot Modrý důl. Dependence of the basic categories of the soil cover on the percentual ratio of the light gaps in the crown canopy was proved. Dependence of the height of the seedlings on the ratio of the light gaps was also tested but it was not statistically proved. The negative dependence of survival on the ratio of the light gaps of the seedlings germinated in 1996 was proved, but not of the seedlings germinated in 2004.
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UNDERSTORY RESPONSE TO SHELTERWOOD AND BURN TREATMENTS IN A DRY QUERCUS FOREST IN INDIANA

Sarah J Rademacher (12469245) 27 April 2022 (has links)
<p>  </p> <p>Alterations to the historic fire regime have contributed to widespread regeneration failure in <em>Quercus</em> L. (oak) forests of the eastern United States. Composition has shifted from <em>Quercus</em> and other fire-adapted species to dominance by mesophytic species. While land managers often focus efforts on restoring <em>Quercus</em> regeneration, the herbaceous layer experiences reduced cover and diversity of herb and graminoid species resulting from the increased woody stem density in fire-suppressed forests. Declining abundance of <em>Quercus</em> species and diversity in the herbaceous layer reduce the overall habitat quality and ecosystem functions provided by the forest. A combination of overstory harvests and prescribed burning are often conducted to restore the plant community in <em>Quercus</em> forests affected by mesophication. Initiated in 2010, our study on the Hoosier National Forest in Indiana conducted shelterwood and midstory (mechanical, chemical, or none) harvests followed by prescribed burning on a less productive site, while leaving a more productive site unburned. Our objective was to evaluate the survival and competitive response of <em>Quercus</em> spp. within the regeneration layer and whether diversity and cover increased in the herbaceous layer following treatments. Using nested circular plots, we measured seedling survival and resprout response, in addition to regeneration density before and after treatments. We measured the percent cover of herbaceous-layer species within quadrats and calculated species richness, evenness, and diversity. Using multiple mixed-effects models, ANOVA, and NMDS ordination, we evaluated woody species regeneration and herbaceous-layer composition before and after treatments. Post-treatment, monitored <em>Quercus</em> spp. seedlings at the burned site displayed greater survival (> 94%) and resprouting (> 92% of monitored stems), which exceeded most competing species, including<em> Acer</em> spp. (~ 59% survival and resprouting) and <em>Fraxinus americana </em>(72% survival and resprouting). <em>Q. alba</em> seedling (< 3.8 cm DBH) densities doubled after burning; it was one of the most abundant species (9,864 stems ha-1) at the burned site. NMDS ordination indicated a clear shift in regeneration species composition with the burn driving a shift away from mesophytic species towards greater importance of <em>Quercus</em> species. Additionally, our burned site had significantly increased herbaceous-layer richness, Shannon diversity index, and total cover compared to pre-treatment. Percent cover increased across all plant functional groups within the herbaceous layer, with trees/shrubs exhibiting the greatest increase. Herbaceous-layer composition at the burned site significantly shifted toward greater importance of graminoids and herbs post-treatment. Post-treatment, the unburned site contained fewer, and less competitive, <em>Quercus</em> seedlings compared to non-<em>Quercus</em> competitors and displayed no significant compositional shifts in seedling species composition post-harvest. Our unburned site exhibited significant, but minor, increases in herbaceous-layer richness, evenness, diversity, and total cover. Herbaceous-layer composition at the unburned site was significantly different post-treatment, shifting towards greater importance of vines, trees/shrubs, and herbs. The more-productive unburned site would likely require multiple burns to produce adequate competitive <em>Quercus</em> seedlings to perpetuate dominance in the developing stand. Burning would also likely result in greater increases in herbaceous-layer diversity compared to harvesting alone. Conversely, the shelterwood, followed by a single burn, on the less productive site had a more substantial effect on the herbaceous layer, and likely produced an adequate density of <em>Quercus</em> reproduction to ensure future dominance by the genus.</p>
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Assessing waterhole design and determining the impact of artificial waterholes in Balule nature reserve, South Africa

Smith, Eilidh 01 1900 (has links)
Herbivores have a significant influence on their environment. Factors that influence herbivore distribution in a landscape are important for conservation. Artificial water provision is one such factor, with water sources being focal points of herbivore activity. Variation between herbivore utilisation of different waterhole types and habitat integrity surrounding the different waterholes is assessed in this study. Correlations are drawn between herbivore utilisation and habitat integrity to quantify the impact that artificial waterholes have on the landscape. A scoring system is devised to investigate the various factors affecting vegetation around artificial waterholes. Results show that there are significant variations between herbivore utilisation for different artificial waterhole types, as well as significant variation in habitat integrity surrounding the different waterhole types. Distance between waterholes and drainage lines, and utilisation by specific herbivore species have a significant impact on habitat integrity - specifically affecting veld condition and disturbance observed on woody plant species. A habitat score that was created by combining data from both the herbaceous and woody layers is not affected by waterhole type, distance from waterholes, or the different herbivore species utilising the different waterhole types. Earth dams have the greatest impact on surrounding vegetation and are the most utilised waterhole type. Closures of earth dams are not recommended due to their importance to herbivores. Less utilised waterhole types are also important, mitigating the impact of herbivore damage to vegetation at earth dams. / Environmental Sciences / M. Sc. (Nature Conservation)

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