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Carbon Pools and Fluxes as an Indicator of Riparian RestorationGiese, Laura 08 February 2001 (has links)
Riparian forests are integral components of the landscape. The inherent biogeochemical processes that occur in such forests provide numerous benefits to wildlife and society. Maintaining good water quality is a major benefit from riparian forests and therefore, the maintenance, creation, or restoration of riparian forests is indispensable. This study was designed to broaden current knowledge of the complex, interrelated biogeochemical processes and determine indices for riparian forest restoration based on the various carbon pools/fluxes that may represent restoration success.
This study was implemented on the Savannah River Site, an Environmental Research Park, where several riparian forests are recovering from thermal disturbances. The streams in these forests were subjected to thermal discharges that increased flows and resulted in removal of soil and a decline in the amount of woody vegetation. Two of these riparian forests are at different ages post-disturbance and represent different stages of recovery, which provides an exceptional opportunity to study successional processes in riparian forests and enhance restoration efforts.
Linear transects perpendicular to the main stream channels were established in 2 recovering riparian forests of different ages (two areas in Pen Branch ~ 8 years post-disturbance; Fourmile Branch ~ 12 years post disturbance) and an undisturbed (thermally) more mature riparian forest (Meyer's Branch ~ 60 years). Along these transects quantitative data were obtained on above and belowground carbon pools and fluxes.
Carbon pools exhibited a close correlation with riparian forest development. Biomass and carbon pools increased with increasing riparian forest stand age. The importance of the herbaceous carbon pool declined relative to the total above ground biomass, and the root carbon pool increased with forest age/succession. In general, net primary production (NPP) in young riparian forests (~8-10 years) rapidly approached and even exceeded NPP of more mature riparian forests. Once the herbaceous stage of succession was surpassed, the litterfall component of NPP plays a greater role riparian forests. As a woody overstory became established (after ~ 8-10 years), annual litterfall rates as a function of NPP were independent of forest age.
Establishment of woody species occurred ~8 to 10 years after thermal disturbance and litterfall amount in young riparian forests rapidly became comparable to mature riparian forests. Lateral litter movement from the riparian forest toward the stream was less than the amount of litter (carbon pool) deposited from upstream into the riparian forest during a flood event. Overall lateral litter movement supplied less energy to the stream system than vertical inputs. A decline in riparian forest floor biomass was observed with increasing riparian forest development. However, a difference in foliar forest floor percent carbon lended itself to a minimal increase in the forest floor carbon pool with increasing riparian forest age. Woody debris in riparian forests comprised a relatively small carbon pool compared to tree and soil carbon pools.
The species composition of litter appeared to be more of an overriding factor influencing decomposition rates than forest age. The influence of litter quality was evident in the decomposition rates of the different litter composites used in this study. In all 4 sites the litter composite from the mature riparian forest decomposed significantly more than the litter composites from the younger riparian forests. The fairly rapid decomposition of red maple (Acer rubrum L.), which was one of the main components in the mature riparian forest litter composite, influenced the greater decomposition rate. The litter composites from the younger riparian forests were similar and both included more decomposition resistant litter types, specifically waxmyrtle (Myrica cerifera L.) and alder (Alnus serrulata (Ait.) Willd.). Decomposition rates did not differ between the individual successional stages.
Riparian forests are intimately associated with their hydroperiod. During flood events the riparian forest receives inputs of organic matter and sediment, and the amount of deposition may decrease along a distance gradient from the main stream channel. The differential amount of inputs could affect forest productivity. However, in these riparian forests, a distance gradient effect was not observed. Trends in herbaceous biomass were evident along a microtopographic moisture gradient. The ridge and swale microtopography prevalent in the younger riparian forests counteracted a distance from the stream channel gradient effect across the riparian forest.
This study provided knowledge of how carbon pools and fluxes change with riparian forest recovery from disturbance as well as through different seral stages. Implementing the findings of this study will enhance restoration evaluation efforts to ensure that these areas continue to provide the numerous benefits gleamed from them. / Ph. D.
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<b>70 years of succession: community assembly of an undisturbed oak-hickory forest</b>Morgan V Ritzi (20378907) 05 December 2024 (has links)
<p dir="ltr">Succession is a foundational idea in ecology and serves as way to study ecological community assembly. Here, we test the three alternative mechanisms for succession: (I) facilitation, where species arrival order is not random and can be categorized as falling into distinct stages of succession such as early and late species; (ii) tolerance, where species arrival is random, but species interactions that promote coexistence or exclusion determine the community structure through time, and; (iii) inhibition, where species arrival is once again random, but species hold space until they die, and only then can there be a change in species composition through colonization of gaps. To do this, we used a 70-year time series of succession in an oak-hickory forest system in northwest Indiana called the Ross Biological Reserve. Every ten years tree species identity and abundance were measured beginning in 1951. Non-metric multidimensional scaling (NMDS) revealed distinct periods of community assembly that we categorized as distinct early, mid, and late successional communities. We used an index of species co-occurrence (the checkerboard score) and found that early successional communities were largely random, while mid and late successional communities were characterized by nonrandom co-occurrence of species. Alpha and gamma richness increased, and species turnover rate also increased. Specific species relative abundance showed typical patterns of species abundance when classified by their successional status. We conclude that facilitation was the predominant mechanism at the landscape scale, while tolerance was more of a driver on a smaller local scale. We found no evidence of inhibition. Succession at the scale we have documented is difficult to study, because of the long times required to document change. More successional studies of this nature will benefit the field of community assembly and ecology as a whole.</p>
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Compositional Change of Ground Flora in Forest Ecosystems of Southeastern Ohio over Twenty YearsAndrew, Erin Elizabeth 11 August 2017 (has links)
No description available.
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Influence of landscape position on succession in forests undergoing mesophication in southeastern OhioPalus, James D. 28 August 2017 (has links)
No description available.
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Lianas hiperabundantes como filtros ecológicos para a sucessão secundária em fragmentos florestais degradados / Hyper-abundant lianas as ecological filters for secondary succession in degraded forest remnantsCesar, Ricardo Gomes 14 February 2014 (has links)
O histórico processo de destruição da cobertura vegetal das florestas tropicais restringiu parte significativa das formações naturais deste bioma a fragmentos florestais pequenos e isolados. Nesse contexto, espécies ruderais de lianas podem se proliferar e rapidamente cobrir o dossel da floresta, prejudicando os indivíduos arbóreos e estagnando ou até mesmo regredindo os processos de sucessão florestal. O presente trabalho busca analisar as barreiras ecológicas que impedem a sucessão florestal em fragmentos florestais degradados dominados por lianas hiperabundantes, fornecer subsídios para estratégias de intervenção visando à restauração da estrutura e composição destes fragmentos e avaliar os efeitos iniciais do corte de lianas na dinâmica e crescimento da comunidade arbórea florestal. Para isso, foram instaladas 35 parcelas em um fragmento de floresta estacional semidecidual degradado e isolado pertencente ao bioma da Mata Atlântica, sendo cinco parcelas instaladas em setores menos degradados, e 30 em setores degradados dominados por lianas hiperabundantes. Destas 30 parcelas, cortaram-se todas as lianas em 20 parcelas, e avaliou-se a chegada de sementes, emergência e estabelecimento de plântulas e crescimento dos indivíduos arbóreos comparativamente entre parcelas com e sem manejo de lianas. Parâmetros da comunidade arbórea foram correlacionados com a densidade de lianas a fim de entender as relações entre estas formas de vida. O tempo necessário para o manejo de lianas foi quantificado e correlacionado com parâmetros da floresta a fim de entender quais fatores afetam o rendimento operacional desta atividade e o plantio de mudas foi testado em parcelas com e sem lianas, como técnica complementar ao manejo. Por fim, analisou-se o efeito do corte de lianas na produção de serapilheira, abertura de dossel, mortalidade dos indivíduos arbóreos e estocagem de carbono na parte aérea dos indivíduos arbóreos. Lianas não afetam a chegada de sementes ou a emergência de plântulas em fragmentos florestais degradados, porém diminuem o estabelecimento de plântulas pioneiras (provavelmente por sombreamento); no entanto, indivíduos arbóreos pioneiros compartilham habitat com as lianas, enquanto que espécies não-pioneiras têm a estrutura e diversidade de suas populações correlacionadas negativamente com a densidade de lianas. A quantidade de homens-hora para o corte de lianas em fragmentos degradados é muito maior que valores estimados para fragmentos florestais conservados, e é inversamente correlacionada com a densidade e área basal das lianas e positivamente relacionado com a densidade e área basal dos indivíduos arbóreos. O corte de lianas alterou a abertura do dossel no curto prazo e a produção de serapilheira, além de aumentar a estocagem de carbono para indivíduos arbóreos menores. O corte de lianas não afetou a mortalidade dos indivíduos arbóreos. Lianas hiperabundantes podem estagnar e até mesmo retroceder a sucessão florestal em fragmentos florestais e o corte de lianas é uma estratégia efetiva para recuperar estes processos. No entanto o manejo deve ser feito de forma contínua, dada a elevada resiliência comunidade de lianas ruderais. O plantio de mudas apresentou alta mortalidade e só é recomendando em casos de elevada abertura de dossel e baixa densidade de indivíduos arbóreos estabelecidos. / The historical human-mediated loss of tropical forest cover has beleaguered significant portions of these biomes in small and degraded forest remnants scattered on the landscape. In this context, ruderal liana species may proliferate and quickly dominate forest canopy, hindering tree individuals and arresting or even reversing forest succession. This study aims at analyzing the ecological barriers that halt forest succession in degraded forest remnants dominated by hyper-abundant lianas, providing ground to develop intervention strategies to restore structure and composition of these remnants and assess the early effects of liana cutting on the dynamic and growth of the forest tree community. We installed 35 plots in a degraded and isolated semideciduous seasonal forest remnant, from which five were installed in less degraded sectors of the forest remnant and 30 were installed in degraded sectors, dominated by hyper-abundant lianas. We chose 20 out of the 30 plots to undergo cutting of all lianas. We compared seed arrival, seedling emergence and establishment and growth of established adult tree individuals among control and liana cutting plots. Tree community parameters were correlated with liana density in order to understand the relation of these two life forms in the degraded forest. Time required, in man-hours, for liana cutting was quantified and correlated with tree and liana community parameters in order to provide ground for estimating labor requirements in similar situations; seedling planting was tested as a complimentary restoration technique. Finally, we assessed the early effects of liana cutting on canopy openness, litter production, tree mortality and carbon stored in the tree community. Lianas do not affect seed arrival or seedling emergence in degraded forest remnants, however, they do increase pioneer seedling mortality (probably through shading); at the same time, established pioneer individuals share habitat with lianas, while non-pioneers have the structure and diversity of their community negatively correlated with liana density. Manhours needed for liana cutting in degraded forest remnants are much higher than estimates for mature forests, and it is inversely correlated with liana density and basal area and positively correlated with tree density and basal area. Early effects of liana cutting included increased canopy openness, reduced litter production and increased carbon uptake by smaller trees. Liana cutting did not affect established trees mortality. Hyper-abundant lianas may stagnate and even reverse forest succession in degraded forest remnants and liana cutting is an effective strategy to recuperate sucessional processes. However, liana cutting must be carried out periodically, given the high resilience of ruderal lianas populations. Seedlings planting had high mortality and it is recommended only when canopy openness is high and density of established tree individuals is low.
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Lianas hiperabundantes como filtros ecológicos para a sucessão secundária em fragmentos florestais degradados / Hyper-abundant lianas as ecological filters for secondary succession in degraded forest remnantsRicardo Gomes Cesar 14 February 2014 (has links)
O histórico processo de destruição da cobertura vegetal das florestas tropicais restringiu parte significativa das formações naturais deste bioma a fragmentos florestais pequenos e isolados. Nesse contexto, espécies ruderais de lianas podem se proliferar e rapidamente cobrir o dossel da floresta, prejudicando os indivíduos arbóreos e estagnando ou até mesmo regredindo os processos de sucessão florestal. O presente trabalho busca analisar as barreiras ecológicas que impedem a sucessão florestal em fragmentos florestais degradados dominados por lianas hiperabundantes, fornecer subsídios para estratégias de intervenção visando à restauração da estrutura e composição destes fragmentos e avaliar os efeitos iniciais do corte de lianas na dinâmica e crescimento da comunidade arbórea florestal. Para isso, foram instaladas 35 parcelas em um fragmento de floresta estacional semidecidual degradado e isolado pertencente ao bioma da Mata Atlântica, sendo cinco parcelas instaladas em setores menos degradados, e 30 em setores degradados dominados por lianas hiperabundantes. Destas 30 parcelas, cortaram-se todas as lianas em 20 parcelas, e avaliou-se a chegada de sementes, emergência e estabelecimento de plântulas e crescimento dos indivíduos arbóreos comparativamente entre parcelas com e sem manejo de lianas. Parâmetros da comunidade arbórea foram correlacionados com a densidade de lianas a fim de entender as relações entre estas formas de vida. O tempo necessário para o manejo de lianas foi quantificado e correlacionado com parâmetros da floresta a fim de entender quais fatores afetam o rendimento operacional desta atividade e o plantio de mudas foi testado em parcelas com e sem lianas, como técnica complementar ao manejo. Por fim, analisou-se o efeito do corte de lianas na produção de serapilheira, abertura de dossel, mortalidade dos indivíduos arbóreos e estocagem de carbono na parte aérea dos indivíduos arbóreos. Lianas não afetam a chegada de sementes ou a emergência de plântulas em fragmentos florestais degradados, porém diminuem o estabelecimento de plântulas pioneiras (provavelmente por sombreamento); no entanto, indivíduos arbóreos pioneiros compartilham habitat com as lianas, enquanto que espécies não-pioneiras têm a estrutura e diversidade de suas populações correlacionadas negativamente com a densidade de lianas. A quantidade de homens-hora para o corte de lianas em fragmentos degradados é muito maior que valores estimados para fragmentos florestais conservados, e é inversamente correlacionada com a densidade e área basal das lianas e positivamente relacionado com a densidade e área basal dos indivíduos arbóreos. O corte de lianas alterou a abertura do dossel no curto prazo e a produção de serapilheira, além de aumentar a estocagem de carbono para indivíduos arbóreos menores. O corte de lianas não afetou a mortalidade dos indivíduos arbóreos. Lianas hiperabundantes podem estagnar e até mesmo retroceder a sucessão florestal em fragmentos florestais e o corte de lianas é uma estratégia efetiva para recuperar estes processos. No entanto o manejo deve ser feito de forma contínua, dada a elevada resiliência comunidade de lianas ruderais. O plantio de mudas apresentou alta mortalidade e só é recomendando em casos de elevada abertura de dossel e baixa densidade de indivíduos arbóreos estabelecidos. / The historical human-mediated loss of tropical forest cover has beleaguered significant portions of these biomes in small and degraded forest remnants scattered on the landscape. In this context, ruderal liana species may proliferate and quickly dominate forest canopy, hindering tree individuals and arresting or even reversing forest succession. This study aims at analyzing the ecological barriers that halt forest succession in degraded forest remnants dominated by hyper-abundant lianas, providing ground to develop intervention strategies to restore structure and composition of these remnants and assess the early effects of liana cutting on the dynamic and growth of the forest tree community. We installed 35 plots in a degraded and isolated semideciduous seasonal forest remnant, from which five were installed in less degraded sectors of the forest remnant and 30 were installed in degraded sectors, dominated by hyper-abundant lianas. We chose 20 out of the 30 plots to undergo cutting of all lianas. We compared seed arrival, seedling emergence and establishment and growth of established adult tree individuals among control and liana cutting plots. Tree community parameters were correlated with liana density in order to understand the relation of these two life forms in the degraded forest. Time required, in man-hours, for liana cutting was quantified and correlated with tree and liana community parameters in order to provide ground for estimating labor requirements in similar situations; seedling planting was tested as a complimentary restoration technique. Finally, we assessed the early effects of liana cutting on canopy openness, litter production, tree mortality and carbon stored in the tree community. Lianas do not affect seed arrival or seedling emergence in degraded forest remnants, however, they do increase pioneer seedling mortality (probably through shading); at the same time, established pioneer individuals share habitat with lianas, while non-pioneers have the structure and diversity of their community negatively correlated with liana density. Manhours needed for liana cutting in degraded forest remnants are much higher than estimates for mature forests, and it is inversely correlated with liana density and basal area and positively correlated with tree density and basal area. Early effects of liana cutting included increased canopy openness, reduced litter production and increased carbon uptake by smaller trees. Liana cutting did not affect established trees mortality. Hyper-abundant lianas may stagnate and even reverse forest succession in degraded forest remnants and liana cutting is an effective strategy to recuperate sucessional processes. However, liana cutting must be carried out periodically, given the high resilience of ruderal lianas populations. Seedlings planting had high mortality and it is recommended only when canopy openness is high and density of established tree individuals is low.
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Wildland Fire Disturbance - Recovery Dynamics in Upland Forests at Acadia National Park, MaineCharpentier, Jessica E. 16 May 2020 (has links)
No description available.
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Dynamic Multi-species Animal Habitat Modeling with Forest Succession ModelsCompton, Stephen A. 01 May 1992 (has links)
This research determines and demonstrates the ability to simulate dynamic multispecies animal habitat suitability with forest succession models. A literature review of dynamic animal habitat models is presented. The structure of an existing forest simulation model (MASS10) was modified from a basal area-based model to a volume-based model (DYNAM10). The forest model was calibrated using data from permanent-plot growth and vegetation samples collected by USDA Forest Service Forest Survey procedures. The theoretical growth parameters used to simulate stand development were validated. Predictions of DBH and height growth, as well as stand-level behavior, were verified. A subroutine, VEGDYN, was added to DYNAMlO to simulate 34 structural vegetation parameters required by animal Habitat Suitability Index (HSI) models. Predictions of the structural parameters were verified. Ten animal-species HSI models were linked to DYNAMlO via the program HSI.FOR, and predicted dynamic HSI values were verified by hand-calculation. Typical patterns of dynamic HSI predictions are presented and discussed.
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É possível reverter a degradação do solo provocada pela mineração de bauxita por meio da restauração florestal? / Is it possible to reverse soil degradation caused by bauxite mining through forest restoration?Bizuti, Denise Teresinha Gonçalves 16 November 2016 (has links)
A mineração é uma das atividades antrópicas mais impactantes aos recursos naturais, e que pode afetar profundamente a resiliência dos ecossistemas em função do elevado nível de degradação do solo e da paisagem. Diante disso, muitas áreas mineradas não são efetivamente recuperadas a ponto de restabelecer parte relevante da biodiversidade e dos serviços ambientais perdidos com a mineração. No entanto, novos métodos de restauração ecológica têm gerados resultados promissores mesmo em situações de degradação tão intensa como as de mineração, o que permitiria rever os níveis mínimos de qualidade ambiental exigidos de áreas que foram mineradas e que precisam passar por um processo de recuperação como forma de mitigação dos impactos causados e cumprimento de demandas legais de compensação ambiental. Assim, o objetivo geral desse estudo é avaliar a recuperação física, química e microbiológica do solo em áreas de mineração de bauxita em processo de recuperação ambiental. Avaliamos inicialmente a restauração do solo em minas de bauxita localizadas em Poços de Caldas-MG, tendo como objetivo contextualizar a melhoria do solo através de vários parâmetros químicos, físicos e microbiológicos em áreas recém-mineradas, em restauração de diferentes idades e remanescentes de floresta nativa. Encontramos que a restauração florestal foi eficiente em desencadear um processo de recuperação do solo, que resultou no restabelecimento, em poucos anos, de características químicas, físicas e microbiológicas já bem similares às do ecossistema de referência. Em seguida, avaliamos a recuperação dos teores de fósforo no solo pela restauração de florestas tropicais em minas de bauxita, e obtivemos como principais resultados a recuperação de importantes frações de P no solo, parte relevante da produção de serapilheira e da estrutura da floresta ao longo da trajetória sucessional nas jovens áreas restauradas após a mineração. A restauração ecológica mostrou-se capaz de restaurar rapidamente importantes atributos do solo, evidenciando o potencial da abordagem de restauração ecológica para mitigar os impactos ambientais negativos da mineração. Dessa maneira, destaca-se que políticas públicas voltadas para a mitigação de danos ambientais causados pela mineração podem exigir níveis mais elevados de qualidade ambiental em áreas de recuperação de minas, protegendo os interesses coletivos envolvidos na mediação de interesses entre empresas e sociedade. / Mining is one of the human activities with the highest impact in natural resources. It can profoundly affect the resilience of ecosystems due to the high level of soil degradation and landscape alteration. Thus, many mined areas are not effectively recovered enough to restore important part of biodiversity and ecosystem services lost. However, new ecological restoration methods showed promising results even in such intense degradation situations such as mining. Thus, it is needed to review the minimum levels of environmental quality required for areas that have been mined and need to recovered to mitigate the impacts and compliance with legal demands of environmental compensation. Thus, the general objective of this study is to evaluate the physical, chemical and microbiological soil in bauxite mining areas under ecological restoration. We initially evaluated soil restoration in bauxite mines located in the county of \"Poços de Caldas\", aiming to contextualize soil improvement through various chemical, physical and microbiological parameters in newly mined areas, restoration of different ages and remaining native forest. We found that forest restoration was effective in triggering a soil recovery process, which resulted in the recuperation, in a few years, of the chemical, physical and microbiological characteristics already very similar values to the references. We then evaluated the recovery of soil phosphorus for the restoration of tropical forests in bauxite mines, and obtained as main results the recovery of important fractions of soil P, litter production and forest structure along the successional trajectory in young restored areas after mining. Ecological restoration proved to be able to quickly restore important soil properties, showing the potential of ecological restoration approach to mitigate the negative environmental impacts of mining. Thus, it is emphasized that public policies to mitigate environmental damage caused by mining may require higher levels of environmental quality in mining recovery areas, protecting the collective interests involved in the mediation of interests between business and society.
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Caracterização florística e fitossociológica de uma área em processo de restauração florestal comparada a uma área em sucessão secundária (regeneração natural) no Sul do Brasil / Floristic and phytosociological description of an area undergoing forest restoration compared to an area under secondary succession (natural regeneration) in Southern BrazilAna Flávia Boeni 03 February 2016 (has links)
Com a intensa degradação histórica dos ecossistemas naturais esforços mundiais estão sendo unidos para a restauração dos ecossistemas degradados. Em vista dessa demanda crescente por restauração florestal e pela diminuição dos custos que dela decorrem, o trabalho objetivou descrever e distinguir a composição florística e fitossociológica atual de uma área em processo de restauração pelo método de plantio total e de outra imediatamente ao lado que foi abandonada e está se recuperando somente pela regeneração natural. Ambas as áreas eram talhões de eucaliptos que foram colhidos há 8 anos, na região da serra do Rio Grande do Sul, que pelas limitações de terreno ainda abrigam diversos remanescentes florestais. A coleta dos dados foi realizada num Horto Florestal do município de Canela. Foram alocadas sistematicamente 20 parcelas de 10 x 10m (100m²) nos locais onde foi realizado o plantio (AP) e 20 parcelas onde ocorreu o estabelecimento da regeneração natural (ARN). Em cada parcela de 100 m² foram coletados dados de todos os indivíduos arbustivo-arbóreos com Diâmetro a Altura do Peito (DAP) ≥ 4,8 cm, os quais tiveram suas alturas totais estimadas. Os exemplares foram identificados e classificados conforme seu grupo (plantados, regenerantes, rebrotas ou remanescentes), sua posição (dossel, sub-bosque ou situados em clareiras) e tamanho de copa (grande, média e pequena). Para amostragem do estrato regenerante, em cada parcela de 100m² foram alocadas duas sub-parcelas de 2 x 2m (4m²), onde todos os indivíduos de altura acima de 0,3 m até DAP = 4,7 cm foram levantados. Todos os indivíduos foram classificados conforme a categoria de status sucessional de suas espécies em: pioneiras, secundárias iniciais, clímácicas e típicas de sub-bosque, bem como segundo a síndrome de dispersão em: zoocóricas (dispersas por animais), anemocóricas (dispersas pelo vento) e autocóricas (mecanismos próprios). Os parâmetros fitossociológicos foram calculados, como densidade, dominância, frequência, valor de cobertura e de importância, além da riqueza de espécies, indicador Jackknife 1 e dos índices de Shannon, Pielou, similaridade de Jaccard e Chao-Jaccard. A densidade, área basal, proporções de categorias sucessionais, síndromes de dispersão, tamanhos de copa, área de projeção de copa e grupos, foram comparados entre as duas áreas utilizando Modelos Lineares Generalizados. Como a paisagem é basicamente composta por florestas maduras, e as áreas de estudo estão localizadas lado a lado, os parâmetros riqueza, diversidade de espécies, densidade de indivíduos, área basal, cobertura florestal e proporções de grupos funcionais (categorias de status sucessional e síndromes de dispersão) praticamente não apresentaram diferenças significativas entre as duas áreas, tanto no estrato arbustivo-arbóreo quanto no estrato regenerante. Os resultados demonstram que neste contexto, o plantio total de mudas não foi necessário para o objetivo de restaurar a estrutura florestal, composição florística e processos ecológicos. Porém mostram a importância de se analisar os fatores como objetivos, composição da paisagem, uso histórico do solo e potencial de regeneração da área a ser restaurada para aproveitar-se do potencial da regeneração natural quando essas condicionantes forem atendidas, o que pode diminuir custos da restauração florestal e torná-la mais atrativa. / Because of the intense historical degradation of natural ecosystems, worldwide efforts are being joined for the restoration of degraded lands. Driven by the growing demand for forest restoration and for the need of reducing its costs, this study aimed to describe and distinguish the current phytosociological aspects and floristic composition of an area undergoing restoration using the total seedling plantation method and an adjacent secondary forest regenerating naturally in abandoned area. Both areas are former Eucalyptus sp. stands that were harvested eight years ago, in the mountainous of Rio Grande do Sul, Brazil, which still shelters many forest remnants, because of the terrain characteristics. The study sites are located in a reserve in Canela, RS, Brazil. Twenty 10 x 10 m plots (100m²) were systematically allocated in the plantations site (AP) and another 20 plots were allocated in the natural regeneration site (ARN). In each plot, all shrub and tree individuals with Diameter at Breast Height (DBH) ≥ 4.8 cm were measured (diameter and total height). The individuals were classified into planted, regenerating, sprouts or remnant, classified according to their position (canopy, understory or located in clearings) and also according to crown size (large, medium and small). For sampling the regenerative stratum, two sub-plots (2 x 2 m; 4 m²) were allocated in each plot, within which all individuals taller than 0.3 m and of DBH smaller than 4.7 cm were measured. All specimens were classified according to their sucessional categories into pioneers, early secondary, climax and typical understory species, and according to their dispersion syndrome into zoochoric, anemochoric and autochoric. After sampling, the following phytosociological parameters were calculated: density, frequency, dominance, coverage and importance value, and also species richness and the indexes of Shannon, Pielou, Jaccard and Chao-Jaccard. Density, basal area, proportions between successional categories, dispersal syndromes, crown sizes, forest cover and groups were compared between the two areas using Generalized Linear Models. As the landscape is basically composed of mature forests, and the study sites are adjacent, the richness parameters, species diversity, density, basal area, forest cover and proportion of functional groups (successional status categories and dispersion syndromes) showed practically no significant differences between the sites, considering both the shrub-tree layer and the regenerative stratum. The results demonstrate that, in this context, the plantation of seedlings in total area was not necessary to restore the forest structure, floristic composition and ecological process. Nevertheless, they show the importance of analyzing factors such as the goal, landscape composition, historical land use and resilience of a degraded land in order to take advantage of its natural regeneration potential when these conditions are met, which may decrease restoration costs and also make it more attractive.
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