Made available in DSpace on 2014-07-29T14:39:36Z (GMT). No. of bitstreams: 1 Thiago Ferreira da Silva.pdf: 1159087 bytes, checksum: aaa7f15e2b0ec95b66d6921b223533b5 (MD5) Previous issue date: 2011-08-25 / (The soil effects on the community structure and the regenerate species distribution in the riparian forests of the basin of Claro River, in Jataí, Goiás State, Brazil). The study was performed in two remnants of the riparian forest and goal to check the structure variations and the regenerate species distribution and possible correlations between the edaphic variables between two established treatments river banks and inside the forest. All the individuals with DBH (diameter at breast height) < 5 cm and height superior to 1m were sampled in 40 plots of 5×5 m2 (a total of 0,01 hectare). Analyses of the chemical and textural soil properties were performed (0-20 cm depth). Comparisons between the two treatments showed differences in diversity index, density and distribution per diameter classes. An canonic correspondence analysis (CCA) indicated that the abundance of species varies according to the gradient of chemical and textural soil properties by both river banks and inside the forest. Some species had an abundance associated to a certain treatment and other species had significant correlations with Al, P, MO proportions, saturation of bases, sand and clay, which suggests that the chemical and textural properties influence the distribution of those species. NOTE: Essay with two chapters. This is a summary of the 1st chapter. / (Efeitos do solo na estrutura da comunidade e distribuição de espécies regenerantes nas matas ciliares da Bacia do Rio Claro, Jataí, GO). O estudo foi realizado em dois remanescentes de mata ciliar na Bacia do Rio Claro, sudoeste goiano, e teve o objetivo de verificar as variações da estrutura e distribuição de espécies regenerantes e possíveis correlações entre as variáveis edáficas entre dois tratamentos estabelecidos: margem de rio e interior de floresta. Todos os indivíduos regenerantes com DAP (diâmetro à altura do peito) < 5 cm e altura superior a 1m foram amostrados em 40 parcelas de 5×5 m2 (um total de 0,01 ha). Foram feitas análises das propriedades químicas e texturais dos solos para cada parcela (0-20 cm de profundidade). Comparações entre os dois tratamentos mostraram diferenças para índice de diversidade, densidade de indivíduos regenerantes e distribuição por classes de diâmetro. Uma análise de correspondência canônica (CCA) indicou que a abundância das espécies variou em função do gradiente de propriedades químicas e texturais dos solos da margem do rio e do interior de floresta. Algumas espécies tiveram abundância associada a um determinado tratamento e outras produziram correlações significativas com proporções de Al, P, MO, saturação por bases, areia e argila, sugerindo que propriedades químicas e texturais dos solos influenciam a distribuição dessas espécies. OBS: Dissertação com 2 capítulos. Este é o resumo do 1º capítulo.

Como uma das ações voltadas à restauração de Áreas de Preservação Permanente (APPs) degradadas do ribeirão Campestre em Saltinho-SP, o presente trabalho construiu, de forma participativa, e avaliou em campo indicadores de avaliação e monitoramento do Potencial de Auto-Recuperação (PAR) de 4 APPs em diferentes estágios de degradação. Inicialmente, por meio de entrevistas semi-estruturadas, exploramos e relacionamos alguns elementos constitutivos da Campesinidade e do Conhecimento Ecológico Local (CEL) dos agricultores interessados em restaurar suas próprias APPs. Os indicativos dessa relação sugerem que a construção de espaços que potencializem a contribuição do CEL em projetos de recuperação de APPs podem ser planejados de acordo com a campesinidade de cada grupo social envolvido. A contribuição do CEL foi levantada a partir da Representação Social dos agricultores participantes sobre sucessão secundária e foi orientada, por meio de um roteiro de entrevista, à construção de indicadores de avaliação e monitoramento do PAR de cada uma das áreas estudadas. Observamos por esta metodologia que o entendimento dos processos ecológicos e os indicadores propostos pelos agricultores guardam correspondência com conhecimento acumulado pela academia. Avaliamos em campo os 7 indicadores sugeridos pelos agricultores que mais se relacionavam à literatura correspondente. Destes indicadores destacaram-se: a) distância e estado de conservação dos fragmentos próximos; b) avifauna; c) umidade relativa do solo e; d) regeneração natural, por representarem melhor o PAR de cada área estudada. Por fim, avaliamos 4 diferentes intervenções, idealizadas pelos agricultores participantes em suas próprias APPs, com propósito de acelerar o processo de restauração ecológica e observamos que, as intervenções dos agricultores de maior campesinidade e, portanto, de maior CEL, apresentaram melhores resultados. / As one the actions aimed to the recovery of degraded Permanent Preservation Areas (PPA's) in Ribeirão Campestre, Saltinho, this dissertation built a mean, participatively, and assessed, in the field, evaluating indicators and the monitoring of the Potential of Self-Recovery (PSR) of 4 PPA's in different stages of degradation. Initially, by means of semi-structured interviews, some constitutive elements of Peasantry and of Local Ecological Knowledge (LEK) of agriculture workers interested in restore their own PPA's were explored. The indicators of such relation suggest that the construction of spaces to potentialize the contribution of LEK in projects aiming the recovering of PPA's may be planned according to the Peasantry of each social group involved. LEK contribution was raised from the Social Representation of participating agriculture workers over secondary succession and was guided, through a script of interview, to the construction of evaluating indicators and monitoring of PSR of each area analyzed/studied. Through this methodology, it was observed that the understanding of ecological processes and the indicators proposed by the agriculture workers have correspondence with the Knowledge added by Academy. It was evaluated, in field, 7 indicators proposed by the agriculture workers that were most related to the correspondent literature. Among these indicators, the following ones are highlighted: a) distance and state of conservation of close fragments; b) avifauna; c) relative humidity of the soil and; d) natural regeneration, for it best represents the PSR of each area analyzed/studied. Finally, 4 different interventions were evaluated, idealized by the participating agriculture workers on their own ppa's, aiming to speed-up the process of ecological restoration and it was observed that the interventions of the agriculture workers with highest level of Peasantry, thus highest LEK, presented better results.

A Euterpe edulis (palmeira juçara) é uma espécie de alta densidade na Floresta Atlântica e sofre processo de extinção devido ao desmatamento e ao corte ilegal para a extração do palmito. Uma alternativa para conservação é o manejo sustentável, utilizando seus frutos para a produção de polpa. O objetivo do trabalho é fornecer subsídios de mensuração para um sistema de manejo, visando à produção de frutos e polpa, através de modelos preditivos e, avaliação da estrutura, dinâmica e a regeneração natural das palmeiras. O levantamento foi realizado no Sertão do Ubatumirim, Ubatuba-SP, em uma área de bananal e uma de floresta secundária, durante 2011 e 2012. Para a construção dos modelos, foram selecionadas matrizes produtoras acompanhadas durante o período de frutificação. Foram coletadas medidas dendrométricas e os frutos maduros foram colhidos, pesados, despolpados e analisada sua massa seca. Foi avaliada qualitativamente a luminosidade recebida pelas matrizes. Foram ajustados e selecionados modelos para a predição da biomassa dos frutos e polpa seca. As variáveis preditoras foram: DAP, altura, e as indicadoras: área, ano e luz, com efeito simples e de interação. As variáveis resposta foram modeladas por regressão linear, com e sem transformação logarítmica. Os critérios de seleção dos modelos foram o coeficiente de determinação ajustado e o valor do Critério de Informação de Akaike (AIC). Para o levantamento das populações, em cada área foram locadas dez parcelas circulares, com 14m de raio, sendo mensuradas e identificadas as espécies arbóreas com DAP >= 5cm. Dentro das parcelas instituiu-se subparcelas para a amostragem da regeneração natural da juçara; com raio de 4,5m para os estádios de desenvolvimento das varas e arvoretas e raio de 3m para plântulas e mudas. Foi estimada a taxa de mortalidade de toda população e das palmeiras adultas. De cada estádio estimou-se os indivíduos por hectare e taxa de mudança anual. A regeneração encontrada foi comparada com uma estrutura padrão, sem ações antrópicas. Foi estimada a biomassa de frutos e de polpa da juçara nas áreas estudadas através de modelos lineares. Os modelos com transformação logarítmica apresentaram bons ajustes sendo os mais adequados os que utilizaram a combinação da variável indicadora altura ou variável combinada (diâmetro ao quadrado vezes altura). Os resultados mostraram efeito de interação da variável combinada e variável ano, o que indicou efeito nulo no ano de alta produtividade. Independente do tamanho das palmeiras, a produção foi igual, e efeito positivo crescente no ano de baixa produtividade. Os levantamentos mostraram que a área de formação secundária possui maior riqueza de espécies que a do bananal, com uma área basal duas vezes maior e menor taxa de mortalidade. Em ambas as áreas, os estádios plântulas e regeneração não se assemelham à população padrão, resultados estes mais drásticos na área do bananal. Isto pode levar à redução da população, com risco de desaparecimento. Na estimativa produtiva dos frutos por matriz, verificou-se o aumento entre os anos de produção. Quando se considera a produção por hectare, ocorre diminuição da produção na área do bananal devido a elevada mortalidade. / Euterpe edulis (juçara palm) occurs in hight density populations in the Atlantic Forest, but due the illegal exploration of its heart palm is a extinction threaten species. An alternative for its conservation is the sustainable management of its populations for fruit production. This study aims to provide measurement and biometric information for the development of a sustainable management system for fruit harvest. Prediction models for fruit and fruit pulp production were developed and the structure and natural regeneration of two populations were studied. The study was carry out in \"Sertão do Ubatumirim\", Ubatuba, in the state of São Paulo, where a banana plantation and a secondary forest were surveyed in the years 2011 and 2012. In order to develop the fruit prediction models, producing fruit palm trees were monitored throughout the period of fructification. Height and diameter measurements were taken in these trees and the ripe fruits were harvested, weighted, pulped and the fruit pulp dry weight was determined. The light intensity received by each tree was qualitatively determined by a ordinal scale with 5 levels. Prediction models for fruit biomass and fruit pulp dry weight were fitted by linear regression. Prediction quantitative variables were diameter (DBH) and height, while prediction qualitative variables, add to the model as indicator variables, were: forest type (banana plantation and secondary forest), harvest year (2011 and 2012) and light intensity. The criteria for selection of the models were adjusted coefficient of determination and the value of the Akaike Information Criteria (AIC). For the population surveys, circular plots of 14m radius were located in the study area, and all trees with DBH equal or greater than 5cm were measured and had its species identified. For the survey of juçara natural regeneration, circular subplots of 4.5m radius, concentric to adult tree plots, were established to enumerate small trees and saplings, and circular subplots of 3m radius were established to enumerate seedlings and small seedlings. Mortality rate was estimated of the entire population and adult juçara palms. For each plant development stage (tree, small tree, sapling, seedling and small seedling), the number of individuals and the annual change rate were also estimated. Best prediction models for individual palm tree fruit and fruit pulp production were logarithmic models, and prediction variable was tree height, followed by the combined variable (squared diameter times height). There was a clear interaction effect of the quantitative prediction variable (combined variable) and the qualitative prediction variable year, as indicator variable. In the hight production year, the quantitative prediction variable was not relevant for fruit and fruit pulp prediction, while in the low production year, there was a positive relationship between production and the quantitative prediction variable. Study sites were very different in forest structure and dynamics. As expected, the secondary forest site had higher species richness than the banana plantation site, as well lower mortality rate and twice its basal area. Compared to what is expected to sustainable juçara populations without human influence, both sites showed lower number of regenerating individuals (seedlings and small seedlings). Over the years, this fact, combined to the harvest of fruits for fruit pulp production, can represent risk to the sustainability of juçara populations in the study sites.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study evaluated the mechanisms of natural regeneration represented by seeds rain, seeds bank of the soil and the regeneration vegetation, considering the seedlings bank and the established regeneration, in a fragment of Estacional Decidual Forest. The evaluation was made with 70 randomized samplings in 14 parcels inside four bands, with systematic distribution in the area. The seeds rain was studied using 70 collectors with 1 m x 1 m, the collected material was analyzed monthly, during a year. In the seeds bank was collect 70 samplings using an iron collector (25 x 25 cm) on the soil surface and adjusting the studied samplings to 5 cm of deep. The collected material was taken to the Laboratory of Silvicultura of the Departament of Ciências Florestais of the Federal University of Santa Maria, where it was evaluated during seven months. The seeds bank was evaluated in 70 sampling units of 2 x 2 m where was identified and measured all plants with h ≥ 30 cm and DBH < 1 cm, the natural regeneration in the area was evaluated in 70 sampling units of 5 x 5 m, in which were identified and measured all plants with 1cm ≤ DBH ≤ 5 cm. The regeneration mechanisms were analyzed in groups formed in the adult vegetation. In the seeds rain it was observed the presence of 73 species, mainly trees. The seeds bank of the soil show predominance of herbaceous species, and some trees and bush-like species, pioneer species and secondary species. In the seedlings bank, was observed the presence of light demanding tree species and eciofiles species, while in the established natural regeneration the predominance was of shadow species. The seed bank of the soil and the established natural regeneration show different comportment for the group 1 and 2 in the adult vegetation, while the seeds rain and seedlings bank show uniformity in the forest. The species with the bigger probability to perpetuate in the studied forest reminiscent and in the near areas were Gymnanthes concolor, Soroceae bonplandii, Eugenia rostrifolia, Trichilia claussenii, Trichilia elegans, Myrocarpus frondosus, Cupania vernalis, Nectandra megapotamica and Dasyphylum spinescens, these species can be used to enrichment and recuperation of the forest. The most restricted species were Cordia tricotoma, Luehea divaricata, Sebastiania commersoniana and Syagrus rommanzoffiana, these species may grow in the forest if used the right treatments to their perpetuation. The indicative species in the adult vegetation groups have the seeds rain and the seedlings bank as the main mechanisms for their conservation in the forest reminiscent. / Este estudo avaliou os mecanismos de regeneração natural, representada pela chuva de sementes, banco de sementes do solo, e vegetação em regeneração, considerando banco de plântulas e regeneração natural estabelecida, em remanescente de Floresta Estacional Decidual. A avaliação foi realizada em 70 subparcelas, aleatorizadas em 14 parcelas, dentro de 4 faixas distribuídas sistematicamente, na área. A chuva de sementes foi estudada em 70 coletores de 1 m x 1 m, cujo material era coletado mensalmente para avaliação, no curso de um ano. No banco de sementes do solo foram coletados 70 amostras, a partir de um gabarito de ferro (25 x 25 cm), que colocado sob a superfície do solo permitia a padronização da área para coleta em 5 cm de profundidade. O material coletado foi levado para o Laboratório de Silvicultura do Departamento de Ciência Florestais da Universidade Federal de Santa Maria, onde foi avaliado durante 7 meses. O banco de plântulas foi avaliado em 70 unidades amostrais de 2 x 2 m, onde identificaram-se e mediram-se todos os indivíduos com h ≥ 30 cm e DAP < 1 cm. A regeneração natural estabelecida foi avaliada em 70 unidades amostrais de 5 x 5 m. Nestas, identificaram-se e mediram-se todos os indivíduos com 1cm ≤ DAP < 5 cm. Os mecanismos de regeneração foram analisados em agrupamentos, formados na vegetação adulta. Na chuva de sementes, observou-se a presença de 73 espécies, principalmente, arbóreas. O banco de sementes do solo teve predomínio de espécies herbáceas, além de arbóreas e arbustivas, espécies pioneiras e secundárias iniciais. No banco de plântulas observou-se a presença de espécies heliófilas e eciófilas, enquanto na regeneração natural estabelecida foi verificado o predomínio de espécies de sombra. O banco de sementes do solo e a regeneração natural estabelecida apresentaram comportamento diferente para o grupo 1 e 2 da vegetação adulta, enquanto a chuva de sementes e banco de plântulas apresentaram uniformidade na floresta. As espécies com maior potencialidade para perpetuar no remanescente de floresta estudado foram Gymnanthes concolor, Soroceae bonplandii, Eugenia rostrifolia, Trichilia claussenii, Trichilia elegans e Dasyphylum spinescens, sendo indicadas para enriquecimento. As espécies com maior restrição, foram Cordia tricotoma, Myrocarpus frondosus, Cupania vernalis, Nectandra megapotamica, Luehea divaricata, Sebastiania commersoniana e Syagrus rommanzoffiana, dependendo de tratamentos silviculturais na floresta para garantir sua perpetuação. As espécies indicadoras dos agrupamentos, na vegetação adulta, têm a chuva de sementes e banco de plântulas como principais mecanismos de conservação das espécies no remanescente.

Les dernières décennies représentent un tournant majeur concernant les invasions biologiques avec une augmentation sans précédent de leur rythme et de leur ampleur, en lien direct avec les activités humaines, en particulier la mondialisation. Certains invasifs se propagent à une vitesse très rapide dans leur nouveau milieu. L’invasion européenne de la punaise Leptoglossus occidentalis, illustre parfaitement ce phénomène et offre un modèle d’étude particulièrement intéressant. Cette thèse a pour but de tester des hypothèses permettant d’expliquer la rapidité de cette invasion. Pour répondre à cet objectif, nous avons choisi d’utiliser une approche pluridisciplinaire combinant des études de génétique des populations (natives et introduites) à des études de biologie et d’écologie des populations invasives. Grâce à l’utilisation de marqueurs moléculaires et de méthodes Bayésiennes (ABC), nous démontrons que l’invasion en Europe suit un scénario " tête de pont ", au sens où la population invasive de l’Est de l’Amérique du Nord a servi de source pour l’invasion européenne. Nos résultats confirment les soupçons d’introductions multiples dans des zones géographiquement déconnectées. En outre, l’étude de génétique des populations, associée aux mesures expérimentales des capacités de vol, indique que les capacités intrinsèques de dispersion de cette espèce sont particulièrement élevées. Les conditions rencontrées en Europe par les populations introduites ne sont pas un frein à l’invasion. L’espèce s’accommode parfaitement des nouvelles essences de conifères rencontrées sur le continent. La polyphagie observée dans la zone native est confirmée dans la zone d’introduction européenne, constituant un atout pour l’établissement des populations. De plus, cette étude révèle les risques écologiques que cette espèce représente pour la flore native européenne. Les dégâts occasionnés semblent s’additionner à ceux des ravageurs natifs, diminuant ainsi le potentiel de régénération naturelle. L’ensemble de ces résultats constitue une contribution à la connaissance des mécanismes sous-tendant les invasions biologiques, notamment sur la rapidité de propagation de certains invasifs, et met l’accent sur des phénomènes sous-estimés il y a encore peu de temps comme le scénario d’invasion " tête de pont ". / During the last decades, biological invasions were observed to increase exponentially, at an unprecedented rate and magnitude, in direct relation with the human activities, especially globalization. In this context, some invasive species spread very quickly in the area of introduction. The European invasion of Leptoglossus occidentalis is a good example of this phenomenon. This study aimed at testing some hypotheses to explain the rapidity of this invasion. To reach this goal, we used a multidisciplinary approach combining population genetics (analyzing samples from native and invaded areas) with a study of biological and ecological characteristics of the invasive populations. Through the use of molecular markers and Bayesian methods (ABC), we confirmed previous suspicions and demonstrated that the European invasion proceeded from multiple introductions in distant geographic areas. Our results also indicated that a primarily invaded area of Eastern North America acted as a bridgehead for the invasion in Europe. Moreover, population genetics, combined with an experimental measurement of the bug flight capabilities using flight mills, revealed that the intrinsic capacities of dispersion of this species are particularly high. The environmental conditions of the newly invaded areas in Europe did not constitute a barrier to the invasion of L. occidentalis. Its high degree of polyphagy was confirmed on European conifers, quite all species being susceptible to be exploited, thus favoring population establishment. . Furthermore, this study highlights the ecological threat represented by this insect which can affect the native flora in Europe. Actually, bug damage which can be important, seems to be additive to those of native insects exploiting cone and seed resources, thus decreasing the potential of natural regeneration. This work contributes to improve knowledge on biological invasions, especially to understand the reasons underlying the rapid spread observed in some invasive species, and highlights phenomenon underestimated until recently such as the Bridgehead scenario.

Orientadores: Carlos Alfredo Joly, Flavio Antonio Maës dos Santos / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-27T11:17:29Z (GMT). No. of bitstreams: 1 Vinha_Daniella_D.pdf: 19806435 bytes, checksum: af3818b4640c3acda5f09a0580ff9346 (MD5) Previous issue date: 2015 / Resumo: Estudos prévios demonstraram baixa sazonalidade na frutificação em florestas tropicais não-sazonais, o que poderia influenciar o padrão temporal e espacial da chuva de sementes e do banco de sementes. Entretanto, esses processos não são conhecidos. O objetivo desse estudo foi determinar como ocorre a regeneração natural via sementes em uma floresta tropical Montana no Parque Estadual da Serra do Mar. Foram testadas as hipóteses: (1) a sazonalidade na chuva de sementes é fraca ou ausente e esse padrão não se diferencia dentro dos modos de dispersão; (2) o banco de sementes é florísticamente relacionado com a chuva de sementes e espacialmente acoplado; (3) o banco de sementes apresenta baixa sazonalidade e esse padrão não difere dentro dos modos de dispersão. Em 2 hectares de floresta, nós registramos o total de 29959-62904 diásporos na chuva de sementes (104-106 spp.), 1029-2999 diásporos no banco de sementes da serapilheira (36-38 spp.) e 6288-7824 plântulas no banco de sementes do solo (74-82 spp.) ao longo de dois anos. Asteraceae, Urticaceae e Melastomataceae foram abundantes na chuva de sementes (63-81%), no banco de sementes da serapilheira (70-73%) e no banco de sementes do solo (77-84%). A maior riqueza de espécies foi de arbóreas na chuva de sementes (59-61%) e banco de sementes da serapilheira (72-68%), e de herbáceas no banco de sementes do solo (ca. 55%). Houve maior proporção de sementes arbóreas em todas as vias de regeneração, assim como maior riqueza de espécies zoocóricas (mais de 50%). Entretanto, a anemocoria contribuiu com a maior proporção do total de sementes no banco de sementes do solo (ca. 75%) e da chuva de sementes de uma das áreas (64%). Houve sazonalidade na chuva de sementes com um único pico na abundância (Out-Nov). Esse padrão foi reforçado pela sazonalidade na abundância e riqueza de espécies da chuva de sementes anemocórica e zoocórica, ambas ocorrendo no período de maior precipitação. A chuva de sementes influenciou a composição de espécies das sementes contidas na serapilheira e no solo. Entretanto, o acoplamento espacial entre as vias de regeneração ocorreu somente em uma das áreas. O banco de sementes não apresentou variações na composição florística e houve fraca variação temporal na densidade e riqueza de espécies, repercutindo igualmente dentro dos modos de dispersão. Esse estudo demonstrou que a chuva de sementes pode ser sazonal em condições de baixa sazonalidade ambiental, independente do modo de dispersão das sementes. A relação entre composição da chuva de sementes e das sementes contidas na serapilheira e no solo revela que essas vias são interligadas e dependentes entre si, resultando em padrões espaciais agrupados. Como resultado, a baixa variação temporal do banco de sementes não pode ser atribuída à baixa sazonalidade na chuva de sementes. O fato de não haver acúmulo de sementes no solo após o período de dispersão sugere o baixo tempo de permanência das sementes. Por outro lado, a falta de acoplamento espacial em uma das áreas sugere processos de pós-dispersão atuando na reestruturação espacial do banco de sementes / Abstract: Previous studies have demonstrated low seasonality in the fruiting phenology in aseasonal tropical forests, which could influence the spatial and temporal pattern of seed rain and seed bank. However, these processes are poorly known. The aim of this study was to determine seed natural regeneration in an Atlantic tropical Montane forest located in southeast of Brazil, Serra do Mar State Park. The hipotheses were tested: (1) seasonality of seed rain is weak or absent and this pattern is no different within the dispersal modes; (2) the floristic composition of seed bank is closely related with seed rain and there is a spatial association between them; (3) the seed bank has a low seasonality and this pattern is the same within the dispersal modes. In two hectares of forest we recorded total of 29959-62904 seeds in the seed rain (104-106 spp.), 1029-2999 seeds in the litter seed bank (36-38 spp.) and 6288-7824 seedlings in the soil seed bank (78-82 spp.) over two years. Asteraceae, Urticaceae and Melastomataceae were abundant in the seed rain (63-81%), litter seed bank (70-73%) and soil seed bank (77-84%). Trees accounted to higher species richness in the seed rain (59-61%) and litter seed bank (72-68%). Herbaceous were most important to the species richness of soil seed bank (ca. 55%). There were more of tree seeds in all regeneration modes, as well as greater zoochorous species richness (more than 50%). However, anemochory had the largest proportion of total seeds in the soil seed bank (ca. 75%) as well as one of the areas where the seed rain was sampled (64%). There was seasonality of seed rain with a single peak in abundance (Oct-Nov). This pattern was reinforced by seasonality in the anemochorous and zoochorous abundance and species richness of seed rain, both occurring in the period of greatest rainfall. Seed rain influenced the species composition of the seeds in the litter and soil. However, the spatial coupling between the regeneration modes occurred in only one area. The soil seed bank showed no changes in the floristic composition and there was a weak temporal variation in density and species richness reflecting also within in the dispersal syndromes. This study demonstrated that seasonality in seed rain can occur even in tropical forests where environmental seasonality is low, regardless of the manner in which the seeds are dispersed. The relationship between seed rain and seed bank composition (litter and soil) reveals that these pathways are interconnected and dependent on each other, resulting in clustered spatial patterns. As a result, the low temporal variation of soil seed bank can not be attributed to the low seasonality of seed rain. Since there is no seed accumulation in the soil after a period of seed dispersal, short residence time of the seed in the soil is suggested. On the other hand, the lack of spatial association between seed rain and seed bank in one of the areas suggests post-dispersal processes acting in the spatial restructuring of the seed bank / Doutorado / Biologia Vegetal / Doutor em Biologia Vegetal

Ziel des Forschungsprojektes war der Gewinn umfassender verjüngungsökologischer Kenntnisse zu den Pionierbaumarten Sandbirke (Betula pendula Roth), Salweide (Salix caprea L.) und Eberesche (Sorbus aucuparia L.) im Hinblick auf eine natürliche, eingriffsfreie Wiederbewaldung von Schadflächen (z.B. nach Sturmwurf). Die Abschätzung des Besiedlungserfolges von Schadflächen durch Pionierbaumarten ist aufgrund unzureichender verjüngungsökologischer Kenntnisse gegenwärtig noch mit großen Unsicherheiten verbunden. Die Untersuchungen fanden auf fünf 4-12 ha großen Kyrill-Sturmwurfflächen in den Hoch- und Kammlagen (750-900 m ü. NN) des Thüringer Waldes statt. Alle potenziellen Samenbäume der Pionierbaumarten wurden in den angrenzenden, geschlossenen Fichtenbeständen lokalisiert. Als Versuchsdesign wurde in Abhängigkeit der vorgefundenen Samenbaumdichten und -verteilungen ein Kreuz- bzw. Sterntransekt auf den Sturmwurfflächen etabliert. Entlang der Transektlinien wurden alle 20 m Samenfallen installiert. Als Samenfallen kamen für die Sandbirke Netztrichterfallen (0,2 m²), für die Salweide Klebfallen (0,043 m²) und für die endozoochore Ausbreitung durch frugivore Vogelar-ten Kotfallen (0,25 m²) zum Einsatz. Für die Modellierung der Samenausbreitung von Sandbirke und Salweide wurden inverse Modelle bzw. geostatistische Modelle erstellt. Zudem wurden auf einer der Sturmwurfflächen genetische Nachkommenschaftsanalysen bei Sal-weide mittels Kern-DNA-Primer durchgeführt. Die Bodensamenbankuntersuchungen fanden in jeweils drei geschlossenen Birkenbeständen, Fichten-Birken-Beständen, Fichtenbeständen mit einer einzeln eingemischten Birke und reinen Fichtenbeständen im Tharandter Wald und Thüringer Wald statt. Mittels eines 10,2 cm breiten Stechzylinders wurden 10 cm tiefe Bodenproben gewonnen. Die Lagerung der Proben fand im Kaltgewächshaus statt, wo alle 14 d die gekeimten Samen erfasst wurden. Weiterhin wurde ein Eingrabungsexperiment installiert. Dafür wurden Sandbirkensamen, Ebereschensamen und Ebereschenfrüchte in 2 cm, 5 cm und 10 cm tiefen Mineralboden vergraben und in sechsmonatigen Intervallen jeweils eine Keimprobe zum Test der verbliebenen Keimfähigkeit entnommen. Die Auswertung der Bodensamenbankuntersuchungen erfolgte mittels GLM und GLMM. Während der zweijährigen Untersuchung zur zeitlichen und räumlichen Samenausbreitung von Salix caprea auf fünf Sturmwurfflächen konnten ein schwächeres und ein stärkeres Samenjahr nachgewiesen werden. Des Weiteren erstreckte sich der Samenflugzeitraum im Frühjahr in Abhängigkeit von den klimatischen Bedingungen über 12 Wochen in 2015 und 6 Wochen in 2016. Die höchsten Samenmengen von 23-156 Samen je Falle wurden jeweils unter den Kronen von Salweiden-Samenbäumen nachgewiesen. Ab einer Entfernung von 350 m zum Samenbaum bis zur untersuchten Distanz von 870 m wurden, unabhängig von der Distanz, der Hangneigung, der Anzahl der Samen-bäume und der Windrichtung (Anisotropie), im Durchschnitt 0,6-2,1 Samen je Falle er-fasst. Die genetischen Analysen zur Nachkommenschaft ergaben, dass 29 % der untersuch-ten Verjüngungspflanzen von einem der 20 lokalisierten Elternbäume in der bewaldeten, 500 m breiten Suchzone abstammten. Die Ausbreitungsdistanzen der nachweislich am erfolgreichsten verjüngten Samenbäume betrugen dabei 550-800 m. Insgesamt zeigte die Salweidenverjüngung eine höhere Allel-Variation, als die 20 Elternbäume, was auf einen externen Genfluss und lange Samen- und Pollenausbreitungsdistanzen hinweist. Im Zuge des zweijährigen Untersuchungszeitraums zur Samenausbreitung von Betula pendula auf zwei Kyrill-Sturmwurfflächen konnten ein Mastjahr und ein Zwischenjahr nachgewiesen werden. Die Ergebnisse der inversen Modellierung mittels isotroper Mo-delle ergaben dabei flächenunabhängig Produktionsmengen für einen Samenbaum von 20 cm im Bhd von 300.000-366.000 Samen je Baum im Zwi-schenjahr 2015 und 1.430.000-1.530.000 Samen je Baum im Mastjahr 2016. Mittels räumlicher Modellierung der Samenausbreitung konnte keine Anisotropie belegt werden. Unabhängig von den beprobten Flächen und Un-tersuchungsjahren, belegen die Modellschätzungen allesamt eine isotrope Ausbreitung der Samen. Die mittleren Ausbreitungsdistanzen (MDD) beliefen sich dabei hangaufwärts auf 86-97 m und hangabwärts auf 367-380 m. Maximal ab-gelagerte Samendichten von 2.015 n m-² im Zwischenjahr und 9.557 n m-² im Mastjahr fanden sich bis 40-50 m Entfernung zum Samenbaum. Die Untersuchungen der endozoochoren Samenausbreitung auf fünf Sturmwurfflächen weisen auf eine bevorzuge Nutzung der Vogelarten von Rast- und Sitzgelegenheiten (Strukturelemente) auf Freiflächen zum Absetzen von Kot hin (2,7 Kothaufen je m²). Unter Freiflächenbedingungen - ohne Strukturelemente - ergaben sich im Mittel 0,4 Kothaufen je m². Die höchsten mittleren Kotdichten wurden unter aufra-genden Totästen (20 n m-²), umgeklappten Wurzeltellern (4,6 n m-²) und Hochstubben (3,9 n m-²) nachgewiesen. Schwach dimensionierte Verjüngungspflanzen der Sandbirke, Eberesche und Fichte, und Strukturelemente unter einem Meter Höhe wurden dagegen weitgehend für das Absetzen von Kot gemieden. Das Vermögen zum Aufbau einer Bodensamenbank durch Betula pendula und Sorbus aucuparia unterschied sich deutlich. 56-100 % der eingegrabenen Sandbirkensamen wa-ren auch nach 2,5 Jahren keimfähig, wohingegen lediglich 3-16 % der eingegrabenen Ebereschensamen ohne Fruchthülle und 0-19 % der eingegrabenen Ebereschensamen mit Fruchthülle vital waren. Die Auswertung mittels GLM prognostizierte einen kom-pletten Verlust der Keimfähigkeit nach 12 Jahren, 4,5 Jahren und 3 Jahren der Sandbirkensamen, sowie der Ebereschensamen mit und ohne Fruchthülle. Ein Einfluss der Lagerungstiefe war nur für Sandbirke nachweisbar. Die Untersuchungen der Bodensamenbank von Birke in Fichtenbeständen mit unter-schiedlichen Birkensamenbaumanteilen ergab einen straffen Zusammenhang zwischen der Anzahl von Samenquellen und den nachgewiesenen Samendichten im Boden. In den Birkenbeständen fanden sich stets die höchsten Dichten von 489-1.142 Birkensamen je m². Die Analyse unterschiedlicher Bodenschichten zeigte zudem signifikant abneh-mende Birkensamendichten mit zunehmender Bodentiefe. Die Ergebnisse der Untersuchungen zeigen, dass die Fruktifikation von Betula pendula, Salix caprea und Sorbus aucuparia durch klimatische Verhältnisse beeinflusst wird, weshalb die drei Pionierbaumarten nicht alljährlich hohe Samenmengen produzieren (Mastjahre und Zwischenjahre). Zum Ausgleich von Produktionsdefiziten in den Zwischenjahren unter-scheiden sich die Pionierbaumarten in ihrer Strategie. Dies gilt es bei der Umsetzung des Konzeptes einer natürlichen, eingriffsfreien Wiederbewaldung von Schadflächen nach Sturmwurf durch die Naturverjüngung von Pionierbaumarten zu beachten. Die einzige der drei Pionierbaumarten, die dem allgemeinen Bild einer Pionierbaumart ent-spricht, ist die Salweide. Ihr Besiedlungserfolg ist allein von den aktuellen, alljährlich variierenden, aber dennoch stets hohen Samenproduktionsmengen und den enorm weiten Aus-breitungsdistanzen (>800 m) abhängig. Hinsichtlich der Samenausbreitung haben die Him-melsrichtung, die Position der Samenbäume und die Anzahl vorhandener Samenquellen ab einer Distanz von 50 m zur Schadfläche keinen bedeutenden Einfluss auf die abgelagerten Samenmengen mehr. Die auf 86-380 m limitierte Samenausbreitung von Sandbirke wurde dagegen stark vom Geländerelief (Hangneigung), der Position der Samenbäume (Tal, Kuppe, Hanglage) und der Distanz der Samenbäume zur Sturmwurffläche beeinflusst. Zum Ausgleich der limitierten Samenausbreitung und deutlich reduzierten Samenmengen im Zwischenjahr ist Sandbirke jedoch zum Aufbau einer short-term persistenten Bodensamenbank befähigt. Den gesamten Verjüngungszyklus betrachtend entspricht die Eberesche eher einer Schluss-waldbaumart. Unter ungünstigen klimatischen Bedingungen kommt es häufig zum kompletten Ausfall der Samenproduktion. Ihr enormes Wiederbewaldungspotential von Sturmwurfflächen speist sich hauptsächlich aus dem Aufbau einer Sämlingsbank und weni-ger durch den aktuellen Samenregen oder der short-term persistenten Bodensamenbank. Die limitierte Samenausbreitung von Sandbirke und Eberesche macht eine „räumliche Optimierung“ der Samenbaumpositionen durch die Forstwirtschaft erforderlich. Aufgrund der allgegenwärtigen Omnipräsenz von Weidensamen ist dies für Salweide nicht zwingend not-wendig. Das detailreiche Wissen zur Verjüngungsökologie der untersuchten Pionierbaumar-ten ermöglicht eine gezielte waldbauliche Steuerung im Sinne des Vorhalts und der Pflege von Pionierbaumarten im Wirtschaftswald. Dies ist gegenwärtig und zukünftig vor allem von besonderer Bedeutung, da aufgrund der zu erwartenden Zunahme von Schadereignissen und deren Unvorhersehbarkeit die Fähigkeit der Wälder zur natürlichen Wiederbewaldung von Schadflächen durch Pionierbaumarten zunehmend an Interesse gewinnen wird.:Table of abbreviations III Summary IV Zusammenfassung VIII Chapter 1 – General introduction 1 1.1 Introduction 2 1.1.1 Importance and relevance of the study 2 1.1.2 Research interest - regeneration ecology 5 1.3 Aims, scope and hypotheses 9 1.4 Study outline 12 1.5 References 13 Chapter 2 – Seed dispersal capacity of Salix caprea L. assessed by seed trapping and parentage analysis 25 2.1 Abstract 26 2.2 Introduction 26 2.3 Materials and methods 29 2.3.1 Study area 29 2.3.2 Experimental design 31 2.3.3 Genetic analysis 32 2.3.4 Seed trap data analysis 33 2.3.5 Geostatistical models 34 2.4 Results 36 2.4.1 Temporal patterns of seed dispersal 37 2.4.2 Dispersal distance and spatial patterns of seed dispersal 37 2.4.3 Genetic parentage analysis 40 2.5 Discussion 42 2.5.1 Seed production and temporal patterns of seed dispersal 42 2.5.2 Dispersal distance and spatial patterns of seed dispersal 43 2.5.3 Genetic parentage analysis 45 2.6 Conclusions for silvicultural practice 46 2.7 References 48 Chapter 3 – Restrictions on natural regeneration of storm-felled spruce sites by silver birch (Betula pendula Roth) through limita-tions in fructification and seed dispersal 57 3.1 Abstract 58 3.2 Introduction 58 3.3 Materials and methods 60 3.3.1 Study area 60 3.3.2 Experimental design 63 3.3.3 Data analysis 64 3.3.4 Seed dispersal model 64 3.3.5 Simulations for practical management decisions 66 3.4 Results 66 3.4.1 Seed production 66 3.4.2 Seed dispersal and spatial patterns 68 3.5 Discussion 71 3.5.1 Seed production 71 3.5.2 Directionality 72 3.5.3 Spatial patterns and seed dispersal distances 72 3.6 Seed dispersal scenarios for silvicultural management decisions 74 3.6.1 Seed dispersal scenarios 74 3.6.2 Conclusions for silvicultural management decisions 76 3.7 References 78 Chapter 4 – The impact of structural elements on storm-felled sites on endozoochorous seed dispersal by birds – a case study 85 4.1 Abstract 86 4.2 Introduction 86 4.3 Materials and methods 88 4.3.1 Study area 88 4.3.2 Experimental design 90 4.3.3 Data analysis 91 4.4 Results 92 4.5 Discussion 95 4.6 Conclusions for silvicultural practice 97 4.7 References 98 Chapter 5 – Soil seed banks of pioneer tree species in European tempe-rate forests: a review 104 5.1 Abstract 105 5.2 Introduction 105 5.3 Methods of literature search 107 5.4 Species-specific reproductive ecology determining the potential of soil seed banks 110 5.5 Characterization and classification of soil seed banks 112 5.5.1 Soil seed bank of Betula spp. 114 5.5.2 Soil seed bank of Alnus glutinosa (L.) GAERTN. 116 5.5.3 Soil seed banks of Salix spp. and Populus tremula L. 117 5.5.4 Soil seed bank of Sorbus aucuparia L. 118 5.6 Conclusions 119 5.7 References 120 Chapter 6 – Do birch and rowan establish soil seed banks sufficient to compensate for a lack of seed rain after forest disturbance? 134 6.1 Abstract 135 6.2 Introduction 135 6.3 Materials and methods 137 6.3.1 Study areas 137 6.3.2 Data collection 139 6.3.3. Statistical analysis 140 6.4 Results 141 6.4.1 Study A - Artificial seed burial experiment 141 6.4.2 Study B - Soil core sampling in the forest 145 6.5 Discussion 147 6.5.1 Study A - Artificial seed burial experiment 147 6.5.2 Study B - Soil core sampling in the forest 149 6.6 Conclusions 151 6.7 References 152 Chapter 7 – General discussion 160 7.1 Discussion of important aspects of regeneration ability 161 7.1.1 Fructification and seed production in Salix caprea, Betula pendula and Sorbus aucuparia 165 7.1.2 Ecological processes within the regeneration cycle of Salix caprea 167 7.1.3 Ecological processes within the regeneration cycle of Betula pendula 168 7.1.4 Ecological processes within the regeneration cycle of Sorbus aucuparia 169 7.2. Conclusions for silviculture and management recommendations 172 7.3 References 175 Table of appendix i / The aim of the study was to obtain comprehensive knowledge of the regeneration ecology of the pioneer tree species silver birch (Betula pendula Roth), goat willow (Salix caprea L.) and rowan (Sorbus aucuparia L.). The findings should contribute to better management of the natural regeneration of disturbed sites (e.g., windthrown sites) by pioneer tree species. Insufficient knowledge of the regeneration ecology of pioneer tree species renders forest managers’ abilities to assess the success of regeneration of windthrown sites uncertain. The study took place in the years 2015 and 2016. The study sites were located on the slopes and mountain tops (plateaus) of the Thuringian Forest (715-900 m a.s.l.), on five windthrown open areas (4-13 ha) created by the storm ‘Kyrill’ in January 2007. All seed trees of pioneer tree species were mapped within the forested search zone around each site. This zone extended 200 m for silver birch and rowan and 500 m for goat willow. Following the mapping of these seed trees and an analysis of their spatial distribution, seed traps were placed along two or four crossing line transects, with intervals of 20 m between traps. The traps were funnel shaped net seed traps for silver birch (0.2 m²), seed traps with a sticky, non-drying glue for goat willow (0.043 m²) and dropping traps for seeds dispersed endozoochorously by frugivorous birds (0.25 m²). A phenomenological model and model-based geostatistics were used to investigate silver birch and goat willow seed dispersal. For goat willow a parentage analysis was performed at one of the study sites using nuclear-DNA-primers. The soil seed bank study was carried out in three birch stands, spruce stands with admixed birch, spruce stands with one isolated birch tree and pure spruce stands in the Tharandter Forest and in the Thuringian Forest. Soil core samples with a diameter of 10.2 cm were taken from the litter layer and the mineral soil to a depth of 10 cm. The soil samples were placed in a greenhouse and seed germination was checked every 14 days. An artificial seed burial experiment was also carried out. Silver birch seeds, rowan seeds and rowan fruits were buried in mineral soil at depths of 2 cm, 5 cm and 10 cm. At intervals of 6 months sample sets were removed from the soil and the germination capacity checked. The analysis of the soil seed banks was based on generalized linear mixed models (GLMM) and generalized linear models (GLM). The 2-year study of the temporal and spatial dispersal of seeds of Salix caprea on five Kyrill-felled areas involved one year with lower seed production and one with more bountiful seed production. The duration of the spring seed rain was about 12 weeks in 2015, and only 6 weeks in 2016 because of contrasting weather conditions. The highest seed numbers of 23-156 n per trap occurred close to the base of the seed trees. Beyond 350 m from the seed trees, up to the maximum distance in the study of 870 m, the average numbers of seeds per trap (0.6-2.1 seeds) were independent of the dispersal distance, inclination, the number of seed sources and the dispersal direction (anisotropy). Parentage analyses showed that 29% of the saplings stemmed from one of the 20 parent trees within the 500 m search zone extending from the edge of the open area. The seed dispersal distances of the most successful seed parents were between 550-800 m. The saplings revealed a higher allelic variation than the 20 parent trees, indicating external gene flow and long seed and pollen dispersal distances. During the 2-year study of Betula pendula seed dispersal on two Kyrill-felled areas there was a mast year and a non-mast year. Independent of the site, the seed production rate of a silver birch seed tree with a mean diameter at breast height (dbh) of 20 cm predicted by isotropic inverse models was approximately 300,000-366,000 seeds in 2015 and 1,430,000-1,530,000 seeds per tree in the mast year 2016. Directionality (anisotropic inverse modelling) of seed dispersal around an individual seed tree could not be confirmed. The model results revealed the isotropic model (no directionality) to be an appropriate approach for all sites and years. The mean dispersal distances (MDD) were 86 m and 97 m (uphill) and 367 m and 380 m (downhill). The maximum seed numbers occurred within 40-50 m of a seed tree, amounting to 2,015 n m-² in the non-mast year and 9,557 n m-² in the mast year. The study of endozoochorous seed dispersal on the five sites felled by the storm Kyrill showed a preference of frugivorous birds for perches and resting places (structural elements) from which to defecate onto open areas (2.7 droppings per m²). On completely open areas – with no structural elements – an average of 0.4 droppings per m² was recorded. The highest mean bird dropping density was observed under towering dead branches (20 n m-²), upturned root plates (4.6 n m-²) and high stumps (3.9 n m-²). Young, small diameter silver birch, rowan and spruce trees, and structural elements less than 1 m in height generally, were avoided by frugivorous birds as a place from which to defecate. The abilities of Betula pendula and Sorbus aucuparia to form a soil seed bank differed. Between 56-100 % of the buried silver birch seeds were still viable after 2.5 years, whereas only 3-16 % of the rowan seeds buried without pulp and 0-19 % of the rowan seeds within pulp were viable. The maximum durations of storage in the soil predicted for silver birch seeds and rowan seeds with and without pulp by GLM were 12 years, 4.5 years and 3 years. An influence of the storage depth was found for silver birch seeds only. The investigation of the soil seed banks of birch in three birch stands and nine spruce forests with different numbers of admixed birch seed trees showed a strong correlation between the number of seed sources and the seed density in the soil. The birch stands contained the highest mean densities of viable birch seeds in soil, between 489-1,142 n m-². The analysis of the different soil layers showed significantly declining birch seed densities with increasing soil depth across all sites. The results of the study showed that the fructification of Betula pendula, Salix caprea and Sorbus aucuparia is influenced by weather conditions, with the three pioneer tree species failing to produce high numbers of seeds every year (mast and non-mast years). The three species differed in their strategies to compensate for low seed production in non-mast years. This must be considered when implementing a concept for the reforestation of disturbed sites based on natural regeneration by pioneer tree species. Goat willow was the only one of the three specie studied with characteristics corresponding to the general assumptions made about pioneer tree species. The regeneration success of goat willow is dependent upon the variable but generally high annual seed production and long seed dispersal distances (> 800 m). The azimuth direction, position and number of seed trees have no meaningful influence on seed numbers at a distance of more than 50 m from the seed source. The limited mean seed dispersal distances of 86-380 m determined for silver birch were influenced by site inclination, the seed tree location (valley, slope or plateau) and the distance between the seed tree and the windthrown site. Silver birch seed shadow is also influenced by the number of seed sources. To compensate for the limited dispersal distances and the significantly lower seed production in non-mast years, silver birch is able to build up a short-term persistent soil seed bank. The regeneration cycle of rowan is more reminiscent of that of a shade-tolerant tree species. Unfavorable weather conditions often result in a complete failure to produce seeds. The enormous regeneration potential of rowan on disturbed sites stems primarily from a seedling bank, which is built up over years. The seed rain in any given year and its short-term persistent soil seed bank are of secondary importance. Forest management targeting a ‘spatial optimization’ of silver birch and rowan seed trees is necessary to ensure successful natural regeneration given the limited seed dispersal. The omnipresence of goat willow seeds renders specific spatial management measures for its establishment unnecessary. Detailed knowledge of the regeneration ecology of the studied pioneer tree species makes possible an approach to silviculture that is targeted to the conservation and revitalization of pioneer tree species in managed forests. The expected increase in the frequency of disturbances, and their unpredictability, means that the ability of forests to naturally regenerate using pioneer tree species is likely to grow in importance.:Table of abbreviations III Summary IV Zusammenfassung VIII Chapter 1 – General introduction 1 1.1 Introduction 2 1.1.1 Importance and relevance of the study 2 1.1.2 Research interest - regeneration ecology 5 1.3 Aims, scope and hypotheses 9 1.4 Study outline 12 1.5 References 13 Chapter 2 – Seed dispersal capacity of Salix caprea L. assessed by seed trapping and parentage analysis 25 2.1 Abstract 26 2.2 Introduction 26 2.3 Materials and methods 29 2.3.1 Study area 29 2.3.2 Experimental design 31 2.3.3 Genetic analysis 32 2.3.4 Seed trap data analysis 33 2.3.5 Geostatistical models 34 2.4 Results 36 2.4.1 Temporal patterns of seed dispersal 37 2.4.2 Dispersal distance and spatial patterns of seed dispersal 37 2.4.3 Genetic parentage analysis 40 2.5 Discussion 42 2.5.1 Seed production and temporal patterns of seed dispersal 42 2.5.2 Dispersal distance and spatial patterns of seed dispersal 43 2.5.3 Genetic parentage analysis 45 2.6 Conclusions for silvicultural practice 46 2.7 References 48 Chapter 3 – Restrictions on natural regeneration of storm-felled spruce sites by silver birch (Betula pendula Roth) through limita-tions in fructification and seed dispersal 57 3.1 Abstract 58 3.2 Introduction 58 3.3 Materials and methods 60 3.3.1 Study area 60 3.3.2 Experimental design 63 3.3.3 Data analysis 64 3.3.4 Seed dispersal model 64 3.3.5 Simulations for practical management decisions 66 3.4 Results 66 3.4.1 Seed production 66 3.4.2 Seed dispersal and spatial patterns 68 3.5 Discussion 71 3.5.1 Seed production 71 3.5.2 Directionality 72 3.5.3 Spatial patterns and seed dispersal distances 72 3.6 Seed dispersal scenarios for silvicultural management decisions 74 3.6.1 Seed dispersal scenarios 74 3.6.2 Conclusions for silvicultural management decisions 76 3.7 References 78 Chapter 4 – The impact of structural elements on storm-felled sites on endozoochorous seed dispersal by birds – a case study 85 4.1 Abstract 86 4.2 Introduction 86 4.3 Materials and methods 88 4.3.1 Study area 88 4.3.2 Experimental design 90 4.3.3 Data analysis 91 4.4 Results 92 4.5 Discussion 95 4.6 Conclusions for silvicultural practice 97 4.7 References 98 Chapter 5 – Soil seed banks of pioneer tree species in European tempe-rate forests: a review 104 5.1 Abstract 105 5.2 Introduction 105 5.3 Methods of literature search 107 5.4 Species-specific reproductive ecology determining the potential of soil seed banks 110 5.5 Characterization and classification of soil seed banks 112 5.5.1 Soil seed bank of Betula spp. 114 5.5.2 Soil seed bank of Alnus glutinosa (L.) GAERTN. 116 5.5.3 Soil seed banks of Salix spp. and Populus tremula L. 117 5.5.4 Soil seed bank of Sorbus aucuparia L. 118 5.6 Conclusions 119 5.7 References 120 Chapter 6 – Do birch and rowan establish soil seed banks sufficient to compensate for a lack of seed rain after forest disturbance? 134 6.1 Abstract 135 6.2 Introduction 135 6.3 Materials and methods 137 6.3.1 Study areas 137 6.3.2 Data collection 139 6.3.3. Statistical analysis 140 6.4 Results 141 6.4.1 Study A - Artificial seed burial experiment 141 6.4.2 Study B - Soil core sampling in the forest 145 6.5 Discussion 147 6.5.1 Study A - Artificial seed burial experiment 147 6.5.2 Study B - Soil core sampling in the forest 149 6.6 Conclusions 151 6.7 References 152 Chapter 7 – General discussion 160 7.1 Discussion of important aspects of regeneration ability 161 7.1.1 Fructification and seed production in Salix caprea, Betula pendula and Sorbus aucuparia 165 7.1.2 Ecological processes within the regeneration cycle of Salix caprea 167 7.1.3 Ecological processes within the regeneration cycle of Betula pendula 168 7.1.4 Ecological processes within the regeneration cycle of Sorbus aucuparia 169 7.2. Conclusions for silviculture and management recommendations 172 7.3 References 175 Table of appendix i

The daunting tasks of responding to climate change and ensuring sustainable development (SD) are high on the political agenda among world leaders. From the onset, the clean development mechanisms (CDM) outlined in Article 12 of the Kyoto Protocol (KP), state that CDM activities should contribute to SD in the host country while reducing greenhouse gas (GHG) emission. Nevertheless, many scholars have criticized CDM for failing to deliver on its twin objectives. In Ethiopia in particular, there was lack of afforestation/reforestation (A/R) CDM research specific to the nation; specifically, research as to whether A/R-CDM met the stipulated twin objectives of SD and mitigation (reducing GHG). This study was conducted in the Humbo district of Wolyaita Zone, Southern Nations - Nationality and People Regional (SNNPR) state of Ethiopia, where A/R-CDM was implemented in pursuit of these twin objectives. Humbo is located between 6°46’48.47 and 6°41’04.28N; and between 37°48’35.44 and 37° 55’14.51E, between altitudinal gradients 1200 and 1900 m.a.s.l. The climate of the study area is characterized by annual temperatures between 25°C and 28°C, and by total annual rainfall between 800 to 1000 mm. The objectives of the study were to quantify the change of above ground and below ground carbon pools of native tree species; to assess the attractiveness of FMNR forestry practices; to examine A/R-CDM contributions to community level SD; and to assess the effectiveness of climate change mitigation policy founded on native tree species-based A/R-CDM. Data regarding above ground biomass (AGB) and below ground biomass (BGB) carbon pools of native tree species was collected through non-destructive techniques to quantify the change in carbon sequestration and associated carbon trading. A multi-stage random cluster household (HH) sampling approach was used to assess the attractiveness of farmer managed natural regeneration (FMNR) forestry practice. To examine the contribution of A/R-CDM to community level SD, three dimensions of SD were evaluated, namely; (local) environmental, social, and economic. Two indicators were considered per each dimension. With regard to local environmental SD, community access to natural resources, as well as changes to the local climate were considered. With regard to the social dimension, job creation and changes to social support structures were considered. With regard to the economic dimension, economic activities of the area and local skill development were considered. Focus group discussions and key informant interviews were used to triangulate the survey as well as to assess policy perspectives. Results revealed that the Humbo native tree species based A/R-CDM, which employed FMNR forestry practices, sequestered a net total of 73,138; 84,848; 103,769 and 111,657 tCO2e along 2011, 2014, 2015 and 2016 years, respectively, across 2,728 ha. In terms of carbon leakage due to fuel wood collection activity displacement, a net zero was found since the average volume of fuelwood collected from the project area, after the area was closed off, was found to be 5.1 - 6.1 M3, while before the area was closed off, that number was 4.3 M3. This was due to the project employing FMNR forestry practices. Similarly, the leakage due to livestock grazing activity displacement also was found to be a net zero, since the number of animals grazing on land adjacent to the project area after four years of the area’s being closed off reached 11,383 cattle, 429 donkeys and 4,108 goats, unlike 8,684 cattle and 2,288 goats before the project. In other words, the number of livestock owned by farmers on the land adjacent to the project site was not adversely affected by the closing off of the site, which prevented grazing on the area allocated to A/R-CDM. The livestock management training provided by project developer improved the farmers’ rearing efficiency. Another expected leakage due to soil pitting for A/R was also found to be nil since soil disturbance did not take place because of FMNR practices. These results indicated that systematic regeneration of native tree species through FMNR forestry practices is an effective method to develop carbon sinks. From the point of view of FMNR attractiveness, the results revealed that the practice improved land cover change. The use of FMNR avoided the projected eight years reforestation investment cost of US$ 2,751,312.00 which could have been used if plantation forestry was undertaken. This showed that Humbo A/R-CDM might not have happened if FMNR is had not been introduced, as CDM has no pre-finance mechanism. With regard to community level SD contributions, the establishment of forest protection and development farmers’ cooperatives, as well as the granting of communal land-user rights certification, resulted in legal ownership of the land to the community, whereas before, the land was considered “no man’s land,” and subject to open access. The land-user rights and carbon ownership in turn empowered the community to sign a contract with an international carbon credit buyer. In terms of the local microclimate, the regeneration of native tree species was correlated with increased rainfall in the area in June, July, August and September (JJAS) and March, April and May (MAM). This suggested that the native tree species based A/R-CDM project played a role in improving the local microclimate. In terms of sociological SD, the study showed that new employment opportunities were created including tree pruning, thinning, forest guarding, and jobs at the community warehouse and community flourmill. The availability of employment opportunities was significantly higher for those who participated in the Humbo A/R-CDM, when compared to those who didn’t. In terms of social support structures, in less than ten years, seven Humbo A/R-CDM project owner farmers’ cooperatives, initially established as owners of the project, evolved into one forest protection and development Union. This enabled the institutionalization of grassroots organizations towards a common communal and international agenda of care for the environment. In terms of economic effects, the project enabled a carbon credit contract worth a total of US$ 3,873,298.00, signed at the sell rate of US$ 4.4 per tCO2e, for a total of 880,295 tCO2e across a 30 year crediting period. This is a new business model for the community, the country, and global businesses, all doing their part in climate change mitigation - CDM. As of the first A/R-CDM verification, the community received a total of US$ 321,807.2 in 2011. Consequently, the community received 373,331.2 in 2014, 456,583.6 in 2015 and 491,290.8 in 2016. In terms of revenue from logging, selective harvesting is planned to take place in years 12, 24 and 36. The community is projected to earn at least US$ 15,150.00 per ha1 (a total of US$ 3.9 million) from the first forest harvest in year 12 alone. These benefits in emission reduction (ER) and SD suggest that massive cross-dimensional benefits were foregone due to the country’s refusal to welcome A/R-CDM in its first commitment period, despite having 36,434,400 ha of land eligible for A/R. The research results in the area of policy perspectives indicated that the Humbo A/R-CDM project, the only one of its kind in Ethiopia, was made possible by environment related constitutional provisions, especially those pertaining to land-user rights, and the existence of a nationally standardized definition of forest that complies with international range. Additionally, the timely ratification of the Kyoto Protocol (KP), the establishment of a designated national authority (DNA) and a letter of approval by the DNA to the project developer were found to be enablers. Yet, defining land use, clarifying carbon ownership rights and bringing an inclusive benefit sharing mechanism for forest carbon are among the key instruments the country has yet to put in place to prove local readiness for such development opportunities. The Humbo A/R-CDM also undertook voluntary assessments to obtain additional certification in the form of the Climate Community Biodiversity (CCB) certification, and was certified to be of gold standard for its premium. However, there were no benefits to the host community and project developer from the CCB gold standard certification. Such ambiguity could have been cleared from the onset. This implied whenever going for market and/or result based climate change mitigation, it is necessary to understand the provisions. This study revealed that the Humbo native tree species-based A/R-CDM via FMNR forestry practices met the CDM twin objectives as specified in Article 12 of the KP in 1997, namely the double aims of achieving mitigations of GHG emissions and assisting developing countries inSD. Yet, more research is needed to understand all eligible A/R carbon pools sequestered at Humbo A/R-CDM site. / Environmental Sciences / Ph. D. (Environmental Management)

Nous avons étudié deux chênaies à la limite de l’aire de répartition de l’espèce que Québec afin de reconstruire son historique de régénération et évaluer quels facteurs gouvernent la régénération juvénile. Dans cette optique, nous avons mené une étude dendrochronologique exhaustive des chênaies et une étude sur le terrain et en serre portant sur la germination, la survie et la croissance de quatre provenances de chêne rouge (gradient nord-sud), avec ou sans herbivorie, et selon plusieurs niveaux de nutriments du sol suivant une fertilisation. Les chênaies présentent des structures d’âge similaire qui coïncident avec les dernières perturbations de feu majeures dans la région autour des années 1920. Toutefois, les chênaies diffèrent quant à la densité et la composition en espèces d’arbres, ce qui suggère des différences de régime de feu ou de statut de succession écologique antérieure au feu. Le site a eu la plus grande influence sur la régénération du chêne rouge. Les semis du site présentant la densité d’arbres, l’indice de surface foliaire (LAI) et la disponibilité en eau les plus élevés ont montré un taux de survie supérieur de 29 %. La protection contre la grande herbivorie a également affecté la performance des semis, résultant en au taux de survie supérieur de 16 % et une plus grande taille des feuilles pour trois des quatre provenances étudiées. La provenance a aussi significativement influencé la performance des semis. La provenance locale (la plus nordique) a montré la plus faible performance, avec des taux de germination, de survie et de croissance inférieures de 28 à 42 % dans les deux expériences, alors que les provenances du sud ont montré une meilleure germination et survie en serre et une meilleure survie sur le terrain. L’augmentation de la fertilité du sol s’est avérée bénéfique dans l’expérience en serre mais n’a provoqué qu’un effet marginal sur la croissance et la survie sur le terrain, suggérant que ce facteur importe moins que les autres (ex. la disponibilité en eau et en lumière) pour les stades initiaux de régénération du chêne rouge. Nos résultats suggèrent que les efforts en sylviculture visant à favoriser le chêne rouge devraient se concentrer sur la sélection rigoureuse de sites et de provenances, et que la disponibilité de l’eau peut être une condition limitante pour le succès de la régénération du chêne rouge aux stades de gland et de semis juvénile (semis de l’année) à la limite nordique de son aire de répartition. / We studied two red oak stands at the northern distribution limit of the species in Quebec as a means to reconstruct regeneration history and assess which factors govern early regeneration. To do so, we conducted a thorough dendrochronological study of the stands as well as germination and seedling growth experiments, both in the field and in the greenhouse, of four red oak provenances (south-north gradient), with and without large herbivory, and along various soil nutrient levels following fertilization. Stands have similar age structures with red oak establishment coinciding with the last major fire disturbance in the area in the early 1920s. However, stands differ in regard to tree species composition and density, suggesting differences in fire disturbance regime or ecological succession status prior to fire. Site had the largest influence on red oak regeneration. Seedlings at the site with the highest tree density, LAI and soil water availability exhibited a 29 % higher survival rate. Protection against large herbivory also significantly impacted red oak seedling performance, leading to a 16 % higher survival rate as well as greater leaf size for three of the four provenances studied. Germination, survival and growth also significantly differed between provenances. The local (northernmost) provenance exhibited the poorest overall performance with 28 to 42 % lower germination, survival and growth rates in the two experiments, while the two southernmost provenances exhibited superior germination and sprout survival in the greenhouse and higher survival in the field. An increase in soil nutrient availability was beneficial to red oak in the greenhouse, but only marginally benefited survival and growth in the field, suggesting that this factor is of less importance than other factors (e.g. water and light availability) for red oak early regeneration. Our findings suggest that silvicultural efforts to favor red oak should focus on site and provenance selection, and that water availability is currently limiting red oak regeneration success at acorn and early seedling life stages (i.e. yearlings) near its northern distribution limit.

A redução da cobertura florestal e o uso agrícola intensivo do solo resultam na necessidade de adoção de intervenções de restauração bastante onerosas, o que restringe a expansão dessa atividade e a mitigação dos impactos das atividades humanas na biodiversidade e nos serviços ecossistêmicos. Nesse sentido, a exploração de madeira em florestas em processo de restauração pode ser uma alternativa para a viabilização econômica dessa atividade. Em particular, merece destaque as oportunidades oferecidas pela exploração de espécies arbóreas exóticas de ciclo curto, que antecipam o retorno econômico da restauração e podem auxiliar na amortização dos custos de implantação dos reflorestamentos. No entanto, embora o cultivo intercalado de árvores exóticas seja autorizado pela legislação ambiental como um método de recomposição ambiental, pouco se sabe sobre os efeitos negativos do uso dessas espécies nos modelos de restauração. Nesse contexto, o objetivo deste trabalho foi avaliar o impacto ecológico e silvicultural do uso e colheita de eucalipto consorciado com espécies arbóreas nativas para a restauração da Mata Atlântica. Avaliamos três experimentos implantados nos estados da Bahia e Espírito Santo, os quais adotaram o eucalipto como espécie pioneira comercial, utilizada para gerar renda no primeiro ciclo de corte (em torno de 4 a 5 anos) e ser então removida da floresta em restauração. Em geral, o uso do eucalipto nesses experimentos foi menos prejudicial do que o esperado. Não houve influência negativa do consórcio de eucalipto com espécies nativas, em comparação com plantios exclusivos de espécies nativas, na sobrevivência e crescimento de espécies nativas madeireiras, bem como na regeneração natural de espécies nativas no sub-bosque dos plantios. Nós avaliamos também os impactos da exploração da madeira do eucalipto em dois desses experimentos, onde verificamos que a operação de colheita do eucalipto gera danos nas árvores nativas plantadas e uma abertura significativa do dossel florestal (considerando que o eucalipto representa 50% dos indivíduos plantados e 90% da área basal nos modelos avaliados), porém esses danos já foram parcialmente minimizados em apenas quatorze meses após a colheita. Assim, concluímos que para as condições ambientais avaliadas, o uso do eucalipto em modelos de restauração florestal não prejudicou o desenvolvimento das árvores de espécies nativas plantadas em consórcio e não prejudicou a expressão da regeneração natural, o que torna seu uso válido para essas condições. Mais estudos são necessários, no entanto, para que se acompanhe as trajetórias sucessionais de modelos de restauração florestal a médio e longo prazo, a fim de validar a recomendação do seu uso a partir de bases científicas mais consolidadas. / The reduction of forest cover and the intensive agricultural use of the soil result in the necessity of adopting expensive restoration interventions, which restrict the expansion of this activity and the mitigation of the impacts of human activities on biodiversity and ecosystem services. Thus, the exploitation of wood in restoration forests may be an alternative for the economic viability of this activity. Particularly noteworthy are the opportunities offered by the exploitation of short rotation exotic tree species, which anticipate the profit obtained from restoration and may contribute to the amortization of implantation costs. However, even though the intercropping with exotic trees is authorized by the current environmental legislation as a method for forest restoration, little is known concerning the possible negative effects of the use of these species in restoration models. This research aimed to evaluate the ecological and silvicultural impacts of the use and harvest of Eucalyptus temporarily mixed with native tree species in the restoration of the Atlantic Forest. We evaluated three experiments in the states of Bahia and Espírito Santo, which used Eucalyptus as a commercial pioneer species to generate income after the first rotation (around 4-5 years) and then removed from the system. Eucalyptus had no negative influence over native species\' survival and growth when compared to pure native species plantations, as well as over natural regeneration of native species in the understory. We also evaluated the impacts of harvesting Eucalyptus in two of these three experiments and found that the Eucalyptus harvesting operation causes significant damage to planted native trees and results in opening of the forest canopy (considering that Eucalyptus represents 50% of the individuals planted and 90% of the basal area), but these damages were partially minimized within only 14 months after harvesting. Thus, we conclude that for the environmental conditions evaluated, the mixture with Eucalyptus in this alternative forest restoration approach did not affect the development of native tree species neither the expression of natural regeneration, which makes its use valuable. Further studies are necessary, however, to follow the succession trajectories of forest restoration models in the medium and long runs, to validate the recommendation of their use with more consolidated scientific basis.