A predação de sementes, juntamente com a dispersão, é um dos principais fatores determinantes no recrutamento de novos indivíduos. Espécies de plantas que oscilam na produção de frutos e sementes podem influenciar os predadores e dispersores, alterando a resposta destes em anos de baixa ou alta oferta de recursos. A araucária (Araucaria angustifolia) é o principal elemento da Floresta Ombrófila Mista e as suas sementes, os pinhões, além de amplamente consumidas pela fauna, são uma importante fonte de renda para muitas famílias. Dentre os animais, os roedores são os principais predadores dessas sementes. O objetivo de nosso estudo foi avaliar a relação entre a abundância dos roedores, a disponibilidade de frutos zoocóricos e de sementes da araucária. Avaliamos também se a disponibilidade de sementes influencia nas taxas de remoção e dispersão da araucária. Realizamos o estudo em oito áreas (quatro nativas e quatro de plantação com araucária) na Floresta Nacional de São Francisco de Paula, nordeste do Rio Grande do Sul. Amostramos os roedores durante cinco noites consecutivas em cada estação do ano (abr/outono, jul/inverno, out/primavera e jan/verão). Para avaliar a produção, acompanhamos mensalmente, entre jan/06 a jan/07, todos os indivíduos frutificando ao longo de duas transecções em cada área. Avaliamos também a predação e dispersão de sementes da araucária entre os meses de mai/06 a ago/06. Nossos resultados demonstraram que as sementes da araucária são um importante recurso nas áreas, principalmente no inverno, período em que houve uma queda acentuada na disponibilidade de outros frutos no solo. A abundância dos roedores variou entre as estações do ano, sendo maior no inverno e menor no verão. A remoção de sementes variou entre as áreas nativas e plantadas e entre os meses. Encontramos uma menor remoção nas áreas plantadas, locais de maior disponibilidade de pinhões no solo. A sobrevivência das sementes também foi maior nessas áreas. Nossos resultados indicaram um padrão de predação variando de acordo com a densidade, com uma correlação negativa entre a produção de sementes e a remoção. Nos locais de maior abundância de roedores e maior disponibilidade de sementes encontramos uma menor taxa de remoção, sugerindo uma possível saciação dos predadores. Essa estratégia pode ter conseqüências para o recrutamento e conservação da araucária, bem como para a dinâmica de predação e dispersão, caso não ocorra um manejo dos impactos associados a essa formação, como por exemplo, a coleta das sementes para comercialização e a presença de gado nas áreas. / Seed predation, as well as dispersion, is one of the determinant factors involved in the recruitments of new plant individuals. Plant species that oscillate in their fruit and seed production may influence their seed predators and dispersers, changing their responses in years with high or low resource offer. Araucaria angustifolia is the main element of the Araucaria Forest. Its seeds are largely consumed by the fauna as well as by people, being an important income source for many families. Among the animals that feed upon this seed, the rodents are the main predators. The aim of this study was to evaluate the relation between rodent abundance and fruit availability as well as Araucaria angustifolia seed availability. We also evaluated if the seed production influences the rate of predation and dispersion of araucaria seeds. We conducted the study in the National Forest of São Francisco de Paula, in Rio Grande do Sul state, southern Brazil. In this area, eight forested study sites were selected, four of them were covered by native vegetation (Mixed Ombrophilous Forest) and four were planted with Araucaria. We sampled the rodents at each site during five consecutive nights in each season (autumn, winter, spring, summer). To evaluate the amount of fruit production, we recorded all fruiting individuals of two transects of each area once a month between Jan/06 and Jan/07. We also evaluated the araucaria seed predation and dispersion between May/06 and Aug/06. Our results showed that Araucaria seeds are an important resource in the area, mainly in winter, on which availability of other fruits on the ground was lower. The rodent abundance changed between seasons, being higher during the winter and summer. Seed removal changed between native and planted sites as well as along months. We found low removal rates in planted areas, where overall seed availability on the ground was higher. Seed survival rate was also higher in these areas. Our results indicated a pattern of seed predation changing according to seed density, with a negative correlation between seed production and removal. In areas with higher rodent abundance, we detected lower removal rates, which suggests predator satiation. Such strategy might have consequences for recruitment and conservation of A. angustifolia, as well as for the predation and dispersion dynamic, in case of inadequate management of this species. Additional impacts on seed numbers, such as seed harvest for commercialization and the presence of cattle should be considered in management projects.

Determinadas espécies arbóreas apresentam ciclos anuais de crescimento e dormência, registrados no lenho por conspícuas estruturas anatômicas – os anéis de crescimento. Nessas árvores pode-se determinar a idade e taxas de crescimento, com resolução calendária anual, através da análise temporal dos anéis de crescimento (dendrocronologia), bem como estudar a variação dessas estruturas segundo as condições ambientais (dendroecologia). Pesquisas recentes têm descrito anéis de crescimento anuais num grande número de espécies tropicais e subtropicais. A exemplo do que ocorre em zonas temperadas e áridas, o desenvolvimento da dendroecologia pode contribuir substancialmente ao conhecimento da dinâmica do clima e da vegetação em ecossistemas tropicais e subtropicais. Nesta tese eu reviso e desenvolvo estudos dendroecológicos em biomas brasileiros, principalmente, em ecossistemas subtropicais montanos, visando solidificar a dendroecologia no país. Segundo ampla revisão bibliográfica, estudos relacionados à dendroecologia nos biomas brasileiros, em sua maioria, versam sobre a anatomia e periodicidade de formação de anéis de crescimento na flora; poucos efetivamente relacionam séries anuais de anéis de crescimento com variações do ambiente. As pesquisas estão concentradas em biomas florestais, notadamente na Amazônia. No intuito de facilitar estudos futuros, apresento uma compilação de 124 espécies que formam anéis anuais. Pesquisas inéditas sobre anéis de crescimento em Araucaria angustifolia, espécie típica de formações florestais e campestres em regiões montanas do sul e sudeste do Brasil, comprovam seu potencial dendroecológico. Através de análise da atividade cambial demonstro que esta espécie forma anéis de crescimento anuais, relacionados à variação sazonal de temperatura e fotoperíodo. Estudando séries temporais de largura de anéis de crescimento verifiquei a existência de padrões regionais de crescimento, relacionados à variação interanual do clima, principalmente da temperatura. Regionalmente, A. angustifolia parece sensível a déficit hídrico em Dezembro e Janeiro, bem como responde de forma complexa às condições térmicas em Maio e Junho. Padrões de crescimento divergente entre árvores de campo e de floresta podem estar relacionados ao regime de queimada da vegetação campestre, por sua vez, moderado pela precipitação no mês de ignição de queimadas (Agosto). / Certain tree species present annual cycles of growth and dormancy, imprinted in wood as conspicuous anatomical structures – the growth rings. Temporal analysis of annual growth rings (dendrochronology) allows the determination of tree age and growth rate, with calendar year resolution, and to study long-term relationship between tree-growth and environmental conditions (dendroecology). Recent studies have found annual growth rings in many tropical and subtropical species. As in temperate and arid zones, dendroecological investigations may contribute for understanding the dynamics of climate and vegetation in tropical and subtropical ecosystems. Here, I review and develop dendroecological studies in biomes of Brazil, aiming to support further advances. According to a broad literature review, dendroecological studies in Brazilian Biomes have focused mostly on anatomy and periodicity of growth ring formation; few of them relate growth ring time-series to environmental conditions. The studies are concentrated in forested biomes, noticebly in Amazonia. In order to assist future studies I present a compilation of 124 species that produce annual growth rings. Novel studies on Araucaria angustifolia, a typical conifer growing in forest and grassland ecosystems of south and southeast Brazilian highlands, confirm its dendroecological potential. By means of cambium activity examination I show that this species produces annual growth rings, related to seasonal variations of temperature and photoperiod. Analyses of ring-width time series revealed regional growth patterns related to inter-annual climate variations. In a regional extent, A. angustifolia trees are, probably, sensitive the water deficit in December and January, as well respond to thermal conditions of May and June, in a complex manner. Divergent patterns between grassland and forest trees may be related to grassland fire regimes, moderated by rainfall during the fire ignition period (August).

Processos ecológicos e antrópicos interagem e produzem padrões estruturais de manchas de vegetação, os quais, por sua vez, atuam sobre os processos ecológicos devido à influência da estrutura e do contexto da paisagem sobre estes processos. A região do Planalto das Araucárias se caracteriza por uma paisagem em mosaico, onde manchas florestais se misturam à matriz campestre, como resultado de um processo natural de expansão florestal. É provável que este processo não ocorra uniformemente na paisagem, dadas as características de relevo e a proximidade de áreas fontes (floresta contínua). Os padrões estruturais de manchas florestais estão baseados no processo natural de formação da paisagem (manchas) e na alteração desses por antropização (fragmentos). Este estudo inicialmente objetivou identificar e diferenciar tipos de manchas florestais através de características estruturais e de contexto na paisagem. Posteriormente, foi avaliada a hipótese de que a ocorrência das manchas florestais seja uma resposta aos padrões de umidade do solo, mediados pela declividade do terreno, orientação solar sul e proximidade de talvegues, através de um modelo espacial de probabilidade de ocorrência de manchas para a região de estudo. Para tanto, comparamos o mapa de uso e cobertura do solo (ano base 2002) com o mapa de vegetação pretérita buscando diferenciar: floresta contínua, manchas florestais (MF), fragmentos de manchas (FRAG-MF) e fragmentos de floresta contínua (FRAG-FC). Os tipos de manchas foram caracterizados quanto à estrutura (forma e área) e contexto (contraste de borda, distância de floresta contínua, de vias e de centros urbanos) e as diferenças entre os tipos foram testadas por meio de análises de variância multivariada. Para a análise de probabilidade de ocorrência de MF em relação às características topográficas e à distância de área fonte, utilizamos uma análise de regressão logística múltipla, sendo os coeficientes e a performance do modelo testados por distintos métodos. Os resultados indicaram que os três tipos de manchas diferem significativamente entre si, sendo os fragmentos maiores e com formas mais complexas que as manchas. As MF se caracterizam pela forma regular, com tendência arredondada. Os FRAG-FC se encontram mais próximos de floresta contínua, vias e centros urbanos que os demais tipos. Ou seja, as características de estrutura e contexto das manchas nos permitiram diferenciar as MF dos fragmentos florestais. Com relação ao modelo de distribuição das MF, foi observado que a maior probabilidade de ocorrência de MF está associada aos locais de declividade suave, distantes de talvegues, distantes da floresta contínua e em terrenos orientados para o sul e o oeste. As condições locais de umidade que parecem influenciar a presença de MF são as encostas orientadas para o sul e oeste. Através do modelo, verificou-se uma concordância de 64% entre os locais preditos pelo modelo e os locais de ocorrência observada. A hipótese de que o processo de expansão florestal não ocorre uniformemente na paisagem se sustenta, uma vez que existem características de relevo que tornam certos locais mais favoráveis à ocorrência de manchas florestais do que outros. / Ecological and anthropogenic processes interact and produce structural vegetation patterns that can in turn act upon ecological processes, since they are influenced by landscape structure and context. The southern Brazilian Plateau (Planalto das Araucárias) is a mosaic landscape where forest patches occur in a grassland matrix as a result natural forest expansion. This process probably does not take place uniformly at the landscape, due to the heterogeneous topography and proximity of source areas (continuous forest). The landscape patterns are based on natural processes that shape the landscape (natural forest patches) and on their modification by anthropogenic activities (forest fragments). This study, had two main objectives. The first objective was to identify and distinguish types of forest patches using metrics of patch structure and context in the landscape. The second one was to evaluate the hypothesis that forest patch occurrence is a response to landscape humidity patterns mediated by terrain slope, solar orientation and talweg proximity. This was done by spatially modeling the probability of forest patch presence in the study area. We compared a 2002 land cover map with a past, pre-european settlement, land use map to identify: continuous forest, natural forest patches (MF), fragments of forest patches (FRAG-MF) and fragments of continous forest (FRAG-FC). Each of these patch types was described in terms of structure (shape and area) and context (edge contrast, distance from continous forest, distance from roads, and distance from urban areas), and the diferences among them were tested by a MANOVA. To model the probability of forest patch occurrence as a function of topographic features and distance from source areas, we used a multiple logistic regression. The results indicated that the all three types of forest patches differed significantly. Fragments tend to be larger and more complex in shape than natural patches, which tend to present a more regular, roundish shape. Fragments of continuous forest are closer to the continuous forests, to roads and urban areas, than are other patch types (FRAG-MF and MF), i.e., natural forest patches could be distinguished from fragmented patches on the basis of their structure and landscape context. The model of MF presence probability showed that higher probabilities are associated to low declivity, south and westward orientated sites, distant from talwegs and from continuous forests. The local moisture conditions that influenced the occurrence of MF are the south and westward aspects. There was a 64% concordance between presence sites predicted by the model and actual observed presence sites. The results provided evidence for the hypothesis that forest expansion is not uniform across the landscape, since topographic features make some sites more favorable than others to the establishment of forest patches.

O horário de atividade é um importante aspecto da vida de um animal, refletindo sua fisiologia, interações com o ambiente e com outros animais. Dentre os sinais exógenos que ajudam a determinar o início e fim de um dia para um animal estão a luz, temperatura, precipitação e disponibilidade de alimento. Em nosso estudo buscamos determinar o horário de atividade de duas espécies de roedores cricetídeos, Akodon montensis e Delomys dorsalis, verificando como este é influenciado por variáveis ambientais (temperatura e umidade) e pela disponibilidade da semente da araucária (pinhão). Para isso, utilizamos 21 armadilhas acopladas com relógios para determinar o horário de captura dos animais em oito grades de floresta com araucária nativa. As armadilhas permaneceram funcionando por cinco noites consecutivas em excursões bimestrais no período de março de 2010 a fevereiro de 2011. Para determinar a influência do pinhão no horário de atividade comparamos a época dentro e fora de sua produção. Também removemos o pinhão, experimentalmente, de quatro das grades para determinar como a ausência desse recurso sazonal afeta o comportamento dos animais (grades remoção). Encontramos um padrão de atividade bimodal para A. montensis e unimodal para D. dorsalis, sendo as duas espécies predominantemente noturnas e apresentando padrões de atividade noturnos distintos. Em A. montensis, verificamos diferenciações no horário de atividade entre o inverno e o verão, com a atividade nos meses mais frios apresentando um pico no início na noite e, nos meses mais quentes, apresentando um pico no fim da noite. A. montensis também apresentou horários médios de atividade diferentes entre as grades controle (21h35min) e remoção (23h51min). Em D. dorsalis verificamos uma relação positiva entre o horário de atividade e a temperatura ambiente. O efeito da remoção do pinhão sobre a atividade de A. montensis reforça a importância dessa espécie para a fauna de pequenos mamíferos. / An important aspect of an animal’s life is its activity pattern, which reflects its physiology, interactions with the environment and with other animals. Among the exogenous signs that help determine the beginning and end of a day to an animal are light, temperature, precipitation and food availability. In our study we aimed to determine the daily activity patterns of two species of cricetid rodents, Akodon montensis and Delomys dorsalis, analyzing how these are influenced by the availability of an important seasonal resource, the seed of the araucaria tree (Araucaria angustifolia), and by environmental variables (temperature and humidity). To do so, we used 21 live-traps equipped with clocks that determined the time an individual was captured in eight grids placed in native araucaria forest. The traps were set on the grids for five consecutive nights during six excursions, which took place between March 2010 and February 2011. To determine the influence of the araucaria seed on the daily activity of the two species, we compared the times of capture registered during the production season of the seed and outside of the production period. We also experimentally removed the araucaria seeds from four of the grids, to determine how the absence of this seasonal resource affects the behavior of the studied species (removal grids). We found a bimodal daily activity pattern for A. montensis and a unimodal pattern for D. dorsalis, and both species were considered predominantly nocturnal and presented distinct nocturnal activity patterns. A. montensis showed a differentiation in its daily activity pattern between winter and summer, presenting a peak of activity in the beginning of the night in the colder months and at the end of night during the warmer months. A. montensis also presented different average activity hours between the control grids (9:35 p.m.) and removal grids (11:51 p.m.). We found a positive relationship between the daily activity time of D. dorsalis and ambient temperature. The effect of the removal of the araucaria seed on the daily activity of A. montensis reinforces the importance of this tree species to the small mammal fauna.

No description available.

Distintos padrões de composição de espécies de plantas podem ser observados ao longo de metacomunidades, pois espécies variam de acordo com os diferentes tipos de ambiente e também com a distância geográfica, dado o processo de dispersão. Ainda, estes mecanismos podem causar variação temporal na composição ou abundância de espécies em um sítio devido a alterações que estes mecanismos podem sofrer. Compreender como as mudanças na composição de espécies no espaço, definida como beta diversidade, ou no tempo estão relacionadas ao clima passado, atual ou futuro podem ajudar no planejamento de conservação de uma região. Assim, esta tese esta dividida em quatro capítulos e aborda questões relacionadas com mudanças espaçotemporais na composição de espécies sob uma perspectiva de planejamento de conservação e mudanças climáticas na Mata Atlântica. O primeiro capítulo apresenta um banco de dados com a informação de ocorrência de 1917 espécies de plantas arbóreas distribuídas em 206 comunidades na Mata Atlântica, em diferentes formações florestais (Floresta Atlântica stricto sensu (s.s.), Floresta com Araucária e Floresta Estacional). O segundo capítulo relacionou padrões de beta diversidade com a efetividade da rede de áreas protegidas nas formações florestais do sul da Mata Atlântica (Floresta Atlântica, Floresta com Araucária e Floresta Estacional). Encontramos altos valores de turnover e baixo aninhamento para todas as formações florestais, por isso recomendamos que esforços adicionais precisam almejar o aumento no número de áreas protegidas, especialmente para a Floresta com Araucária e a Floresta Estacional. A maioria das áreas protegidas no sul da Mata Atlântica estão concentradas na região leste, priorizando a Floresta Atlântica s.s. O terceiro capítulo trouxe novas perspectivas sobre a dinâmica da Floresta com Araucária no tempo através da modelagem de nicho ecológica. Durante as flutuações climáticas do Quaternário, estudos palinológicos indicavam uma expansão da Floresta com Araucária, porém nossos resultados demonstraram uma retração da área de cobertura desta floresta, principalmente nas zonas de contato com outras formações florestais. Também observamos que futuramente, se a temperatura continuar aumentando como previsto, a Floresta com Araucária sofrerá uma drástica redução na sua distribuição. Por fim, o capítulo quatro investigou como as espécies de árvores estão respondendo aos efeitos de mudanças climáticas em parcelas permanentes localizadas em ecótonos de florestas Atlânticas. Os resultados mostram que espécies tropicais estão migrando em direção a áreas de maior altitude, ou seja mais frias. Espécies tropicais que já ocorrem em áreas vi de Floresta com Araucária estão apresentando maiores taxas de recrutamento e crescimento, e menor mortalidade do que espécies temperadas, características da Floresta com Araucária. / Distinct patterns of plant species composition can be observed along metacommunities, as species vary in relation to different types of environment and also to the geographic distance, given the dispersal process. These mechanisms may yet lead temporal variation in species composition or abundance in a given place due to fluctuations on these mechanisms. Understanding how changes in species composition across the space, defined as beta diversity, or in time are related with past, current and future climate changes can help conservation planning in a given region. Thus, this thesis is divided into four chapters and discusses shifts in species composition across space and time under the perspective of conservation planning and climate changes in the Atlantic Forest. The first chapter shows a database with 1917 tree species occurrence distributed in 206 sites across distinct forest formations in the Atlantic Forest biome (Atlantic Rainforest, Araucaria Forest and Seasonal Forest). The second chapter related beta diversity patterns with the effectiveness of the current network of protected areas in southern Brazilian Atlantic forests (Atlantic Rainforest, Araucaria Forest and Seasonal Forest). We found high values of turnover and low nestedness for all forest formations, thus additional conservation efforts must target an increase in the number of protected areas, especially for the Araucaria Forest and the Seasonal Forest. Most protected areas are currently limited to the eastern region and prioritize the Atlantic Rainforest. The third chapter brought new insights about the Araucaria Forest dynamics in time through ecological niche models. During the climatic fluctuations of the Quaternary, palynological studies indicated an expansion of the Araucaria Forest, however our results demonstrated an overall retraction of the cover area, mainly in boundary zones with other forest formations. Yet, we showed that in the future, if the temperature continues to increase as expected, the Araucaria Forest would suffer a drastic reduction in its distribution. Finally, the fourth chapter investigated how tree species are responding to climatic changes in permanent plots located in Atlantic forests ecotones. Our results showed that tropical species are migrating towards to colder areas in higher altitudes. Tropical species that already occur in Araucaria Forest areas are even presenting higher rates of recruitment and growth, and lower mortality than temperate species characteristics from the Araucaria Forest.

Submitted by Mariana Dornelles Vargas (marianadv) on 2015-05-05T17:02:23Z No. of bitstreams: 1 padroes_historias.pdf: 488314 bytes, checksum: 941fd4b4c3b3ef436c122f26fe6f483a (MD5) / Made available in DSpace on 2015-05-05T17:02:23Z (GMT). No. of bitstreams: 1 padroes_historias.pdf: 488314 bytes, checksum: 941fd4b4c3b3ef436c122f26fe6f483a (MD5) Previous issue date: 2011 / Nenhuma / A história de vida das espécies pode ser contada através de suas características fenotípicas, pois elas são resultantes dos processos ocorridos ao longo do tempo evolutivo. Para definir padrões estruturais e de luminosidade entre as espécies arbóreas de uma Floresta com Araucária do Sul do Brasil, características importantes de história de vida foram utilizadas com o intuito de entender as relações existentes entre as espécies encontradas dentro deste ambiente. A filogenia também foi levada em conta e analisada através de um teste de Mantel entre as características de vida e as distâncias filogenéticas das espécies avaliadas. Os resultados revelaram as relações existentes entre as variáveis de história vida e os eixos da PCA que foram divididos em 7: retenção de tecidos, crescimento vertical, alcance luminoso, comprimento da semente, trade-off da dispersão zoocórica, crescimento rápido e trade-off da captura de luz. Já as correlações de Pearson com as posteriores correções através do método de Benjamini & Hochberg apontaram 6 correlações significativas envolvendo os regenerantes 1 e 2. A análise de agrupamento separou as espécies em quatro grupos diferentes: tolerantes à sombra, intermediárias zoocóricas, intermediárias preferencialmente não zoocóricas e espécies com alta intensidade de radiação solar (com destaque para Araucaria angustifolia). Este estudo possibilitou a compreensão das estratégias de vida adotadas pelas espécies arbóreas de uma Floresta com Araucária do Sul do Brasil, além de ser uma nova ferramenta para conservação e manejo destas espécies que poderá ser utilizada nos estudos posteriores. / The life history of species can be expressed by their phenotype features, because trait characteristics are determined by processes occurring in an evolutionary timescale. In this study I analyzed morphological and demographic traits to reveal life histories of Araucaria forest trees species. Possible influence of phylogeny in life history traits was taken into account by a Mantel test between traits and the phylogenetic distance. Trait patterns were then evaluated through ordination, classification and correlation analyses of species per trait matrixes. The Mantel test showed no significant influence of phylogeny in species traits. Principal Component Analysis showed seven life history axes, named as tissue retention, vertical growth, light range, seed length, zoochory trade-off, fast growth and light capture trade-off. Pearson correlations with Benjamini & Hochberg corrections resulted in 6 significant associations between regenerates 1 and 2. Cluster analysis separated the species in four different groups: shade tolerant, zoochoric intermediaries, non-zoochoric rather intermediaries and species with high intensity of solar radiation (especially to Araucaria angustifolia). This study enabled the comprehension of the strategies of life adopted by tree species in the Araucaria Forest, besides becoming a new means of conservation and management of these species.

<p>Human disturbance has led to excessive deforestation and to a very limited forest cover in the Afromontane zone of Ethiopia, which forms a large part of the country. Thus urgent conservation measures are required to ameliorate the situation. Understanding the natural regeneration processes and the dynamics of plant populations of tree and shrub species has a practical application in the restoration of these habitats. </p><p>The present study focuses on the population dynamics and regeneration of an early successional shrub <i>Dodonaea angustifolia</i> and a late successional tree <i>Olea europaea</i> ssp. <i>cuspidata </i>in southern Wello, Ethiopia. Population structure and dynamics, regeneration and seed banks in dry Afromontane habitats were considered. </p><p>For both species, three population structure patterns were identified: 1) high density, reversed J-shape structure with many seedlings and few large individuals, 2) lower density, unimodal structure with higher proportions of plants of intermidiate size, 3) high density with higher proportions of large plants , in some cases bimodal with small and large individuals. Vegetation type and protection time were found to have a significant effect on the population structure of both species. <i>Dodonaea</i> can establish itself on degraded land, once the disturbance has ceased</p><p>Projection matrix analysis on observations from permanent plots in <i>Dodonaea</i> populations in protected and unprotected sites resulted in one declining population, and one increasing in the protected site and declining populations at the unprotected site. The overall projected growth rate in <i>Dodonaea</i> calculated from a pooled matrix indicated positive population growth. The factors influencing the population growth, recruitment and survival are discussed.</p><p>The persistence of <i>Olea </i>populations seems to depend on the more stable environmental conditions in later successional stages of forest vegetation. There are possibilities of natural regeneration of <i>Olea</i> if regenerating individuals still occur in the area. Rainfall seasonality is a dominant factor in regulating establishment, recruitment, survival and growth, particularly during the seedling stage. Moreover, shade and herbivory are factors that need consideration. Since <i>Olea</i> grows better under shade than in the open sun, successful regeneration for this species relies on shade from other plants and on protection from grazing, at least during the seedling stage.</p><p>Most of the species that germinated from the seed banks were herbs and grasses with very few shrub and tree species. There was low correspondence between species composition of the seed banks and that of the standing vegetation. </p><p>Spatial and temporal variation in demographic parameters among populations of <i>Dodonaea</i> and <i>Olea </i>can be attributed to human and environmental influence. Under protection, both <i>Dodonaea</i> and <i>Olea</i> seem to have a possibility to regenerate naturally. Further research should consider factors mentioned in detailed investigations of other dominant Afromontane forest species.</p>

Human disturbance has led to excessive deforestation and to a very limited forest cover in the Afromontane zone of Ethiopia, which forms a large part of the country. Thus urgent conservation measures are required to ameliorate the situation. Understanding the natural regeneration processes and the dynamics of plant populations of tree and shrub species has a practical application in the restoration of these habitats. The present study focuses on the population dynamics and regeneration of an early successional shrub Dodonaea angustifolia and a late successional tree Olea europaea ssp. cuspidata in southern Wello, Ethiopia. Population structure and dynamics, regeneration and seed banks in dry Afromontane habitats were considered. For both species, three population structure patterns were identified: 1) high density, reversed J-shape structure with many seedlings and few large individuals, 2) lower density, unimodal structure with higher proportions of plants of intermidiate size, 3) high density with higher proportions of large plants , in some cases bimodal with small and large individuals. Vegetation type and protection time were found to have a significant effect on the population structure of both species. Dodonaea can establish itself on degraded land, once the disturbance has ceased Projection matrix analysis on observations from permanent plots in Dodonaea populations in protected and unprotected sites resulted in one declining population, and one increasing in the protected site and declining populations at the unprotected site. The overall projected growth rate in Dodonaea calculated from a pooled matrix indicated positive population growth. The factors influencing the population growth, recruitment and survival are discussed. The persistence of Olea populations seems to depend on the more stable environmental conditions in later successional stages of forest vegetation. There are possibilities of natural regeneration of Olea if regenerating individuals still occur in the area. Rainfall seasonality is a dominant factor in regulating establishment, recruitment, survival and growth, particularly during the seedling stage. Moreover, shade and herbivory are factors that need consideration. Since Olea grows better under shade than in the open sun, successful regeneration for this species relies on shade from other plants and on protection from grazing, at least during the seedling stage. Most of the species that germinated from the seed banks were herbs and grasses with very few shrub and tree species. There was low correspondence between species composition of the seed banks and that of the standing vegetation. Spatial and temporal variation in demographic parameters among populations of Dodonaea and Olea can be attributed to human and environmental influence. Under protection, both Dodonaea and Olea seem to have a possibility to regenerate naturally. Further research should consider factors mentioned in detailed investigations of other dominant Afromontane forest species.

Vegetative annuals are currently popular in the ornamental horticulture industry. Many crops are newly domesticated species and little is known about how they perform during shipping or in the retail environment. Nine species and 21 cultivars were grown and underwent simulated shipping after harvest or nitrogen toning two weeks before harvest. Shipping was not found to affect the number of flowers on all but two cultivars post ship. Nitrogen toning affected vegetative growth of most Bracteantha bracteata (bracteantha) cultivars at harvest. All species had an effect due to toning postharvest. Bractenatha and Diascia ×hybrida (diascia) were chosen for further study due to their performance during these experiments. The effect of thidiazuron (TDZ) as a foliar spray and nitrogen toning on leaf yellowing and plant growth of bracteantha were evaluated. The two treatments were then combined to see how the two treatments worked together. It was found TDZ decreased leaf yellowing but its effects can be negated if the plants were not toned. Nitrogen toning reduced vegetative growth of the bracteantha without affecting the number of flowers on the plants. Diascia was found to have flower abscission in response to shipping. Further trials were conducted using 1- methylcyclopropene (1-MCP) an ethylene inhibitor. The effects of shipping duration and temperature were investigated. 1-MCP was found to hold flowers on treated plants longer postharvest than those not treated. Plants shipped for one day had no differences from the control but shipping for two days had a negative effect on plant quality. Postharvest shelf life was decreased when diascia was shipped at 24 °C when compared to cooler shipping temperatures. These results indicate shipping for no longer than one day and at less than 24 °C is recommended for diascia.