Título original: Efeitos do tempo de restauração e da estrutura da paisagem sobre a frugivoria em áreas em processo de restauração / Orientador: Marco Aurélio Pizo / Coorientador: Milton Cezar Ribeiro / Banca: Debora Cristina Rother / Banca: Karl Stephan Mokross / Resumo: Áreas em restauração florestal são importantes campos experimentais para compreender o processo de sucessão ecológica, sendo que o contexto da paisagem de entorno e a presença de animais dispersores de sementes são fatores fundamentais para o equilíbrio dinâmico das mesmas. Durante a sucessão ecológica, as comunidades animais e vegetais passam por diversas alterações em suas estruturas. Para uma maior compreensão dessas mudanças, este estudo tem como objetivo verificar a interação entre a fauna e os frutos artificiais em áreas em processo de restauração com diferentes idades, além de analisar se essa interação é influenciada pela cobertura vegetal na paisagem do entorno. Para isso, foi conduzido um experimento com frutos artificiais em 11 áreas em processo de restauração com diferentes idades, e consequentemente, diferentes estágios sucessionais. Em cada área, foram selecionados 15 pontos e, em cada ponto, foram fixados 15 frutos artificiais vermelhos em arbustos ou árvores jovens. Os frutos ficaram expostos à fauna local e após 7 dias foram recolhidos e analisados visualmente em busca de sinais de interação. Os dados obtidos foram correlacionados à idade da área e à cobertura vegetal na paisagem de entorno em 5 escalas espaciais (250, 500, 1000, 1500 e 2000 metros) através de Modelos Lineares Generalizados. Os resultados indicaram que aves e insetos são os principais grupos interagindo com os frutos, sendo que a porcentagem de interação foi inversamente proporcional ao aumen... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Forest restoration areas are important experimental fields to understand the process of ecological succession, and the characteristics of the surrounding landscape and the presence of animals that can disperse seeds are fundamental factors to the dynamic balance of them. During ecological succession, the animal and plant communities experience several changes in their structure. This study aims to verify the interaction between fauna and artificial fruits in restoration areas with different ages, besides analyses if this interactions are influenced by the vegetal cover in the surrounding landscape. Therefore, an experiment with artificial fruit was carried in 11 restoration areas with different ages, and consequently, different successional stages. In each area, 15 points were selected and, at each point, 15 red artificial fruits were fixed in shrubs or young trees. The fruits were exposed to the local fauna and after 7 days were collected and analyzed visually for signs of interaction. The data obtained were correlated to the age of the area and to the vegetation cover in the surrounding landscape in 5 spatial scales (250, 500, 1000, 1500 and 2000 meters) using Generalized Linear Models. The results indicated that birds and insects are the main groups interacting with fruits, and the percentage of interaction was inversely proportional to the increase on the age of the area under restoration. The amount of vegetation cover in the landscape of 1000 meter radius had a greater ... (Complete abstract click electronic access below) / Mestre

Thesis (MSc. (Plant production)) -- University of Limpopo, 2016 / Seriphium plumosum is a declared indicator of bush encroachment, and poses a serious threat to the management of sustainable utilization in all grasslands. The successful invasiveness of S. plumosum is attributed to its competitive ability and high allelopathic potential. A trial was established at the University of Limpopo to investigate the interference between S. plumosum and four plant species, namely: Eragrostis curvula, E. tef, Panicum maximum and Lactuca sativa. Plant material of S. plumosum were collected and used to make infusions which were used on the receiver species. The infusion inhibited the germination of all the receiver species, and it was highly significant (P ≤ 0.01), compared to control treatments where no inhibition occurred. All receiver species were sensitive to roots and shoots infusions, but the effect of shoots infusion differed significantly (P ≤ 0.01) from those of roots infusion. All receiver species were sensitive to both summer and winter collected materials, but plant material collected in winter had a bigger effect (P ≤ 0.01) than plant material from summer. All receiver species were sensitive to both fresh and stored plant material, but inhibition effects were not statistically significantly different (P ≥ 0.05). All receiver species were sensitive to both fresh and stored soils collected in infested areas, but effects were not significantly different (P ≥ 0.05), while the effects of infested and un-infested soils differed significantly (P ≤ 0.01). All receiver species were sensitive to soils collected during summer and winter. Where infested soils were concerned, all receiver species were sensitive to infested soils, compared to control treatments where no effects occurred. Where stored infested soils were concerned, all receiver species were sensitive to both fresh and stored infested soils. It was concluded that both plant material of S. plumosum and soils from areas encroached by S. plumosum have a negative effect on seed germination of the four receiver species. Should a farmer control this species by means of cutting, it should be quickly removed to allow the gass to recover. The farmer must not expect quick recovery of grasses due to the presence of allelopathic substances in the soil. / Agri-seta

Human activities have fundamentally shaped ecosystems across the globe. While this is often associated with degradation, cultures with alternative philosophies can leave a different kind of legacy. First Nations in the temperate rainforest of coastal British Columbia, like the Heiltsuk and Wuikinuxv, have inhabited the land for over 14,000 years, leaving behind tangible legacies in the plant communities we see today. From fine-scale effects of enriched plant leaves to landscape-level species distributions, this research investigates the ecological legacies of human land use and management—both past and present. In one chapter, I test if plants growing on ancient, human-modified soils are enriched in nutrients. I find that plants growing on these sites contain more phosphorus and sodium, which generally benefit fruit production and overall growth. This aligns with oral histories that describe fertilized shrubs as having berries that are bigger, healthier, tastier, and more productive. In the following chapter, I create models that predict the distribution of culturally important plants. With the Heiltsuk Integrated Resource Management Department, I develop a framework for habitat suitability modelling that can be used as a tool for aiding their resource management decisions. All models performed well (AUC = 0.9 overall), and offer insight into suitable habitat across a 3,600 km2 area. Out of five predictor variables, distance to shore, site series (a vegetation index), and human influence contributed the most to model performance. This research contributes a practical tool for resource management and adds to the growing body of interdisciplinary knowledge that uses scientific methods to answer questions of cultural significance. In a time of overlapping environmental crises—like climate change and biodiversity loss—it is important to be aware of the positive influence humans can have on the environment, and how this can offer a hopeful direction for resource management into the future. / Graduate

Invasive plants are widely cited as a major threat to native plant communities, and the correlation between plant invasions and a subsequent decline in native species is well documented at some scales. However, one outstanding question is the degree to which invasive species are a driver of native plant declines versus a correlate of other drivers, such as habitat disturbance. These two hypotheses to explain the dominance of invasive species in communities have been termed the ‘driver’ and ‘passenger’ models, respectively. In order to understand the impacts of plant invasion on native plants we need more studies that consider the role of correlated environmental predictors, which may play unseen roles in the response and recovery of native plant communities frequently attributed to invasion alone. Using a large database of plant community and environmental data from sites across Southern Ontario, I used path analyses to examine the direct and indirect relationships between disturbance, exotic and native plant richness, and relative abundance. Counter to my initial predictions, I found support for both the partial passenger and partial driver models of invasive dominance, while full passenger models were outright rejected. The causal hypotheses consistent with the data indicated significant relationships between native and exotic species richness and native and exotic relative abundance across models. An exploratory analysis, which examined species-specific models, found that the data was consistent with seven out of twelve causal hypotheses. Models that could not be rejected were split almost evenly across full passenger, partial passenger, and partial driver models. Model support varied according to the species included in the dataset suggesting that the best fit underlying model of invasive dominance likely varies by species. While the partial passenger and partial driver models were recurrently consistent with the data, no single model described the underlying patterns of invasive dominance across all systems.

High structural diversity amongst plant species in the arid winter rainfall region of southern Africa is common to other arid regions of the world. Details of the range and combinations of structural attributes in species, and within plant communities, are not widely known for southern African arid ecosystems. Hence little is known of how plant-form distributions vary within and between arid ecosystems. and of the environmental factors that may be responsible for any variations found. Nor is much information available on how phenological behaviour relates to the structural attributes of plant species. This study examined structural attributes of perennial plant species on the Worcester Veld Reserve, southwestern Cape. in relation to their distribution and phenology. Species were grouped on the basis of above ground structural and anatomical criteria. The distribution of species and plant-forms was assessed through a phytosociological survey along an environmental gradient in the area, and their phenology determined through qualitative and quantitative monitoring of species phenophases over a two year period. The results show that species of the predefined structural groups i) Co-occur throughout the area. but relative abundances vary from site to site and in relation to topography. aspect and the presence of Mirna-like mounds; ii) Phenological patterns for the flora overall are strongly seasonal, but the timing and periods of phenophases differ between, but are relatively uniform within, the defined structural plant groups. Since phenological patterns are indicative of resource-use patterns. these results indicate that the different plant-forms have different functional responses to the conditions of limited water availability and summer drought. This conceivably facilitates the co-existence of species in this water-limited environment. Habitat variability. which can be related to land-form patterns. is also implicated as a factor facilitating the co-existence of a diversity of species and plant-forms. Structural functional relationships known for arid region plants help to explain the relative uniformity of behaviour within plantform groups. and aid in understanding the ecological significance of distribution patterns of plant-forms in the arid landscape. The conclusion is reached that because of the close coupling between photosynthesis and water-use. the water storage potential and photosynthetic organ type are plant attributes which can serve as useful criteria by which arid region species can be grouped into ecologically meaningful categories or functional guilds. The formulation of a practical and meaningful functional classification is necessary to facilitate the understanding of complex vegetation patterns and processes within arid ecosystems. and allow for meaningful inter-ecosystem comparisons.

Mt. Tamalpais, 2571 feet in elevation, is found eighteen miles north of San Francisco in southern Marin County (see Plate 1). Despite its close proximity to a world port and metropolis, its slopes still display a wildness and natural beauty that have remained relatively unaltered as compared with other areas of the Bay Region and demonstrates ready accessibility to detailed ecological study. The study began during the spring of 1963 when plant specimens were first collected. After a period of reconnaissance and mapping of the vegetation, quantitative samples were taken in the study area in hopes that relationships could be established between plant communities and environmental factors.

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Thesis (Ph.D.)--University of the Witwatersrand, Faculty of Science, School of Animal, Plant and Environmental Sciences, 2004

No description available.

Achieving societal well-being goals is inextricably linked to the preservation of many ecosystem functions. This dissertation adopts a plant lens, to contribute to our understanding of sustainable ecosystem functioning. Specifically, it sheds light on some plant physiology, phenology, and ecology processes, which matter for sustainable development: tree growth response to high temperatures, annual fluctuations in the timing of plant flowering, and ecological benefits of crop diversity that translate into economic returns. In addition, it illustrates how large-scale data proxies can be used to document large scale patterns that arise from individual plant processes. Chapter 1 documents a new methodology for estimating tree-level temperature response curves, using tree ring data and a degree-day framework. It uses those curves to document harmful impacts of high temperatures for tree growth across the US, and shows that there is limited acclimatization, but some adaptation to those high temperatures in a sample of climate sensitive and long-lived trees. Chapter 2 shows that satellite imagery and deep learning tools can be leveraged, to monitor interannual variations in the timing of plant flowering at large scales. It documents the predictive performance of two models: one adapted to monitoring crop flowering, the other adapted to monitoring shifts in the onset of spring flowering. Finally, chapter 3 highlights remaining gaps between empirical evidence of crop diversity benefits, and portrayal of those benefits in economic models of optimal crop diversity choice. Together, these chapters illustrate that bridging scales and disciplines is a difficult task, although it is necessary for understanding the sustainability of the human environmental footprint.