Dominant understorey species, such as herbs, ferns, palms and shrubs may influence forest tree species diversity and dynamics. Their influence may be through shading the forest floor, thereby affecting regeneration of shade-intolerant species and reducing species diversity, or it may be through competition with seedlings for space and belowground resources, thus modifying or changing the structure of the forest. These effects may be compounded if the life cycle of the understorey species consists of synchronized reproductive and mortality events. This study examines the influence of a dominant understorey species, Isoglossa woodii (Acanthaceae), on regeneration of trees in Indian Ocean subtropical coastal dune forest in southern Africa. The species is a semiwoody herb and has population-wide synchronous reproduction at 4-7 year cycles after which it dies and regenerates from seed. In this thesis I examine three aspects of the ecology of this suppressive herb: (i) the ecological and environmental correlates of the distribution of I. woodii; (ii) the evolutionary advantages of synchronous monocarpy; and (iii) the ecological effects of the extensive cover and putative recruitment window caused by I. woodii on forest tree seedling dynamics and diversity. Isoglossa woodii covered 65–95 % of the understorey, while gaps in this understorey cover occupied the remaining 5–35 % of the area. The spatial distribution of I. woodii was strongly related to tree canopy structure, with the species excluded from sites with dense canopy cover. Woody seedling establishment was inhibited by low light availability ( / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

Monospecific stands of Acacia karroo establish naturally on disturbed coastal dunes in KwaZulu-Natal, South Africa. While the A. karroo successional pathway is successful in rehabilitating mined dunes at the Richards Bay Minerals mining company (RBM), the same pathway has become arrested in the coastal dune forest at Cape Vidal in the Greater St. Lucia Wetland Park. This study examines the efficacy of the A. karroo successional pathway for restoring disturbed coastal dune forests. Dispersal of seeds and successful recruitment of seedlings are essential for habitat restoration. Seed and seedling banks were compared between previously disturbed A. karroo stands and adjacent forest at Cape Vidal. Different seed bank composition and higher seed bank richness in the forest suggest that seed dispersal into A. karroo stands is limited. Protected seed banks in A. karroo stands had increased seedling richness, indicating that dispersal limitation does not fully explain the lack of seedling establishment. At RBM, the seed bank richness of A. karroo stands increased with age since mining. While cumulative species richness of the seed bank of the oldest A. karroo stand at RBM was marginally lower than that at Cape Vidal, successful rehabilitation at RBM is associated with low seedling mortality. Consequently, forest tree species richness is high at RBM in the A. karroo stands and is converging on natural forest richness and composition. Although seed dispersal is reduced, it does not totally limit establishment of forest tree species in A. karroo stands at Cape Vidal, which implicates a post-establishment factor. Soil fertility potentially reduces seed germination and seedling growth. Soil nutrients in A. karroo stands at Cape Vidal were similar to those in the adjacent forest, and total nitrogen levels in A. karroo stands at Cape Vidal were higher than at RBM. Thus, soil conditions were unlikely to be limiting tree regeneration in A. karroo stands. Total nitrogen accumulated in the oldest stand at RBM at a rate of 10.0 g.m2.y(1 and a similarly rapid rate occurred at Cape Vidal. Therefore the A. karroo stands were not nitrogen limited. Nitrogen supplementation experiments at Cape Vidal demonstrated that a range of forest tree species establish in A. karroo stands regardless of nitrogen level, but there is low survival of seedlings. Thus, nitrogen availability is not arresting succession at Cape Vidal. Herbivory can also inhibit seedling recruitment. Selective feeding may enhance the persistence of species with defences against herbivory, such as A. karroo, ultimately altering the tree community composition. Browsing and trampling by large mammalian herbivores in A. karroo stands at Cape Vidal decreased survival and growth of forest tree seedlings. Large herbivores such as kudu, waterbuck, bushbuck and red duiker preferentially used the A. karroo stands as they offer abundant food and their topography allowed easy movement. This topdown pressure reduced recruitment, growth, and survival of seedlings of undefended species. Few wild herbivores occur at RBM, which allowed succession to proceed unhindered, ultimately restoring coastal dune forest at this site. Despite successful rehabilitation of coastal dune forest on mined dunes at RBM, limited seed dispersal and high levels of herb ivory have arrested succession at Cape Vidal. Thus, the A. karroo successional pathway must be implemented only after careful consideration of site-specific factors such as distance to a source of propagules and the intensity of herbivory in the system. In areas where herbivore densities are high, management interventions focusing on reducing herb ivory and encouraging visitation by seed dispersers are necessary for the successful use of this successional pathway. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.

Obesity and overweight have reached epidemic proportions and their prevalence has increased dramatically in the last decades worldwide. This has resulted in a dramatic increase in the incidence of obesity-associated metabolic alterations including type 2 diabetes, cardiovascular complications, and certain types of cancer. Evidences suggest that bioactive compounds present in fruit and vegetables, including polyphenols (or phenolic compounds), may exert beneficial effects against the development of obesity and associated alterations. Brazil is the world\'s third largest fruit producer and the seventh largest producer of tropical fresh fruits; however, only a few of them are being exploited commercially, perhaps due to the limited amount of information available about their chemical composition, and biochemical, nutritional and functional properties. Cagaita (Eugenia dysenterica DC.) and cambuci (Campomanesia phaea Berg.) are fruit species of the Myrtaceae family growing in the regions of the Brazilian Cerrado and Atlantic Coastal Forest biomes, respectively. Cagaita and cambuci fruits are used in various typical preparations, mainly jams, jellies, ice-cream, and liqueurs; whereas both fruit and leaves are used as popular alternative medicine by local communities to treat various disturbs such as diarrhea, diabetes, and jaundice. Previous studies have demonstrated the antioxidant and antidiabetic potential from cagaita and cambuci polyphenols in in vitro assays. Thus, in the present study, we investigated whether the administration of polyphenol-rich extracts from cagaita and cambuci, at two different doses, protect mice from diet-induced obesity and associated alterations. Two biological models, preventive and therapeutic, were designed for cagaita, and preventive for cambuci. For the preventive protocols, C57BL/6J mice fed either with a chow or a high-fat, high-sucrose (HFHS) diets were daily treated by gavage with water or polyphenols-rich extracts at two doses for 8 weeks. The findings demonstrate that polyphenols from cagaita prevented body weight and fat mass gains, attenuated fasting hyperglycemia and dyslipidemia, and reduced hepatic lipid accumulation. On the other hand, polyphenols from cambuci showed absence of changes in body weight and adiposity; however, an attenuation of adipose tissue inflammation was observed for both doses tested. Additionally, polyphenols from cambuci were effective in ameliorating glucose tolerance, as well as reducing fasting hyperglycemia, and improving dyslipidemia. For the therapeutic protocol, C57BL/6J obese mice induced by the intake of a HFHS diet for six weeks were treated with polyphenols from cagaita at two doses by oral gavage for further 8 weeks. Polyphenols from cagaita improved glucose homeostasis and attenuated dyslipidemia in obese mice, without affecting body weight and adiposity. Mechanistically, these beneficial actions seem to be mediated, at least in part, through a reduction in hepatic inflammation. In conclusion, polyphenols from cagaita and cambuci have a potential protective role in diet-induced obesity and their metabolic alterations. / A obesidade é considerada uma das grandes epidemias do século XXI, devido ao aumento de sua prevalência nos últimos anos e às diversas co-morbidades decorrentes destas alterações metabólicas como diabetes mellitus tipo 2, doenças cardiovasculares e alguns tipos de câncer. Evidências sugerem que compostos bioativos presentes em frutas e vegetais, incluindo os polifenóis (ou compostos fenólicos), podem exercer efeitos benéficos contra o desenvolvimento de obesidade e suas alterações associadas. O Brasil é o terceiro produtor mundial de frutas e o sétimo na produção de frutas tropicais, no entanto, um grande número de espécies frutíferas nativas permanece inexplorado em relação a seu potencial nutricional e funcional. Cagaita (Eugenia dysenterica DC.) e cambuci (Campomanesia phaea Berg.) são espécies frutíferas originárias das regiões do Cerrado e da Mata Atlântica, respectivamente, cujos frutos são usados na elaboração de diversos produtos alimentícios, e frutos e folhas de cagaita são usados na medicina popular. Estudos prévios têm demonstrado o potencial antioxidante e antidiabético in vitro dos polifenóis de ambas as frutas. Neste contexto, no presente estudo, foi investigado se a administração de extratos ricos em polifenóis de cagaita e cambuci, em duas doses diferentes, protegem camundongos de obesidade induzida por dieta a suas alterações associadas. Dois modelos biológicos, preventivo e terapêutico, foram desenvolvidos para cagaita, e preventivo para cambuci. Para os protocolos preventivos, foram usados camundongos da linhagem C57BL/6J alimentados com dieta rica em gorduras e sacarose (high-fat high-sucrose diet, HFHS), aos quais foram administrados água (controle) ou extratos ricos em polifenóis por gavagem em duas doses por 8 semanas. Os resultados demonstraram diferentes efeitos para os dois extratos. Os polifenóis de cagaita preveniram ganho de peso corporal e adiposidade, atenuaram hiperglicemia de jejum e dislipidemia, e reduziram acumulação de lipídeos hepáticos. Por outro lado, polifenóis de cambuci não contribuíram na prevenção do ganho de peso corporal e adiposidade, no entanto, foi observada uma atenuação na inflamação do tecido adiposo, em ambas as doses avaliadas. Adicionalmente, polifenóis de cambuci melhoraram a tolerância à glicose, assim como reduziram a hiperglicemia de jejum e atenuaram a dislipidemia. Para o protocolo terapêutico, camundongos da linhagem C57BL/6J foram induzidos à obesidade pela ingestão da dieta alta em gorduras e sacarose por 6 semanas e posteriormente foram tratados com polifenóis de cagaita, em duas doses, por gavagem por 8 semanas. Os polifenóis de cagaita melhoraram a homeostase glicêmica e atenuaram a dislipidemia em camundongos obesos, sem afetar peso corporal e adiposidade. Estes benefícios aparentam ser mediados, ao menos em parte, através da uma redução da inflamação hepática. Em conclusão, polifenóis de cagaita e cambuci têm um papel protetor potencial em obesidade induzida por dieta e suas alterações metabólicas.

"SELECT CD is a site-specific, decision-support tool for selecting ecologically viable tree species, reproduction cuttings, and regeneration methods in the coastal forest (CDF, CWH, and MH zones). SELECT CD integrates information from several existing guides with new information from literature and recent research into a single, user-friendly resource. SELECT CD also includes a rich library of visuals and an illustrated glossary of technical terms."

農林水産研究情報センターで作成したPDFファイルを使用している。

Forestry operations in Sweden can be traced a long way back in history. The overall emphasis has traditionally been on the forests’ economic or profitable role, even though they are also of great ecological and social interests. Nevertheless, the focus has shifted during the last decade due to the impact of sustainable development. A new Forestry Act has now provided the Swedish forestry with a new policy which is guided by two equally-weighted objectives; production and environmental concern. The European Union (EU) has also adapted to the direction of sustainable development. It places particular interest in the creation of sustainable coastal areas within the union. The aim of the Bachelor of Science thesis was to investigate how Swedish coastal forest owners define their role in the creation of sustainable coastal forests. The study is built on interviews which were conducted with seven forest owners, all of whom have properties in the coastal zones of Östergötland and Kalmar. These two counties are situated in the south-eastern part of Sweden. The study raises three different issues. The first is the manner in which the informants shape their knowledge of the existing forestry legislation, based on their identities and responsibilities. The second concerns the preconditions with which they are faced when managing their coastal forest properties and whether or not they see the new legislation as a shift in focus. The final issue highlights the importance of local knowledge and looks at the participation of the informants in the development of new regulations. The following conclusions are drawn from the investigations. Many owners of forest properties do not identify themselves as forest owners; it is therefore important to be aware of this distinction which is made between being a forest owner and being the holder of a forest property. The coastal forest owners who were interviewed run their forests according to their individual situations. Because of this they do not appear to be part of any shift of focus within the Swedish forestry. As a result, they may not have a defined role in its development. This role would probably be clearer or greater if their local knowledge were more explicitly valuated.

Resprouting is an important means of plant regeneration especially under conditions that do not favour regeneration through seeding such as frequent disturbances, low productivity, unfavourable soil conditions, extreme cold and limited understorey light availability. Sprouts may be advantageous over seedlings because they have higher survival and growth rates than seedlings, since they use resources from parent plants unlike seedlings that have to acquire their own resources. Resprouting is well documented for ecosystems that experience severe disturbances that damage aboveground biomass. For example, resprouting is important for plant persistence against fire in fire-prone savannas and Mediterranean shrub-lands, and hurricanes and cyclones in tropical forests. In these ecosystems, resprouting often results in multi-stemming, because this dilutes the risk of damage among many stems, improving the chances of individual survival. This study was conducted at coastal dune forest at Cape Vidal in north-eastern South Africa, where there is a high incidence of multi-stemmed trees due to resprouting in response to chronic disturbances of low severity. This study examines (1) the importance of resprouting to tree survival and dynamics in an environment where disturbance severity is low but pervasive, and (2) how this resprouting strategy differs from the more familiar sprouting response to severe disturbances such as fire and hurricanes. Analysis of the relationship between multi-stemming and a number of disturbances potentially causing multi-stemming revealed that stem leaning and substrate erosion were the most important disturbances associated with multi-stemming. There were fewer multistemmed trees on dune slacks that had a stable substrate and were protected from sea winds than on dune crests and slopes that had unstable substrate and were exposed to sea winds. Trees resprouted and became multi-stemmed from an early stage to increase their chances of survival against leaning caused by strong sea winds and erosion, and occasional slumping of the unstable dune sand substrate. These low severity disturbances are persistent and are referred to as chronic disturbances in this thesis. As a result of these chronic disturbances, both single and multi-stemmed trees had short stature because taller individuals that emerged above the tree canopy would be exposed to wind damage. Under chronic disturbances plants may manifest a phylogenetically determined sprouting response. However, in this study resprouting and multi-stemming were the results of the tree-disturbance interaction and not a property of a plant or species and were not phylogenetically constrained. Because the disturbances are predominantly of low severity, leaning trees were able to regain the vertical orientation of the growing section by turning upward (a process referred to as ‘turning up’ in this study) and hence survive without resprouting. Species that were prone to turning upward had a low incidence and degree of leaning of their individuals, low frequency of loss of primary stems and high abundance of individuals. Although turning up is less costly to the individual than resprouting, it could only be used by leaning trees that had small angles of inclination and were not eroded. High intensities of the latter require that individuals resprout to survive. The form and function of resprouting varied between seedlings and juvenile and mature trees. Resprouting in seedlings resulted in a single replacement shoot, unlike sprouting in juvenile and mature trees that resulted in multi-stemmed trees. Like sprouting in juvenile and mature trees, sprouting in seedlings was not phylogenetically constrained. Resprouting in seedlings increased seedling persistence; hence species with more sprout seedlings had larger individual seedlings and seedling banks. Resprouting in seedlings increased the chances of seedling recruitment, whereas resprouting in juvenile and mature trees increased the chances of an established plant maintaining its position in the habitat. After disturbances of high severity, which destroy the photosynthesizing parts, plants resprout using carbohydrates stored below- or above ground. In this study, good resprouters stored more carbohydrates both below- and above ground than poor resprouters. The carbohydrates were mobilized for resprouting after disturbance. More carbohydrates were stored in stems than in roots because the prevailing disturbances were mostly of low severity and hence above ground resources were readily available. Similar to storage by plants in severely disturbed habitats, carbohydrates were stored by reserve formation, which competes for carbohydrates with growth and maintenance and forms permanent storage, rather than accumulation, which temporarily stores carbohydrates in excess of demands for growth and maintenance. Stored carbohydrates are not necessary for resprouting of plants after disturbances of low severity because they can resprout using resources remobilized directly from the disturbed photosynthesizing parts. However, in this study, stored carbohydrates served as a bet-hedge against occasional severe disturbances that occurred in addition to chronic disturbances. Allocation of carbohydrates to permanent storage diverts them from growth and reproduction and hence good resprouters had lower growth rates, seed output, seed size and seedling recruitment than poor resprouters. However, the costs of these traits that resulted in low recruitment from seed by good resprouters, were compensated for by high persistence of established individuals of good resprouters through recruitment of sprout stems. This study demonstrates that resprouting is not only advantageous in severely disturbed environments, but also in environments where disturbances are of low severity but nevertheless confer an advantage on individuals that persist. Thus in forest environments where aboveground biomass is seldom destroyed and individuals are relatively long-lived, resprouting can confer significant fitness and selective advantage on individuals. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

The aim of this study was to understand the contribution of Linear Alkylbenzene Sulfonates (LAS) to the decline of Mediterranean coastal forest exposed to marine aerosols. LAS are a group of synthetic anionic surfactants widely used in the composition of household or industrial detergents and agrochemicals. This study was part of a large project (RISICO) aiming the assessment of the environmental impact of the LAS at multiple levels: biodegradation in the coastal waters, sorption – desorption processes in the sediments, toxicity to the aquatic life and toxicity to the coastal forest (by aerosolisation of the sea water). <p>Previous studies pointed out this group of surfactants as the main cause of the coastal forest decline. However, the quantification of this surfactant in the environmental samples (mainly sea water and foliar deposition) was done using non-specific analytical methods as methylene blue active substances (MBAS), leading to overestimation of the environmental concentrations of LAS. <p>The work hypothesis was that at actual environmental concentrations, the LAS does not play a key role in the foliar uptake of the sea salt deposited on the coastal vegetation by the marine aerosols, therefore the LAS may not be the main cause of the coastal forest decline. <p>The research involved both greenhouse experiments and field measurements. The experimental work was conducted on young Mediterranean trees (Laurus nobilis L. Quercus ilex L. and Pinus halepensis P. Mill.) and investigated the synergistic toxic effects of exposure to simulated marine aerosol contaminated with surfactants. An array of endpoints was used including photosynthetic activity, relative water content, foliar deposition and uptake of salt and LAS, and pigments analysis. The results of those experiments revealed that LAS itself did not have phytotoxic effects. Nevertheless, the surfactant was shown to enhance the foliar uptake of the salt in the tested species, especially in Pinus halepensis, confirming the conclusions of previous studies regarding the sensitivity of this species to polluted marine aerosols. <p>The field work was conducted in San Rossore National Park (Italy) and Porquerolles Island (France) and was focused on evaluating the health status of the Mediterranean forest (Quercus ilex L. Pinus halepensis Mill. and Pinus pinaster Aiton.) and also on quantification of LAS in coastal aerosols using highly specific analytical methods, like the mass spectrometry (MS). The frequencies and extent of injuries in the coastal trees were found to be correlated to the salt but not with the LAS content of the leaves. The concentrations of LAS in the Pinus and Quercus leaves were comparable in the two studied sites but the concentrations of salt were extremely high in San Rossore, suggesting that other factors may determine the excessive salt foliar uptake. The parallel MS and MBAS carried out in the same set of aerosol samples revealed that MBAS measurements were not relevant for LAS concentrations in the marine aerosols. Projecting the experimental results to the real LAS and salt exposure of the coastal forest, we concluded that LAS may play a marginal role in coastal vegetation decline. <p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

This research examines the relationship between understory plant diversity and logs in a Pacific Northwest (PNW) Sitka spruce (Picea sitchensis)-western hemlock (Tsuga heterophylla) old-growth, coastal forest. These forests are renowned for their high forest productivity, frequent wind storms, and slow log decomposition rates that produce unmatched accumulations of coarse woody debris (CWD) yet few studies have examined the relationship between CWD and understory vegetation ecology. My research addressed this topic by comparing understory plant census data between paired fallen log and forest floor sites (n=20 pairs). My objectives were to: 1) determine the influence of substrate type on community composition and diversity, and 2) examine successional pathways and species assemblage patterns on CWD in various stages of decomposition. To meet these objectives I employed non-metric multidimensional scaling (NMDS) ordinations and unsupervised cluster analyses to identify and compare community assemblages on both substrates. These methods revealed similar species diversity and evenness between log and forest floor sites with compositional differences within and between substrates corresponding to habitat availability for colonization and light and moisture gradients. My results also suggest understory successional pathways related to decay class and characterized by an initial abundance of bryophytes, forbs, and seedlings followed by woody shrubs. Understory communities developing on logs also experienced increasing diversity, evenness, and divergence from forest floor communities consistent with log decomposition. These results differ from findings for boreal forests that reveal increasing similarity between substrate communities with increasing decay class. Recommendations for future research include the employment of a more robust sample size and direct measurements of environmental variables. Additional comparator studies are also needed to confirm the effects of forest type and decomposition on the relationship between CWD and forest understory communities. This study demonstrates how fine-scale wind disturbance fosters biodiversity through the creation of CWD substrate. My results and future research are essential for the development of silvicultural models designed to promote biodiversity in PNW coastal forests.