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Transplante de epífitas entre Florestas Estacionais Semideciduais para enriquecimento de florestas em processo de restauração / Enrichment of forests in process of restoration through epiphytes transplantation, in Semideciduous Seasonal ForestDuarte, Marina Melo 06 March 2013 (has links)
O enriquecimento com diferentes formas de vida, como com epífitas, é fundamental para o desenvolvimento de florestas em restauração, em paisagens fragmentadas, onde a dispersão natural é limitada. Epífitas são plantas que crescem sobre outras (forófitos). Têm papel ecológico importante, realizando ciclagem de nutrientes e oferecendo microambientes e alimentos a outras formas de vida. Características de forófitos, clima e microclima influenciam populações locais de epífitas. Para aumentar o sucesso do enriquecimento em florestas em restauração, é importante determinar quais filtros podem atuar no processo. Fizemos o censo de áreas que receberam autorização para supressão vegetal e obtivemos que, a cada ano, cerca de 500 ha de Florestas Estacional Semidecidual e Ombrófila Densa, em diferentes estágios de regeneração, são desmatados, apenas no estado de São Paulo. Elas podem fornecer material que pode ser recuperado e empregado na restauração de outras florestas. Neste trabalho, damos enfoque às epífitas que podem ser disponibilizadas a partir desse desmatamento. Transferimos 360 indivíduos de seis espécies delas, entre Bromeliaceae (Aechmea bromeliifolia e Tillandsia pohliana), Orchidaceae (Catasetum fimbriatum e Rodriguezia decora) e Cactaceae (Lepismium cruciforme e Rhipsalis floccosa) para duas Florestas Estacionais Semideciduais em processo de restauração, uma com 13 anos e outra com 23. As médias anuais de cobertura de dossel, entre os forófitos escolhidos, variaram entre 62,2 e 85,0% na floresta de 13 anos e entre 79,3 e 92,9% na floresta de 23 anos. Taxas de sobrevivência das diferentes espécies de epífitas foram superiores em floresta mais jovem, variando de 63.33 a 100%, enquanto em floresta mais madura variaram entre 55,17 e 89,66%. Transplantes usando fibra de palmeiras, capaz de reter água, e realizados no início de estação chuvosa podem ter explicado o maior sucesso em floresta mais nova. Taxas de sobrevivência, fixação, ramificação, floração e frutificação não estiveram relacionadas à espécie de forófito, à rugosidade de casca ou à posição de transplante. Por outro lado, elas estiveram relacionadas às espécies das próprias epífitas. Apenas em algumas situações e para determinadas espécies, taxas de fixação, ramificação e reprodução sexuada estiveram relacionadas aos valores de cobertura de dossel. Animais podem ter importantes papéis como polinizadores e dispersores de epífitas, o que mostra que sua presença na floresta é fundamental para a permanência dessas plantas em longo prazo. Ao final, separamos as principais conclusões tiradas deste trabalho e fizemos um guia de procedimentos práticos a serem adotados no enriquecimento de florestas em restauração usando epífitas provenientes de florestas a serem suprimidas. / Enrichment using non-arboreal life forms, such as epiphytes, is critical to the development of forests under restoration, in fragmented landscapes, where natural dispersal is scarce. Epiphytes are plants that grow on top of other plants (phorophytes). They play very important ecological role, performing nutrient cycling and providing microenvironments and food to other life forms. Features of phorophytes, climate, and microclimate influence local diversity of epiphytes. In order to improve success of enrichment in areas under restoration, it is important to determine what filters may play a role in this process. We censused areas that received authorization for vegetation removal and found out that, every year, about 500 ha of Semideciduous Seasonal Forests and Rainforests, in different regeneration stages, are legally cut down, only in the state of Sao Paulo. They can provide material that can be recovered and used to restore other forests. In this work, we focused on the epiphytes that may become available from deforestation. We transferred 360 individuals of six species of this life form among Bromeliaceae (Aechmea bromeliifolia and Tillandsia pohliana), Orchidaceae (Catasetum fimbriatum and Rodriguezia decora) and Cactaceae (Lepismium cruciforme and Rhipsalis floccosa) to two different Semidecidual Seasonal Forests in process of restoration, one of them was 13 years old and the other, 23 years old. Annual canopy cover averages provided by diffferent phorophytes ranged from 62.2 to 85.0% in 13-year old forest and from 79.3 to 92.9% in 23-year-old forest. Survival rates of epiphytes species were higher in the younger forest, from 63.33 to 100%, compared to the ones obtained in the more mature forest, from 55.17 to 89.66%. Transplants performance using palm tree fiber, which enables higher water retention, and at the beginning of rainy season may have been responsible for higher survival rates in the young forest. Survival, rooting, sprouting, flowering and fruiting rates were not related to phorophyte species, to their bark roughness nor to the position of transplantation. On the other hand, they were always relatated to epiphyte species. Only in some cases and for determined species, rooting, sprouting, flowering and fruiting were related to canopy cover. Animals can play important roles as pollinators and dispersers of epiphytes, which shows that their presence in forests is fundamental for the long-term persistance of these plants. In the end, we gathered the main results taken from this work and organized a guide of practical procedures to be adopted in enrichment of areas using epiphytes from forests about to be suppressed.
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Remediation and restoration of ocean exposed cliff-top, in the context of Dounreay (Scotland) nuclear power plant decommissioningBraidwood, David Walter January 2018 (has links)
Restoration ecology continues to become ever more relevant as legislation demands we prevent biodiversity losses. Post-industrial restoration sites pose a number of additional challenges, including balancing ecological need with logistical and financial constraints. In the North of Scotland, one such site is the Dounreay Nuclear Power Plant, now undergoing decommissioning. The intention is to restore cliff-top habitat with native vegetation, blending in with its surroundings and necessitating minimal maintenance. The overall objective of this PhD research was to help develop a plan for the restoration of the site. A key challenge in this particular case was the residual low level radioactivity at depth in some areas, and a restoration layer is required to prevent contamination of bioreceptors at the surface, however, topsoil availability is limited. The cliff top site, and exposure to salt spray driven by strong winds, meant the identification of suitable vegetation communities for different areas could be crucial to its success. Vegetation and soil surveys across nine reference sites along the North coast of Scotland identified five non-peat vegetation communities suitable for Dounreay's restoration. Restoration ecology continues to become ever more relevant as legislation demands we prevent biodiversity losses. Post-industrial restoration sites pose a number of additional challenges, including balancing ecological need with logistical and financial constraints. In the North of Scotland, one such site is the Dounreay Nuclear Power Plant, now undergoing decommissioning. The intention is to restore cliff-top habitat with native vegetation, blending in with its surroundings and necessitating minimal maintenance. The overall objective of this PhD research was to help develop a plan for the restoration of the site. A key challenge in this particular case was the residual low level radioactivity at depth in some areas, and a restoration layer is required to prevent contamination of bioreceptors at the surface, however, topsoil availability is limited. The cliff top site, and exposure to salt spray driven by strong winds, meant the identification of suitable vegetation communities for different areas could be crucial to its success. Vegetation and soil surveys across nine reference sites along the North coast of Scotland identified five non-peat vegetation communities suitable for Dounreay's restoration. This prompted the development of a novel concept: that of utilising restoration sites as 'protorefuges' or 'protorefugia', i.e. restoration sites where threatened species at the leading edge of climate change can be translocated ahead of the climate changing. There, they would be joined by individuals of the wider population naturally dispersed as the climate shifts. Overall, these results enabled the development of a refined restoration plan for Dounreay, which takes into account the particular setting, constraints and timelines involved. With the decommissioning of an increasing number of nuclear sites across Britain and Europe taking place in the coming years, this research should be developed further. In particular our novel concept of protorefugia could even be put into practice, benefiting both restoration and conservation.
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Leaf-litter and microsite on seedling recruitment in an alley-planted E. sargentii and Atriplex spp. saline agricultural systemFarrell, Claire January 2008 (has links)
[Truncated abstract] In order to assess the sustainability of mixed plantings on saline land, this thesis examined the importance of leaf-litter trapping and microsites on recruitment in a salt affected alley-belted (tree/shrub) agricultural system in Western Australia. Located in the low rainfall region (MAR <330 mm) of the wheatbelt, the 60 ha site consists of concentric rows of Eucalyptus sargentii trees with mounded (6 - 11 cm high) 10 -15 m inter-rows of Atriplex spp. Sustainability of this system and fulfilment of productive and ameliorative functions is dependant on successful recruitment (perennials). Although the present study site was conducted on farmland in a Mediterranean-type climate, low annual rainfall and spatial arrangement of perennial shrubs and trees, allow useful comparisons to be made with naturally occurring banded semi-arid systems and vice-versa. Of key interest were leaf-litter redistribution and trapping by tree and shrub rows and whether litter-cover/microsites facilitated/interfered with seedling recruitment (establishment, growth and survival). Litter from the tree row, redistributed by prevailing winds and rain, accumulated adjacent to saltbush seeding mounds, creating a mosaic of bare and littered areas across the site (total litter 10 t/ha over 22 months). Accumulated litter was hypothesized to differentially influence seasonal soil abiotic parameters (depending on litter-cover density) including; salinity, water availability, infiltration rates, water repellency and temperature. These abiotic conditions were also hypothesized to vary between tree and shrub microsites. Biotically, recruitment at this site was also hypothesized to be determined by interactions (positive and negative) between perennial components and understorey annuals/perennial seedlings. Accumulation of litter and resultant heterogeneity was influenced by shrub morphology, microtopography, wind direction and distance from litter source, with increased litter on the leeward sides of hemispherical Atriplex undulata shrubs and shrubs closest to tree rows. ... The importance of tree/shrub microsites varied seasonally, with no influence in winter due to moderate temperatures and increased water availability. In warmer months saltbush mid-row microsites were most favourable for seedling recruitment due to moderate litter-cover; reducing salinity, temperatures and increasing infiltration; and reduced root-competition/shading by the tree row. Tree microsites also directly inhibited seedling recruitment through increased salinities and water repellency. However, trees also indirectly facilitated recruitment in adjacent areas through provision of leaf-litter. As litter-trapping and recruitment patterns at this site mirror those found in semi-arid natural and artificial systems, the results of this study provide useful insights into creating appropriate mimics of low rainfall natural banded woodland and chenopod shrublands. Saltbush seeding mounds, shrub morphology and litter were key components for litter trapping and recruitment heterogeneity at this site. In this tree/shrub alley planting, where litter quantities directly influence vegetation cover densities, future saline plantings need to consider appropriate tree/shrub row spacings and orientation for efficient resource (seeds, litter and water) capture.
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Plant community recovery after high severity wildfire and post-fire management in the Klamath Region /Lopez Ortiz, Maria Jose. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 98-108). Also available on the World Wide Web.
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Emergency fire rehabilitation of BLM lands in the Great Basin : revegetation & monitoringMcArthur, Ted O. 20 February 2004 (has links)
The Bureau of Land Managements (BLM) Emergency Fire Rehabilitation
(EFR) policy was developed in 1985 to encourage protection of sites from soil erosion
and to minimize potential changes in vegetation communities that may result from the
dominance of weedy species. To achieve the goals of EFR policy, managers often
used introduced perennial grasses that established quicker and competed better with
introduced annuals than did native plants. However, the change of sagebrush-grass
communities to communities dominated by introduced forage grasses has led to
concerns for wildlife habitat. This concern contributed to a policy change encouraging
the use of native species, when available, for rehabilitation projects.
This study attempts to assess the effectiveness of BLM EFR projects in
meeting the stated goals of the BLM EFR policy in the Great Basin. To do this, two
field offices per state were randomly selected from an inclusive list of all Great Basin
field offices. In 2001, we randomly selected three EFR projects per field office from
those projects that used native species. On each project site, we used a common
monitoring technique in association with monitoring techniques implemented by the
BLM to assess if national EFR objectives were being met.
A semi-structured survey was developed to determine the potential reasons
why native and introduced plants were either used or not used, why monitoring was
and was not proposed, and whether monitoring was implemented in rehabilitation
projects.
BLM monitoring techniques did not adequately evaluate EFR goal
achievement. The time it took to implement any of the BLM methods did not differ
significantly from the time needed to implement the common protocol on the two
projects where BLM had implemented monitoring and used native plants (F[subscript 3,12]=1.63,
P=0.23). Cost to implement the common monitoring technique was minimal and it
directly measured aspects of stated EFR policy goals.
Vegetative cover of all natives, seeded and volunteers, contributed half of the
overall cover on EFR projects and was significantly higher than sown introduced
species. Invasive species were intermediate and did not differ significantly from either
the natives or the introduced. The seeded species were a subset of the native or
introduced classes. Composition by cover between sown native, sown introduced, and
invasive species did not differ significantly. Vegetation cover increased the surface
soil stability 39% of the time and subsurface stability 56% beneath the vegetation.
Respondents of the survey stated that they generally use more natives and
more complex seed mixtures than they did historically. Many also stated that they
prefer to use native over introduced species. However, most felt that introduced
species are more effective in meeting EFR goals on the degraded sites than native
species. All respondents would like to access a summarized report of other
rehabilitation projects. The respondents were split between accessing it through the
World Wide Web or through a written report. We believe that a common database
could be created and maintained on the World Wide Web if a common sampling
protocol was implemented. / Graduation date: 2004
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Regeneration failure and the Acacia karroo successional pathway in coastal dune forests in KwaZulu-Natal, South Africa.Boyes, Lauren J. January 2007 (has links)
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.
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A PLANT TRAIT-BASED APPROACH TO EVALUATE THE ABILITY OF NATIVE C<sub>3</sub> AND C<sub>4</sub> GRASSES TO RESTORE FUNCTIONALITY TO A REMNANT BLUEGRASS SAVANNA-WOODLAND IN KENTUCKY, USA.Fry, Jann E 01 January 2014 (has links)
Temperate Midwestern oak savannas are considered imperiled ecosystems with < 1 % remaining since the time of European settlement and are identified as critical areas for preservation. Restoration of Midwestern oak savannas is challenging due to the lack of accurate historical data, few intact remnants remaining to study, and lack of restoration ecology studies. A plant trait-based approach was used to evaluate the ability of six C3 and three C4 native bunchgrasses to restore functionality to a remnant savanna–woodland of the Bluegrass Region of Kentucky. The response and effect framework was used to assess the response of the nine native grasses according to the habitat filters of interannual precipitation, inter- vs. intra-specific competition, and simulated grazing. The effect traits associated with plant-soil nitrogen and carbon cycling were also assessed. The response traits of interannual competition and inter- vs. intra-specific competition along with the effect traits plant-soil nitrogen and carbon cycling were measured in a monoculture experiment conducted at Griffith Woods WMA. The simulated grazing or clipping experiment was conducted over three months in a heated greenhouse experiment.
Four of the C3 species were of the genus Elymus which had significant differences in life history traits compared to the other species and made them particularly well adapted to the Bluegrass Savanna-Woodland. The Elymus species were not well adapted to the most intense clipping treatment. For the other two C3 species, C. latifolium would be a better competitor than D. clandestinum under normal conditions. D. clandestinum had the most number of plastic traits and was the only species to exhibit all three grazing strategies. Comparing the C4 species, T. flavus and P. anceps grew well in the monoculture but A. virginicus did not. The life history traits of A. virginicus does not make this species a good candidate for restoration at this site. The three C4 species were well adapted to clipping. The results of this study suggest that the C3 species, particularly the Elymus, are well adapted to the eutrophic mesic conditions of the Bluegrass Savanna-Woodland, and that the C4 species are better adapted to disturbance.
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Rehabilitation as a method of understanding vegetation change in Paulshoek, Namaqualand.Simons, Liora-lee January 2005 (has links)
The main aim of this study was to test rehabilitation interventions in a system altered by heavy grazing, and to develop methods of monitoring these interventions.
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Comparison of bare root vs. potted plants, species selection, and caging types for restoration of a prairie wetland, and quantitative analysis and descriptive survey of plant communities and associations at Lewisville Lake Environmental Learning Area (LLELA), Lewisville, TXBuckallew, Robin Randolph. Dickson, Kenneth L., January 2007 (has links)
Thesis (Ph. D.)--University of North Texas, May, 2007. / Title from title page display. Includes bibliographical references.
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Confronting the challenges of tidal flat conservation spatial patterns and human impacts in a Marine Protected Area in southern NSW, Australia /Winberg, Pia Carmen. January 2008 (has links)
Thesis (Ph.D.)--University of Wollongong, 2008. / Typescript. CD-ROM contains full thesis, appendix II database and abstract. Includes bibliographical references: p. 169-198.
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