Made available in DSpace on 2014-06-12T15:02:37Z (GMT). No. of bitstreams: 2 arquivo1769_1.pdf: 806134 bytes, checksum: 002023eeb6b3afc4ae5d5f612abd6479 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2007 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Devido a importância de pesquisas sobre a ecologia da pteridoflora ocorrente no Nordeste brasileiro, foi realizado um estudo para analisar a variação das pteridófitas quanto a riqueza, abundância, diversidade e aspectos ecológicos nos ambientes de interior e borda de um fragmento de Floresta Serrana. O fragmento estudado é conhecido como Mata da Reserva (08°32 20 S- 35°43 22 W) e encontra-se inserido no complexo da Serra dos Macacos, localizada no município de Bonito, estado de Pernambuco. O estado detém poucos remanescentes desse tipo de floresta, que são verdadeiros refúgios biológicos para muitas espécies de pteridófitas. Para verificar a riqueza, abundância e diversidade das pteridófitas nos dois ambientes foram estabelecidas 20 parcelas de 10X20m (200m2), sendo dez para cada ambiente. Os dados foram analisados utilizando o Índice de Shannon-Wiener e o Teste T com o auxílio do programa Statistica 6.0. Também correlacionou-se os dados de abundância com os fatores abióticos de temperatura e umidade, utilizando o Coeficiente de Correlação de Spearman. As identificações das espécies , assim como a determinaçao das espécies raras seguiram bibliografias especializadas. Foram contabilizados 891 indivíduos de pteridófitas, distribuídos em 27 espécies, 21 gêneros e 11 famílias, sendo a família Polypodiaceae a mais representativa em número de espécie. Porém quanto a abundância de indivíduos a família que se destacou foi a Dryopteridaceae. O inventário das parcelas delimitadas trouxe quatro novas referências para a Mata da Reserva, Cyathea microdonta (Desv.) Domin, Cochlidium linearifolium (Desv.) Maxon ex C. Chr., Dicranoglossum desvauxii (Klotzsch) Proctor e Pecluma pectinatiformis (Lindm.) M.G. Price, sendo estas duas últimas novos registros para o complexo da Serra dos Macacos. Na categoria de espécies raras foram classificadas Pecluma plumula (Humb. & Bonpl. ex Willd.) M.G. Price, Cochlidium linearifolium, C. serrulatum (Sw.) L. E. Bishop e Rumohra adiantiformis (G. Forst.) Ching. Na análise da riqueza não houve diferença significativa entre os ambientes de interior (15 espécies) e borda (14 espécies). Porém as diferenças são encontradas quanto a composição florística, ficando claro que o interior do fragmento estudado constitui um ambiente totalmente distinto do ambiente de borda, no que se refere à comunidade pteridofítica. Através do Teste T foi observada uma grande variação na abundância entre as comunidades avaliadas (p= 0,0008). O interior do fragmento apresentou uma grande abundância de indivíduos em relação ao ambiente de borda. Não foi observada correlação significativa entre a abundância e os fatores abióticos de temperatura e umidade relativa do ar, provavelmente a abundancia esta relacionada a fatores abióticos não analisados no presente estudo ou a atributos geomorfológicos. Pôde-se concluir que os aspectos físicos fornecidos pelo ambiente de borda, tais como a grande incidência luminosa, pouca disponibilidade hídrica e uma maior intensidade dos ventos, além de perturbações provenientes da matriz adjacente são importantes agentes selecionadores das espécies pteridofíticas capazes de colonizá-los

Made available in DSpace on 2014-06-12T15:03:08Z (GMT). No. of bitstreams: 2 arquivo2134_1.pdf: 3360789 bytes, checksum: 2d5b1a9180b6f5c6cdd46d9026fd0c3e (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Universidade Federal de Pernambuco / As Araceae apresentam grande variedade de formas de vida, tendo sua maior diversidade em hábitats úmidos, sendo por isso considerada boa indicadora de ambientes conservados. A Mata Atlântica se destaca como um dos centros de diversidade para a família. Devido à carência de trabalhos desenvolvidos no Nordeste do Brasil, foi realizado um estudo taxonômico das espécies de Araceae ocorrentes em fragmentos de Mata Atlântica pertencentes à Usina São José, no município de Igarassu, litoral Norte de Pernambuco. A partir deste estudo, identificaram-se os padrões de agrupamento e distribuição geográfica das espécies através de análise de similaridade florística e levantamento em herbários e literatura específicas, respectivamente. A similaridade foi obtida entre nove fragmentos selecionados para o estudo, pelo método UPGMA e por PCA a partir do índice de similaridade de Jaccard. Além disso, a relação espécie-área foi testada através de uma análise ANOVA 1 fator e de uma regressão linear simples. Foram registradas 18 espécies distribuídas em nove gêneros, dos quais Philodendron e Anthurium foram os mais representativos, com oito e três espécies, respectivamente. Doze espécies são hemiepífitas, três são geófitas, duas epífitas e uma aquática emergente. Caladium, Heteropsis, Montrichardia, Monstera, Syngonium, Taccarum e Xanthosoma apresentaram uma espécie cada. São apresentadas chaves de identificação, descrições, ilustrações, dados sobre hábitat de ocorrência, fenologia, heteroblastia foliar e informações morfológicas relevantes. Foram identificados os padrões: amplo (interamericano, centro-sulamericano e sulamericano) e restrito (Nordeste Oriental), onde 67% das espécies apresentaram disjunção entre as Províncias Atlântica e Amazônica. A similaridade florística revelou a formação de dois grupos principais, sendo diferenciados principalmente pela ocorrência do habitat Sítio Ripário em seu interior. A relação espécie-área foi negativa, ou seja, o tamanho dos fragmentos não influenciou na riqueza de Araceae, o que pode auxiliar na indicação de fragmentos pequenos como candidatos a Unidades de Conservação

In this thesis, I describe three experimental studies that investigate the hotly debated role of competition in structuring communities in unproductive habitats. The studies were done in a boreal forest understory plant community in the southwestern Yukon. The first study was a traditional neighbour removal experiment. Ten of the most common species were transplanted as seedlings into transects with and without neighbours in a factorial design with two levels of water addition and two levels of fertilizer addition. The presence of neighbours increased survival and biomass of 6 species indicating a facilitative effect of neighbouring plants. The second study used the Community Density Series (CDS) methodology. The first of these was a 10-speciesexperimental community established from seed and grown in sandboxes at 6 densities with 2 watering levels and 2 fertilizer levels in a factorial design. At the community level, density dependence was observed at all life stages, but was not consistently competitive or facilitative - both emergence and final per plant shoot mass were density dependent, while survival to the end of the season was inversely density dependent. The effect of water was positive at seed emergence whereas fertilizer negatively affected survival. Species specific responses were also dependent on life stage. The final study was a 4-year CDS in the field using 9 common understory species at 6 densities and 3 fertilizer levels. Density negatively affected the community every year except for the first with competition being important at all densities above x1/8th the average community density. Constant final yield was reached in plots above the naturalx1 density for the last two years of the study. Responses to density were species-specific and 7 species declined with increasing density. No facilitative effects were observed. These studies demonstrate that density dependence is important in structuring this unproductive boreal understory habitat. The CDS approach allows us to quantify both the intensity and importance of plant competition at the community and species levels and to determine whether the importance of these biotic interactions depend on abiotic factors. The results clearly show that species-specific responses to biotic interactions are not necessarily the same as community level responses and if we are to understand community structure, it is necessary to use appropriate methodologies. / Science, Faculty of / Botany, Department of / Graduate

Made available in DSpace on 2014-06-12T23:02:06Z (GMT). No. of bitstreams: 2 arquivo8221_1.pdf: 6794681 bytes, checksum: 9e21bd693267c06a920d3723dd2c8f78 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2005 / O objetivo deste estudo foi reconhecer as atuais características fisiográficas e sedimentológicas da plataforma continental adjacente ao município de Tamandaré-PE, localizado na Área de Proteção Ambiental Costa dos Corais, através de um mapeamento sonográfico. Foram realizados 20 perfis batimétricos e sonográficos, utilizando-se um sonar de varredura lateral Sea Scan® PC e uma ecossonda GARMIN GPSMAP 185 Sounder. Estes perfis estavam situados a cada 500 m e se estenderam entre as profundidades de 15 e 25 m. 26 amostras de sedimento foram coletadas e submetidas a análises de granulometria e teores de carbonato de cálcio. As imagens acústicas digitais geradas pelo sonar de varredura lateral foram georreferenciadas através de reamostragem e os padrões de eco e textura, bem como os resultados das análises sedimentológicas permitiram identificar e localizar três fundos distintos. A fisiografia submarina da área foi caracterizada por relevos positivos (recifes submersos) e negativos (paleocanal), intercalados por superfícies com declive mais suave. Substratos consolidados indicam que, durante flutuações do nível do mar, provavelmente a linha de costa já esteve a aproximadamente 16, 20 e 22 m abaixo do nível atual. Os fundos (habitats bentônicos) foram classificados como: rochosos, lamosos e arenosos. Este último habitat foi predominante na área amostrada, sendo composto preferencialmente por areias carbonáticas grossas a muito grossas. Os fundos lamosos apresentaram uma distribuição mais restrita, localizados entre as linhas de arenitos de praia observados a 16 e 20 m de profundidade e principalmente junto a uma suave depressão a leste da Baía de Tamandaré. Os ambientes rochosos, representados por tacis e cabeços, ocorreram nas faixas de profundidade de 16, 20 e 22 m. A localização destes habitats é uma contribuição para os programas nacional e global de monitoramento de recifes de coral. Além disso, no caso de fundos lamosos explorados pela pesca do camarão, sua localização é relevante para o levantamento do estoque pesqueiro

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

La structure de taille et la distribution spatiale du zooplancton ont été étudiées dans deux écosystèmes : une baie de la côte Ouest de la péninsule antarctique et le golfe du Lion en mer méditerranée occidentale. L'acquisition des spectres a été permise par l'utilisation de deux capteurs optiques : le ZooScan / ZooProcess et le Laser Optical Plankton Counter (LOPC). L'impact de différents types de forçages sur les spectres de taille des communautés zooplanctoniques a été mis en évidence dans les deux écosystèmes côtiers, notamment grâce aux caractéristiques des spectres de biomasse normalisée. Le long de la péninsule Antarctique, la fin de l'automne est une période charnière à tous les niveaux trophiques avec la baisse de la production primaire et l'agrégation du krill (Euphausia superba) dans les baies continentales. Les données ADCP ont permis de localiser dans une des baies le plus grand banc de krill échantillonné depuis 20 ans. L'étude du comportement alimentaire du krill en réponse à la baisse de la production primaire a montré l'impact du krill sur les spectres de taille des communautés mésozooplanctoniques, et en particulier sur les espèces de petites tailles. Un autre type de forçage a été mis en avant dans le golfe du Lion, où les structures physiques très variables induites par les apports du Rhône, le courant Liguro-Provençal et les vents influent directement sur la distribution spatiale du zooplancton. Des sous-régions ont été identifiées à partir de corrélations entre des paramètres physiques tels que la stratification de la colonne d'eau et des paramètres biologiques tels que la concentration en chl-a ou la pente des spectres de biomasse normalisée. / Zooplankton size structure and spatial distribution were investigated in a bay along the West Antarctic Peninsula (WAP) and in the Gulf of Lion in Western Mediterranean Sea. Zooplankton size spectra were determined with the use of two optical sensors, the Laser Optical Plankton Counter (LOPC) and the ZooScan / ZooProcess system. Using features of the biomass size spectrum is was possible to identify different forcing processes that affected zooplankton size spectrum and spatial distribution in the two ecosystems. In WAP, late fall is a transition time at all the trophic levels, with the decrease of primary production and the aggregation of Antarctic krill (Euphausia Superba) in continental bays. ADCP data permitted to find in a bay the largest Antarctic krill swarm reported in the last twenty years. Study of krill feeding behavior in response to the decrease of primary production showed impact of krill on mesozooplankton size spectrum and especially a decrease of the small size species abundance. A different type of forcing was found in the Gulf of Lion, where zooplankton spatial distribution was affected by physical structures such as the inputs by the Rhône river, the Liguro-Provençal current and winds. The correlation between physical and biological parameters e.g. water masses stratification, chl-a concentration, slope of the normalized biomass size spectrum (NBSS), allowed the identification of three different regions in the Gulf of Lion. These potential habitats show different zooplankton size structure, with strong NBSS slopes close to the coast and weaker NBSS slopes in the zone of the Rhône plume influence.

[Truncated abstract] Spatially explicit marine habitat data is required for effective resource planning and management across large areas, although mapped boundaries typically lack rigour in explaining what factors influence habitat distributions. Accurate, quantitative methods are needed. In this thesis I aimed to assess the utility of ecological models to determine what factors limit the spatial extent of marine habitats. I assessed what types of modeling methods were able to produce the most accurate predictions and what influenced model results. To achieve this, initially a broad scale marine habitat survey was undertaken in the Recherche Archipelago, on the south coast of Western Australia using video and sidescan sonar. Broad and more detailed functional habitats types were mapped for 1054km2 of the Archipelago. Broad habitats included high and low profile reefs, sand, seagrass and extensive rhodolith beds, although considerable variation could be identified from video within these broad types. Different densities of seagrass were identified and reefs were dominated by macroalgae, filter feeder communities, or a combination of both. Geophysical characteristics (depth, substrate, relief) and dominant benthic biota were recorded and then modelled using decision trees and a combination of generalised additive models (GAMs) and generalised linear models (GLMs) to determine the factors influencing broad and functional habitat variation. Models were developed for the entire Archipelago (n=2769) and a subset of data in Esperance Bay (n=797), which included exposure to wave conditions (mean maximum wave height and mean maximum shear stress) calculated from oceanographic models. Additional distance variables from the mainland and islands were also derived and used as model inputs for both datasets. Model performance varied across habitats, with no one method better than the other in terms of overall model accuracy for each habitat type, although prevalent classes (>20%) such as high profile reefs with macroalgae and dense seagrass were the most reliable (Area Under the Curve >0.7). ... This highlighted not only issues of data prevalence, but also how ecological models can be used to test the reliability of classification schemes. Care should be taken when mapping predicted habitat occurrence with broad habitat models. It should not be assumed that all habitats within the type will be defined spatially, as this may result in the distribution of distinctive and unique habitats such as filterfeeders being underestimated or not identified at all. More data is needed to improve prediction of these habitats. Despite the limitations identified, the results provide direction for future field sampling to ensure appropriate variables are sampled and classification schemes are carefully designed to improve descriptions of habitat distributions. Reliable habitat models that make ecological sense will assist future assessments of biodiversity within habitats as well as provide improved data on the probability of habitat occurrence. This data and the methods developed will be a valuable resource for reserve selection models that prioritise sites for management and planning of marine protected areas.

In estuarine and other aquatic systems, it is possible for water to transport locally produced carbon (food) across habitat boundaries, and provide nutrition for animals remote from the carbon source. In estuarine and marine systems, early work examining the movement of carbon from saltmarsh habitats in the USA suggested that carbon may move large distances from inshore to offshore environments. Upon closer examination, however, evidence did not support this paradigm of large-scale carbon movement, referred to as the outwelling hypothesis, in some estuaries. Physical characteristics of estuaries in which large-scale carbon movement did not occur, such as restricted access to the sea, were proposed as a possible explanation, and for these estuaries, movement of carbon among estuarine habitats was considered more likely. A mosaic of saltmarsh and mangrove habitats dominate the subtropical barrier estuary of southern Moreton Bay, Queensland, but there have been no studies that examine the movement of carbon among habitats within this system. Previous studies that examine the movement of carbon have mostly been done in saltmarshes in the northern hemisphere or in tropical mangrove systems. Different vegetation and tidal regimes in temperate marshes of the northern hemisphere preclude generalisations of carbon movement to tropical and subtropical systems. Our understanding of carbon movement in tropical systems may extend to subtropical waters, but the saltmarsh-mangrove mosaic in the subtropics distinguishes them from their tropical counterparts. The mosaic of saltmarsh and mangrove habitats among the barrier islands of southern Moreton Bay thus provide a unique opportunity to examine the small-scale movement of carbon among adjacent habitats in a subtropical system. Stable isotopes of carbon have been used successfully to trace the transfer of carbon from autotrophs to consumers at a range of spatial scales. This method is able to distinguish among carbon sources where autotrophs have different ratios of 13C/12C, and consumers take on the ratio of their food source. The success of stable isotopes in clarifying food web processes, however, depends on isotope ratios changing in predictable ways as elements are processed. As isotope ratios may be influenced by changes in productivity, and differences in nutrient source, they may vary across small and large spatial scales that may confound interpretation of food web processes. In this study I measured small and large-scale spatial variability of three estuarine autotrophs (the saltmarsh grass, Sporobolus virginicus, the seagrass Zostera capricorni and the algal community epiphytic on Z. capricorni) and showed the small-scale spatial variability to be negligible and insufficient to preclude the use of carbon and nitrogen isotopes in food web studies. Large-scale variability was more pronounced and may be useful for spatial correlation of food webs for more mobile species. The small-scale homogeneity and clearly distinguished isotope ratios of the dominant autotrophs in adjacent saltmarsh and mangrove habitats in southeast Queensland are therefore ideally suited to the study of small-scale carbon movement between adjacent habitats. Carbon isotopes of estuarine invertebrates were used to estimate the movement of particulate carbon between adjacent saltmarsh and mangroves at the tens-of-metre scale. Carbon isotope values of two crab species (Parasesarma erythrodactyla and Australoplax tridentata) and two snail species (Salinator solida and Ophicardelus quoyi) in saltmarsh closely match those of the saltmarsh grass, and suggest that the movement and assimilation of carbon occurs at a scale much smaller than has previously been examined. In mangroves, the results of this study indicate that microphytobenthos with some contribution of mangrove carbon is the most likely food source for P. erythrodactyla and A. tridentata, although contribution of carbon from saltmarsh is also possible. Under this latter scenario, carbon movement in mangroves would be considered to occur at a scale larger than that in saltmarsh habitat. A study that examined the movement and assimilation of carbon by crabs and an estuarine slug (Onchidina australis) at a finer resolution (i.e. metres) supported the original findings and indicated that the movement and assimilation of carbon occurs 5 - 8 m either side of the saltmarsh-mangrove interface. At this small-scale, the movement and subsequent foraging of crabs among habitats, the movement of particulate carbon among habitats, or a combination of crab and particulate carbon movement are three alternative models that provide plausible explanations for the pattern in carbon isotope values of crabs. Crab movement among these habitats was measured using an array of pitfall traps perpendicular to the saltmarsh-mangrove interface. To test for carbon movement, samples of detritus were collected at 2 m intervals across this same interface and the carbon isotopes analysed. For the majority of crabs (up to 90% for both species), movement up or down the shore was less than 1 m from the place of initial capture. Thus, crab movement cannot explain the trend in carbon isotope values of crabs. The pattern in detrital isotope values was similar to that of crabs and indicates that the movement of particulate carbon across the saltmarsh-mangrove interface is the most likely explanation for crab isotope ratios. Sources of carbon for estuarine invertebrates can also depend on the size of the saltmarsh patches. Examination of the movement and assimilation of carbon by crabs in saltmarsh patches of different sizes adjacent to mangroves indicates that saltmarshes less than 0.3 ha in area are subsidised by the import of allochthonous carbon, most likely from mangroves. These findings contribute substantially to our understanding of the food web value of estuarine habitats and provide an important link between landscape and food web ecology. They also have important implications for determining the conservation value of estuarine habitats with respect to their functional (food web) value. The scale-dependent sampling used in this thesis also provides important evidence for the fine-scale movement of estuarine carbon that has not previously been examined.

Around the world, forests are generally being fragmented and as plant populations decline in both sizeand number of individuals, the genetic variation will also decrease whitch in the end leads to totalextinction of the plant. In this paper, I wanted to investigate what specific species of trees and shrubsyou usually find in the edge and core habitats in some of the forests in the Baltic Sea region. I alsowanted to identify the edge effects and their sources and finally compare the results between thedifferent regions.The data sources used are derived from the ongoining research project Landscape structures, patterns ofbiodiversity and conservation strategies in the Baltic Sea region by Kari Lehtilä, Patrik Dinnétz ochTiina Vinter who have made a record of all herbaceous plant species in four randomly chosen forestregions situated around the Baltic Sea: Estonia, Skåne, Södermanland and Germany. I made statisticalanalyses, using the computer program R, concerning the distribution of species in the edge habitats ofthe forests as well as in the core habitats. I performed generalized linear models and then variationanalyses with the factors light and biomass in order to investigate wether edge effects might appear dueto these factors. I also used the ecological characteristics – Ellenberg indicators – light, soil pH andnitrogen performing linear regression models. I then compared the results – within the regions but alsobetween them.As the results showed great variancy both within the regions and between them no general explanationto the edge effects could be affirmed. The Ellenberg analyses showed no difference between the species,i. e. the ecological characteristics could not explain why some species were associated to edge habitatsand some were not. All four regions had in common that the greatest biodiversity were to be found inthe edge habitats, which is characteristical for a habitat in an early successional state. Due to the thefeatures of the forests, the specific species that received the label ”edge species” or ”core species” werenot always mutual in all regions. For example Quercus robur turned out to be a typical forest species inGermany while in Estonia it was strongly associated to edge habitats and in this investigation one mightdiscuss later states of successions in Germany rather than stronger edge effects in Estonia.

Urbanization is considered one of the leading threats to biodiversity and wildlife habitat (McKinney 2002; Shochat et al. 2006). Urban environments are humandominated systems, yet they support wildlife habitat and provide meaningful ecological functions. Methods to conserve biodiversity and minimize habitat loss and fragmentation in urban environments include utilizing private residential yards and gardens to enhance habitat connectivity. Private residential yards or gardens designed to attract and support wildlife are known as backyard habitats and wildlife gardens. The City of Austin, Texas initiated Wildlife Austin in 2007. Wildlife Austin coordinates backyard habitats in Austin as a National Wildlife Federation Community Wildlife Habitat [trademark]. My research analyzes the goals of the Wildlife Austin from the perspective of landscape ecology and urban ecology; reviews research related to backyard habitats in order to identify ways of enhancing habitat connectivity for bird communities; and provides recommendations for a more scientifically grounded approach and management in the promotion of backyard wildlife habitat. / text