Connectivity in ecological systems is a broad concept that embodies the transmission of ecosystem components throughout landscapes at multiple spatial and temporal scales. Of relevance to the present study are the connections (or lack thereof) among local populations of stream fauna - population connectivity in lotic systems. Dispersal, recolonisation and migration are the demographic forms of population connectivity, and gene flow is the genetic aspect of population connectivity. Both forms of population connectivity have underpinned some of the classic theories and hypotheses in stream ecology, and have implications for pure and applied stream ecology, including ecosystem restoration. Conceptual models in ecology can facilitate understanding and predictability of the ecosystem processes they represent, and have potential applicability as management tools or 'rules of thumb' in conservation and restoration programs. Various theoretical models describe potential patterns of connectivity among local populations and in this thesis these models were used to evaluate population connectivity in a freshwater fish (southern pygmy perch, Nannoperca australis) and two reproductively isolated genetic lineages of freshwater shrimp (Paratya spp.) in small, geomorphically degraded streams in south eastern Australia. These streams (the Granite Creeks) have been the focus of a recent habitat restoration trial and several studies have examined fish and macroinvertebrate community responses to the experiment. It was the purpose of this study to contribute information about population connectivity in the selected species to complement these community ecology studies. Population connectivity was examined in these species using molecular data (mitochondrial and nuclear genetic data) and natural abundance isotopic signatures of nitrogen and carbon. At the landscape scale, results showed that populations of N. australis and the P. australiensis lineages were isolated among the streams and among sites within streams, and that there was no consistent pattern of isolation-by-distance in genetic data for any species. Thus, classic models of population connectivity, such as the Island Model and Stepping-Stone Model, were not supported by this study. Results indicated that population models that incorporated more complex aspects of stream structure may be more appropriate than these classic models for approximating observed patterns of population connectivity in lotic systems. The Stream Hierarchy Model (SHM) predicts that the hierarchical aspect of stream structure (i.e. stream confluences) have a dominant role in shaping patterns of population connectivity in lotic fauna, whereby populations among streams are more isolated than those within them. Although stream confluences were found to have an important role in population subdivision for the species examined in this study, the expectations of the SHM were met for only N. australis. For the P. australiensis lineages, the influence of topography (i.e. the longitudinal aspect of stream structure) was just as important as stream confluences in isolating local populations. Large-scale determinants of population isolation were thus found to be associated with both the hierarchical and longitudinal aspects of stream structure, and were not well represented by any single theoretical model of population connectivity. At within-stream scales, upland populations tended to be extremely isolated from other populations and had temporally stable genetic signatures. In contrast, lowland populations were connected to other lowland populations within the same stream to a greater degree, although the connections were patchy and a slight signature of temporal instability in the genetic data was evident for one of the P. australiensis lineages. Thus, metapopulation or patchy population models were found to represent connections among lowland populations within the same stream, although they were not appropriate for describing connectivity among upland populations. This finding highlights the importance of the longitudinal aspect of stream structure in shaping ecological patterns in lotic systems, and demonstrates that local patterns of population connectivity can vary over relatively small spatial scales. Overall, the results illustrate that both hierarchical and longitudinal aspects of stream structure can have important roles in isolating populations of stream fauna. They therefore also represent constraints for the ability of aquatic fauna to colonise restored habitat in streams. The corollary of this, however, is that such isolated populations of stream fauna represent appropriate population units at which to target habitat restoration. The hierarchical and longitudinal aspects of stream structure may thus represent 'rules of thumb' or 'landscape filters' that stream restoration ecologists could use to predict likely isolated populations of lotic fauna across the landscape. Such a 'rule of thumb' might be the inclusion of multiple isolated population units in restoration programs, as this strategy is likely to generate the greatest biological response to the restoration at the landscape scale, particularly with respect to intra-specific genetic diversity captured by restoration. At small spatial scales, such as for a single stream or tributary, the longitudinal aspect of stream structure can be an important factor to consider when designing stream habitat restoration programs. In this study, lowland sites were unstable and there were patchy connections among local lowland populations within the same stream, whereas upland populations were isolated at this scale. In contrast, other studies have found that upstream populations of some species can be connected in a patchy fashion in other systems. For such unstable sections of stream, where there are patchy patterns of local population connectivity, the inclusion of multiple restored patches, especially refugial habitat, is likely to produce the greatest biotic response at the patch scale, particularly with respect to demographic responses (such as local colonisation). Multiple restored refugial patches will enable species to persist throughout the stream section during adverse environmental conditions, will allow for variation in local movement patterns and distances between species and between years with contrasting environment conditions (e.g. stream flow), and may harbour different species assemblages and intraspecific genotypes due to stochastic processes (i.e. have functional heterogeneity). The hierarchical and longitudinal aspects of stream structure are thus important determinants of population connectivity at both large and small spatial scales, and have implications for how stream biota will respond to restoration at patch and landscape scales.

Ecological restoration has the potential to stem the tide of habitat loss, fragmentation and transformation that are the main threats to global biological diversity and ecosystem services. Through this thesis, I aimed to evaluate the ecological consequences of a 33 year old rehabilitation programme for coastal dune forest conservation. The mining company Richards Bay Minerals (RBM) initiated what is now the longest running rehabilitation programme in South Africa in 1977. Management of the rehabilitation process is founded upon the principles of ecological succession after ameliorating the mine tailings to accelerate initial colonisation. Many factors may detract from the predictability of the ecological succession. For example, if historical contingency is a reality, then the goal of restoring a particular habitat to its former state may be unattainable as a number of alternative stable states can result from the order by which species establish. Succession appears to be a suitable conceptual basis (at this stage in regeneration at least) for the restoration of coastal dune forest. Patterns of community characteristics observed in rehabilitating coastal dune forest sites were similar to those predicted by ecological succession, with few exceptions. Changes in the species pool such as the establishment of strong dominants may lead to divergence of regenerating trajectories away from the desired endpoints. The species composition of herbaceous plants in regenerating coastal dune forest sites became increasingly uniform as the time since disturbance increased. Despite initially becoming more similar they II deviated away from an undisturbed reference site. Contrary to our expectations, non-native species did not contribute the most to dissimilarity. The deviation from the reference forest is attributable to the higher abundance of a native forest specialist in the reference site and the higher abundances of native woodland adapted species in the rehabilitating sites. Changes in the disturbance regime under which species have evolved may lead to arrested succession. The rehabilitation of coastal dune forest relies on the Acacia karroo successional pathway which, has been criticised because Acacia dominated woodlands may stagnate succession. The patterns of species composition within regenerating coastal dune forest are a response to the canopy characteristics and represent an early stage in forest succession. Succession did not appear to be stagnant. Ecological succession does not pay much heed to the role that the surrounding landscape composition can play in the assembly of communities. The theory of Island biogeography provides predictions about how landscape composition influences community assembly. Landscape spatial parameters, measuring edge, isolation, and area explained the patch occupancy of the several bird and tree species, however, responses to patch characteristics were varied and idiosyncratic. For restoration to succeed, managers need to consider the spatial configuration of the landscape to facilitate colonization of rehabilitating patches. From this thesis and previous work, it appears that processes are in place that will lead to the reassembly of dune forest communities. As the rehabilitating sites are at an early stage of regeneration this may take some time to give rise to these coastal dune forest communities, and the management of rehabilitating coastal dune forest must allow for this. In addition, it is III important to remember that time may be interacting with the landscapes spatial attributes, which may limit the presence of certain species. / Thesis (PhD)--University of Pretoria, 2011. / Zoology and Entomology / unrestricted

Proper habitat management is essential for the survival and reproduction of species, especially those listed under state or federal laws as endangered, threatened or of special concern, and those with small local populations. Land managers use a combination of mechanical cutting and prescribed burning to manage and restore degraded scrub habitat in east central Florida. This approach improves habitat for the endangered Florida scrub-jay (Aphelocoma coerulescens), but little is known about its effects on other taxa, especially the threatened southeastern beach mouse (Peromyscus polionotus niveiventris). This single species approach may not be beneficial to other taxa, and mechanical cutting and prescribed burning may have detrimental effects on P. p. niveiventris. To evaluate the effects of land management techniques on P. p. niveiventris, I live trapped populations at Cape Canaveral Air Force Station near Titusville, Florida during 2004-2005. I evaluated the relative abundance and related demographic parameters of small mammal populations trapped in compartments under different land management treatments, and investigated the relationship between Florida scrub-jay breeding groups using these compartments and abundance of southeastern beach mice. My results suggest that P. p. niveiventris responded positively to prescribed burning, while the cotton mouse (P. gossypinus) responded positively to the mechanical cutting. Reproduction and body mass of southeastern beach mice were similar across land management compartments. Abundance of Florida scrub-jay breeding groups and southeastern beach mice were positively correlated suggesting that both listed species benefited from the same land management activities. A mosaic of burned and cut patches should be maintained to support small mammal diversity. In addition, adaptive management should be used at CCAFS to understand how small mammals, particularly the southeastern beach mouse, respond to land management activities.

Made available in DSpace on 2015-03-05T16:19:37Z (GMT). No. of bitstreams: 0 Previous issue date: 27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Atividades de mineração causam alterações nas paisagens, acarretando mudanças na vegetação e nas propriedades e topografia do solo que acabam por afetar a fauna. Para minimizar os efeitos da mineração, empresas mineradoras freqüentemente implementam procedimentos de recuperação ambiental exigidos por lei. O presente estudo aborda o efeito e a influência da estrutura da vegetação nas comunidades de aves em áreas recuperadas após processos de mineração em florestas no município de São Mateus do Sul, sudeste do Estado do Paraná e em áreas de campo em Candiota no Rio Grande do Sul No Paraná selecionei quatro áreas para as amostragens: três delas, com 5, 10 e 20 anos de recuperação vegetal (A05, A10 e A20, respectivamente) encontram-se na Unidade da Petrobrás (Superintendência de Industrialização de Xisto) e a quarta área de estudo é um fragmento florestal que não sofreu interferências de mineração (A50). Em Candiota selecionei três áreas com vegetação nativas nunca antes mineradas e três áreas recuperadas. Nos do / Mining activities cause severe alterations in natural landscapes, changing the vegetation and the properties and topography of the soil, and thus altering habitats and the associated fauna. To minimize the effects of mining, mining companies implement procedures of environmental recuperation demanded by law. The present study investigates the influence of vegetation structure on bird communities in reclaimed areas after mining in forest and grassland habitats in south Brazil. Forested areas were studied in the State of Paraná, while grasslands were studied in the Pampa biome in Rio Grande do Sul. In Paraná I sampled four areas, three of them (with 5, 10 and 20 years of vegetation recuperation named, respectively, A05, A10, and A20), were located in the Unit of Petrobrás, and the fourth was a forest fragment that did not suffer mining interferences (A50). In Rio Grande do Sul I selected six areas, three with native vegetation never mined before and three reclaimed areas. I sampled the avifauna using the point

¡§Zhou-Zai Wetland Park¡¨ is a specific prototype of created wetland ecosystems constructed in urban areas, This park represents integration between development and preservation of a wetland habitat through ecotechnology. It is a created wetland designed to conserve the endangered species of Jacanas in Taiwan, which were suffered from the destruction of habitat in the past. The wetland comprises pool and marsh types of wetland systems, and the inflow of the systems is pumped from the Lian-Chih Lake. Several problems were found when we operated and managed the park including eutrophication, low water exchange rate, and hypoxia in some water areas, emergence, and invasive alien species. The current management strategies are difficult to improve the status. Therefore some suggestions are given to solve such problems including constructing a treatment wetland in injection area in order to improve the water quality of influent and then provide a better water environment of habitat for water fowls as well as to prevent the intrusion of invasive alien species.

Scotts Creek, in Santa Cruz County, Calif., supports the southernmost extant population of Coho Salmon (Oncorhynchus kisutch) in North America. In 1997, the California Department of Fish and Game (now Fish and Wildlife) conducted an extensive habitat typing survey of mainstem Scotts Creek, describing all habitat units from the top of the estuary to the limit of anadromy approximately 12 km upstream. I repeated this survey in 2013 to (1) assess changes in the quantity and quality of instream habitat, (2) compare the current condition to goals and standards established in the federal Central California Coast (CCC) Coho Salmon Recovery Plan, and (3) identify opportunities for possible future restoration. A comparison of the two surveys revealed an overall increase in mean canopy cover, mean bank vegetation, mean percentage instream cover, pool depth diversity, and percentage riffles since 1997, and decreases in mean residual pool depth, percentage flatwater, and number of primary pools. Overall, the percentage of the total mainstem classified as pool habitat did not change between the two survey periods. Results for individual habitat metrics were more variable when the stream was broken into discrete reaches delineated by major tributary junctions. Although a large woody debris (LWD) survey was not conducted as part of the 1997 survey, contrasting our results with data collected during intervening years indicated that instream LWD has become more abundant, primarily due to increases in hard-wood species (i.e., red alder [Alnus rubra] and California bay [Umbellularia californica]). When compared to habitat goals established in the federal CCC Coho Salmon Recovery Plan, Scotts Creek has adequate canopy cover and percentage pools, but is lacking in percentage riffles, instream cover, key pieces of LWD per100 m, and percentage primary pools.

En av de naturtyper med flest antal växtarter i världen är hävdade gräsmarker som är präglade av traditionell skötsel. Denna naturtyp har minskat kraftigt i area och för att förhindra framtida artutdöenden är restaureringsåtgärder viktiga. Syftet med denna rapport var att med hjälp av vetenskapliga publikationer undersöka vilken effekt restaurering av före detta hävdade gräsmarker i norra och centrala Europa har på växtartrikedomen. Mer specifikt undersöktes effekten av olika restaureringsmetoder på totala antalet arter, arttätheten och artsammansättningen. Utöver detta undersöktes vilka faktorer som påverkar möjligheten till restaurering. Resultatet tyder på att restaurering med bete eller slåtter är mest framgångsrik av de olika undersökta metoderna. Restaurering med bete eller slåtter visade sig kunna ha en positiv effekt på totala antalet arter, arttätheten och artsammansättningen. Enbart rensning av träd och buskar var inte en långsiktigt hållbar metod för restaurering eller bevarandet av artrikedomen eller arter associerade med hävdade gräsmarker. Det finns många faktorer som påverkar möjligheten till restaurering och alla är inte entydiga. Något som kan vara intressant att vidare utforska är vilken betydelse de olika artrikedomsmåtten och artsammansättningen har för att kunna optimera restaureringsprojekt. Förutom att restaurering av hävdade gräsmarker både kan bidra till att utöka Natura 2000-nätverket och uppfylla de globala målen, ger det oss mängder med ekosystemtjänster och bevarande av kulturlandskap.

In recent years, the importance of sagebrush to shrub-steppe ecosystems and associated plant and animal species has been recognized. The historical removal of herbaceous species by excessive and uncontrolled livestock grazing on many of our sagebrush ecosystems has resulted in a stagnant state where dense, competitive stands of sagebrush prevent herbaceous species from recovering. Most early research on sagebrush control was directed toward eradication to increase herbaceous forage for livestock production, rather than sagebrush thinning to improve shrub vigor and understory production for wildlife habitat and community diversity. Mechanical treatments have the ability to retain shrub and herbaceous components, while improving diversity within degraded sagebrush communities. This study evaluated the effects of 6 mechanical treatments and revegetation of a Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) community in northern Utah that were treated in the fall of 2001 and spring of 2002 (aerator only). Disking and imprinting killed 98% of the sagebrush and significantly (p < 0.05) lowered cover and density of sagebrush more than any other treatment. Disking and imprinting was the only mechanical treatment to reduce cover and density of residual understory species, but also to successfully establish seeded grasses. One-way Ely chaining, 1-way and 2-way pipe harrowing, and aerating in the fall and spring reduced sagebrush cover from greater than 20% to less than 5% and reduced density by about half. Two years after mechanical treatment surviving sagebrush had greater leader and seed stalk growth than untreated sagebrush. Choice of a mechanical treatment to increase and diversify the perennial herbaceous component and retain the shrub component of sagebrush communities depends on the amount of residual herbaceous species, as well as economics. Chaining is potentially most economical for diversifying communities with a residual herbaceous perennial component. It is uncertain whether successful revegetation from disking and imprinting was a result of significant reduction in sagebrush, residual perennial herbaceous species, or both. Response of sagebrush communities with a very limited perennial herbaceous understory needs to be tested to determine how much and what kind of mechanical reduction in sagebrush is needed for successful revegetation.

Many species naturally occupy discrete habitat patches within a mosaic of habitats that vary in quality. The Florida scrub-jay (Aphelocoma coerulescens) is endemic to Florida scrub, a habitat that is naturally patchy and greatly reduced in area over recent decades owing to development and urbanization. Because of this habitat loss, future management of Florida scrub-jays will focus on smaller, fragmented tracts of land. My study examines such a tract, Lyonia Preserve, southwest Volusia County, FL. This preserve was unoccupied by scrub-jays prior to habitat restoration. The preserve is now frequently managed exclusively for scrub-jays as a habitat island surrounded by development. Management of the preserve includes roller chopping, root raking, timbering, and "oak stripping" where islands of oak patches are left intact while the rest of the area is roller chopped. I investigate what, if any, demographic consequences may be associated with the habitat management and the spatial setting of the preserve. I used population data collected in this area since 1992 to examine population growth and responses to habitat restoration within the preserve and habitat destruction outside the preserve. I mapped territories and measured survival and recruitment of scrub-jays, and dispersal into and out of the study area, for two and a half years. Since restoration, the population has shown logistic growth, with the area supporting higher than average densities of scrub-jay family groups. Observed density of the population and territory size varied between study years. Breeder survival values were positively related to territory size and significantly lower during periods of highest observed density. However, recruitment (yearling production) showed no relationship to territory size. Dispersal to isolated habitat patches was observed; likewise, several failed dispersal events were noted. No immigration into the study area was observed; however these data may be underrepresented since not all scrub-jays in and outside of the preserve were banded, and data collection was limited during the initial colonization period. High densities inside the preserve may therefore be both a result of frequent habitat management in the form of mechanical treatment as well as crowding of individuals due to outside habitat destruction. The results indicate that carrying capacity of habitat for scrub-jays may be raised by frequent, mechanical management; however, if the area is isolated, management may result in high densities and negative demographic consequences, e.g., reduced breeder survival. Negative effects of management may be avoided by subjecting smaller areas to mechanical treatment with increased time between treatments. Land managed for Florida scrub-jays should be contiguous or connected with other scrub habitats so that surplus birds from the managed areas have a refuge and do not contribute to increased densities. Regulatory officials should use caution when allowing for "take" of scrub-jay habitat as the effects may extend beyond the local habitat being destroyed.

No description available.