While much evidence suggests that ecosystem functioning is closely related to biodiversity, present rates of biodiversity loss are high. With the emergence of the metacommunity concept ecologists have become increasingly aware that both local processes (e.g. competition, predation), and regional processes (e.g. dispersal and regional heterogeneity) affect ecological communities at multiple spatial scales. I experimentally investigated the effects of habitat connectivity and regional heterogeneity on biodiversity, community composition, and ecosystem functioning of artificial pond metacommunities of freshwater invertebrates at the local (α), among-community (β), and regional (γ) spatial levels. There was a significant effect of habitat connectivity on mean local richness, but mean local Simpson diversity, mean local functional diversity (FD), and all the three indices of ecosystem functioning investigated (regional abundance, invertebrate biomass, and chlorophyll a concentration) were unaffected by connectivity levels. Regional heterogeneity had no effect on local diversity, but enhanced both among-community richness and among-community Simpson diversity. Conversely, connectivity reduced among-community Simpson diversity. All indices of regional diversity were unaffected by either connectivity or heterogeneity. Despite expectations that there would be strong interactions between the effects of connectivity and heterogeneity on species richness, there were no interactions for any index of biodiversity at any spatial scale. Invertebrate community composition was unaffected by either connectivity or heterogeneity, though there was a significant effect of heterogeneity on its variance. Neither connectivity nor heterogeneity had significant effects on any index of ecosystem functioning, nor among-community coefficients of variation of ecosystem functioning. Connectivity appears to act mainly as a force homogenizing habitat patches in a region, as opposed to having strong effects in and of itself on communities. Conversely, heterogeneity acts largely as a diversifying force, maintaining differences between communities within a region, but, similar to connectivity, it does not have clear effects on communities at the local scale. Despite the different processes expected to act in homogeneous and heterogeneous regions, it does not appear that connectivity and heterogeneity interact strongly. / Thesis (Master, Biology) -- Queen's University, 2008-10-16 09:06:33.103

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

Model of landscape connectivity for European otter Abstract Landscape connectivity is one of the main functions that mitigate the effects of landscape fragmentation on organisms. It allows organisms to move through habitat areas to natural habitat. Given of the overall decline in biodiversity, conservation of landscape connectivity is one of the main objectives of current nature protection. The greatest impact of landscape fragmentation on the population of European otters is mortality on roads. The most of the dead otters are found every year in the Jihočeský and Vysočina regions. That is why this region is an adequate model area for determining the connectivity of the landscape from the perspective of otters. This thesis deals with landscape fragmentation, habitat connectivity and landscape resistance. CIRCUISCAPE is the main tool used to solve connectivity modelling. From the resulting connectivity, landscape resistance and mortality values, risk areas for migration were selected. The telemetry data from the area around Dačice were used to validate this model. Keywords: habitat connectivity - landscape resistance - telemetry - European otter

In tropical seascapes, coral reefs often exist in proximity to marine vegetated habitats such as seagrass, mangroves, and macroalgae. This habitat mosaic offers the possibility for connection and exchange of both organisms and nutrition between habitats, mediated by biological and physical processes. This dissertation examines flows of organisms and nutrition between coral reefs and tropical vegetated habitats in the central Red Sea through 3 different mechanisms: 1) Use of multiple habitat types by tropical marine fishes, 2) Transport of algal material to coral reefs via the foraging behavior and movements of herbivorous fishes, and 3) Physical flow of water between coastal habitats. The results of this thesis suggest that coastal tropical habitats maintain a variety of ecological links at different spatial and temporal scales. A large fraction (36%) of fish species found on coral reefs are also found in at least one marine vegetated habitat in the central Red Sea, with many species mainly living in vegetated habitats as juveniles. This demonstrates the value of mangrove, seagrass, and macroalgae habitats to coral reef fishes, and suggests that many species make ontogenetic migrations between reef and non-reef habitats through their lives. Two species of herbivorous reef fishes (Naso elegans and N. unicornis) were found on coral reefs with algae in their guts which likely originated from nearby Sargassum-dominated macroalgae canopies, representing a fish-mediated, cross-habitat flux of nutrition from macroalgae habitats to coral reefs. Finally, we used a combination of remote sensing, a dye tracer study, and in-water measurements to observe water movement from shallow seagrass and mangrove habitats to nearby lagoon and coral reef habitats. Water exiting seagrass and mangrove habitats had altered concentrations of various nutrients (such as increased particulate organic carbon or decreased dissolved nutrients), suggesting that Red Sea mangroves and seagrasses change nutrient concentrations in water and the movement of water from these habitats to coral reefs could supply reefs with an allochthonous source of nutrition. These various linkages, controlled by a range of physical and biological processes, highlight the interconnected nature of tropical coastal ecosystems, and thereby the need to conserve whole habitat mosaics in the pursuit to protect coral reefs and maintain healthy and functioning coastal ecosystems.

The role of mangroves as essential fish habitat has been a focus of extensive research. However, recent evidence has shown that this role should not be evaluated in isolation from surrounding habitats such as seagrass beds and hard-bottom communities. For example, submerged aquatic vegetation (SAV) communities provide potential sources of food and shelter for fish species that may reside in the mangroves, but may also undergo ontogenetic migrations and daily home-range movements into neighboring habitats. The connectivity between the mangrove fish community and the surrounding seascape may be influenced by the level of patchiness, fragmentation, and spatial heterogeneity of adjacent SAV habitats (i.e., SAV seascape structure). The spatial patterns and heterogeneity of SAV seascape structures are driven by internal and external regulatory mechanisms operating at different spatial and temporal scales. In addition, it is likely that many fish species inhabiting the mangrove zones have different home ranges, and foraging and migratory patterns; therefore, different mangrove fish species may respond to seascape heterogeneity at different scales. There are few studies that have assessed the influence and connectivity of benthic habitats adjacent to mangroves for estuarine fish populations at multiple scales. The present research used an exploratory seascape approach in Biscayne Bay (Florida, USA) to evaluate patterns in the patch composition and configuration of SAV communities, and to examine relationships between seascape structural metrics and the abundance, diversity, and distribution of fishes that utilize the adjacent mangrove shoreline as nursery and/or adult habitat. This seascape approach consisted of: a) the multi-scale characterization of the SAV distribution across the seascape with metrics developed in Landscape Ecology, Geographic Information Systems and Remote Sensing; b) multivariate analyses to identify groups with significantly distinct SAV seascape structures within the most heterogeneous scale, and identify possible mechanisms driving the observed SAV seascape structures; and c) an assessment of the mangrove fish community responses to SAV seascape structures. By applying a set of multivariate analyses (e.g., ANOSIM, MDS plots, hierarchical clustering), the buffer within 200 m from shore was identified as the scale with the highest structural heterogeneity. At this scale, two major SAV seascape structures (i.e., areas with similar SAV spatial arrangement and composition) were identified: a fragmented SAV seascape (FSS) structure and a continuous SAV seascape (CSS) structure. Areas with CSS were characterized by large, uniform SAV patches. In contrast, areas with FSS were characterized by a higher density of smaller, more complex SAV patches. Furthermore, the areas with CSS and FSS structures clustered in zones of the bay with distinct salinity properties. The areas with CSS structures were mostly located in zones characterized by high and stable salinity. However, the areas with FSS concentrated in zones that are influenced by freshwater discharges from canals and with low and variable salinity. The responses of fish diversity metrics were not constrained to the scale at which the greatest spatial heterogeneity of SAV seascape structures was observed (i.e., the seascape composition and configuration within 200 m from shore), but was related to SAV seascape characteristics across different scales. The majority of the variability of the fish diversity metrics in the mangrove shoreline was explained by SAV seascape structures within the smaller scales (i.e., 100-400 m from shore), and SAV seascape structures that represented the level of fragmentation and/or the percent of suitable habitat. Different conceptual models were proposed to illustrate and understand the ecological dynamics behind the relationship between the diversity of the mangrove fish community and the structure of the adjacent SAV seascape. In general, the diversity and abundance of fishes is influenced by the type and level of fragmentation of the SAV seascape, which, in turn, influence the proportion of the seascape used for foraging and refuge by fish. In conclusion, this research quantified how the release of large pulses of freshwater into near-shore habitats of coastal lagoons can influence the seascape structure of SAV communities. Namely, freshwater inputs produce fragmentation in otherwise fairly homogeneous SAV meadows. The outcome of this research highlights the importance of seascape characteristics as indicators of ecosystem-level modifications and alterations affecting the spatial distribution, assemblage, and diversity of marine nearshore habitats in coastal regions heavily influenced by human activities. In addition, the results illustrated the cascading effects and synergistic influences of near-shore habitat spatial assemblages on the composition and diversity of estuarine fish communities. Lastly, and very importantly, the relationships established in this project provide quantitative and qualitative information on patterns of species-habitat associations needed for the improved synergistic management and protection of coastal habitats and fisheries resources.

The coexistence of species is probably one of the most interesting and complex phenomenon in nature. We constructed an agent based model to study the coexistence dynamics of prey - predator populations by varying productivity levels of producers in fragmented and connected habitats along with different levels of quality of predators. Our results indicated that productivity levels of producers in fragmented and connected habitats along with levels of predator quality are significantly responsible for overall predator - prey population size and survivorship. In the absence of predation, competition between identical prey populations is more probable in connected habitats than in unfragmented or fragmented habitats. Implementing low quality predators in the habitats positively influences the overall coexistence dynamics whereas implementing high quality predators tend to decrease the prey populations. Fragmented habitats provide for greater prey population survival time in highly productive environments but low prey population survival time in less productive environments.

Insect pollinators provide indispensible ecosystem services for agricultural, natural and urban ecosystems, and have been declining drastically around the globe. These declines are largely due to fragmentation and loss of habitat resulting from urbanization and intensification of agriculture, and raise concerns over global food security. The purpose of this paper is to investigate the effects of urbanization on abundance, species richness and diversity of insect pollinators, and whether urban environments have potential as sites for conservation. Cities are highly heterogeneous environments with ample foraging and nesting opportunities and can house an abundance and diversity of pollinators. Urban environments can serve as refuges for many pollinator species. Effective city planning and mixed conservation strategies can help to promote healthy populations of insect pollinators in urban environments, which can help to stabilize populations in rural settings, thereby ensuring pollination services for agriculture and terrestrial ecosystems. / Pollinerande insekter (pollinatörer) bidrar med oumbärliga ekosystemtjänster till jordbruk och naturliga och urbana ekosystem, och de har minskat drastiskt i antal runt hela jorden. Dessa nedgångar orsakas till största del av habitatförstöring och -fragmentering, och väcker oro över den globala matsäkerheten. Syftet med den här uppsatsen är att undersöka hur urbanisering påverkar abundans, artrikedom och biodiversitet hos pollinatörer, samt om urbana miljöer har potential som platser för bevarande av pollinatörer. Städer är mycket heterogena områden med gott om matresurser och boplatser, och kan husera en mångfald av pollinatörer. Urbana miljöer lämpar sig bra som platser för bevarande av pollinatörer. Med effektiv stadsplanering och en blandning av olika bevarandestrategier kan städer uppehålla hälsosamma populationer av pollinatörer. Detta kan hjälpa till att stabilisera populationer på landsbygden och därmed säkerställa pollinationstjänster till såväl jordbruk som naturliga terrestra ekosystem.

Abstract Describing how and why species composition of ecological communities varies across spatial and temporal scales is a primary objective for ecological research. A key challenge is to distinguish changes in community composition resulting from external factors from the natural background variability. In this thesis I aimed to study: 1) the level of temporal variation in community composition of stream macroinvertebrates, 2) the role of different environmental factors to temporal variability, 3) the effect of temporal variability on bioassessment outcomes, and 4) comparability of different approaches to study community variability through time. A majority of the studied macroinvertebrate communities showed lower level of inter-annual variation, i.e. temporal turnover, than expected by chance. The observation of high community stability was further supported by the low level of inter-annual variation in taxonomic completeness (quotient of observed and expected number of species, O/E). Despite the low absolute variation in O/E, ecological status assessments varied annually. Thus the use of one year data may bias management decisions. Macroinvertebrate communities experienced similar dynamics across several spatial extents, from riffles within a stream to streams among regions, suggesting that large-scale extrinsic factors are the major driver of community dynamics. Especially climatically exceptional years may have a strong imprint on community variability. However, at the within-stream scale, coherence was lower than expected, indicating that community dynamics may be driven by different processes at different spatial extents. Stream macroinvertebrate community dynamics were strongly related to in-stream vegetation, temporal variability decreasing with increasing macrophyte cover. Importantly, the effect of in-stream vegetation on temporal turnover of macroinvertebrate communities was masked by the stochastic effect of habitat connectivity, suggesting that unless stochastic effects are controlled for, the role of deterministic processes may be obscured, thus affecting our ability to understand and predict community changes through time. In addition, different approaches to study temporal variability may disagree on estimates for the level of temporal turnover and factors explaining it – a fact that should be taken into account when planning and comparing studies. / Tiivistelmä Yksi ekologisen tutkimuksen keskeisistä tavoitteista on kuvata, miten ja miksi eliöyhteisöjen koostumus muuttuu paikasta ja ajankohdasta toiseen. On tärkeää pystyä erottamaan erilaisten ulkoisten tekijöiden aiheuttamat muutokset luonnollisesta taustavaihtelusta. Väitöskirjani tavoitteena oli selvittää 1) miten paljon virtavesien pohjaeläinyhteisöissä tapahtuu ajallista vaihtelua 2) mitkä ympäristötekijät vaikuttavat yhteisöjen ajalliseen vaihteluun 3) miten ajallinen vaihtelu vaikuttaa ympäristön tilan arviointiin ja 4) kuinka vertailukelpoisia ovat eri lähestymistavat ajallista vaihtelua tutkittaessa. Valtaosa tutkituista pohjaeläinyhteisöistä vaihteli vuosien välillä vähemmän kuin olisi sattumalta odotettavissa osoittaen varsin suurta ajallista pysyvyyttä. Käsitystä yhteisöjen pysyvyydestä tuki myös vähäinen vuosittainen vaihtelu ekologista tilaa kuvaavassa taksonomisessa eheydessä (=havaitun ja odotetun lajiston suhde O/E). Huolimatta näennäisen pienestä vaihtelusta O/E suhteessa paikkakohtaiset tilaluokka-arviot saattoivat vaihtua vuodesta toiseen. Yhden vuoden aineistoon perustuvat tilan arvioinnit voivat siis johtaa virheellisiin johtopäätöksiin. Pohjaeläinyhteisöjen ajallinen vaihtelu oli samankaltaista eri mittakaavoilla niin peräkkäisten koskipaikkojen kuin eri alueilla sijaitsevien purojen välillä. Suuren mittakaavan ympäristötekijät näyttävät siis säätelevän eliöyhteisöjen ajallista vaihtelua. Erityisesti ilmastotekijöiltään poikkeukselliset vuodet säätelevät eliöyhteisöjä, ja niiden vaikutus voi näkyä vielä useiden vuosien kuluttua. Vaihtelun samankaltaisuus peräkkäisten koskipaikkojen välillä oli kuitenkin odotettua pienempää. Yhteisöjä voivat siis säädellä osittain eri tekijät eri mittakaavoilla. Tutkittujen pohjaeläinyhteisöjen ajallisen vaihtelun voimakkuus liittyi erityisesti vesikasvillisuuden määrään: vaihtelu väheni kasvillisuuden lisääntyessä. Kasvillisuuden määrän vaikutus peittyi kuitenkin satunnaisten tekijöiden alle. Jos satunnaisia tekijöitä ei huomioida, deterministiset syy-seuraussuhteet voivat jäädä huomaamatta heikentäen mahdollisuuksiamme ymmärtää ja ennustaa eliöyhteisöjen vaihtelua. Lisäksi eri lähestymistavat ajallista vaihtelua tutkittaessa voivat johtaa erilaisiin arvioihin vaihtelun suuruudesta ja siihen vaikuttavista tekijöistä, mikä tulisi ottaa huomioon tutkimuksia suunnitellessa ja niiden tuloksia vertailtaessa.