The Unsettled Landscape: The Core to Coastal Fabrics

<p>‘The Unsettled Landscape’ considers an alternative sustainable manner in which communities can settle New Zealand’s coastland. Living at the ocean edge is ingrained in the way many of our urban settlements have formed, and is intricately linked with how we define ourselves. Unfortunately the way these places have manifested in reality has produced ecological barriers to natural cycles paramount to ecosystem health. Sea walls, housing, roads and many other infrastructural typologies resist the natural ‘flux’ of these areas, which results in dysfunctional ecosystems as well as putting residents of these places at risk of numerous threats which occur along these interface sites. Earthquakes, river movement, erosion, sea level rise, flooding and the continual movement of the dunes are just some of the issues coastal settlements face. The conflict forms where the sought after coastal environments are applied to in a permanent manner that is irresponsive of a landscape which functions in a most dynamic way. This thesis looks towards the geomorphological patterns in the coast as an indicator for how a complete shift in infrastructural application might occur responsively. This new fabric distinguishes stable components in this shifting landscape, utilising them as a stable network from which settlement can develop. This network could become the basis of more responsive settlements, stronger communities, and will act as a way to future proof inhabitation of these fragile yet hazardous places. Design research explores the physical as well as intangible aspects of settlement application, and focuses on communities forming the ‘real’ foundation of these temporal environments. Responsive communities arise ‘reactively’ avoiding hazards, and allowing inhabitants to take advantage of what these precious sites offer.</p>

The Unsettled Landscape: The Core to Coastal Fabrics

<p>‘The Unsettled Landscape’ considers an alternative sustainable manner in which communities can settle New Zealand’s coastland. Living at the ocean edge is ingrained in the way many of our urban settlements have formed, and is intricately linked with how we define ourselves. Unfortunately the way these places have manifested in reality has produced ecological barriers to natural cycles paramount to ecosystem health. Sea walls, housing, roads and many other infrastructural typologies resist the natural ‘flux’ of these areas, which results in dysfunctional ecosystems as well as putting residents of these places at risk of numerous threats which occur along these interface sites. Earthquakes, river movement, erosion, sea level rise, flooding and the continual movement of the dunes are just some of the issues coastal settlements face. The conflict forms where the sought after coastal environments are applied to in a permanent manner that is irresponsive of a landscape which functions in a most dynamic way. This thesis looks towards the geomorphological patterns in the coast as an indicator for how a complete shift in infrastructural application might occur responsively. This new fabric distinguishes stable components in this shifting landscape, utilising them as a stable network from which settlement can develop. This network could become the basis of more responsive settlements, stronger communities, and will act as a way to future proof inhabitation of these fragile yet hazardous places. Design research explores the physical as well as intangible aspects of settlement application, and focuses on communities forming the ‘real’ foundation of these temporal environments. Responsive communities arise ‘reactively’ avoiding hazards, and allowing inhabitants to take advantage of what these precious sites offer.</p>

Citrine Wagtail migration on the Indo-European flyway: a first geolocator track reveals alternative migration route and endurance flights to cross ecological barriers

Most long-distance migrating passerines that breed in Europe spend their winters in Africa, with only a few species migrating eastward to spend the non-breeding period in South Asia. The use of the Indo-European flyway is rare and has been poorly studied so far. However, it is extremely interesting as within that system we are currently witnessing a recent range expansion of European breeding long distance migrants and thus the lengthening of migration routes. It may therefore conceal a unique migratory strategies and behaviour that can help us to understand the underlying factors and mechanisms determining the evolution of migration routes, strategies and breeding range extinction. Based on light-level geolocator we reveal a first track of the Citrine Wagtail (Motacilla citreola) migration, providing insight into the migration pattern, timing and behaviour of the species that recently has extended its migration routes. Unexpectedly, the studied individual did not retrace a recent range expansion that runs north and east from the Caspian Sea but followed a migration route running south form the Caspian sea, suggesting possible presence of an alternative species range expansion. The overall migration distance between the breeding site in Poland and the non-breeding site in Pakistan was about 10,420 km and included two endurance movement phases (920 and 2240 km) covering 30% of the whole journey length, with an average movement speed of 574 km/day. We explain this migration behaviour as an adaptation for crossing the ecological barriers imposed by arid environments.

DISTRIBUTION OF ALIEN ZOOBENTHIC SPECIES ON THE SHELF OF THE BLACK SEA

The number of alien species in the zoobenthos of the Black Sea increased up to 65 species. Depending on the scale of their distribution in the Black Sea, non-native zoobenthos species are combined into three groups: 1) 5 species have spread in the entire sea, 2) 35 species were found in several areas, and 3) 25 species were found only in one of the areas of the sea. Six areas of the Black Sea shelf have been identified (Varna - Burgas, Danube, Northwestern, Crimean, Caucasian and Anatolian) in accordance with the seasonal and annual values of the thermohaline characteristics. The zoobenthos differed not only in quantity, but also in the composition of non-native species between the six areas of the shelf. The results of multivariate statistical analysis revealed a low level of similarity between these areas of the Black Sea shelf. The greatest similarity in the composition of alien species of zoobenthos was observed for the Danube region with the Varna and Burgas bays, which border each other. The species composition of the alien species of the Caucasian shelf was more similar to the Varna - Burgas and Danube areas than to the neighboring Crimean and Anatolian areas. Spatial gradients of temperature and salinity form hydrological fronts of water masses, which are a kind of ecological barriers and can limit the natural exchange of alien species between shelf areas.

The role of sexual isolation during rapid ecological divergence: evidence for a new dimension of isolation in Rhagoletis pomonella

The pace of divergence and likelihood of complete speciation may depend how and when different types of reproductive barriers evolve. After initial reproductive barriers evolve, questions remain about how subsequently evolving barriers may facilitate additional divergence and potential speciation. We tested for the presence of sexual isolation (reduced mating between populations due to divergent mating preferences and traits) in Rhagoletis pomonella flies, a model system for incipient ecological speciation. We measured the strength of sexual isolation between two very recently diverged (~170 years) sympatric populations, adapted to different host fruits. We found that sexual isolation was significantly stronger than expectations of random mating. Thus, sexual isolation may play an important role in reducing gene flow allowed by earlier-acting ecological barriers. We also found that sexual isolation was markedly asymmetric between the sexes of each population. Lastly, we tested how warmer temperatures predicted under climate change could alter sexual isolation and found that mating interactions were sensitive to temperature experienced during development. Our findings provide a window into the early divergence process and the role of sexual isolation after initial ecological divergence, in addition to examining multiple factors that could shape the likelihood of further divergence.

The emergence of ecotypes in a parasitoid wasp: a case of incipient sympatric speciation in Hymenoptera?

Background To understand which reproductive barriers initiate speciation is a major question in evolutionary research. Despite their high species numbers and specific biology, there are only few studies on speciation in Hymenoptera. This study aims to identify very early reproductive barriers in a local, sympatric population of Nasonia vitripennis (Walker 1836), a hymenopterous parasitoid of fly pupae. We studied ecological barriers, sexual barriers, and the reduction in F1-female offspring as a postmating barrier, as well as the population structure using microsatellites. Results We found considerable inbreeding within female strains and a population structure with either three or five subpopulation clusters defined by microsatellites. In addition, there are two ecotypes, one parasitizing fly pupae in bird nests and the other on carrion. The nest ecotype is mainly formed from one of the microsatellite clusters, the two or four remaining microsatellite clusters form the carrion ecotype. There was slight sexual isolation and a reduction in F1-female offspring between inbreeding strains from the same microsatellite clusters and the same ecotypes. Strains from different microsatellite clusters are separated by a reduction in F1-female offspring. Ecotypes are separated only by ecological barriers. Conclusions This is the first demonstration of very early reproductive barriers within a sympatric population of Hymenoptera. It demonstrates that sexual and premating barriers can precede ecological separation. This indicates the complexity of ecotype formation and highlights the general need for more studies within homogenous populations for the identification of the earliest barriers in the speciation process.

Water stress-associated isolation barriers between two sympatric oak species

Drought and waterlogging impede tree growth and may even lead to tree death. With climate change, these environmental factors are a growing source of concern, particularly for temperate forests. Oaks, an emblematic group of tree species, have evolved a range of adaptations to cope with these constraints. The two most widely distributed European species pedunculate oak (PO) and sessile oaks (SO) have overlapping ranges, but are highly constrained locally by soil water content variation. These differences in local ecological requirements provide a powerful biological model for studying the role of ecological barriers in speciation. We used an experimental set-up mimicking the ecological preferences of these species, in which seedlings were subjected to waterlogging and drought. We studied gene expression in roots by RNA-seq and identified genes differentially expressed between treatments with different outcomes depending on species. These ″species x environment″ responsive genes revealed adaptive molecular strategies involving adventitious and lateral root formation, aerenchyma formation in PO, and osmoregulation and ABA regulation in SO. With this experimental design, we also identified genes with expression profiles presenting a ″species″ effect regardless of imposed constraints with important roles in intrinsic reproductive barriers. Finally, we compared our findings with those for a genome scan of species divergence and found that the candidate genes were enriched in highly differentiated SNPs. This suggests that many of the genes involved in the contrasting transcriptomic responses are subject to natural selection and that gene regulation helps to maintain these two different oak species in sympatry.

The interplay of wind and uplift facilitates over-water flight in facultative soaring birds

Flying over the open sea is energetically costly for terrestrial birds. Despite this, over-water journeys of many birds, sometimes hundreds of kilometres long, are uncovered by bio-logging technology. To understand how these birds afford their flights over the open sea, we investigated the role of atmospheric conditions, specifically wind and uplift, in subsidizing over-water flight at a global scale. We first established that Δ T , the temperature difference between sea surface and air, is a meaningful proxy for uplift over water. Using this proxy, we showed that the spatio-temporal patterns of sea-crossing in terrestrial migratory birds are associated with favourable uplift conditions. We then analysed route selection over the open sea for five facultative soaring species, representative of all major migratory flyways. The birds maximized wind support when selecting their sea-crossing routes and selected greater uplift when suitable wind support was available. They also preferred routes with low long-term uncertainty in wind conditions. Our findings suggest that, in addition to wind, uplift may play a key role in the energy seascape for bird migration that in turn determines strategies and associated costs for birds crossing ecological barriers such as the open sea.

Recurrent allopolyploidization events diversify eco-physiological traits in marsh orchids

Whole-genome duplication, in particular allopolyploidy, has shaped the evolution of angiosperms and other organisms. Structural reorganization of chromosomes and repatterning of gene expression is frequently observed in early generation allopolyploids, with potential ecological consequences. The relative contributions of environmental and intrinsic drivers to these changes are unknown. We show here that in marsh orchids (Dactylorhiza, Orchidaceae), recurrently-formed allopolyploids are characterized by distinct eco-physiologies matching their respective environments, providing us with an excellent study system to address this question. Here we integrate eco-physiological and transcriptomic comparative studies to reveal a complex suite of intertwined, pronounced differences between sibling allopolyploids. We show that Dactylorhiza majalis that is distributed in Central and Southern Europe favors meadows with mesic soils. Its sibling allopolyploid D. traunsteineri occurs in fens, characterized by soils depleted by macro- and micronutrients, mainly in previously glaciated European areas. We further uncover distinct features in their nutrient transport, leaf elemental chemistry, light-harvesting, photoprotection, and stomata activity, that appear all linked to their distinct ecologies, in particular soil chemistry differences at their native sites. Recurrent polyploidization hence enriches biodiversity through eco-physiological diversification, providing the opportunity for sibling allopolyploids to evolve as distinct evolutionary units, despite pervasive interspecific gene flow.Significance StatementWhole-genome duplication resulting in polyploidy has underpinned the evolution of flowering plants and other organisms, and is important for many crops. However, the ecological implications of polyploidy remain little understood. Here, we demonstrate that two sibling allopolyploid marsh orchid species prefer distinct habitats, and have evolved a suite of distinctive ecophysiological characters (e.g. nutrient transport, energy harvesting and photoprotection). We argue that the divergence of these characters in the nascent polyploids drove adaptation into distinct ecological niches (low nutrient fens versus meadows with mesic soils), generating ecological barriers that maintains distinct, independent lineages, even in the presence of interspecific gene flow.

Social-Ecological Barriers to Student-parents’ Academic Success: A Systematic Review

Students who are parents in higher education (HE) in the United States encounter competing demands and challenges while navigating multiple roles as parents, students, and employees. These challenges are multifaceted and can hinder their degree attainment. Using the socio-ecological model, we systematically summarized existing literature published between 2009 - 2020 to understand the experiences and predictors of student-parents academic outcomes in HE. The reviewed articles included students from two-year and four-year institutions (community college, undergraduates, and graduate students). The analysis revealed that the constraints to student-parents academic success are a system-level problem. Most of the barriers and facilitators identified were related to structural policies adopted by HE. This study concludes with recommendations for future research, policymakers, and the school ecosystem.