The aim of this report was to investigate if the number and distribution of sea holly (Eryngium maritimum) on the island of Gotska Sandön in the Baltic sea north of Gotland have, and to explore if there is a link between change in plant habitat and change in number of sea holly individuals on the island. To do so a plant inventory was made in 2021 and compared to a previous inventory that was done in 2009. The number of individuals was counted and the habitat which they grey in was noted. Moreover, the presence of japanese rose (Rosa rugosa), and the expansion of scots pine (Pinus sylvestris) was also noted in each locality where sea holly was found. The number of individuals of sea holly on Gotska Sandön went from 9353 in 2009 to 8310 in 2021, mainly becuase of fewer individuals in the largest locality of sea holly on the island. This is probably due to an increase in the proportion of individuals growing on the wooded dunes compared to 2009 and an expansion of japanese rose in the locality. The localities where no scots pine or japanese rose grew in the grey- and white dunes the individuals of sea holly stayed the same or increased in numbers. Despite this, no link could be found between the change in sea holly individual numbers and what plan habitat they grew on Gotska Sandön 2021.

The dynamics of coastal landscapes following major storm events and human interventions significantly impact nesting habitat use by species like the piping plover (Charadrius melodus) along Atlantic coastlines. Our study focused on Fire Island, New York, assessing changes in vegetation succession, plover nesting habitat selection, and suitable nesting habitat availability from 2010 until eight years after Hurricane Sandy. We analyzed classified imagery to quantify vegetative cover changes across the landscape and at nest sites. Results showed an increase of 11.5% change in vegetative cover across the study area, and nest sites experienced an increase in vegetation cover from 0.1% to 6.2% between 2015 and 2020. Selection for four habitat variables (i.e., distance to ocean, least-cost distance to bay, elevation, backshore width) was consistent throughout the study, but post-hurricane nests were situated farther from development and closer to bay areas (Euclidean distance) compared to pre-hurricane. Moreover, suitable nesting habitat peaked immediately post-stabilization but declined in subsequent years. Understanding these landscape shifts provides insights into species prioritization of habitat characteristics during nesting. Piping plovers face predation threats during breeding seasons while balancing consideration of the aforementioned habitat considerations, leading to specific nest placement strategies. Our study examined the relationship between nest site selection and the area visible from nests (viewshed) and evaluated its addition in nest site selection models including habitat variables. Piping plovers exhibited a preference for nest sites with increased predator visibility compared to random selection, indicating a strategic selection process. Initially influential (β = 0.43; CI = 0.28 – 0.58), the role of this predator visibility ('viewshed') diminished (β = -0.13; CI = -0.23– -0.04) as the landscape underwent ecological succession. Topographic variation caused greater visual obstruction at nest sites than vegetation. This study on piping plovers offers insights into the interaction between landscape changes, habitat selection, and predator visibility. The evolving importance of viewshed in nest site selection underscores the dynamic nature of nesting strategies in response to changing environments, and incorporation of this variable can improve the predictive ability of other models as it did for this study. These findings have broader implications for ground-nesting bird species and highlight the importance of considering landscape changes and predator visibility in land management strategies to safeguard vulnerable avian populations. / Master of Science / This is a study of piping plover (Charadrius melodus) nesting behaviors and nesting habitat conditions on Fire Island, New York prior to and following Hurricane Sandy in 2012. Over a decade, our observations documented remarkable alterations in both the landscape and nesting preferences of these birds. Vegetation that was initially covered by overwashed sand from the storm re-emerged in many areas across the study area and reduced the amount of suitable nesting habitat for plovers. Although some factors consistently influenced nesting site selection, after Hurricane Sandy, plovers nested farther from human development and closer to the coastal bay. Moreover, our investigation extended to understanding how these birds strategically choose safe nesting grounds with optimal visibility to potential predators. Initially, plovers nested in areas with greater visibility of predators, but as the landscape experienced vegetation succession nest-site viewshed became less of a priority. We also documented sources of visual obstruction at nests and determined that the topographic features obstructed more area than vegetation; however, sand captured by vegetation contributes to hummocks and dune creation. These findings illuminate the adaptability of piping plover nesting behaviors in response to the changing landscapes. Understanding how the environment changes and how animals adapt to these changes is crucial for creating strategies to protect vulnerable bird populations like piping plovers in coastal areas.

Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2009.

The quality of terrestrial invertebrates as indicators for the detection of ecological change associated with disturbance is widely acknowledged. Invertebrates, at the community level, are often more sensitive to changes than are plants or vertebrates. Both ants and beetles have been studied extensively; changes in ant community composition have been applied successfully as an indication of restoration success. Ants are ideal due to their high abundances and diversity, their ecological importance at all trophic levels, their relative sampling and sorting ease and their sensitivity to ecological change. A detailed understanding of community dynamics greatly facilitates the correct interpretation of signals provided by indicator taxa. Beetles to a great extent, are useful ecological or biodiversity indicators and have been adopted as suitable indicators in environmental monitoring and assessment, as well as to facilitate the evaluation of conservation of biodiversity in landscapes subjected to harvesting. It is well known that ground-dwelling beetle assemblages (especially ground and rove beetles) are sensitive to habitat structure, microclimate and biodiversity management strategies. The use of bio-indicators with regard to land management is becoming increasingly common in ecological studies, because the results obtained can hopefully provide a framework of reference for the prediction of ecosystem response and the means to select the best land use practices. Such predictions will become useful when considering the consequences of ecological perturbations such as fire regimes, bush encroachment, grazing, mining activity, etc. The objectives of this particular study are to determine the effect that past fire treatments may have had on vegetation structure and how ant and beetle assemblages respond to such changes, and what such changes in habitat structure mean in terms of increased bush density. It is expected that the results obtained will provide an indication of the manner in which ecosystem change affects bio-indicator community assemblages, and how this can be applied with regard to future restoration efforts. These organisms were sampled by means of pitfall traps placed within strategic sites varying in vegetation composition and sampled over a number of days. The content of each trap was sorted to genus level, and where possible, to species level and their application of selected invertebrates as indicators of ecosystem change due to veld fires, species richness, abundance and composition determined. The data obtained was analysed statistically using STATISTICA, CANOCO, PRIMER and Microsoft Excel. Four sites with different burn histories were selected: an unburnt site, one burnt in 2002, one burnt in 1997, and one burnt in 1992. Soil characteristics were found to be relatively homogenous throughout all the sample sites, while each of the burn treatment replicates could be characterised by a particular plant structural arrangement. With regards to the ant assemblages, both in terms of species composition and functional group composition, low species diversity appeared to segregate the 1997 burn treatment replicates markedly from the other three burn treatments, with a high degree of species dominance exhibited by Anaplolepis steingroeveri. The ants seem to indicate higher species diversity in the burn treatment sites that had a more diverse vegetation structure. This occurrence however seems to alter over time after a fire incident, before returning to as close to its original state as possible. The beetles, however, displayed very haphazard assemblages, and did not show any discernable significant results that may be used to describe the environmental parameters in question.The reaction of the ants seemed to occur over an extended period of time, with immediate effects of the burn being an increase in non-specialised and opportunistic species abundances, possibly due to a decrease in competition with other species and taxa. Changes in ant assemblages became more apparent after seven years of the burn incident, seemingly linked to structural changes in the plant community. Ant species diversity increased again at the twelve year recovery time, with and associated change in plant habitat structure. The ants thus, in conclusion, show significant results towards indicating a response to habitat change brought on by fire. It is a requirement that this experiment be replicated in order to establish more discernable patterns. Additional recommendations to improve on this study are also discussed. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2009.

The quality of terrestrial invertebrates as indicators for the detection of ecological change associated with disturbance is widely acknowledged. Invertebrates, at the community level, are often more sensitive to changes than are plants or vertebrates. Both ants and beetles have been studied extensively; changes in ant community composition have been applied successfully as an indication of restoration success. Ants are ideal due to their high abundances and diversity, their ecological importance at all trophic levels, their relative sampling and sorting ease and their sensitivity to ecological change. A detailed understanding of community dynamics greatly facilitates the correct interpretation of signals provided by indicator taxa. Beetles to a great extent, are useful ecological or biodiversity indicators and have been adopted as suitable indicators in environmental monitoring and assessment, as well as to facilitate the evaluation of conservation of biodiversity in landscapes subjected to harvesting. It is well known that ground-dwelling beetle assemblages (especially ground and rove beetles) are sensitive to habitat structure, microclimate and biodiversity management strategies. The use of bio-indicators with regard to land management is becoming increasingly common in ecological studies, because the results obtained can hopefully provide a framework of reference for the prediction of ecosystem response and the means to select the best land use practices. Such predictions will become useful when considering the consequences of ecological perturbations such as fire regimes, bush encroachment, grazing, mining activity, etc. The objectives of this particular study are to determine the effect that past fire treatments may have had on vegetation structure and how ant and beetle assemblages respond to such changes, and what such changes in habitat structure mean in terms of increased bush density. It is expected that the results obtained will provide an indication of the manner in which ecosystem change affects bio-indicator community assemblages, and how this can be applied with regard to future restoration efforts. These organisms were sampled by means of pitfall traps placed within strategic sites varying in vegetation composition and sampled over a number of days. The content of each trap was sorted to genus level, and where possible, to species level and their application of selected invertebrates as indicators of ecosystem change due to veld fires, species richness, abundance and composition determined. The data obtained was analysed statistically using STATISTICA, CANOCO, PRIMER and Microsoft Excel. Four sites with different burn histories were selected: an unburnt site, one burnt in 2002, one burnt in 1997, and one burnt in 1992. Soil characteristics were found to be relatively homogenous throughout all the sample sites, while each of the burn treatment replicates could be characterised by a particular plant structural arrangement. With regards to the ant assemblages, both in terms of species composition and functional group composition, low species diversity appeared to segregate the 1997 burn treatment replicates markedly from the other three burn treatments, with a high degree of species dominance exhibited by Anaplolepis steingroeveri. The ants seem to indicate higher species diversity in the burn treatment sites that had a more diverse vegetation structure. This occurrence however seems to alter over time after a fire incident, before returning to as close to its original state as possible. The beetles, however, displayed very haphazard assemblages, and did not show any discernable significant results that may be used to describe the environmental parameters in question.The reaction of the ants seemed to occur over an extended period of time, with immediate effects of the burn being an increase in non-specialised and opportunistic species abundances, possibly due to a decrease in competition with other species and taxa. Changes in ant assemblages became more apparent after seven years of the burn incident, seemingly linked to structural changes in the plant community. Ant species diversity increased again at the twelve year recovery time, with and associated change in plant habitat structure. The ants thus, in conclusion, show significant results towards indicating a response to habitat change brought on by fire. It is a requirement that this experiment be replicated in order to establish more discernable patterns. Additional recommendations to improve on this study are also discussed. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2009.

Renewable energy is a promising alternative to alleviating fossil fuel-based dependencies, but its development can require a complex set of environmental trade-offs for bird communities in the area, ranging from effective and physical habitat loss to direct collision-related mortality. The wide variation in the nature and significance of predicted impacts of utility-scale photovoltaic (PV) facilities on birds, and the low levels of confidence attending these predictions, has emphasised the need for scientific research. This study assesses the risks to bird populations and guilds at one of South Africa's largest PV developments. Firstly, in order to identify functional and structural changes in bird communities in and around the development footprint, bird transect data were gathered, representing the solar development, boundary, and untransformed landscape. Secondly, to assess the risk of collision mortality with solar-related infrastructure, representative samples (core vs. edge) were surveyed for bird carcasses and other signs of collision for three months covering 20-30% of the facility at search intervals of 4, 7 and 14 days. In order to account for potential biases in carcass detection, searcher efficiency and carcass persistence trials were conducted. The distribution of birds in the landscape changed, from a shrubland to open country and grassland bird community, in response to changes in the distribution and abundance of habitat resources such as food, water and nesting sites. These changes in resource availability patterns were detrimental to some bird species and beneficial to others. Shrubland specialists, such as the black-chested prinia (Prinia flavicans) and chestnut-vented tit-babbler (Parisoma subcaeruleum), appeared to be negatively affected by the presence of the PV facility. In contrast, open country/grassland and generalist species, especially species such as the Cape sparrow (Passer melanurus) and familiar chat (Cercomela familiaris), were favoured by its development. Utility-scale PV facilities inevitably will not substitute for the natural habitats they have replaced, but might offer opportunities for climate protection that do not necessarily conflict with nature conservation. Monitoring success of avian mortality was significantly influenced by variation in detection rates by size class (60 and 95% for birds <100 g and >100 g, respectively) and the location of carcasses relative to the solar panel units (65 and 90% for birds adjacent and under the units, respectively) as well as decreasing persistence rates per search interval (57, 53, and 40% after 4, 7, and 14 days, respectively). Only injuries associated with non-fatal collision of large-bodied birds with the underside of the panels and entrapment between fencing could be concluded with reasonable certainty. An extrapolated fatality estimate of 4.53 fatalities.MW⁻¹.yr⁻¹ (95% CI 1.51-8.50), short study period, and lack of comparable results from other sources made it difficult to provide a meaningful assessment on avian mortality at PV facilities. Despite these limitations, the few bird fatalities that were recorded might suggest that there is no significant link with collision-related mortality at the study site. In order to fully understand the risk of solar energy development on birds, further collation and analysis of data from solar energy facilities across spatial and temporal scales, based on scientifically rigorous research designs, is required.

The western mourning dove (Zenaida macroura) population has been declining since 1966. Data collected in 1951-52, in Fillmore, Utah, provided us a baseline for comparison with our study in the same area. Our approach was to determine whether a local population decline had occurred since the original data were collected, assess if trichomoniasis has impacted the local population, determine if changes in habitat structure affect foraging site selection, quantify changes in habitat, identify which habitats doves preferred, ascertain whether doves had responded to habitat change by changing food habits, and assess if changes in habitat were responsible in part for the local population decline. We found that population counts declined 72% and 82% from 1952 to 1992 and 1993, respectively. We determined that trichomoniasis was not an factor. in the decline. We observed that doves preferred foraging habitat characterized by a short and open structure and will not forage in the taller, denser vegetation that now dominates the study area. The most dramatic change in habitat was an 82% decline of land in winter wheat production. In 1951-52 and 1992-93, doves consumed wheat in greater frequency and volume than any other food item. Habitats selected for foraging were wheat fields following harvest, feedpens, hay storage yards, and weedy patches. Of these habitats, area in wheat fields and number of feedpens had changed extensively. The decline in wheat availability, either at harvested fields or feedpens, appears to have contributed to the local population decline. We used regression analysis to test the statewide relationship between the decline in the mourning dove population index, area in winter wheat production, and the number of farms with cattle and obtained significant results (R2 = .42, P = 0.001).

The piping plover (Charadrius melodus) is an imperiled migratory shorebird that nests on mainland and barrier island beaches on the Atlantic coast of North America. Its population decline was attributed to habitat loss, predation, coastal development, and disturbance. Hurricane Sandy reached the Northeast United States in October, 2012. The storm breached and overwashed two barrier islands of New York that support breeding piping plovers, Fire Island and Westhampton Island. In response to geomorphic island changes, the U.S. Army Corps of Engineers stabilized the islands by filling breaches, building dunes, and nourishing beaches. In accordance with the U.S. Fish and Wildlife Service and the Endangered Species Act, the U.S. Army Corps of Engineers constructed piping plover nesting habitat to mitigate the loss of habitat from engineering. The objectives of this study were to assess habitat selection and quantify suitable habitat before and after Hurricane Sandy and to investigate survival and migration of fledgling piping plovers within their first year. We studied piping plover nest-site selection, habitat, and abundance before (2010) and after (2015) Hurricane Sandy and engineered response. Before the storm, piping plovers selected nest sites (n=62) farther from the ocean (x̄ least-cost distance = 82.8 m) and bay (x̄ Euclidean distance = 697.7 m; x̄ least-cost distance = 24,160.6 m) than would be expected if they were selecting nest sites at random. Following the storm, piping plovers selected nest sites (n=45) that were close to, and had unobstructed walking access to, the ocean (x̄ least-cost distance = 123.4 m) and newly-created bayside foraging habitats (x̄ Euclidean distance = 468.0 m; x̄ least-cost distance = 728.9 m). Areas overwashed by the hurricane contained the most suitable piping plover habitat across all new habitat types. Piping plover abundance increased 93% by 2018 from pre-Hurricane Sandy abundances, with most pairs nesting in new habitats. However, only 58% of suitable piping plover habitat was protected from recreational use and only 4% of piping plovers used unprotected habitats for nesting during 2015–2017. We assessed post-fledging survival with radio telemetry and mark-recapture methods. We banded and monitored 292 fledged chicks from 2013–2018. We affixed nanotags to 43 pre-fledged chicks and tracked them to document mortality on their natal grounds. We used a multi-state open robust design model to estimate post-fledging survival within the first year and migration and return probabilities. Daily survival rate as estimated with nanotags was the same as estimated with mark-recapture methods (0.997). Post-fledging survival did not vary in the six years following the storm, nor did it vary across stages within an individual's first year (0.36; 95% CI = 0.31–0.42). Fledgling migration occurred between July 1 and September 22 and reached its peak between August 15–23 (Ψ = 0.97, 95% CI: 0.92–0.98). Individuals with earlier fledge dates migrated earlier (β = ˗1.51, 95% CI: ˗1.11–˗1.91). Second-year plovers returned to the breeding grounds between February 20 and May 8, with a peak occurring in late April and early May (Ψ = 0.55, 95% CI: 0.41–0.70). Given that newly-created storm and engineered habitats benefitted nesting and brooding plovers, ensuring protection of these and other suitable habitats would likely safeguard fledglings that persist on Fire Island for more than a month before departure. / Master of Science / The federally threatened piping plover (Charadrius melodus) is a migratory shorebird that breeds on sandy beaches along the Atlantic coast of North America. Coastal development, recreational use, and habitat loss are major factors that contributed to its listing under the Endangered Species Act in 1986. Hurricane Sandy reached the Northeast United States in October, 2012. The storm breached and overwashed Fire Island and Westhampton Island, prompting the U.S. Army Corps of Engineers to stabilize the islands by filling breaches, building dunes, and nourishing beaches. Because the islands support a breeding population of piping plovers, the U.S. Army Corps of Engineers also constructed piping plover habitat to mitigate the loss of habitat due to engineering. The objectives of this study were to assess habitat selection of plovers before and after Hurricane Sandy and to investigate survival and migration of fledgling piping plovers within their first year. We studied piping plover nest-site selection, suitable habitat, and abundance before (2010) and after (2015) Hurricane Sandy and engineered response. Before the storm, piping plovers selected nest sites farther from the ocean and bay than would be expected if they were selecting nest sites at random. Following the storm, piping plovers selected nest sites that were close to, and had unobstructed walking access to, the ocean and newly-created bayside foraging habitats. Areas overwashed by the hurricane contained the most suitable piping plover habitat across all new habitat types. Piping plover abundance increased 93% by 2018 from pre-Hurricane Sandy abundances, with most pairs nesting in new habitats. However, only 58% of suitable piping plover habitat was protected from recreational use and few piping plovers used unprotected habitats for nesting. From 2013–2019, we monitored post-fledging piping plovers through their first year. We estimated post-fledging survival and estimated fall and spring migration timing. Post-fledging survival was constant across their first year of life. Fledgling migration occurred between July 1 and September 22 and reached its peak between August 15–23. Individuals with earlier fledge dates migrated earlier. Plovers returned to the breeding grounds between February 20 and May 8 of their second year, with a peak occurring in late April and early May. Given that post-Hurricane Sandy habitats were suitable for plover nests and broods, ensuring protection of suitable habitats would also benefit fledglings that persist on Fire Island for more than a month before departure.

Changes of habitats are amongst the main drivers of evolutionary processes. Corresponding shifts in the behaviour and life history traits of species might in turn also alter ecosystem attributes. The reproduction of Western European fire salamanders (Salamandra salamandra), in small pond habitats instead of first order streams, is one example of a recent local adaptation. Since fire salamander larvae are important top-predators in these fish free habitats, their presence likely changes various aspects of ecosystem functioning. Here, it was analysed how the ecological performance of salamander larvae in ponds in the Kottenforst in Western Germany changed in comparison to sympatric stream populations. Further, it was analysed how their presence in ponds influenced key ecosystem attributes such as prey density and diversity and aquatic-terrestrial linkage. To assess the impact of the life cycle shifts in salamanders on the pond functioning, detailed investigations of salamander larvae population dynamics, phenology, and macroinvertebrate community development in ponds were combined with experimental manipulations of the salamander presence. In the first part of this study, the impact of pond presence of fire salamanders in terms of ecosystem functioning focussing on aquatic terrestrial subsidy transfer was calculated. The study could show, that the adaptation of fire salamanders to breed in pools led to strong increases of animal-mediated import of terrestrial matter into the aquatic habitats. The hypothesis about the impact on macroinvertebrate communities derived from these calculations was then tested experimentally. It was shown, that presence of salamander larvae could influence some taxa of macroinvertebrates but they had only limited effects on the food web structure in their aquatic habitats. Yet, a high relevance of the subsidy exchange from aquatic to terrestrial and its high relevance for the predator persistence in the system could again be confirmed. Moreover, it was demonstrated, that the larval behaviour and performance could have a high inter-annual variability as a reaction to contrasting ecosystem constraints in comparison to the stream habitats. A fact that integrally separates the pond ecotype from stream ecotype conspecifics.

Changes of habitats are amongst the main drivers of evolutionary processes. Corresponding shifts in the behaviour and life history traits of species might in turn also alter ecosystem attributes. The reproduction of Western European fire salamanders (Salamandra salamandra), in small pond habitats instead of first order streams, is one example of a recent local adaptation. Since fire salamander larvae are important top-predators in these fish free habitats, their presence likely changes various aspects of ecosystem functioning. Here, it was analysed how the ecological performance of salamander larvae in ponds in the Kottenforst in Western Germany changed in comparison to sympatric stream populations. Further, it was analysed how their presence in ponds influenced key ecosystem attributes such as prey density and diversity and aquatic-terrestrial linkage. To assess the impact of the life cycle shifts in salamanders on the pond functioning, detailed investigations of salamander larvae population dynamics, phenology, and macroinvertebrate community development in ponds were combined with experimental manipulations of the salamander presence. In the first part of this study, the impact of pond presence of fire salamanders in terms of ecosystem functioning focussing on aquatic terrestrial subsidy transfer was calculated. The study could show, that the adaptation of fire salamanders to breed in pools led to strong increases of animal-mediated import of terrestrial matter into the aquatic habitats. The hypothesis about the impact on macroinvertebrate communities derived from these calculations was then tested experimentally. It was shown, that presence of salamander larvae could influence some taxa of macroinvertebrates but they had only limited effects on the food web structure in their aquatic habitats. Yet, a high relevance of the subsidy exchange from aquatic to terrestrial and its high relevance for the predator persistence in the system could again be confirmed. Moreover, it was demonstrated, that the larval behaviour and performance could have a high inter-annual variability as a reaction to contrasting ecosystem constraints in comparison to the stream habitats. A fact that integrally separates the pond ecotype from stream ecotype conspecifics.