Undeveloped Sites Research Articles

Differential impacts of land‐use change on multiple components of common milkweed (Asclepias syriaca) pollination success

AbstractLand‐use change is one the greatest threats to biodiversity and is projected to increase in magnitude in the coming years, stressing the importance of better understanding how land‐use change may affect vital ecosystem services, such as pollination. Past studies on the impact of land‐use change have largely focused on only one aspect of the pollination process (e.g., pollinator composition, pollinator visitation, and pollen transfer), potentially misrepresenting the full complexity of land‐use effects on pollination services. Evaluating the impacts across multiple components of the pollination process can also help pinpoint the underlying mechanisms driving land‐use change effects. This study evaluates how land‐use change affects multiple aspects of the pollination process in common milkweed populations, including pollinator community composition, pollinator visitation rate, pollen removal, and pollen deposition. Overall, land‐use change altered floral visitor composition, with small bees having a larger presence in developed areas. Insect visitation rate and pollen removal were also higher in more developed areas, perhaps suggesting a positive impact of land‐use change. However, pollen deposition did not differ between developed and undeveloped sites. Our findings highlight the complexity evaluating land‐use change effects on pollination, as these likely depend on the specific aspect of pollination evaluated and on the of the intensity of disturbance. Our study stresses the importance of evaluating multiple components of the pollination process in order to fully understand overall effects and mechanisms underlying land‐use change effects on this vital ecosystem service.

Isotopic compositions of organic and inorganic nitrogen reveal processing and source dynamics at septic influenced and undeveloped estuary sites

Historically, dissolved organic nitrogen (DON) has not been characterized in the nitrogen profiles of most estuaries despite its significant contribution to total nitrogen and projected increase in loading. The characterization of dissolved inorganic nitrogen (DIN) and DON processing from groundwater to surface water also remains unconstrained. This study attempts to fill in these knowledge gaps by quantifying the DON pool and potential sources in a semiarid, low inflow estuary (Baffin Bay, Texas) using stable isotope techniques. High NO3− and DON concentrations, and high δ15N-NH4+ (+55.0 ± 56.7 ‰), δ15N-NO3− (+23.9 ± 8.6 ‰) and δ15N-DON (+22.3 ± 6.5 ‰) were observed in groundwaters of a septic-influenced estuarine area, indicating coupled septic contamination and nitrification/denitrification. In contrast, groundwater of an undeveloped area provided evidence of inundation by bay water through high NH4+ concentrations and δ15N-NH4+ (+8.4 ± 3.0 ‰) resembling estuary porewater. NH4+ was the dominant nitrogen species in porewater of both areas and δ15N-NH4+ indicated production via organic nitrogen mineralization and dissimilatory nitrate reduction to ammonium. Surface water had similar nitrogen profiles (DON constituted ∼98 % of dissolved nitrogen pool) and potential source contributions, despite distinct nitrogen processing and profiles found in each water table. This was attributed to low nitrogen removal rates and prolonged mixing associated with long residence time. This study emphasizes the importance of DON in a low-inflow estuary and the isotopic approach to comprehensively examine both inorganic and organic N processing and sources serving as a guide to investigate N cycling in high DON estuaries globally.

LANDSCAPE AND ECOLOGICAL POTENTIAL OF VACANT LANDS IN THE CITY OF ASTRAKHAN

The article provides a multicriterial assessment of urban vacant lands in the city of Astrakhan. Urban vacant lands are defined as undeveloped and unused sites, not attributed to green zones in the city plan. The purpose of the assessment is to recognize the most valuable vacant sites. Their conservation and rehabilitation could enhance the quality and attractiveness of urban environment, while less valuable sites could be recommended for urban development. The work evaluates four landscape functions that correspond to the main problems of the city: 1) runoff regulation function is assessed by the means of morphometric analysis of flow channels and field data on erosion and water logging; 2) climate regulation function is assessed using InVEST urban cooling model; 3) recreational function is evaluated by field and remote sensing data about the current state of vegetation on the vacant sites and by the demand of recreational zones estimated by walking time to the nearest park; 4) air pollution mitigation function is evaluated by the rate of environment child diseases and the density of green spaces in the city districts. Integral assessment of vacant sites helps to provide recommendations on their preferable use. Landscape and ecological potential of vacant lands varies significantly between different parts of the city. Vacant sites of the northeastern outskirts of the city, located within the lower part of the Volga delta, received the highest values, while the small sites in the city center and the industrial zone in the eastern outskirts received the lowest values. As a result, 2570 ha of vacant lands were recommended for greening and rehabilitation, and 327,9 ha for construction.

Detection of heavy metals and VOCs in streambed sediment indicates anthropogenic impact on intermittent streams of the U.S. Virgin Islands

Global surges in industrialization and human development have resulted in environmental contamination. Streambed sediment contamination threatens ecological and human health due to groundwater leaching and downstream contaminant mobilization. This is especially true in the wider Caribbean region, where streambed sediment contamination is understudied. In the current study, we assessed human impact on intermittent streams by measuring heavy metals and volatile organic compounds (VOCs) in streambed sediment on St. Croix in the United States Virgin Islands (USVI), where intermittent streams receive limited conservation and research attention. In contrast to our hypothesis that streambed sediment pollutant concentrations would be higher in developed, compared to undeveloped areas, contaminant concentrations did not vary significantly according to land cover. Elevated lead, mercury, and zinc concentrations were correlated with commercial building density, suggesting an unnatural origin of these elements in streambed sediment. At some sites, levels of arsenic, cadmium, chromium, nickel, lead, thallium, or zinc exceeded regulatory limits. The most prevalent VOCs at both developed and undeveloped sites were benzene and toluene. Sub-groups of heavy metals identified by principal component analysis indicated potential pollution sources, including fuel combustion (chromium, nickel, arsenic, selenium), vehicle exhaust, oil refining, and gasoline leaks (2-butanone and xylenes), and plastics (acetone and styrene). Our results suggest USVI intermittent streams require further research attention and intervention strategies for pollution reduction.

Effects of solar energy development on ants in the Mojave Desert

AbstractLand‐use change from solar energy development may affect desert ecosystems and the soils, plants, and animals therein, yet our understanding of these interactions is nascent. With their ubiquity, criticality as ecosystem constituents, and sensitivity to environmental variation, ants may be useful study organisms for elucidating ecological effects of solar energy development in deserts. Our objectives were to disentangle the response of a desert ant community to solar energy development decisions and test the efficacy of ants as bioindicators at a solar power facility (392 MW) in the Mojave Desert, USA. We used pitfall traps to collect ants in treatments representing different solar energy development decisions, including variably intense site preparation practices: blading (i.e., bulldozing) and mowing, and establishment of undeveloped patches in solar fields, replicated across three power blocks comprising the facility and in undeveloped control sites surrounding the facility. We determined that ant abundance, species richness, Shannon Diversity Index, and functional richness were lower in bladed treatments than in all other treatments and controls. For most taxonomic and functional ant responses, we detected no difference between nonbladed treatments and controls; these results suggest that less intensive site preparation and increased spatial heterogeneity (i.e., undeveloped patches in solar fields) can reduce the negative effects of solar energy development on desert ants. However, our results indicate that ants may serve as useful bioindicators of the severity of anthropogenic disturbance from solar energy development in deserts, and indicator analysis signifies that solar energy infrastructure may negatively affect some species with high ecological value (e.g., harvester ants). Negative effects of solar energy development on ants can have significant implications for desert ecosystem function and integrity, but conservation‐minded solar facility design and construction may lead to avoidance of “bottom‐up” ecological ramifications of increased solar production during the renewable energy transition.

Health of wild fish exposed to contaminants of emerging concern in freshwater ecosystems utilized by a Minnesota Tribal community.

Fish serve as indicators of exposure to contaminants of emerging concern (CECs)-chemicals such as pharmaceuticals, hormones, and personal care products-which are often designed to impact vertebrates. To investigate fish health and CECs in situ, we evaluated the health of wild fish exposed to CECs in waterbodies across northeastern Minnesota with varying anthropogenic pressures and CEC exposures: waterbodies with no human development along their shorelines, those with development, and those directly receiving treated wastewater effluent. Then, we compared three approaches to evaluate the health of fish exposed to CECs in their natural environment: a refined fish health assessment index, a histopathological index, and high-throughput (ToxCast) in vitro assays. Lastly, we mapped adverse outcome pathways (AOPs) associated with identified ToxCast assays to determine potential impacts across levels of biological organization within the aquatic system. These approaches were applied to subsistence fish collected from the Grand Portage Indian Reservation and 1854 Ceded Territory in 2017 and 2019. Overall, 24 CECs were detected in fish tissues, with all but one of the sites having at least one detection. The combined implementation of these tools revealed that subsistence fish exposed to CECs had histological and macroscopic tissue and organ abnormalities, although a direct causal link could not be established. The health of fish in undeveloped sites was as poor, or sometimes poorer, than fish in developed and wastewater effluent-impacted sites based on gross and histologic tissue lesions. Adverse outcome pathways revealed potential hazardous pathways of individual CECs to fish. A better understanding of how the health of wild fish harvested for consumption is affected by CECs may help prioritize risk management research efforts and can ultimately be used to guide fisherymanagement and public health decisions. Integr Environ Assess Manag 2024;20:846-863. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Coccidioides undetected in soils from agricultural land and uncorrelated with time or the greater soil fungal community on undeveloped land.

Coccidioidomycosis is a typically respiratory fungal disease that, in the United States, occurs primarily in Arizona and California. In California, most coccidioidomycosis cases occur in the San Joaquin Valley, a primarily agricultural region where the disease poses a risk for outdoor workers. We collected 710 soil samples and 265 settled dust samples from nine sites in the San Joaquin Valley and examined how Coccidioides detection varied by month, site, and the presence and abundance of other fungal species. We detected Coccidioides in 89 of 238 (37.4%) rodent burrow soil samples at five undeveloped sites and were unable to detect Coccidioides in any of 472 surface and subsurface soil samples at four agricultural sites. In what is the largest sampling effort undertaken on agricultural land, our results provide no evidence that agricultural soils in the San Joaquin Valley harbor Coccidioides. We found no clear association between Coccidioides and the greater soil fungal community, but we identified 19 fungal indicator species that were significantly associated with Coccidioides detection in burrows. We also did not find a seasonal pattern in Coccidioides detection in the rodent burrow soils we sampled. These findings suggest both the presence of a spore bank and that coccidioidomycosis incidence may be more strongly associated with Coccidioides dispersal than Coccidioides growth. Finally, we were able to detect Coccidioides in only five of our 265 near-surface settled dust samples, one from agricultural land, where Coccidioides was undetected in soils, and four from undeveloped land, where Coccidioides was common in the rodent burrow soils we sampled. Our ability to detect Coccidioides in few settled dust samples indicates that improved methods are likely needed moving forward, though raises questions regarding aerial dispersal in Coccidioides, whose key transmission event likely occurs over short distances in rodent burrows from soil to naïve rodent lungs.

The impact of the urban park sunset rule on land value: The case of Yongin in Gyeonggi Province, South Korea

Intense urbanization across the world has increased land scarcity, making it challenging to secure land for public parks and open spaces. To construct urban green space, the Korean government expropriated 904.1 km2 of private land from the 1960s onward. However, under the Urban Park Sunset Rule (UPSR), approximately 405.7 km2 of undeveloped green space sites were released and returned to their owners by 2020. This study investigates the time-varying effect of the UPSR using a two-way fixed effect panel model, covering the period from announcements of the UPSR in 2000 and 2005 to its implementation from 2015 to 2020. We found that the UPSR exerted a small positive externality on the adjacent land market. After the first UPSR announcement, the effect was negative for several years; however, released land began to exert a stronger positive externality after the second announcement, and the maximum effect was observed two years after the first implementation: a 5.71% increase in value per 100-m approach to the subject land. Before the first announcement, the effect was mainly observed within 500 m of released sites. After the second announcement, the effect was observed within the 500–1000-m zone. This study suggests that land use deregulation may generate effects in nearby areas that vary in terms of distance and magnitude in relation to the timing of announcements and implementation.

Nitrate concentrations predominantly driven by human, climate, and soil properties in US rivers

Nitrate is one of the most widespread and persistent pollutants in our time. Our understanding of nitrate dynamics has advanced substantially in the past decades, although its predominant drivers across gradients of climate, land use, and geology have remained elusive. Here we collated nitrate data from 2061 rivers along with 32 watershed characteristic indexes and developed machine learning models to reconstruct long-term mean (multi-year average) nitrate concentrations in the contiguous United States (CONUS). The trained models show similarly satisfactory model performance and can predict nitrate concentrations in chemically-ungauged places with about 70% accuracy. Further analysis revealed that five (out of 32) indexes (drivers) can explain about 70% of spatial variations in mean nitrate concentrations. The five influential drivers are nitrogen application rates Nrate and urban area Aurban% (human drivers), mean annual precipitation and temperature (climate drivers), and sand percent Sand% (soil property driver). Nitrate concentrations in undeveloped sites are primarily modulated by climate and soil property; they decrease with increasing mean discharge and Sand%. Nitrate concentrations in agriculture and urban sites increase with Nrate and Aurban% until reaching their apparent maxima around 10,000 kg/km2/yr and around 25%, respectively. Results indicate that nitrate concentrations may remain similar or increase with growing human population. In addition, nitrate concentrations can increase even without human input, as warming escalates water demand and reduces mean discharge in many places. These results allude to a conceptual model that highlights the impacts of distinct drivers: while human drivers predominate nitrogen input to land and rivers, climate drivers and soil properties modulate its transport and transformation, the balance of which determine long-term mean concentrations. Such mechanism-based insights and forecasting capabilities are essential for water management as we expect changing climate and growing agriculture and urbanization.

Mitigating urban heat with optimal distribution of vegetation and buildings

The impact of climate change on cities poses a growing global threat, which is exacerbated by the urban heat island (UHI) effect. The optimal distribution of vegetation and buildings in urban areas is critical to control the UHI effect and stabilize long-term temperature changes. In this article, we develop an optimization model to maximize revenue while limiting UHI intensity under several restrictions. We run simulations in two urban areas in Brisbane, Australia to test the model's theoretical predictions. Our results show that a revenue increase by AUD 4.32 billion in Brisbane City and by AUD 1.19 billion in Hamilton involves an increase of the maximum temperature difference between the developed and undeveloped sites from 4 to 5° C through an increase of buildings and thus a decrease of porosity and an increase of population density.

Evaluating bat diversity and activity in developed and undeveloped locations of West Virginia’s northern panhandle

Bat populations are declining due to habitat loss and the spread of the deadly fungal pathogen, white-nose syndrome. Increased studies of bat populations and their diversity are necessary to ensure their survival. Bat diversity and activity levels are understudied in the Northern Panhandle of West Virginia. For our study, sixteen sites were selected (four in each county: Ohio, Brooke, Hancock and Marshall). Using mobile ultrasonic bat detectors, bat calls were detected from different species at each location while walking a 1-kilometer transect after sunset. In addition, stationary recorders were placed in all four counties over the summer and in a subset of the counties during the fall and spring. Our null hypothesis suggests that sites/transects will not show any statistical difference of bat diversity in developed or undeveloped locations of West Virginia’s Northern Panhandle. Our alternative hypothesis formulates that bat diversity will be statistically different between developed and undeveloped transects. Results from the summer transects show a significant difference between activity in developed and undeveloped sites (p = 0.008433). Sites were, and still are, being evaluated based on the number of species recorded at each site.

Normative practices of property rating in Ghana: towards improving policy on rating undeveloped urban lands in secondary cities

PurposeThe paper examined how local authorities have attempted to rate undeveloped land as a means of mobilising revenues and the challenges associated with implementing this policy guideline. It focused on current practices in terms of policy and administration, the availability of undeveloped urban land, its revenue potential, and ways to improve policy for local land taxation.Design/methodology/approachDrawing from the mixed-method approach both qualitative and quantitative data were collected. Officials of the Wa Municipal Assembly, Lands Commission, Land Use and Spatial Planning Authority were purposely selected based on their knowledge and the roles they play in property rating practice. They were interviewed to understand their perceptions and views on rating undeveloped lands. Stratified proportionate and simple random sampling methods were used to select respondents. The respondents included land and landed property owners in three selected neighbourhoods.FindingsThe paper found that there was the prevalence of undeveloped lands mainly held by speculators and individuals constrained by financial challenges to develop their parcels. The Wa Municipal Assembly is unable to implement the policy guideline on charging rent on undeveloped lands due to lack of adequate information and generally unwillingness to implement this provision. Besides, the current guideline is too prohibitive and cannot be implemented in its current form. However, there is a window of opportunity for the Assembly to build data on undeveloped lands and moderately begin the implementation of the policy guideline.Practical implicationsUrban growth in Ghana is characterised by leapfrog development with many patches of undeveloped land in and around cities. The property taxation policies largely do not focus on undeveloped land or unimproved site value. In Ghana, property rate policy on the tax base excludes undeveloped land. However, government policy guidelines prescribe the charging of rent on these lands by local authorities. This paper provides a comprehensive discussion on the revenue potential of undeveloped urban land and why local government authorities have not been able to harness this potential. The paper has therefore recommended ways local authorities can use to mobilise revenue from undeveloped urban land.Originality/valueThere is limited research in rating undeveloped urban land especially looking at it from the perspective of policy and implementation as well as current practices. The paper shed light on the prevalence of undeveloped urban land and the guidelines that exist help local governments mobilise revenue from these lands. It contributes to the understanding that local government can harness the revenue potential of undeveloped land if policy design and implemented regarding these lands is enhanced. The paper also provides a good background and framework for further studies.

Precipitation-Driven Anthropogenic Pollutant Fluctuations Within Standing Water Sources of the Edwards Aquifer Region, Texas

The objective of this study was to assess the contribution of urban runoff in pollutant delivery to standing water pools within the Edwards Aquifer region of Texas. Grab samples of water were collected weekly over 5 months at one urban pool, one undeveloped pool, and one control pond that received minimal runoff. Samples were tested for nitrates, total dissolved phosphorus, Escherichia coli, and other coliform bacteria. The urban site had higher nitrate, E. coli, and other coliform bacteria concentrations than the undeveloped site. Significant positive linear relationships between weekly antecedent rainfall and both nitrate and E. coli were found at the urban site but not the undeveloped site. Water quality parameters at the control site remained stable, suggesting increases in nitrate and E. coli at the urban site were caused by runoff. Using publicly available data, relationships between water quality and weekly antecedent discharge were tested at 24 additional sites varying in land use. Positive relationships for E. coli were found at several urban sites, supporting runoff as a contributor to bacterial loading. Relationships for nitrate were variable, but all additional sites had flowing water, suggesting a unique response of water quality to urban runoff at the sampled urban pool.

Solar energy development impacts flower-visiting beetles and flies in the Mojave Desert

Deserts support a high diversity of insect pollinators and vascular plants with which pollinators have coevolved. Deserts are increasingly prioritized as recipient environments for ground-mounted solar energy development, which represents a novel, anthropogenic disturbance in desert ecosystems and drives land-use change across desert landscapes. Pollinators confer ecosystem services, yet anthropogenically driven land-use change has played a large role in their decline globally. Our objective was to elucidate relationships between solar energy development and non-bee insect flower visitors (i.e., beetles, flies, moths, and wasps) at Ivanpah Solar Electric Generating System (ISEGS, 392 MW) in the Ivanpah Valley of the Mojave Desert. We used blue vane traps to collect non-bee insect flower visitors in treatments that represent different solar energy development decisions, including two types of site preparation practices (blading and mowing) and establishment of habitat patches in solar fields, replicated across three power blocks in ISEGS and in undeveloped control sites surrounding ISEGS. We determined that count and taxa richness of non-bee insect flower visitors and counts of individual non-bee insect flower visitor taxa were greater in undeveloped controls than in ISEGS. Our results indicate that disturbance from solar energy development negatively affected non-bee insect flower visitors, including beetles and flies, and that small habitat patches within solar fields in ISEGS largely did not support non-bee insect flower visitors. Disruption of non-bee insect flower visitor communities from solar energy development in deserts may lead to cascading effects on biodiversity, including potential decreases in globally imperiled and highly valuable cacti populations dependent on insect pollination. Losses in biodiversity from solar energy development in deserts may be eliminated by alternative siting (e.g., contaminated lands, rooftops), while gains can be achieved by sustainable decision making guided by solutions-oriented, collaborative research and techno-ecological synergies.

The effect of the character of urban development on the small mammal communities in a northern city

Communities of small mammals on the territory of Yakutsk and in its vicinity have been studied. Residential areas, undeveloped sites, suburban zone, and agricultural lands are covered. A total of 2,736 cone-days and 525 trap-days are accumulated and 388 specimens of small mammals from 13 species belonging to Rodentia and Eulipotyphla orders are collected. The abundance of small mammals in different types of environment have varied from 2.2 to 22.9 individuals per 100 cone-days. The highest values of species diversity are found in the suburban zone in the areas of surviving natural biotopes. The zone of the city’s residential areas is characterized by the lowest abundance and species diversity of small mammals, primarily Eulipotyphla, and also by the presence of eusynanthropicMus musculus and Rattus norvegicus. The undeveloped territories of the city are characterized by a high total abundance of small mammals, but poor community composition, which is close in its structure to floodplain biotopes. Communities of agrocenoses are also poor, due to elimination of forest species, and characterized by uneven distribution of small mammals among the biotopes. On the whole, the anthropogenic effect of urbanization is manifested in poor composition of communities and changes in the dominance structure. The appearance of the house mouse in the zone of detached housing indicates intensifying urbanization of the territory and ongoing synantropization of the fauna.

Influences of land use and ecological variables on trematode prevalence and intensity at the salt marsh‐upland ecotone

AbstractHuman‐altered shorelines make up approximately 14% of the coastline in the United States, with consequences for marsh ecosystems ranging from altered physical and biological variables, to direct loss of intertidal marsh habitat, to diminished land–sea connectivity. Trophically transmitted parasites that require connectivity between upland host species and marsh host species to complete their complex lifecycles could be particularly sensitive to the effects of shoreline alterations. They can additionally respond to gradients in natural physical and biological factors, including the host communities, that are often sharp at the land–sea ecotone. Across 27 salt marshes over 45 km, we evaluated the effects of environmental variables and three types of land use (undeveloped; single‐house adjacent to the marsh with small‐scale shoreline armoring; and single‐house adjacent to the marsh without shoreline armoring), on infection prevalence and intensity of the trematode Microphallus basodactylophallus in its second intermediate crab host, Minuca pugnax. The first intermediate hosts of M. basodactylophallus are Hydrobiid snail species that are obligate marsh residents, while the definitive hosts are terrestrial rodents and raccoons. Thus, trematode transmission must depend on cross‐boundary movement by the definitive hosts. We found that although there was a trend of lower infection prevalence at undeveloped forested sites, there was no significant effect of adjacent land development on infection prevalence or intensity. Instead host, biotic and abiotic factors were correlated with infection; namely, larger M. pugnax had higher prevalence and intensity of M. basodactylophallus, and higher soil moisture and lower density of the ribbed mussel (Geukensia demissa) were associated with increased M. basodactylophallus prevalence. The small, indirect influence of upland development suggests that movement of definite hosts across the ecotone may be largely unaffected. Further, the robust trematode levels signify the ecosystem and the species interactions, upon which its complex lifecycle depends, are largely intact.

Identifying Toxicologically Significant Compounds in Urban Wildfire Ash Using In Vitro Bioassays and High-Resolution Mass Spectrometry.

Urban wildfires may generate numerous unidentified chemicals of toxicity concern. Ash samples were collected from burned residences and from an undeveloped upwind reference site, following the Tubbs fire in Sonoma County, California. The solvent extracts of ash samples were analyzed using GC- and LC-high-resolution mass spectrometry (HRMS) and using a suite of in vitro bioassays for their bioactivity toward nuclear receptors [aryl hydrocarbon receptor (AhR), estrogen receptor (ER), and androgen receptor (AR)], their influence on the expression of genetic markers of stress and inflammation [interleukin-8 (IL-8) and cyclooxygenase-2 (COX-2)], and xenobiotic metabolism [cytochrome P4501A1 (CYP1A1)]. Genetic markers (CYP1A1, IL-8, and COX-2) and AhR activity were significantly higher with wildfire samples than in solvent controls, whereas AR and ER activities generally were unaffected or reduced. The bioassay responses of samples from residential areas were not significantly different from the samples from the reference site despite differing chemical compositions. Suspect and nontarget screening was conducted to identify the chemicals responsible for elevated bioactivity using the multiple streams of HRMS data and open-source data analysis workflows. For the bioassay endpoint with the largest available database of pure compound results (AhR), nontarget features statistically related to whole sample bioassay response using Spearman's rank-order correlation coefficients or elastic net regression were significantly more likely (by 10 and 15 times, respectively) to be known AhR agonists than the overall population of compounds tentatively identified by nontarget analysis. The findings suggest that a combination of nontarget analysis, in vitro bioassays, and statistical analysis can identify bioactive compounds in complex mixtures.

Assessment of Ecotourism Potentials in Afikpo, Ebonyi State, Nigeria

This paper asserts the case for developing the ecotourism potential in Afikpo, Ebonyi state. The main aim of the study is to assess the ecotourism potentials in Afikpo with a view to recommending means to enhance these potentials for development. The following objectives were underpinned (i) To examine the nature of tourism sites in Afikpo, (ii) To identify the potentials, (iii) To determine the extent, the potentials have been harnessed, (iv) To identify factors that hinders the potentials of tourism. The study adopted a survey design approach. Data was collected from both primary and secondary source through orals interview, questionnaire, and direct observation methods. Four hundred questionnaires were administered in the three communities that were selected for this study. The sample size of 400 respondents was determined from the sample population of 130,329 resident’s population of Afikpo north using De Vaus Formula. Three hundred and eighty (380) were returned representing 95% questionnaire utilization. Simple random sampling and a purposive sampling techniques were employed to select the respondents who were the residents. The study identified factors that hinder tourism development in Afikpo and a breakdown showed that four out of the thirty one (31) variables were identified as the major factors that hinder the development of potential tourist sites. The findings revealed that lack of political will was the most prominent factor responsible for the undeveloped sites. This was followed by political bureaucracy, and political instability. The study therefore recommended amongst others the intervention of the government in the development of the tourism potentials in Afikpo, Ebonyi State.

DESIGN AND CONSTRUCTION OF LOW-STOREY HOUSING IN THE LATE 1950s IN LVIV

In 1957-1960, the mass construction of one-story attics and two-story buildings began to solve the problem of providing housing for workers of newly established enterprises. Lviv architects on a competitive basis designed a number of projects, on the basis of which the State Construction Committee of the UkrSSR proposed to the Lviv branch of Dipromist on their basis to develop a unified series of projects of typical one-and two-storey buildings. 136 hectares of land were allocated for housing construction, on which, according to the city master plan, low-rise buildings are planned. It was planned to build houses and separate groups on undeveloped sites in the old residential areas where there were already utilities. New housing construction with a high level of engineering equipment contributes to the improvement of working areas. In residential areas, the construction of schools, children's institutions, cinemas, clinics, shops, consumer services is planned. - Levandivka is transformed into a landscaped village. The quarters are planned according to the manor type. The area of ​​the plot is 0.06 - 0.08 hectares per one-apartment house, ie - 0.03 - 0.04 ha per apartment. It should be noted that the architects of Lviv in their functional-spatial and architectural-planning solutions used the experience of low-rise construction of the period of functionalism of Lviv in the 1930s. Today, many enterprises, near which low-rise buildings were built, have ceased to exist, and multi-storey residential and public buildings are being built on their territory. Part of the low-rise buildings of that period have also been lost, and part is in the process of transformation. Didyk V. and Morklyanyk O. (2003-2018) studies the socio-political preconditions of housing design and construction, localization of construction in the spatial structure of Lviv, analysis of architectural-planning and stylistic solutions of housing and its architectural-spatial transformation. The article analyzes the individual and typical projects of low-rise buildings and notes that despite the simple facades, the houses are architecturally quite expressive. Part of the low-rise buildings of that period has been lost, part is in the stage of transformation and a small part is still preserved almost unchanged. Therefore, those fragments of low-rise buildings and individual houses that still retain architectural expressiveness and functional aesthetics should be preserved as monuments of urban art, architecture and culture.

Evaluating tourism potentials for site development tourism along River Ethiope, Abraka, Nigeria

Purpose: The empirical research study evaluated environmental potentials of site locations for Tourism development along River Ethiope, Abraka Delta State, Nigeria, Four(4)sites’ 40 environmental features were considered important in the tourism sites evaluation. The primary data sources used include oral interview and administration of questionnaires. Research methodology: These are physical, biological and human components of tourism destinations, evaluated for each of the 4sites, and compared. Each of the 40 factors was measured using appropriate instruments like measuring tape and floater (for velocity). Students t test was undertaken to compare the evaluations of the two groups of professional and non-professional assessors. With a calculated value of 0.143, and table value of 0.283, with df2:3 at 0.05 level, the difference in site ranking between the first and second evaluation was not considered significant. High confidence or reliability can therefore be placed on the tourism site evaluation results obtained at the 0.05 significance level. The use of nominal or interval scales was to estimate variables, which were not subject to direct measurements in interval scale. Three groups of sites emerged from the preliminary survey of those selected: Natural or undeveloped sites, relate. Results: Result obtained showed that undeveloped and natural sites emerged most highly rated in environmental potentials for tourism site development compared to underdeveloped or highly developed sites. Limitation: The area lies within tropical equatorial rain forest vegetation which is an impenetrable ticket of under growth with trees and climbers. Moreover, dangerous reptiles especially (snakes and crocodile) as well as insect (Mosquitos and tsetse fly) are present and harmful to man in the environment. Contribution: The study concludes and suggests natural sites be accord priority in tourism site development along River Ethiope and invariably other related natural area worldwide for maximum patronage implications based on advocated research methodology. Keywords: Tourism, Site, Evaluation, Development, River Ethiope, Abraka