Urban ecology (Biology)

The aim of this study consisted in describing the interactions between individuals that form an aggregation of birds that visit an artificial food source. The study area was an artificial feeder located in the gardens of the Simón Bolívar University (Caracas). Were recorded 20 sessions of one hour last between 15:00 and 17:00 for November 2008 to March 2009. Each episode of simultaneous visits of birds around the feeder is called burst. The number and duration of visits in group and individually, number and duration of bursts, bursts initiating species, aggressions and interspecific hierarchical relationships are quantified. The species that visited the feeder were: Pitangus sulphuratus, Turdus leucomelas, Tachyphonus rufus, Thraupis episcopus, Thraupis palmarun, Turdus nudigenis, Tangara gyrola and Ramphocelus carbo. Were registered that 75% of visits were in group and 91% were performed in bursts. No significant differences were found between the duration of visits or vigilance time in group and alone. T. rufus and P. sulphuratus was dominant, while T. nudigenis and R. carbo were subordinate. Finally, it was found that T. nudigenis, P. sulphuratus and T. episcopus were the species that initiated the bursts in most cases. The results indicate that species come to the feeder mostly in groups and so contagious in time.

Although much has been written on the subject of ancient Mediterranean harbours, the relatively new area of harbour
geoarchaeology remains dispersed in the geoscience and archaeological literature. Over a decade of research has amassed rich and varied datasets of anthropogenically forced coastal evolution, with a remarkable number of between-site analogies. This new research field also shows the rich potential of geoscience to reconcile important archaeological questions. No single publication, however, has yet drawn on these geological patterns to yield a detailed overview suitable for geoscientists and environmental archaeologists. The aim of this review article is to
(1) discuss how ancient harbours have come to be preserved in the geological record;

(2) expound the basic principles and palaeoenvironmental tools underpinning ancient harbour geoarchaeology;

(3) outline some of the most significant research advances made; and

(4) discuss a new chrono-stratigraphic model applicable to harbour.
sequences.

Urbanisation is a rapidly growing phenomenon that is affecting global biodiversity, but the integration of conservation goals into urban planning can minimise ecological damage. Conservation planning for birds can be informed by knowledge of species-habitat relationships, but opportunities for studying these relationships before urbanisation occurs are rare. Our study took place in the Molonglo Valley, southeastern Australia, where approximately 30% of the area will be developed for new human settlement over the next 30 years. We surveyed 80 sites for birds and used multiple regression to explore the role that land use, vegetation cover and structure play on total species richness, woodland species richness and prevalence (proportion of total species), and also on the presence of ten woodland species. We found that total species richness was higher in river corridors and eucalypt woodland. Woodland species richness was higher in river corridors and eucalypt woodlands, and when leaf litter was present. Woodland species prevalence was higher in river corridors and when leaf litter and eucalypt regeneration were present. Individual woodland species showed a range of responses to five main structural and compositional categories: (1) land use, (2) tree cover and composition, (3) eucalypt regeneration, (4) shrub cover, and (5) ground cover attributes. We use these data on bird-habitat relationships to develop five recommendations on: (1) eucalypt woodland, (2) high quality riparian areas, (3) scattered trees, (4) eucalypt regeneration, and (5) structurally complex habitats, to aid policy makers, planners and developers to integrate conservation for woodland birds into their urban planning.

Although much has been written on the subject of ancient Mediterranean harbours, the relatively new area of harbour geoarchaeology remains dispersed in the geoscience and archaeological literature. Over a decade of research has amassed rich and varied datasets of anthropogenically forced coastal evolution, with a remarkable number of between-site analogies. This new research field also shows the rich potential of geoscience to reconcile important archaeological questions. No single publication, however, has yet drawn on these geological patterns to yield a detailed overview suitable for geoscientists and environmental archaeologists. The aim of this review article is to (1) discuss how ancient harbours have come to be preserved in the geological record;

Many studies have reported negative effects of urbanisation on bird breeding success, with the role of food thought to play a particularly significant role. The negative effects of city environments on birds have lead researchers to suggest that urban areas may represent ecological traps, whereby individuals settle preferentially in urban habitats but show poor reproductive success relative to other available rural habitats. In this context, this thesis sought to test the effects of urbanisation measured at two spatial scales on both the breeding success of great tits Parus major, and its food during the breeding season. A nested design was used in study sites in northern Belgium with a priori quantified degrees of urbanisation at both local and regional scales. Results found breeding success to vary at one or both spatial scales of urbanisation for all measured parameters: in urban areas great tits displayed advanced laying dates and breeding success was lower than in rural areas, with smaller clutch sizes, lower nestling masses and fewer fledglings per egg. Results regarding food showed that the proportion of caterpillars provisioned to nestlings varied with local scale urbanisation, with significantly lower proportions of caterpillars provisioned to nestlings in urban areas. Moreover, the proportion of caterpillars provisioned was found to have a significant positive effect on nestling mass. Provisioning rates and caterpillar lengths were not found to vary with urbanisation. Results of this study suggest that food quality plays a key role in breeding success in cities, highlight the importance of utilising multiple spatial scales in analysing urbanisation effects, and ultimately provide support to the ecological trap hypothesis.

Golf is a popular sport, with increasingly large areas of urban and peri-urban land being designated for golf course development.
Yet, more than half of the land area of a typical golf course is considered rough and out-of-play areas that can, if managed
appropriately, provide habitats for wildlife. Using pitfall traps, 6944 carabid beetles belonging to 72 species were collected from five
urban golf courses and three areas designated for golf course development around the city of Helsinki, Finland in 2007. The courses
were rich in carabid species and distinct in their species assemblages. Golf courses were dominated by habitat generalists, species
capable of flight and medium to large-sized species. The three courses with areas designated for further golf course development
showed that the assemblages of beetles associated with these golf courses have retained many elements from the pre-existing
habitats. The oldest golf course is characterised by a more evenly distributed and diverse carabid beetle assemblage, probably due to
its higher habitat heterogeneity and longer successional development. However, even this golf course is dominated by generalist species,
implying that golf courses may not provide suitable habitats for specialists. It is assumed that the high species richness of golf
courses is attributed to the high habitat diversity of these environments, ranging from the strongly human-modified to more natural patches, which provide habitats for many generalist and open-habitat species. Golf courses may, however, with the appropriate management of out-of-play areas provide an opportunity for conserving biodiversity.

Análisis de la variación de uso de suelo en el entorno de S'Ena Arrubia, situada en el golfo de Oristano, en el centro oeste de Cerdeña. Este estanque está clasificado como Lugar de Importancia Comunitaria (LIC) y Zona de Protección Especial para las Aves (ZEPA) de acuerdo con las Directivas 92/43 y CEE 79/409, siendo una importante vía para las aves. Fue activada como un refugio de avifauna y reserva natural sufriendo a lo largo de los años de varias modificaciones ambientales. Hemos procedido a una recopilación de datos sobre la flora, la fauna y el estado de uso de suelo alrededor de la charca teniendo en cuenta las normativas ambientales europeas sobre los límites posibles en la presión humana para los LIC en Italia. Finalmente se ha realizado un estudio SIG de los cambios ambientales y de uso del suelo sufrido en la cuenca considerando una distancia máxima de 15 km de distancia al fin de comparar nuestros resultados con los datos procedentes de la investigación bibliográfica. Introducción Las actividades de estrés medioambiental en un estanque cerca de una zona periurbana son: la ganadería y las actividades agrícolas que proporcionan un paisaje antrópico es decir principalmente las presiones constantes y difusas a lo largo del tiempo han producido un cambio radical respecto a su aspecto original. Este estudio ha intentado a abordar a los problemas teóricos y prácticos que plagan a la conservación de los entornos naturales por la actividad humana. Se ha procedido a una investigación con datos de libre acceso y se han creados modelos SIG del uso del suelo para evaluar la tendencia evolutiva ambiental (Uzunov, 2003). Los datos recopilados y procesados de manera conjunta describen por un lado el estado actual de charca y por otro como la actividad humana que manipula el equilibrio natural de la charca y su entorno. Nuestro objetivo es medir como la constante presión antrópica en una zona de humedal periurbano afecta al equilibrio medioambiental protegido por las directivas europeas medioambientales.

Urbanization is one of the most pervasive processes of landscape transformation, responsible for novel selection agents promoting functional community homogeni-zation. Bats may persist in those environments, but the mechanisms responsible for their adaptability and the spatial scales in which the landscape imposes environmental filtering remain poorly studied in the Neotropics. We tested the hypothesis that landscape composition interacts with the spatial scale to affect the functional diversity of phyllostomids in an urban-rural gradient. Based on functional traits, we calculated indices of functional richness, divergence, evenness, and community-weighted means of morphological traits, and classified species into functional groups. We evaluated the changes in those variables in response to forest, grassland, and urbanized areas at 0.5, 1.25, and 2km scales. The number of functional groups, functional richness, and functional evenness tended to be higher in areas far from cities and with higher forest cover, whereas functional divergence increased in more urbanized areas. Our results show that the mean value of wing loading in the assemblage was negatively associated with landscape transformation at several spatial scales. However, environmental filtering driven by grass cover was particularly robust at the 0.5km scale, affecting big-sized species with long-pointed wings. Retaining natural forest in cattle ranging systems at ~12 km 2 appears to favor the functional evenness and number of functional groups of phyllostomids. Recognizing the scale of the effect on phyl-lostomid functional responses appears to be a fundamental issue for elucidating the spatial extent to which phyllostomid conservation planning in urban-rural landscapes should be addressed. Abstract in Spanish is available with online material.

Urban regions often contain remnants of ecologically valuable habitats. Whilst meadow habitats have been recognized as ecologically important and much studied, little attention has been given to meadow assemblages of urban locations. We studied the effects of meadow type, urbanization level, and management on vascular plant species richness, field layer diversity and soil chemistry in 18 grassland sites in the Helsinki Metropolitan Area (60°E, 25°N), on the southern coast of Finland during the summer of 2007. We recorded a total of 252 species, though the average number of species per m2 was only 12.6. The negative effects of urbanization on forbs seemed to result in particular from increased soil nitrate (NO3
- -N) concentration. The highest NO3
- -N and Fe concentrations and ratios of total inorganic nitrogen (Ntot) to phosphorus (P) and potassium (K), were recorded from the soils of urban rocky meadows. Management by mowing decreased soil NO3
- -N and Fe concentrations, ratios of Ntot:P and Ntot:K, and increased species richness and diversity. Elevated NOx deposition is considered as a major driver of urbanization effects on vegetation, though changes in soil pH and metal concentrations, such as zinc (Zn), may also negatively affect the frequency of both forbs and grasses. This study shows that regular management by mowing and removal of hay mitigates these effects. We also recommend increasing the provision of dry meadows and maintaining more areas of supplementary semi-natural grassland habitats in urban green space as concrete measures for the conservation of dry meadow assemblages and urban biodiversity.

Материалы областной краеведческой конференции (5 июня 1998 г.) Динамика флоры окрестностей Владимира за последние 130 лет А.П. Серегин (г. Владимир) 1999 Серегин А.П. Динамика флоры окрестностей Владимира за последние 130 лет // Материалы областной краеведческой конференции (5 июня 1998 г.). Владимир, 1998. С. 178-180. Территории, на которых человек селился издревле, особенно подвергаются интенсивному воздействию человеческой деятельности. Здесь происходят быстрые и глубокие изменения растительного мира, нуждающиеся в специальном изучении. Окрестности Владимира находятся на стыке трех природных районов: Клязьминско-Нерлинской низины, Мещеры и Ополья, и поэтому особенно интересны во флористическом отношении. Но вплоть до 70-х гг. XIX века исследования флоры этого района носили отрывочный и бессистемный характер.

Unsere Städte und Gemeinden stehen vor vielfältigen Herausforderungen. Dazu zählen etwa die Anpassung an den Klimawandel, die Anpassung technischer und sozialer Infrastruktur oder auch der Verlust der urbanen biologischen Vielfalt. Um sich diesen Herausforderungen stellen zu können, unterstützen Bund und Länder die Kommunen mit umfangreichen Finanzhilfen. Ziel ist die Behebung städtebaulicher und sozialer Missstände. Um dieses Ziel zu erreichen, wurden und werden vielfach urbane Grünflächen entwickelt. Allerdings, so der Eindruck, tragen diese Flächen nur selten zum Schutz und zur Weiterentwicklung der urbanen biologischen Vielfalt bei, sondern orientieren sich vor allem an ökonomischen, sozialen und städtebaulichen Aspekten. Wenngleich die Städtebauförderung vielfältige Anknüpfungs-punkte für den Schutz der urbanen biologischen Vielfalt bietet, bedarf es einer Weiterentwicklung der rechtlichen Rahmenbedingungen und der Aktivierung der prozessgestaltenden Akteure auf allen relevanten Handlungsebenen. Stadtentwicklung-Naturschutz-Städtebauförderung-biologische Vielfalt Abstract Our cities and towns face many challenges. These include adaptation to climate change, the transformation of technical and social infrastructure, and the loss of urban biodiversity. To meet these challenges, federal and state governm~nts support local authorities with extensive grants. The aim is to remedy urban and social ills. To achieve this goal, urban green spaces are often developed. However, the impression is that these areas rarely contribute to the conservation and development of urban biodiversity, but are primarily oriented to economic, social and urban-planning aspects. While urban development offers many starting points for the conservation of urban biodiversity, a need remains to refine the legal framework and activate the stakeholders who shape processes at all relevant levels of action. Urban development-Nature conservation-National urban development programme-Urban biodiversity

We report the extraction of a bed bug mitogenome from high-throughput sequencing projects originally focused on the nuclear genome of Cimex lectularius. The assembled mitogenome has a similar AT nucleotide composition bias found in other insects. Phylogenetic analysis of all protein-coding genes indicates that C. lectularius is clearly a member of a paraphyletic Cimicomorpha clade within the Order Hemiptera.

Large trees are considered keystone structures in agricultural and forestry production landscapes, but research demonstrating this in urban landscapes is urgently needed. If large trees are keystone structures in urban parks, it is imperative that this is recognized in policy to ensure their ongoing existence. We studied the role of large native trees for birds in urban parks in Canberra, Australia. We found that (1) large trees had a consistent, strong, and positive relationship with five measures of bird diversity, and (2) as trees became larger in size, their positive effect on bird diversity increased. Large urban trees are therefore keystone structures that provide crucial habitat resources for wildlife. Hence, it is vital that they are managed appropriately. With evidencebased tree preservation policies that recognize biodiversity values, and proactive planning for future large trees, the protection and perpetuation of these important keystone structures can be achieved.

We evaluated damage to commercial crops caused by the monk parakeet, Myiopsitta monachus, in the Baix Llobregat agricultural area (1,024 ha) bordering the city of Barcelona, Spain. Average crop loss was 0.4% for tomatoes, 28% for corn, 9% for red plums, 36% for round plums, 37% for pears, 17% for persimmons, and 7% for quinces. Our data show that the potential damage to crops by monk parakeets in this invaded area is now a reality. As a wait–and–see approach is likely to be a more costly strategy in the long–term, policy makers should assess issues such as the extent of damage, feasibility/cost benefit analysis, and public opinion so as to avoid greater damage and loss in the future

Key words: Monk parakeet, Myiopsitta monachus, Damage to crops, Invasive species

Golf is a popular sport, with increasingly large areas of urban and peri-urban land being designated for golf course development. Yet, more than half of the land area of a typical golf course is considered rough and out-of-play areas that can, if managed appropriately, provide habitats for wildlife. Using pitfall traps, 6944 carabid beetles belonging to 72 species were collected from five urban golf courses and three areas designated for golf course development around the city of Helsinki, Finland in 2007. The courses were rich in carabid species and distinct in their species assemblages. Golf courses were dominated by habitat generalists, species capable of flight and medium to large-sized species. The three courses with areas designated for further golf course development showed that the assemblages of beetles associated with these golf courses have retained many elements from the pre-existing habitats. The oldest golf course is characterised by a more evenly distributed and diverse carabid beetle assemblage, probably due to its higher habitat heterogeneity and longer successional development. However, even this golf course is dominated by generalist species, implying that golf courses may not provide suitable habitats for specialists. It is assumed that the high species richness of golf courses is attributed to the high habitat diversity of these environments, ranging from the strongly human-modified to more natural patches, which provide habitats for many generalist and open-habitat species. Golf courses may, however, with the appropriate management of out-of-play areas provide an opportunity for conserving biodiversity.

Успешно начавшаяся урбанизация самых разных видов птиц в Москве 1970-90-х гг. почти везде сорвана направленным уничтожением их местообитаний в городе в 2000-2010е гг., как «стартовых», соответствующих природным и лишь захваченным внутрь урболандшафта при его расширении (каковы городские ООПТ), так и их "техногенных аналогов", какие ещё остаются, вроде старых парков, отдельных участков промзон и проточных подтоплений в городе, до микрофрагментов растительности среди застройки, заселяемых самыми продвинувшимися по пути урбанизации видами.
Т.е. направленно уничтожаются потенции "города как заказника" , существовавшие до 2000-х, отчасти и до 2010-х. Лишь 25-30 видов птиц имеют перспективы сохраниться на гнездовании в Старой Москве (в черте МКАД) из более чем 150, гнездившихся здесь в поздне-советское время

Em uma Formação Arbustiva Inundável de restinga no município de Carapebus/RJ, foram mapeadas 104 moitas de vegetação em 1 ha de área, o que correspondeu a um total de 44% de área vegetada. Na área amostral total de 1.413,8 m 2 , foram amostrados todos os indivíduos lenhosos cujo diâmetro maior de copa fosse igual ou superior a 0,50 m. Destes indivíduos foram estimadas as áreas basais, alturas, além da identificação e parâmetros fitossociológicos. À exceção das áreas basais os mesmos critérios e estimativas foram empregados com indivíduos da espécie Allagoptera arenaria. Foram contabilizados 329 indivíduos da espécie A. arenaria e 1.135 lenhosos, distribuídos em 43 espécies, 38 gêneros e 25 famílias. No que tange à area vegetada (av) foi verificada uma densidade de 3.522 ind/av e dominância de 9,81 m 2 /av. As espécies Protium icicariba, Humiria balsamifera e Ocotea notata corresponderam conjuntamente a 55% do total de VC, sendo as famílias Burseraceae, Myrtaceae e Lauraceae as de maior representatividade numérica. De um modo geral a altura média dos indivíduos lenhosos é de 1,43 ? 0,78 m e áreas basais médias equivalentes a 0,0028 ? 0,02 m 2 . A área basal total foi de 3,16 m 2 . A altura média estimada para A. arenaria foi de 0,70 ? 0,33 m.

1. Habitat loss and modification are hallmarks of anthropogenic ecosystems, but the consequences for ecosystem functioning and service provisioning often remain unclear. Understanding these links in cities is complicated by strong but fine-scale differences in habitat structure among green space patches, and a high variance in habitat amount across urban landscapes. 2. We used airborne laser scanning data to disentangle the effects of 3D woody habitat heterogeneity of urban home gardens, and woody habitat amount at four landscape spatial scales (50, 100, 250, and 500 m), on the predation risk of artificial sentinel prey by birds and arthropods. 3. In both predator groups, and at all the investigated spatial scales, cross-scale interactive effects between garden habitat heterogeneity and habitat amount in the urban landscape were the main drivers of predation. Risk of predation by birds was highest in heterogeneous garden habitats, but only in densely built urban landscapes where habitat amount was low to intermediate (10%-20%) at large spatial scales (250-500 m). It dropped independently of garden habitat heterogeneity when habitat amount became too low (<10%) at small (50-100 m) spatial scales. In contrast, risk of predation by arthropods mostly peaked in homogeneous garden habitats when habitat amount was intermediate (20%) at large spatial scales. 4. Our findings show that the ability of urban green space patches, such as gardens, to sustain ecosystem functions in cities mainly depends on cross-scale interactive effects with larger scale habitat amount. In birds, predation activity can increase when high patch-scale habitat heterogeneity contrasts with reduced larger scale habitat amount, suggesting concentration effects. Yet, thresholds exist under which ecosystem functioning drops independently of habitat structure. 5. Synthesis and applications. The potential of small-scale interventions to enhance habitat heterogeneity (e.g., by planting native trees with understorey shrubs) for restoring ecosystem functions, such as bird predation, in urban areas is dependent on wider landscape habitat structure. Urban planning should therefore adopt a multiscale approach to sustain and restore ecosystem functions and services; a simple but still not broadly recognized finding. Airborne laser scanning is a useful tool to infer habitat structure across a hierarchy of scales in spatially heterogeneous anthropogenic ecosystems.

The skin functions as the primary interface between the human body and the external environment. To understand how the microbiome varies within urban mass transit and influences the skin microbiota, we profiled the human palm microbiome after contact with handrails within the Hong Kong Mass Transit Railway (MTR) system. Intraday sampling time was identified as the primary determinant of the variation and recurrence of the community composition, whereas human-associated species and clinically important antibiotic resistance genes (ARGs) were captured as p.m. signatures. Line-specific signatures were notably correlated with line-specific environmental exposures and city characteristics. The sole cross-border line appeared as an outlier in most analyses and showed high relative abundance and a significant intraday increment of clinically important ARGs (24.1%), suggesting potential cross-border ARG transmission, especially for tetracycline and vancomycin resistance. Our study provides ...

1. Habitat loss and modification are hallmarks of anthropogenic ecosystems, but the consequences for ecosystem functioning and service provisioning often remain unclear. Understanding these links in cities is complicated by strong but fine-scale differences in habitat structure among green space patches, and a high variance in habitat amount across urban landscapes. 2. We used airborne laser scanning data to disentangle the effects of 3D woody habitat heterogeneity of urban home gardens, and woody habitat amount at four landscape spatial scales (50, 100, 250, and 500 m), on the predation risk of artificial sentinel prey by birds and arthropods. 3. In both predator groups, and at all the investigated spatial scales, cross-scale interactive effects between garden habitat heterogeneity and habitat amount in the urban landscape were the main drivers of predation. Risk of predation by birds was highest in heterogeneous garden habitats, but only in densely built urban landscapes where habitat amount was low to intermediate (10%-20%) at large spatial scales (250-500 m). It dropped independently of garden habitat heteroge-neity when habitat amount became too low (<10%) at small (50-100 m) spatial scales. In contrast, risk of predation by arthropods mostly peaked in homogeneous garden habitats when habitat amount was intermediate (20%) at large spatial scales. 4. Our findings show that the ability of urban green space patches, such as gardens, to sustain ecosystem functions in cities mainly depends on cross-scale interactive effects with larger scale habitat amount. In birds, predation activity can increase when high patch-scale habitat heterogeneity contrasts with reduced larger scale habitat amount, suggesting concentration effects. Yet, thresholds exist under which ecosystem functioning drops independently of habitat structure. 5. Synthesis and applications. The potential of small-scale interventions to enhance habitat heterogeneity (e.g., by planting native trees with understorey shrubs) for

The current research focused on the study of birds checklist, systematic updates, diversity, distribution, abundance and present status at Jamnagar, Gujarat, India. A total of 04 urban and 13 rural sites of the study area surveyed throughout the 18 months from July 2015 to December 2016. Data collection with a visual encounter survey method at random 01 to 08 days every month by three man-hours. A total of 103 species of birds were recorded belonging to 42 families, 81 genera and 19 orders during the study period. Family Scolopacidae represents the significant number of species (13) and family Laridae represents the significant number of individuals (5535) during the survey. From local status 69 rare, 19 Occasional, 13 frequent, 01 common and 01 abundant species reported; As per International Union for Conservation of Nature status, total 90 Least Concern, 12 Nearly Threatened and 01 Vulnerable species were recorded; from migratory status, a higher number of species were recorded fr...

Recent studies have emphasised the increasing impact, both negative and positive, of Linear Transport Infrastructures (LTIs) on biodiversity. A significant body of scientific and technical knowledge is more and more available to help guide restoration practices concerning especially urban areas. This study explores a comprehensive approach to estimating restoration potential along the LTI edges in the Greater Paris region (in France) in terms of potential biodiversity. Our work consists in inventorying and analysing the Potential Biodiversity Index, PBI, on sites along two LTIs crossing a forest in the northern part of this district. The study concerns a Natura 2000 area, La Poudrerie Park. A total of 84 surveys were carried out corresponding to the 33 hectares surveyed. We studied sites along the LTIs. For this purpose, we chose 84 sites in the traffic corridors. Biodiversity parameter evaluations were performed for each site. These parameters are related to functional traits that make it possible to determine the Potential Biodiversity Index (PBI). These site assessments by PBI may reveal the positive impact of the LTI edges in developing biodiversity. We may establish that there is a positive impact of LTIs edges for ecological restoration and revegetation in an urban context.

Two sediment profiles in the ancient harbour of Marseilles were investigated for their Pb concentration and isotopic composition. Sediments dated from the Roman Period show a large increase of Pb concentration and a shift in the Pb isotope ratio. This is an evidence of a Pb pollution in the harbour by the surrounding metallurgical activities. The origin of the Pb used at this time determined by the Pb isotopic composition is probably a mixture of French and Spanish Pb.

Urban regions often contain remnants of ecologically valuable habitats. Whilst meadow habitats have been recognized as ecologically important and much studied, little attention has been given to meadow assemblages of urban locations. We studied the effects of meadow type, urbanization level, and management on vascular plant species richness, field layer diversity and soil chemistry in 18 grassland sites in the Helsinki Metropolitan Area (60°E, 25°N), on the southern coast of Finland during the summer of 2007. We recorded a total of 252 species, though the average number of species per m2 was only 12.6. The negative effects of urbanization on forbs seemed to result in particular from increased soil nitrate (NO 3 - -N) concentration. The highest NO 3 - -N and Fe concentrations and ratios of total inorganic nitrogen (Ntot) to phosphorus (P) and potassium (K), were recorded from the soils of urban rocky meadows. Management by mowing decreased soil NO 3 - -N and Fe concentrations, ratios of Ntot:P and Ntot:K, and increased species richness and diversity. Elevated NOx deposition is considered as a major driver of urbanization effects on vegetation, though changes in soil pH and metal concentrations, such as zinc (Zn), may also negatively affect the frequency of both forbs and grasses. This study shows that regular management by mowing and removal of hay mitigates these effects. We also recommend increasing the provision of dry meadows and maintaining more areas of supplementary semi-natural grassland habitats in urban green space as concrete measures for the conservation of dry meadow assemblages and urban biodiversity.