Plant functional type affects nitrogen dynamics in urban park soils similarly to boreal forest soils

Purpose Although plant functional type can modulate soils and their processes in natural, nitrogen (N)-limited ecosystems, little is known about their ability to influence soil N dynamics in urban ecosystems that have high excess N input. We investigated whether i) plant functional type effects on soil N dynamics in urban parks follow the same pattern as those in undisturbed natural/semi-natural forests, and ii) park age influences plant functional type effects on soil N dynamics under boreal climate. Methods We selected 13 urban parks of varying ages (young: 10 to 15, old: > 70 years), and 5 undisturbed natural/semi-natural forests (> 80 years) in southern Finland. In these parks and forests, we measured soil total N concentration, availability of inorganic N, nitrous oxide (N2O) flux and earthworm biomass under three plant functional types (evergreen tree, deciduous tree, lawn). Results Our results showed that plant functional type influenced N dynamics also in urban greenspace soils, which may relate to the clear effect of plant functional type on earthworm biomass. Evergreen trees tended to have the highest ability to foster N accumulation and reduce N2O emissions in urban parks. Moreover, with increasing park age, N accumulation increased under trees but decreased under lawns, further emphasising the role of vegetation in affecting soil N dynamics in urban greenspaces. Conclusions Our results show that, similar to natural/semi-natural forests, plant functional type, irrespective of park age, can influence soil N dynamics in urban parks.Peer reviewe

Carabid beetles of tropical dry forests display traits that cope with a harsh environment

The tropical dry forest (TDF) ecosystem is characterised by strong seasonality exasperated periodically by the El Nino/southern oscillation (ENSO). The environment produced by this event could constrain the survival of small organisms, such as insects. Carabid beetles were collected in a TDF in Armero, Colombia, during wet and dry seasons in both El Nino and non-El Nino periods. A series of traits linked to desiccation resistance were measured to characterise their adaptation to the TDF environment and to investigate changes experienced by carabid beetles during both episodes in quantitative (assemblage) and qualitative (traits) parameters. We found no difference in the presence of traits between El Nino and non-El Nino episodes, but carabid assemblages changed significantly in composition and assemblage structure between these episodes. During both periods, small-sized and nocturnal species dominated the assemblages, but in terms of number of individuals, medium and large-sized, and visual hunter species dominated. Calosoma alternans and Megacephala affinis were the most abundant species with high dispersal capacity. Carabid beetles exhibited morphological traits well-adapted to drought experienced in TDF, including when it is exasperated by ENSO. However, long-term studies can help to elucidate the real effects of ENSO and to confirm the adaptation of carabid beetles to cope with this extreme environment.Peer reviewe

Neo-spaces for urban livability? Urbanites' versatile mental images of green roofs in the Helsinki metropolitan area, Finland

Within the context of enhancing sustainable and livable urban environments, one aim is to establish multifunctional green infrastructure (GI). We argue that in order to successfully plan and manage the development of GI, an inclusive and future-oriented stance concerning the needs and expectations of urbanites is required. By using green roofs as an example, the aim of this paper was to offer insights into how people envisage novel GI in urban environments and to reveal the scope of meanings and values people attach to these kinds of green infrastructure. We present results based on 149 stories collected with the method of empathy-based stories. Respondents were asked to use their imagination to produce mental images of not-yet-existing green roofs in different urban situations. Our results reflect a rich set of dimensions of green roofs that the respondents vividly imagined. Green roofs may contribute to the livability of urban areas in multiple ways, such as strengthening social cohesion, providing space for everyday renewal and restoration, offering interesting sceneries and multisensory experiences, softening the hard cityscape, showing ephemeral events and making experiences of "height" possible, as well as increasing the "contact with nature" experiences for residents, e.g. through biodiverse nature in the middle of built environments. Furthermore, the need for local, customized solutions that offer different benefits and experiences was expressed. Using both qualitative and quantitative analyses, we idealized four green roof meta-types for understanding the diverse expectations people may have for green roofs in urban area: Urban farm, Oasis, Urban hill and Meadow. Based on our results we suggest that comprehensive experiences and needs of people should be taken into account when designing urban green roofs or urban green in general not only, e.g. visual pleasure. Also, site- and user-specific solutions should be considered instead of generally applied ones. Our results offer tools for, e.g. urban planners to understand the value of diverse green roof solutions to the user. (C) 2016 The Authors. Published by Elsevier Ltd.Peer reviewe

Quantifying Long-Term Urban Grassland Dynamics: Biotic Homogenization and Extinction Debts

Sustainable urban nature conservation calls for a rethinking of conventional approaches. Traditionally, conservationists have not incorporated the history of the landscape in management strategies. This study shows that extant vegetation patterns are correlated to past landscapes indicating potential extinction debts. We calculated urban landscape measures for seven time periods (1938–2019) and correlated it to three vegetation sampling events (1995, 2012, 2019) using GLM models. We also tested whether urban vegetation was homogenizing. Our results indicated that urban vegetation in our study area is not currently homogenizing but that indigenous forb species richness is declining significantly. Furthermore, long-term studies are essential as the time lags identified for different vegetation sampling periods changed as well as the drivers best predicting these changes. Understanding these dynamics are critical to ensuring sustainable conservation of urban vegetation for future citizens

The invasive herb Lupinus polyphyllus can reduce plant species richness independently of local invasion age

The ecological impacts of invasive species may change or accumulate with time since local invasion, potentially inducing further changes in communities and the abiotic environment. Yet, time since invasion is rarely considered when investigating the ecological impacts of invasive non-native species. To examine the effect of time since invasion on the ecological impacts of Lupinus polyphyllus, a perennial nitrogen-fixing herb, we surveyed vascular plant communities in the presence and absence of L. polyphyllus in young, intermediate, and old semi-natural grassland sites (ca. 5, 10, 15 years representing both time since lupine invasion and plant community age). We analyzed vascular plant community composition, vascular plant species richness, and the cover of various ecological plant groups and L. polyphyllus. In contrast to our hypotheses, we found no change in the mean cover of L. polyphyllus (about 35%) with time since local invasion, and an ordination did not suggest marked changes in plant community composition. L. polyphyllus was associated with lower species richness in invaded plant communities but this effect did not change with time since invasion. Invaded plant communities were also associated with lower occurrence of generalist, oligotrophic (low-nutrient-adapted) and copiotrophic (nutrient-demanding) species but no temporal dynamics were detected. We conclude that even the intermediate cover of L. polyphyllus can reduce plant species richness, but the ecological impact caused by this invader might not dramatically change or accumulate with time since invasion.Peer reviewe

Habitat specialization, distribution range size and body size drive extinction risk in carabid beetles

The worldwide biodiversity crisis is ongoing. To slow down, or even halt future species loss it is important to identify potential drivers of extinction risk. Species traits can help to understand the underlying process of extinction risk. In a comprehensive study on 464 carabid beetle species, we used ordinal logistic regression to analyze the relationship of species traits to extinction risk in Central Europe, taking phylogenetic relatedness into account. To consider varying trait responses in different habitat types, we also tested models for species groups associated with different habitat types (forest, open, riparian and wetland). Our results identified three traits of particular importance as predictors for high extinction risk: (1) high habitat specialization, (2) small distribution range size (which is not considered in the categorization of the German Red List), and (3) large body size. Furthermore, large macropterous species showed high extinction risk. Overall, species associated with mountainous, coastal and open habitats generally revealed a high risk of extinction, while most forest species showed a low extinction risk. However, forest species with predatory feeding behavior were threatened, as were wetland species that reproduce in autumn. Phylogenetic relatedness had no influence on how species traits predict carabid beetle extinction risk. In the light of these results, management and recovery plans for species which exhibit characteristic traits strongly associated with extinction risks, as well as the conservation and restoration of mountain, coastal and open habitats, have to be prioritized.Peer reviewe

Ectomycorrhizal Fungal Communities in Urban Parks Are Similar to Those in Natural Forests but Shaped by Vegetation and Park Age

Ectomycorrhizal (ECM) fungi are important mutualists for the growth and health of most boreal trees. Forest age and its host species composition can impact the composition of ECM fungal communities. Although plentiful empirical data exist for forested environments, the effects of established vegetation and its successional trajectories on ECM fungi in urban greenspaces remain poorly understood. We analyzed ECM fungi in 5 control forests and 41 urban parks of two plant functional groups (conifer and broadleaf trees) and in three age categories (10, similar to 50, and > 100 years old) in southern Finland. Our results show that although ECM fungal richness was marginally greater in forests than in urban parks, urban parks still hosted rich and diverse ECM fungal communities. ECM fungal community composition differed between the two habitats but was driven by taxon rank order reordering, as key ECM fungal taxa remained largely the same. In parks, the ECM communities differed between conifer and broadleaf trees. The successional trajectories of ECM fungi, as inferred in relation to the time since park construction, differed among the conifers and broadleaf trees: the ECM fungal communities changed over time under the conifers, whereas communities under broadleaf trees provided no evidence for such age-related effects. Our data show that plant-ECM fungus interactions in urban parks, in spite of being constructed environments, are surprisingly similar in richness to those in natural forests. This suggests that the presence of host trees, rather than soil characteristics or even disturbance regime of the system, determine ECM fungal community structure and diversity. IMPORTANCE In urban environments, soil and trees improve environmental quality and provide essential ecosystem services. ECM fungi enhance plant growth and performance, increasing plant nutrient acquisition and protecting plants against toxic compounds. Recent evidence indicates that soil-inhabiting fungal communities, including ECM and saprotrophic fungi, in urban parks are affected by plant functional type and park age. However, ECM fungal diversity and its responses to urban stress, plant functional type, or park age remain unknown. The significance of our study is in identifying, in greater detail, the responses of ECM fungi in the rhizospheres of conifer and broadleaf trees in urban parks. This will greatly enhance our knowledge of ECM fungal communities under urban stresses, and the findings can be utilized by urban planners to improve urban ecosystem services.Peer reviewe

Landscape adaptation to climate change : Local networks, social learning and co-creation processes for adaptive planning

The development of legitimate, operative, and feasible landscape adaptation planning for climate change is dependent on the specific characteristics of the landscape and its inhabitants. Spatial patterns, culture, governance systems, socio-economic structures, planning methods, history, and collectively envisioned futures need to be accommodated. The literature suggests that landscape is a complex and dynamic socio-ecological system, the management and adaptation of which requires systemic and integrative approaches to respond to a wide variety of drivers of change, challenges, and interests. Based on activities developed in 15 European pilot landscapes, we identify some of the key factors and conditions affecting the generation of representative local networks for landscape adaptation to climate change. We illustrate how social learning and co-creation processes can be implemented in them and how their co-produced outcomes can help local communities overcome barriers and address critical issues in adaptive planning. Our results provide a framework for the creation of similar networks in other landscapes, exploring at the same time the interactions between the composition of networks, social learning, and the quality of the co-produced outputs as a fundamental step for the development of Landscape Adaptation Plans to Climate Change.Peer reviewe

A revised terminology for vegetated rooftops based on function and vegetation

The proliferation of vegetated, or green roofs, warrant a revisit of the terminology used in order to efficiently, and without confusion, convey information among scientists, policy makers and practitioners. A Web of Science and Google Scholar search (from 1996 to 2018) showed a steady increase in green roof articles, reaching close to 300 per year in WOS and ca. 2500 in Google Scholar, with approximately 10-20%, and up to 40 % of all articles using the terms extensive and/or intensive, especially in recent years. We evaluated the use of these terms, including 'green roof, and 'intensive and extensive roof', found that they are used in confusing ways, and provide compelling evidence that there is a need for revising the terminology. Acknowledging that most, if not all, vegetated roofs are multifunctional, we propose a new classification system based on the roof's primary function(s) and vegetation, such as "stormwater meadow roof", "biodiversity meadow roof", "biodiversity forest roof", or even "multifunctional meadow roof". This new terminological sphere is not meant to be rigid, but should be allowed to evolve so that useful combinations survive the scrutiny of academia and practitioners, while less useful ones go extinct. A clear and standardized terminology will serve to avoid confusion, allow for generalizations and aid in the development of this rapidly-expanding field.Peer reviewe

Dealing with varying detection probability, unequal sample sizes and clumped distributions in count data

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