Aim: Urbanization as a major global trend profoundly changes biodiversity patterns, and homogenization of urban biota due to expanding exotic species and declining native species is of increasing ...concern. Previous studies on this topic have mostly taken place at large scales that include high habitat heterogeneity. Here, we aimed at disentangling the effects of urbanization and plant invasion on species composition through the analysis of similarity patterns of urban plant assemblages at the community scale where species interact. Location: Berlin, Germany. Methods: We analysed how different levels of urbanization, specific components of the urban matrix and the dominance of a native (Betula pendula) versus an exotic tree species (Robinia pseudoacacia) affect alpha and beta diversity of urban woodland understorey vegetation in sixty-eight 100-m2 plots. Results: Exotic dominance reduced alpha diversity, but not beta diversity of the total species pool. Comparing beta diversity among different species groups revealed significant but divergent effects of exotic dominance, habitat connectivity and levels of urbanization in native and non-native species assemblages. In particular, urbanity proved to homogenize the native species pool, whereas the beta diversity of the non-native species pool showed a more pronounced response to exotic dominance. Main conclusions: Our data provide evidence that both the urban context and the dominance of exotic species can modify homogenization processes at the community level. These novel insights into the mechanisms of biotic homogenization of urban floras may contribute to mitigating the effects of urbanization on biodiversity.
Understanding and explaining the use of green spaces and forests is challenging for sustainable urban planning. In recent years there has been increasing demand for novel approaches to investigate ...urban green infrastructure by capitalizing on large databases from existing citizen science tools. In this study, we analyzed iNaturalist data to perform an assessment of the intentional use of these urban spaces for their value and to understand the main drivers. We retrieved the total number of observations obtained across a set of 672 European cities and focused on reporting from mapped green areas and forests. We used two separate multivariate explanatory models to investigate which factors explained variations in the number of observations for green areas and forests. We found a relatively heterogeneous use of these two urban green spaces. Gross domestic product was important in explaining the number of visits. Availability and accessibility also had positive relationships with the use of green areas and forests in cities, respectively. This study paves the way for better integration of citizen science data in assessing cultural services provided by urban green infrastructure and therefore in supporting the evaluation of spatial planning policies for the sustainable development of urban areas.
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•Forest multi-taxon studies have similar aims but different sampling protocols.•The most sampled taxonomic groups are plants, beetles, lichens, birds, fungi.•Soil, litter and canopy ...resulted as undersampled forest habitats.•Sampling units and substrates differed widely within and among taxonomic groups.•Sampling methods for stand structure were relatively homogeneous.
Forests host most terrestrial biodiversity and their sustainable management is crucial to halt biodiversity loss. Although scientific evidence indicates that sustainable forest management (SFM) should be assessed by monitoring multi-taxon biodiversity, most current SFM criteria and indicators account only for trees or consider indirect biodiversity proxies. Several projects performed multi-taxon sampling to investigate the effects of forest management on biodiversity, but the large variability of their sampling approaches hampers the identification of general trends, and limits broad-scale inference for designing SFM. Here we address the need of common sampling protocols for forest structure and multi-taxon biodiversity to be used at broad spatial scales. We established a network of researchers involved in 41 projects on forest multi-taxon biodiversity across 13 European countries. The network data structure comprised the assessment of at least three taxa, and the measurement of forest stand structure in the same plots or stands. We mapped the sampling approaches to multi-taxon biodiversity, standing trees and deadwood, and used this overview to provide operational answers to two simple, yet crucial, questions: what to sample? How to sample? The most commonly sampled taxonomic groups are vascular plants (83% of datasets), beetles (80%), lichens (66%), birds (66%), fungi (61%), bryophytes (49%). They cover different forest structures and habitats, with a limited focus on soil, litter and forest canopy. Notwithstanding the common goal of assessing forest management effects on biodiversity, sampling approaches differed widely within and among taxonomic groups. Differences derive from sampling units (plots size, use of stand vs. plot scale), and from the focus on different substrates or functional groups of organisms. Sampling methods for standing trees and lying deadwood were relatively homogeneous and focused on volume calculations, but with a great variability in sampling units and diameter thresholds. We developed a handbook of sampling methods (SI 3) aimed at the greatest possible comparability across taxonomic groups and studies as a basis for European-wide biodiversity monitoring programs, robust understanding of biodiversity response to forest structure and management, and the identification of direct indicators of SFM.
The present landscape structure and function is the result of centuries of changes produced both by natural processes and human driving forces. For centuries many mountain and hillside areas have ...been the subject of deforestation to create space for agriculture and grazing, although the abandonment of traditional mountain agriculture has produced a natural forest recovery in many regions of the world. The physical changes imposed on the landscape by the development of secondary woodland have brought both positive and negative consequences, depending on the geographical and economic context and on the scale of the sites. Among the ecological problems caused by natural reforestation, one of great interest is the reduction of open spaces resulting in a loss of landscape heterogeneity and mosaic features. This review paper focused its attention on landscape metrics or indices that are frequently used to assess the structural characteristics of the landscape and to monitor changes in land use: mean patch size (MPS), connectivity (CONN), boundary length (BL) and the patch number (NP). Through the analysis of 52 selected papers and 53 case studies, we identified the main gaps in current knowledge, providing directions for further research. Most of the reviewed studies focused only on a portion of the spatial attributes that we were interested in and only 32 case studies reported accurate data both on forest expansion rate and time range analyzed in the study area. We conclude that the study of changes in all the spatial attributes considered within the same case study is a key to explain ecological consequences in mosaic cycles or in stochastic dynamic landscapes that emerged from the interplay of several processes, and to predict and explain their spatial and temporal characteristics. The current knowledge of how changing spatial attributes affect biodiversity, habitats, and ecosystem functions is limited by the scarcity of studies that explicitly consider the shifting in time of the four spatial attributes together.
On 1 January 2015 a new European regulation on invasive alien species entered in force. Key aspects of this regulation are the adoption of a list of invasive alien species which are of European Union ...concern, the requirement for specific prevention measures, the establishment of early detection and fast eradication measures, and the management of the widely spread invasive alien species. We highlight the potential contribution of the forestry sector to promote the implementation of this regulation. There is a wealth of experience on positive and negative responses of invasive alien species to forestry interventions. This knowledge should be synthesized and further developed to help prevent and manage invasions in forests and adjacent habitats and to minimize the risks of invasive alien species. We thus recommend that decisions regarding the application of the regulation will include actors responsible for, or involved in, the management and use of forests and related semi-natural habitats.
The
maggenghi
are mid slope meadows typical of all the southern and of great parts of the northern European Alps, for centuries managed with traditional and low intensity techniques. Usually, they ...are scattered patches in surrounding forests. The spontaneous expansion of trees and shrubs, favored by the recent decline of mountain agriculture, lead the
maggengo
patches patterns and shapes to change. Our objective was to analyze the effect of this change on current plant diversity of the remnant patches, as the adaptive response could be slow and possibly related more to historical than to current landscape patterns. We analyzed the trend of the size, shape, elongation, fractal dimension and connectivity of
maggengo
patches of a Central-Eastern Italian Alpine district, in four time steps, from 1973 to 2006, and in 1859, when mountain agriculture was still widespread. Then, we studied the relationships between those landscape metrics and two current patch-level plant diversity measures: interior species richness and species density. Aerial photographs were used to investigate that trend, while a historical cadastral map was used to assess the landscape metrics in 1859. As expected, in the last 30 years, the total size of
maggenghi
has been reduced by 57% while their shapes have been progressively simplified. Interior species richness was positively related to size, both in 2006 and over the past 30 years, but not to any 1859 measures. Conversely, species density was positively correlated only with 1859 size, shape index and connectivity. We conclude that the historical shape, size and connectivity are some of the key variables affecting the plant species density of
maggengo
patches, but not of their interior plant species richness.
Capacity development is essential for the effective management of protected areas and for achieving successful biodiversity conservation. European Natura 2000 sites form an extensive network of ...protected areas and developing the capacity of staff at all levels is a priority that will positively influence the appropriate implementation of conservation actions. In this study we identify the main challenges and potential solutions to developing the skills, knowledge and tools required for effective Natura 2000 site management. Our findings are based on a case study of the European project LIFE e-Natura2000.edu, which focuses on capacity development in practical biodiversity conservation and management through integrated and blended learning experiences (i.e. a combination of face-to-face and virtual teaching). We illustrate the main elements for successfully building capacity within a variety of knowledge and experience backgrounds and operating levels related to the management of Natura 2000 sites. Multifaceted, blended learning approaches are key to tackling the various needs of Natura 2000 managers in terms of skills, knowledge and tools.
Agro-pastoral decline in European mountain areas has recently caused changes to traditional landscapes with negative consequences on semi-natural grassland conservation and the associated ...biodiversity and ecosystem services. In the Italian Alps, grassland patches enclosed in a forest matrix are progressively disappearing. Two alpine valleys (Pesio and Pejo), having similar land-use history, were chosen as representative of management conditions of western and eastern Italian Alps, respectively. This study aims at interpreting the effect of abandonment on grassland patch plant diversity, considering land cover changes of the last 60 years, and assessing the role of ecological, topographic, management and landscape configuration on current grassland species richness. The total area of grassland patches has declined by 54 and 91 % at Pesio and at Pejo, respectively. Actual grassland patch species richness was mostly influenced by ecological factors, such as quantity of light, soil moisture and reaction, then by topographic features, especially slope, and finally by management intensity. Landscape factors exerted a slightly significant effect on plant diversity. In the two valleys, differences on management practices were detected. Even though in the western valley the conservation of several grazing activities contributed to slow down the process of patch reduction, many species-rich grasslands were generally under-grazed. Conversely, in the eastern valley, despite a denser road network, the stronger decline of grassland patch extension was linked to the hay making decline. At the same time, overuse of grassland patches near farms reduced plant species richness. As a conclusion, plant species richness was weakly related to the area of grassland patches and current and historical landscape configuration were of relatively lower importance than ecological, topographic and management factors, when evaluated at patch-level.
•Spontaneous woodlands support a range of social, cultural and ecological services.•Italian urban plans are deficient in spontaneous urban woodlands consideration.•Recognition of spontaneous ...woodlands recognition in urban plans can support regeneration strategies.•Citizens are pivotal to maintain and value spontaneous urban woodlands.
Urban forests have manifold social, economic, cultural and ecological benefits and are major components of the urban green infrastructure. Among them, spontaneous urban woodlands develop unintentionally on abandoned lands in both growing and shrinking cities and deserve additional attention. We aimed to describe the planning and social processes linked to failures and successes in recognising spontaneous woodlands in Italy. We collected data on the woodland area characteristics, urban settings, and former land use as well as on the planning and property evolution (e.g. land use zone designations) and citizens involvement for 19 sites in 13 representative Italian cities. Our results highlighted that spontaneous woodlands are heterogeneous in size and age, and grow on a variety of previous land uses, with residential and industrial being the most dominant. More than half of the urban plans designated land uses that require new soil sealing and tree plantations instead of maintaining the existing woodlands. Only in four case studies, urban plans recognised the spontaneous woodland, at least partially, as an element of the city’s green infrastructure. We pinpoint an overall deficiency of the planning process in considering spontaneous urban woodlands, although with some exceptions that can represent models for future planning. The role of citizens seemed pivotal, even if not necessarily decisive, in the promotion and maintenance of these woodlands as a real social and ecological asset. A complex and modern array of approaches should capitalise on the potential benefits of spontaneous urban woodlands with the participation of citizens as a strong element of governance.
The ongoing biodiversity crisis necessitates greater efforts to ensure the adequate conservation of critical habitat types. Even though the identification of protected areas is still required in ...Europe, conservation efforts are now focusing on management requirements for protected areas and habitat types. Establishing effective management approaches is important for the conservation of the natural and semi-natural habitat types that are identified under the Habitats Directive framework. In this study, we propose a methodology for determining priorities in the conservation management of habitat types based on readily available data. This method relies on four simple criteria to rank habitat types, which includes: conservation condition, biodiversity value, pressure factor, and the cover relevance of habitat types (indicating regional responsibility in terms of area covered). After ranking the habitat types based on the sum of the scores given to all of the criteria, the 25% top-ranking habitat types were prioritized. The pressure factors are analyzed using cluster analysis to better convey information regarding the management needs of groups of habitat types. This prioritization method was tested in habitat types occurring within the Italian Alpine and Continental biogeographical regions. From this analysis, forests, bogs and fens, and dry grasslands were identified as conservation priorities for the Alpine region; meanwhile, a wider variety of habitat types were identified for the Continental region. Important pressure factors were identified (e.g., roads and motorways) for these two biogeographical regions of Italy, which could be used to suggest specific conservation measures. The proposed approach represents a transparent and reliable method for outlining habitat-type priorities based on conservation, biodiversity, pressure, and cover factors, which can be applied to identifying conservation measures that can help achieve biodiversity targets.
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