Urban greenspace provides important conservation, climatic and social benefits. The importance of greenspace is reflected in its inclusion in global initiatives such as the Kunming Montral Global Biodiversity Framework, which includes a target to increase the area of cities that is classified as greenspace. Zoological collections are increasingly recognised as multifunctional greenspaces, but their contribution to greenspace has not been examined in spatially explicit terms. Here we digitised the boundaries of 208 European zoological collections across 163 Functional Urban Areas to assess the proportion of functional urban areas that are covered by zoos. Using the Urban Atlas, we also assess the proportion of green urban areas within functional urban areas that are covered by zoos and seek to understand how zoos are classified in land use/land cover data. We demonstrate that on average, zoos occupy a small proportion of functional urban areas and identify geographic variation that is likely driven by the historical development of zoos in these countries. A larger, but still small proportion of green urban areas within functional urban areas are covered by zoos. As individual greenspaces, zoos are on average significantly larger than other individual green urban areas. Whilst these findings suggest a limited spatial contribution to greenspace, zoos may make a disproportionate functional contribution through their conservation, education and wellbeing roles. Inconsistencies in how zoos are classified in land use/land cover data were identified. Whilst the mixed classes seen most frequently reflect true heterogeneity in zoo landscapes, they contradict established definitions and mapping guidelines, which has implications for effective monitoring of progress towards global biodiversity targets.
Urban karst forests are biodiversity-rich but environmentally fragile ecosystems that are increasingly fragmented into isolated remnants by rapid urbanization. In such constrained landscapes, habitat size may reshape biodiversity through changes in vertical vegetation stratification, yet layer-specific responses remain poorly resolved. We investigated how habitat size influences vegetation structure and plant diversity across tree, shrub, and herb layers in Guiyang City, China. Using high-resolution satellite imagery and field surveys across 12 remnant karst mountains categorized as small (< 5 ha), medium (5–10 ha), and large (> 10 ha), we quantified vegetation coverage, vertical stratification, and plant diversity within 326 nested plots. Mountain size influenced vegetation structure, although the magnitude of the response differed among vegetation layers. Relative to small remnants, large remnants supported higher understory diversity: herb-layer richness increased by 24.3
Urban riparian zones are critical for maintaining biodiversity in highly urbanized landscapes, particularly during winter when environmental constraints intensify. However, scale-dependent effects of environmental factors on bird community structure and species composition remain poorly understood. Bird communities in urban streams were investigated during the wintering season in Pyeongtaek, South Korea, through surveys conducted at 20 sites from October 2025 to February 2026. Communities were analyzed by migratory status (resident vs. migratory) and habitat association (waterbirds vs. terrestrial birds). Environmental variables were quantified at local (100–200 m) and landscape (500–1000 m) scales. Generalized linear mixed models were used to assess community-level responses, while redundancy analysis was used to examine species-level patterns. Optimal spatial scales were 150–200 m at the local level and 500 m at the landscape level. Riparian complexity was the dominant local gradient, while water resources and urbanization intensity structured landscape patterns. Redundancy analysis showed group-specific reorganization of species composition. Resident and terrestrial birds were associated with riparian complexity and water resources, reflecting dependence on structurally complex habitats. In contrast, migratory birds and waterbirds showed contrasting responses, with some species (e.g., Eurasian Teal, Eurasian Coot) linked to urbanized environments, whereas others (e.g., Mallard, Common Merganser) preferred less disturbed habitats. These results highlight scale-dependent and species-specific responses of urban bird communities, emphasizing the need for multi-scale conservation strategies that integrate habitat complexity, resource availability, and reduced urban disturbance.
Accurate measurements of individual-tree structure and its aboveground biomass (AGB) are critical for urban forest management andcarbon accounting. We evaluated the potential of backpack laser scanning (BLS) for non-destructive woody AGB estimation of urban street trees in Qingdao, China. Diameter at breast height (DBH) and tree height derived from BLS were validated against field measurements for 2259 trees representing 15 species. Three leaf-wood separation algorithms (LeWoS, SSSC, and GBS) were compared visually, and the resulting woody point clouds were used to construct TreeQSM models. Tree volume was converted to AGB using published species-specific wood densities. BLS-derived DBH agreed closely with field measurements (R2 = 0.99; RMSE = 1.57 cm), whereas tree height estimates were less precise (R2= 0.89; RMSE = 1.18 m), particularly for conifers. The visual comparison suggested that LeWoS produced the most continuous woody structures, but no quantitative classification reference was available. Destructive-harvest validation showed strongly species-dependent AGB performance. Agreement was high for Ginkgo biloba (CCC = 0.97; rRMSE = 6.73
Exotic species can interact positively or negatively with other exotic species. The patches of original vegetation immersed within some urban centers may be vulnerable to invasion by exotic species, which may compromise the value of these urban ecological reserves for the conservation of native biodiversity. We used four years of data to examine potential spatial interactions between different exotic plant and animal species, employing two-species, multi-season occupancy models in an ecological reserve immersed within a megacity. We tested the hypothesis that the human activities taking place in the urbanized areas that surround the reserve should promote spatial co-occurrence (aggregation). Conversely, the conservation areas may represent biotic barriers for exotic species and, hence, antagonistic processes (lack of co-occurrence) should occur in these areas. We detected 10 positive and two negative spatial interactions. Eucalyptus camaldulensis, Schinus molle, and Passer domesticus were the species that had the greatest influence on other exotic species. All spatial interactions between animal species were positive. Many of the observed spatial interactions occurred during the warm-dry season. We did not find evidence supporting the hypothesis that aggregation should occur in the periphery of the reserve where humans provide resources to exotic species. In addition, we did not detect negative spatial associations between exotic species in the conservation areas. Given the potential synergistic effects that may result from the observed co-occurrence between distinct exotic species, we emphasize the importance of their early detection and management to prevent facilitation processes between them that could increase their spread within urban reserves.
Street greenery is an important component of urban green infrastructure. However, existing studies have mostly focused on single cities, lacking systematic cross-city comparisons, which limits understanding of spatial differences and patterns of street greenery. Therefore, this study constructs a multidimensional evaluation framework based on street view imagery and road network data, incorporating the Green View Index (GVI), road betweenness, and greenery variability to quantify street greenery equity across cities. Following this, three cities with distinct differences in scale and spatial structure—Nanjing, Suzhou, and Huai’an—are selected for comparative analysis. The results show that: (1) GVI differs significantly among the three cities, with Huai’an highest and Nanjing and Suzhou similar; (2) after incorporating road betweenness, the degree of greenery inequality decreases in all three cities, indicating that highly trafficked roads tend to have better greenery provision; (3) the comprehensive evaluation reveals that Nanjing has a moderate level of greenery but relatively high inequality, Suzhou demonstrates a more balanced distribution, and Huai’an is characterized by both high greenery levels and high variability. From a cross-city comparative perspective, this study provides a methodological reference for evaluating the equity of street greenery across cities.
Urban agriculture is expanding rapidly in densely populated cities, yet the ecological functioning of rooftop soils relative to ground-level gardens remains poorly understood. We evaluated soil carbon and nitrogen cycling, microbial activity, and broad microbial community structure in five urban gardens in Mexico City (three ground-level, GL, and two rooftop, RT), sampled in the dry and wet seasons, established either on ground-level soils or on rooftop substrates. We hypothesized that shared management would promote functional convergence across systems, while differences in substrate origin would maintain distinct microbial communities. Univariate analyses revealed few differences between garden types in microbial biomass, enzyme activities, and several soil chemical properties. However, multivariate analyses showed that seasonality and its interaction with establishment condition—rather than garden type per se—were the dominant factors structuring soil biogeochemical space. In design-aware PERMANOVA, season (R² = 0.13, p < 0.001) and the condition × season interaction (R² = 0.07, p = 0.007) were significant, whereas establishment condition tested at the garden level was not (R² = 0.16, p = 0.70), indicating partial functional convergence rather than full equivalence. Seasonality strongly reorganized soil functioning: moisture, pH, ammonium, and enzyme activities exhibited pronounced seasonal shifts, and redundancy analysis (adjusted R² = 0.21, p = 0.002) identified moisture (p = 0.002) and pH (p = 0.021) as the dominant drivers of microbial functional patterns. Microbial biomass pools were comparatively stable, whereas process-related traits and fungal guild composition were more responsive. Whole-cell fatty acid profiles obtained in the wet season showed similar total bacterial and fungal biomass across systems and no overall difference in guild composition (PERMANOVA p = 0.50); nevertheless, the arbuscular mycorrhizal-to-saprotrophic fungi ratio was lower in rooftop gardens (p = 0.026), a guild-specific signal consistent with persistent soil legacy effects. Overall, rooftop gardens sustained much of the microbial and biogeochemical functioning observed in ground-level soils, yet their functioning was reorganized seasonally and retained a guild-specific mycorrhizal legacy. These findings indicate that rooftop agriculture can support soil functioning broadly comparable to that of ground-level gardens, shaped by the interaction of design, management, legacy, and seasonal forcing, and highlight the need to evaluate both functional convergence and compositional differentiation when assessing the ecological potential of urban agriculture.
Seaports are major gateways for the introduction of exotic species, such as the brown rat (Rattus norvegicus) and roof rat (Rattus rattus) whose global distribution has been largely facilitated by maritime transport. Despite their long-standing association with humans and their widespread presence in cities, the spatial ecology of these species in urban environments, particularly under sympatric conditions, remains poorly understood. This study analyzed movement patterns and space use of rats within a port area of Buenos Aires City, Argentina using two low-cost and easy-to-implement field techniques: spool-and-line devices and the biomarker Rhodamine B. Movement metrics along with activity area overlap and environmental element selection were assessed with the spool-and-line technique, using generalized linear mixed models. Results show that R. norvegicus and R. rattus traveled similar distances and covered comparable daily minimum activity areas; however, R. rattus exhibited more sinuous paths throughout the study area. Daily minimum activity area size was positively associated with body length and higher herbaceous vegetation cover. Both species used the same environmental elements for movement, selecting those that could provide food or protection. In areas where interspecific activity areas overlap, R. rattus frequently used elevated strata, while R. norvegicus remained at ground level. The Rhodamine B biomarker allowed for the estimation of movement distances without the need to release rats, proving to be a viable alternative for studying their movements. Understanding how these species use their environment is essential for improving evidence-based management and control strategies.
The green belt of the Seoul Metropolitan Area (SMA) has been gradually damaged by human activities, even though it provides ecosystem services and is crucial for inhibiting indiscriminate urban expansion. Since the function of this green belt as a habitat for wildlife has been affected, it is necessary to establish a systematic restoration strategy. Therefore, this study identified 910 degraded areas by comparing and analyzing the 2001 and 2024 land cover maps to evaluate changes in cumulative and normalized current flow before and after simulated restoration, using circuit theory-based landscape connectivity analysis. The simulation indicated a substantial increase in mean CCF within the degraded patches (a 79.52
Citizen science (CS) is increasingly used for urban biodiversity research. It exploits digital opportunistic-open-data-collection platforms such as iNaturalist that enable broad participation. However, the relative contributions of expert-led initiatives compared to observations collected outside organised events remain insufficiently explored. This locally grounded exploratory case study examined the contribution of these two approaches in the framework of the Siena BiodiverCity (SBC) project. By analysing biodiversity observations recorded in Siena (Italy) until June 2024, we distinguished observations associated with expert-led activities (e.g. BioBlitzes, workshops) and observations recorded outside the corresponding event windows. Participants were further classified as engaged users (active beyond events), event-dependent users (active only during guided initiatives) and occasional users (contributing independently). Taxonomic patterns were compared, as well as SBC data with those from the Global Biodiversity Information Facility (GBIF). Expert-led initiatives generated the largest share of records and were associated with a higher representation of less frequently recorded groups such as fungi, molluscs and arachnids. However, only a minority of participants remained active after events, and many limited their contributions to the duration of the guided initiatives. Occasional users added a substantial body of biodiversity data, showing the complementary value of occasional CS alongside expert-led events. Many occasional users were classified as probable visitors using an activity-based criterion, although this classification should be interpreted cautiously in a mainland context. SBC also contributed to the GBIF dataset for Siena: iNaturalist-based records from Siena increased thanks to the project and hundreds of species were documented for the first time in GBIF for the Siena municipality through expert-led initiatives. These findings highlight the dual importance of expert-led and occasional CS in urban biodiversity documentation. Future work should combine structured events with strategies aimed at supporting longer-term participation, while also investigating the possible contribution of visitor-generated observations.
Urbanization is widely recognized as a major driver of biodiversity loss, yet its effects on the trophic structure of reptile communities remain poorly understood. This study re-analysed reptile presence–absence data from urban green-space fragments in Rome, Italy, to examine how urban habitat simplification affects the snake component and the trophic and functional structure of reptile assemblages. Fifteen reptile species were classified into functional and trophic groups, and several assemblage metrics were evaluated, including snake richness, lizard and gecko richness, trophic complexity, community trophic index, and dominance of urban-tolerant species. These metrics were related to fragment size, woodland cover, wetland presence, connectivity, and distance from the city centre. Results revealed a sharp, data-supported transition in snake occurrence across the woodland-cover gradient. Small fragments with limited woodland cover were dominated by urban-tolerant lizards and geckos, while snakes were largely absent. In contrast, larger and more structurally complex fragments retained diverse snake assemblages, particularly where wetlands were present. Woodland cover and wetlands were the strongest predictors of snake richness, whereas snake occurrence was best explained by total fragment size and wetland presence. Additional sensitivity analyses showed that the main pattern was robust to the exclusion of empty fragments and to alternative trophic-scoring schemes, although the strength of the trophic-complexity signal was reduced under the most conservative classification. Overall, our results suggest that urbanization-related habitat simplification is associated with taxon-linked trophic and functional simplification: small fragments retain some urban-tolerant lizards and geckos, but largely lose the snake component of the assemblage. These findings indicate that reptile assemblages can provide useful information on functional erosion in urban landscapes, while also emphasizing that trophic position, taxonomic affiliation and habitat-use traits may be difficult to disentangle in small vertebrate assemblages.
The accelerated loss of biodiversity is one of the major concerns for conservation actions. In Colombia, much of the urban and cultivated areas are concentrated in the Andean region, a global biodiversity hotspot that retains less than 15
As a core component of socio-ecological systems, blue-green space (BGS) plays a key role in enhancing regional resilience and informing planning for sustainable socio-ecological transformation. However, the relationship between BGS and regional resilience has not yet been systematically examined. To address this gap, this study develops a social-ecological analytical framework and, following the PRISMA guidelines, reviews literature retrieved from the Web of Science database to examine how BGS contributes to regional resilience through ecological and social mechanisms. The findings show that BGS enhances ecological resilience through habitat provision and biodiversity support, climate regulation and heat mitigation, stormwater regulation, and disaster risk reduction. It also promotes social resilience by supporting public health, strengthening risk perception and environmental awareness, facilitating social interaction and community cohesion, and contributing to livelihood support and regional coordination. These ecological and social mechanisms are not independent but are closely interdependent and mutually reinforcing. The review further reveals that the resilience effects of BGS are spatially differentiated. In urban contexts, BGS is more closely associated with heat mitigation, stormwater management, accessibility, and environmental justice. In rural contexts, it is more strongly linked to ecological continuity, agricultural adaptation, livelihood resilience, and community-based participation. Existing studies remain largely urban-centered, with relatively limited attention to biodiversity conservation, livelihood transformation, and social-ecological feedbacks in rural and peri-urban areas. This study contributes to the literature on regional resilience by integrating ecological and social mechanisms into a unified analytical framework and by highlighting urban-rural context as a key factor shaping the pathways through which BGS contributes to resilience.
Rapid urbanisation and the expansion of impervious surfaces are increasing pressure on urban green infrastructure (UGI), potentially reducing its capacity to provide regulating ecosystem services (RES) and contributing to socio-ecological inequalities. This study integrates biophysical structure, participatory mapping and population exposure to examine the spatial relationships between UGI availability, perceived RES provision and ecosystem disservices in Bucharest, Romania. Urban vegetation structure and RES potential were assessed using i-Tree Canopy, while citizens’ perceptions were collected through a Public Participation Geographic Information System survey involving 816 respondents. Spatial hotspot analysis, Random Forest and regression models were combined with a population-UGI classification to identify socio-ecological mismatches between existing green infrastructure, population pressure and perceived RES provision. Tree canopy covered approximately 18
Urbanization exposes biodiversity to multiple, spatially heterogeneous environmental pressures, and pollinators provide informative models for evaluating these effects. We conducted a bibliometric and systematic review of 200 studies published between 2006 and 2024 to examine how urbanization affects pollinators, the response patterns reported, and persistent knowledge gaps. To provide a structured synthesis, we classified 328 environmental predictors into five non-exclusive, mechanistically informed dimensions—habitat loss and fragmentation (D1), resource modification (D2), thermal and abiotic stress (D3), biotic pressure (D4), and chemical contamination (D5)—and examined whether the consistency of reported responses differed among dimensions across 2,233 predictor–response relationships. D1 comprised 66.6
Urban trees provide vital ecosystem services in cities, including temperature regulation, air purification and climate adaptation. However, their growth is increasingly threatened by changing climate and air pollution. This study investigated the long-term effects of climate variability and air pollutants on radial growth of two commonly planted tropical tree species (Swietenia macrophylla and Samanea saman) in Sylhet City, a rapidly urbanizing area in northeastern Bangladesh. Using the dendrochronological approach, we developed tree-ring chronologies for both species and assessed correlations with precipitation, temperature, and air pollutants — particulate matter (PM₂.₅ and PM₁₀), Nitrogen oxide (NOₓ) and Ozone (O₃). Both species responded positively to monsoonal precipitation, highlighting the importance of seasonal water availability on tree growth. Conversely, the rising mean temperature significantly reduced radial growth in both species, particularly in April (S. macrophylla: r = -0.35, p = 0.02; S. saman: r = -0.33, p = 0.03) and June (S. macrophylla: r = -0.39, p = 0.01; S. saman: r = -0.42, p = 0.005). Among the pollutants, PM2.5 and O3 were associated with reduced growth in both species during February and January, respectively. These findings revealed that rising temperatures and high pollutant concentrations negatively influence tree growth in Sylhet City. Tree rings of both species can be used as a biomonitoring tool for tracking urban environmental change. Our study highlights the importance of climate-resilient and pollution-tolerant species selection to ensure sustainable urban forestry in tropical cities.
Urban environments vary widely in their physical and ecological characteristics, yet understanding of urban biodiversity remains limited by uneven coverage of variables known to shape urban plant and animal communities. Building on and updating a global systematic review of urban biodiversity (Rega-Brodsky et al. 2022), this study synthesized 675 peer-reviewed publications reporting diversity trends of 12 taxonomic groups in cities across the United States to identify geographic (i.e., state, city), urban intensity (i.e., metropolitan and micropolitan core-based statistical areas), ecoregional, and taxonomic trends in the literature. Each study was classified by its corresponding core-based statistical area and ecoregion to assess spatial and taxonomic representation across urban systems. Results revealed that urban biodiversity research in the United States was heavily concentrated in a few major metropolitan regions (e.g., Chicago, Phoenix), with extensive gaps across the northern Intermountain West and Great Plains. Only 5
Urban areas are among the places where the effects of global climate change are felt most strongly. Therefore, nature-based solutions have become increasingly important for climate adaptation. This study aims to assess the Urban Cooling Effect Values (UCEV) of commonly used urban trees with different textures, ground-cover shrubs, and paving materials. Temperature measurements were carried out from the shade of 16 tree species, over 17 ground cover shrub species, and from the surface of 17 paving materials frequently used in urban open green spaces in Bursa during July–September 2024 and April–October 2025. A thermal camera and an anemometer were used for data collection, and relative humidity, wind speed, and air temperature for the study area conditions. The data were analyzed using SPSS software through normality, variance, and correlation analyses. Statistical evaluations were conducted separately for the overall period (April–October) and the summer months (June–August). The results show that, compared to the control group (open-area grass surfaces), Salix babylonica (4.39 °C) had the highest UCEV among tree species, while Albizia julibrissin (2.16 °C) had the lowest. During summer, Salix babylonica (4.88 °C) and Tilia tomentosa (4.78 °C) showed the highest cooling effect, whereas Tamarix tetrandra (0.25 °C) again exhibited the lowest values. No significant differences were observed among texture classes during the April–October period; however, in summer period, coarse- and medium-textured plants showed stronger cooling effects than fine-textured species. Among the shrub species, Euryops pectinatus exhibited the highest UCEV across all reference surfaces during the April–October period. The lowest UCEV was recorded for Festuca glauca relative to the grass reference surface (0.51 °C), whereas Abelia × grandiflora exhibited the lowest UCEV relative to the hardscape (14.14 °C) and soil (20.14 °C) reference surfaces. During the summer period, Euryops pectinatus again showed the highest UCEV relative to the grass reference surface (6.92 °C), while Euonymus fortunei exhibited the lowest UCEV relative to the grass (0.83 °C), hardscape (15.93 °C), and soil (24.92 °C) reference surfaces. Based on measurements conducted on paving materials, with soil as the control surface, water surfaces (16.72 °C) and grass areas (13.32 °C) exhibited the highest cooling effects, whereas rubber (− 18.22 °C) and artificial grass (− 15.66 °C) showed the lowest. These findings provide a basis for informed plant and material selection in climate-sensitive urban landscape design.
Urban green spaces (UGS) provide important ecological, social, and climatic functions, but their effectiveness depends not only on their extent but also on their vertical vegetation structure. To this end, we present a high-resolution urban green space typology (UGST) for four Swiss cities (Basel, Bern, Geneva, and Zurich) derived from remotely sensed thematic (NDVI) and structural (vegetation height and VCI) data, comprising 33 classes. The structural heterogeneity of the vegetation cover was consistently bimodal, with low-complexity vegetation (grass) or tall, high-complexity wooded areas dominating, while intermediate structures were underrepresented. The UGST was used to assess species richness across five taxonomic groups and a multidiversity score (mean normalized richness across all groups) using GAMs under varying thematic resolutions. Results indicated taxon-specific, generally non-linear associations between normalized recorded species richness or multidiversity and the individual component scores or percentage cover of several UGST classes. The fine-grained joint models had higher in-sample deviance and explained more variance compared to highly aggregated-class and total-green-cover formulations, although the formulations differed in complexity and were not evaluated out of sample.
Butterflies are widely regarded as sensitive indicators of ecosystem health, so their declining populations in urban areas are a cause for concern. This study documented butterfly species and butterfly–plant associations across five green spaces in the Bangkok Metropolitan Region, Thailand (Bang Kachao, Bang Ramat, Benjakitti Park, Phutthamonthon Park, and Suan Rot Fai Park). Butterfly observations were collected opportunistically along public walking paths from 2020–2025, primarily included larvae and adults. The butterfly species and their associated host plants were recorded. Because sampling intensity was uneven among sites, pooled data were used to describe the regional butterfly–plant community. Bipartite interaction networks were constructed for pooled data that included: a network with combined adults and larvae, an adult butterfly-plant network, and a larval butterfly-plant network. Across all sites, 83 butterfly species from five families were recorded from 484 observations on 50 plant species and 23 plant families. When analyzing the networks by life stage, the adult network exhibited 2.5 times more unique interaction links, with 1.7 times more butterfly species and 1.6 times more host plant species included. In contrast, the larval network showed 1.5 times higher specialization compared to the adult network, indicating a rigid dependency on specific host taxa during the larval stage. These results serve as a baseline for comprehending the structure of butterfly-plant interactions within the Bangkok Metropolitan Region. They also offer valuable insights into the urban management implications for urban planning and the design of biodiversity-friendly green infrastructure, which can enhance ecosystem functions and services in tropical cities.
