Abstract Questions: Does the soil seed bank resemble the former early successional stages of a dune slack system more than the established later successional vegetation? Does it have the potential to contribute to the conservation of a highly endangered habitat? Location: Dune slacks at Newborough Warren, UK. Methods: The composition of the soil seed bank in two depth layers was determined using the seedling emergence method between March 2004 and April 2005. Long‐term monitoring data on the floristic composition of the established vegetation were obtained from the national conservation agency, and additional monitoring was undertaken in 2003. Floristic composition, seed weights, seed longevity of component species and Ellenberg indicator values were used to compare the seed bank and established vegetation. Results: The soil seed bank was diverse and contained typical dune slack species, species of early successional stages and species of conservation interest. A comparison between the composition of the seed bank and historical data on the composition of the established vegetation showed that the seed bank reflects earlier successional stages more closely than the current aboveground vegetation. This study increases the scarce information currently available on the seed bank ecology of several species, including two orchid species. Conclusions: The soil seed bank can be expected to contribute to vegetation change after disturbance. Stimulation of germination from the seed bank through management may contribute to the conservation of both characteristic and threatened species typical of dune slacks.
Urbanisation has led to numerous challenges for human sustenance, which have been aggravated by progressive climate change. Green Infrastructure (GI), which involves working with nature has gained increasing recognition as a multifunctional approach to address urban heat island challenges, including heat mitigation, thermal comfort enhancement, and air pollution reduction. However, it is crucial to establish the multi-benefits of GI in the early stages of the design process to effectively evaluate their impact. Whilst there are scientific studies showing the singular benefit of GI (e.g., heatwave reduction), studies have rarely quantified their multi-benefits. As a result, GI is often undervalued, constituting a barrier to its implementation. This study aims to evaluate the co-benefits of urban parks for reducing the harmful effects of urban heating, improving thermal comfort, and reducing air pollution using mobile monitoring measurements. To achieve this, a comprehensive monitoring campaign was conducted, collecting data inside an urban park and surrounding area to find out the extent of co-benefits provided by urban parks.The data for this study was collected via mobile monitoring along a fixed route during summer. Meteorological parameters and air pollutant levels were measured using a set of different sensors. The study's findings reveal significant benefits provided by the urban park environment. The mean air temperature during morning runs recorded 18.2°C within the park, compared to 19.6°C in the surrounding built-up area, demonstrating a 1.4°C (7.1%) reduction. In the afternoon, the average temperature within the park was 24.6°C, contrasting with 27.0°C in the built-up area, highlighting a 2.4°C (8.9%) decrease. These results underscore the park’s role in mitigating urban heat, especially during the hotter parts of the day. Furthermore, the park environment exhibited lower average particulate matter (PM) levels than the built-up area. PM10 and PM1 levels decreased by 1 µg/m³ (8%) and 0.2 µg/m³ (9.7%) respectively during morning runs, while the afternoon runs showed a 0.6 µg/m³ (13.3%) reduction in average PM2.5 values within the park. Additionally, CO2 levels were reduced by 22 ppm (4.5%) during morning and afternoon runs in the park compared to the built-up area.These findings demonstrate the substantial reduction in air temperature and pollutants, such as CO2 and PM, with increasing distance from the built-up area towards the park. Understanding the interactions within and around urban parks regarding temperature, air pollution gradients, and thermal comfort compared to surrounding built environments is paramount. These insights can inform urban planning and design strategies to create healthier and more sustainable cities, thereby addressing contemporary urban challenges and fostering the well-being of urban populations. 
Urban spatial expansion poses a threat to regional ecosystems and biodiversity directly through altering the size, shape, and interconnectivity of natural landscapes. Monitoring urban spatial expansion using traditional area-based metrics from remote sensing provides a feasible way to quantify this regional ecological stress. However, variation in landscape-adjacency relationships (i.e., the adjacency between individual landscape classes) caused by urban expansion is often overlooked. In this study, a novel edge-based index (landscape-adjacency index, LAdI) was proposed based on the spatial-adjacency relationship between landscape patches to measure the regional ecological stress of urban expansion on natural landscapes. Taking the entire Yangtze River Delta Urban Agglomerations (YRD) as a study area, we applied the LAdI for individual landscape classes (Vi) and landscape level (LV) to quantitatively assess change over time in the ecological stress of YRD from 1990 to 2015 at two spatial scales: municipal scale and 5 km-grid scale. The results showed that the vulnerable zones (LV ≥ 0.6) were mainly distributed in the north of the YRD, and cultivated land was the most vulnerable natural landscape (Vi ≥ 0.6) at the 5 km-grid scale. The most vulnerable landscape at the municipal scale was cultivated land in 19 of 26 cities in each period, and that in the remaining 7 cities varied at distinct urbanization stages. We used scatter diagrams and Pearson correlation analysis to compare the edge-based LAdI with an area-based index (percent of built-up area, PB) and found that: LV and PB had a significant positive correlation at both the municipal scale and 5 km-grid scale. But there were multiple LVs with different values corresponding to one PB with the same value at the 5 km-grid scale. Both indexes could represent the degree of urban expansion; however, the edge-based metric better quantified ecological stress under different urban-sprawl patterns sharing the same percent of built-up area. As changes in land use affect both the size and edge effect among landscape patches, the area-based PB and the edge-based LAdI should be applied together when assessing the ecological stress caused by urbanization.
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An experiment was conducted in a suite of eight Solardome glasshouses program med to provide a factorial combination of two levels of CO, concentrations (ambient and ambient plus 340 ppm) and two levels of temperature (ambient and ambient +3°C) with two replicates for each C02 x temperature combination. Plants were grown in 0.11 m diameter pots made from 1.5m lengths of drainage pipes, filled with washed silica sand and supplied with full strength Long Ashton solution. Combined and independent increases in [CO,J and temperature promoted leaf extension and increased final leaf length, particularly during the early stages of the growing season (July) the absence of any CO, effect on leaf extension later in the season (August) in Dactylis glomerata was possibly due to its large canopy, with leaf extension more closely coupled to canopy microclimate than externally imposed treatments. Elevated C02 concentrations had no significant effect on leaf numbers.Elevated temperature significantly increased leaf production in Helianthemum nummularium (p<0.05), but only in combination with an increase in [CO,] in Plantago lanceolata (p<0.05).Elevated CO, promoted early leaf senescence (p<0.05) with the exception of Poa alpina which was more sensitive to a 3C increase in growth temperature (p<O.O I ). The greater sensitivity of P. alpina to elevated temperature than [CO,] may reflect its alpine habit. • Elevated [CO] increased leaf size but not leaf n umber and promoted early leaf senescence in most species. • There was little evidence of any interaction between elevated [CO2] and temperature on plant canopy development.
Urban Green Infrastructure (GI) provides multiple benefits to city inhabitants and can be an important component in nature-based solutions (NBS), but the ecosystem services that underpin those benefits are inconsistently quantified in the literature. There remain substantial knowledge gaps about the level of service supported by less studied GI types, e.g. cemeteries, or less-studied ecosystem services, e.g. noise mitigation. Decision-makers and planners in cities often face conflicting or incomplete information on the effectiveness of GI, particularly on their ability to provide a suite of co-benefits. Here, we describe a feature-based typology of GI which combines elements of land cover, land use and both ecological and social function. It is consistent with user requirements on mapping, and with the needs of models which can conduct more detailed ecosystem service assessments which can guide NBS design. We provide an evidence synthesis based on published literature, which scores the ability of each GI type to deliver a suite of ecosystem services. In the multivariate analysis of the typology scores, the main axis of variation differentiates between constructed (or hybrid) GI types designed primarily for water flow management (delivering relatively few services) and more natural green GI with trees, or blue GI such as lakes and the sea, which deliver a more multi-functional set of regulating services. The most multi-functional GI on this axis also score highest for biodiversity. The second element of variation separates those GI which support very few cultural services and those which score highly in enabling physical wellbeing and social interaction and, to a lesser extent, restoring capacities. Together the typology and multi-functionality matrix provide a much needed assessment for less studied GI types, and allow planners and decision-makers to make a-priori assessments of the relative ability of different GI as part of NBS to address urban challenges.
The combined impacts of simulated increased nitrogen (N) deposition (75kgNha−1 yr−1) and increasing background ozone (O3) were studied using two mesotrophic grassland species (Dactylis glomerata and Ranunculus acris) in solardomes, by means of eight O3 treatments ranging from 15.5ppb to 92.7ppb (24h average mean). A–C i curves were constructed for each species to gauge effects on photosynthetic efficiency and capacity, and effects on biomass partitioning were determined after 14 weeks. Increasing the background concentration of O3 reduced the healthy above ground and root biomass of both species, and increased senesced biomass. N fertilisation increased biomass production in D. glomerata, and a significantly greater than additive effect of O3 and N on root biomass was evident. In contrast, R. acris biomass was not affected by high N. The study shows the combined effects of these pollutants have differential implications for carbon allocation patterns in common grassland species.
