Does time spent on visits to green space mediate the associations between the level of residential greenness and mental health?

ObjectiveThe objective of the current study was to explore whether time spent visiting green space near home acts as a mediator in the association between level of residential greenness and perceived mental health.MethodsQuestionnaire data and satellite data of residential greenness were gathered in four European cities (total n = 3748): Barcelona (SP), Doetinchem (NL), Kaunas (LT) and Stoke-on-Trent (UK).ResultsMediation analyses showed that time spent visiting green space near home was a weak, but statistically significant, mediator in the pooled data and in the Dutch sample only.ConclusionsThe findings provide little support for the hypothesis that purposeful visits are a mediator linking indirectly greenness with mental health. More research is needed to explore other mediators related to different exposure pathways, such as visual exposure, and alternative mechanisms, such as (perceived) safety.     

Normalized difference vegetation index (NDVI) as a marker of surrounding greenness in epidemiological studies: The case of Barcelona city

The normalized difference vegetation index (NDVI) is often used as a marker of surrounding greenness in epidemiological studies aiming to evaluate the health effects of green space in urban settings. However, it is not clear the relationship between built environment characteristics, including green space, and NDVI. We aimed to evaluate the relationship between built environment characteristics, based on land-use and land-cover maps, and NDVI as a marker of surrounding greenness in the city of Barcelona. We used data from an already existing cohort of pregnant women in Barcelona (N = 8402). NDVI was derived and averaged within buffers of 100 m and 300 m for each participant, and categories of the built environment (m²) were derived from land-use and land-cover maps of Barcelona. We conducted ANOVA models to calculate the contribution (R²) of each land-use (or land-cover) category. The variability in NDVI in Barcelona was mainly explained by urban green (R² between 0.32 and 0.53) and natural green areas (R² between 0.19 and 0.52), although for the latter less than 4% of the participants were exposed to this. Both land-use and land-cover maps explained NDVI at 300 m better (full models explaining 76% and 78%, respectively) than at 100 m buffers (full models explaining 55% and 54%, respectively). Results of the present study indicate that NDVI can be a useful greenness metric depending on the hypothesis and area of study. However, for certain sizes of study areas (buffers smaller than 100 m), NDVI might have a lower predictive value. Results of the present study should be replicated in studies from other cities with different urban characteristics and climate conditions.     

Responses of four hornet species to levels of urban greenness in Nagoya city,Japan: Implications for ecosystem disservices of urban green spaces

Although there is a common trend towards increasing green space in modern cities, urban green spaces provide not only ecosystem services but also disservices for urban dwellers. However, the relationship between urban greenness and ecosystem disservices has been poorly examined. We aimed to understand the effect of greenness level on the abundance and species composition of hornets – critical pests in Japan and to identify the best spatial scale for estimating their abundance with reference to greenness levels. We used a dataset that contained eight years of abundance data for four hornet species at 11 sites in Nagoya city. The levels of greenness around the hornet sampling points were measured using averages from the Normalized Difference Vegetation Index (NDVI) with radiuses of 0.1–10.0 km. We analysed the relationship between abundance and species composition of hornets and NDVI at different spatial scales using generalized linear mixed models. Higher NDVI values positively affected the abundance of all the hornet species except Vespa analis. The abundances were estimated most effectively using the NDVI average with a 1–2 km radius for all species. The species composition of hornets drastically changed along the gradient of NDVI values; V. mandarinia was dominant in greener areas (over 0.2–0.3 NDVI average with a 2 km radius) and V. analis in less green areas (below 0.2–0.3 NDVI average). Our study showed that the abundance and species composition of hornets were both strongly associated with the level of urban greenness. This suggests that increases in the greenness of urban areas can increase hornet abundance and alter the species composition of hornets; a more aggressive species, V. mandarinia, may also increase in urban areas, although V. analis is currently the most critical species according to regional consultants. Balancing ecosystem services and disservices has become crucial for the planning and management of green spaces, particularly when urban green space increases. We also demonstrate how human tolerance towards wildlife may have to be improved in order to live in greener environment where wildlife can be expected.     

Weather effect on thermal and energy performance of an extensive tropical green roof

This study investigated the weather effect on thermal performance of a retrofitted extensive green roof on a railway station in humid-subtropical Hong Kong. Absolute and relative (reduction magnitude) ambient and surface temperatures recorded for two years were compared amongst antecedent bare roof, green roof, and control bare roof. The impacts of solar radiation, relative humidity, soil moisture and wind speed were explored. The holistic green-roof effect reduced daily maximum tile surface temperature by 5.2 °C and air temperature at 10 cm height by 0.7 °C, with no significant effect at 160 cm. Green-roof passive cooling was enhanced by high solar radiation and low relative humidity typical of sunny summer days. High soil moisture supplemented by irrigation lowered air and vegetation surface temperature, and dampened diurnal temperature fluctuations. High wind speed increased evapotranspiration cooling of green roof, but concurrently cooled bare roof. Heat flux through green roof was also weather-dependent, with less heat gain and more heat loss on sunny days, but notable decline in both attributes on cloudy days. On rainy days, green roof assumed the energy conservation role with slight increase instead of reduction in cooling load. Daily cooling load was 0.9 kWh m^?2 and 0.57 kWh m^?2, respectively for sunny and cloudy summer days, with negligible effect on rainy days. The 484 m² green roof brought potential air-conditioning energy saving of 2.80 × 10⁴ kWh each summer, equivalent to electricity tariff saving of HK$2.56 × 10⁴ and upstream avoidance of CO₂ emission of 27.02 t at the power plant. The long-term environmental and energy benefits could justify the cost of green roof installation on public buildings.     

Plant establishment on a green roof under extreme hot and dry conditions: The importance of leaf succulence in plant selection

Plant selection for extensive green roofs has largely been based on cool, temperate climate research. However, as green roof implementation in hotter and drier climates increases, there is a need to evaluate plant performance under these climatic conditions. Succulents have been shown to be successful in hot and dry green roofs, although survival differs between species and the role of leaf succulence in survival has not been fully explored. For non-succulent plants, habitats with conditions similar to green roofs (‘habitat templates’) have been used to select plants, although few studies have discussed the performance of these selections under green roof conditions. Therefore, we evaluated establishment of 32 plant species on an unirrigated extensive (125 mm deep) green roof in Melbourne, Australia over a 42 week period (from winter through summer into autumn). Plants were selected on the basis of life-form, succulence, appropriate habitat templates and/or successful use on green roofs internationally. Climatic conditions during the experiment were often extreme, with evaporation regularly exceeding rainfall and a hot and dry summer (mean maximum air temperature 35 °C and 80.6 mm total rainfall), leading to roof temperatures of 65 °C. After 42 weeks, only succulent plants remained alive and only three of the succulent species had 100% survival. Survival was positively related to the degree of leaf succulence (g H₂O leaf area cm⁻¹) making this a useful trait for plant selection for unirrigated green roofs in hot, dry climates. The failure of most species, despite being chosen from appropriate habitats, demonstrates the need to evaluate potential plants on green roofs under extreme climatic conditions. Supplementary irrigation may be essential to sustain non-succulent species during extreme weather in hot and dry climates.     

Mapping leaf area of urban greenery using aerial LiDAR and ground-based measurements in Gothenburg,Sweden

Leaf area of urban vegetation is an important ecological characteristic, influencing urban climate through shading and transpiration cooling and air quality through air pollutant deposition. Accurate estimates of leaf area over large areas are fundamental to model such processes. The aim of this study was to explore if an aerial LiDAR dataset acquired to create a high resolution digital terrain model could be used to map effective leaf area index (L_e) and to assess the L_e variation in a high latitude urban area, here represented by the city of Gothenburg, Sweden. L_e was estimated from LiDAR data using a Beer-Lambert law based approach and compared to ground-based measurements with hemispherical photography and the Plant Canopy Analyser LAI-2200. Even though the LiDAR dataset was not optimized for L_e mapping, the comparison with hemispherical photography showed good agreement (r² = 0.72, RMSE = 0.97) for urban parks and woodlands. Leaf area density of single trees, estimated from LiDAR and LAI-2200, did not show as good agreement (r² = 0.53, RMSE = 0.49). L_e in 10 m resolution covering most of Gothenburg municipality ranged from 0 to 14 (0.3% of the values >7) with an average L_e of 3.5 in deciduous forests and 1.2 in urban built-up areas. When L_e was averaged over larger scales there was a high correlation with canopy cover (r² = 0.97 in 1 × 1 km² scale) implying that at this scale L_e is rather homogenous. However, when L_e was averaged only over the vegetated parts, differences in L_e became clear. Detailed study of L_e in seven urban green areas with different amount and type of greenery showed a large variation in L_e, ranging from average L_e of 0.9 in a residential area to 4.1 in an urban woodland. The use of LiDAR data has the potential to considerably increase information of forest structure in the urban environment.     

Variations of urban greenness across urban structural units in Beijing,China

Urban structural units (USUs) are work (or similar) units in urbanized areas. In this study, USUs based on urban land use and land cover were used to explain and compare urban ecological conditions within Beijing. This study focused on the spatial pattern of land use for different USUs in urban areas. The results showed that 453 USUs belong to 12 primary USUs and to 38 different secondary USUs. The percentage of built-up area was highest in those regions with hotels, and lowest in areas with cemeteries. The percentage of woodland area was highest in primary and middle schools, and the lowest in entertainment plazas. The percentage of grassland area was highest in farmland or orchards, and lowest in Siheyuan (courtyards). The percentage of green space is highest in lands dedicated to middle and primary schools, and lowest in areas with museums. There is no significant linear relationship between construction period and green space percentage in Colleges/Universities (R = 0.045, p = 0.806 > 0.05) and Parks (R = 0.13, p = 0.43 > 0.05). However, there was an inverted-U curve relationship with the relevant housing price in the residential area, a relationship that can be described by the equation: f = 17736.45 + 348.21x ? 4.15 x², p = 0.0022 < 0.05. This relationship implied that the socio-economic factors like housing prices may be a factor in determining the green space pattern of urban ecosystems in Beijing.     

Enhancing plant diversity and mitigating BVOC emissions of urban green spaces through the introduction of ornamental tree species

Promoting the plant diversity of urban green spaces is crucial to increase ecosystem services in urban areas. While introducing ornamental plants can enhance the biodiversity of green spaces it risks environmental impacts such as increasing emissions of biogenic volatile organic compounds (BVOCs) that are harmful to air quality and human health. The present study, taking Qingdao City as a case study, evaluated the plant diversity and BVOC emissions of urban green spaces and tried to find out a solution to increase biodiversity while reducing BVOC emissions. Results showed that: (1) the species diversity and phylogenetic diversity of trees in urban green spaces were 22% and 16% lower than rural forest of this region; (2) urban areas had higher BVOC emission intensity (2.6 g C m⁻² yr⁻¹) than their rural surroundings (2.1 g C m⁻² yr⁻¹); (3) introducing the selected 11 tree species will increase 15% and 11% of species diversity and phylogenetic diversity, respectively; and (4) the BVOC emissions from green spaces will more than triple by 2050, but a moderate introduction of the selected low-emitting trees species could reduce 34% of these emissions. The scheme of introducing low-emitting ornamental species leads to a win–win situation and also has implications for the sustainable green space management of other cities.     

Seasonal variations in the cooling effect of urban green areas on surrounding urban areas

We measured air temperature in an urban green area that includes forest and grassland and in the surrounding urban area for a full year in Nagoya, central Japan, to elucidate seasonal variations of the difference in air temperature between urban and green areas. We determined the range of the “cool-island” effect as well as the relationship between vegetation cover and air temperature throughout the year. The temperature difference between urban and green areas was large in summer and small in winter. The maximum air temperature difference was 1.9 °C in July 2007, and the minimum was ?0.3 °C in March 2004. The difference was larger during the day than during the night in summer, whereas in winter the opposite relationship was true. However, winter diurnal variation was not particularly noticeable, a behaviour thought to be related to reduced shading by deciduous trees in the green area. During the night, the cooling effect of the green area reached 200–300  m into the urban area. During the day, the cooling effect between August and October 2006 exceeded 300 m and varied widely, although there was no correlation beyond 500 m. The correlation between air temperature and forest-cover ratio within a radius of 200 m from each measurement site was significant from 16:00 to 19:00. There was also a correlation during the night; this correlation was weakest in the early morning. The effect of the forest-cover ratio on air temperature was most pronounced in August 2006 and June 2007.     

Variations in land surface temperature and cooling efficiency of green space in rapid urbanization: The case of Fuzhou city,China

Rapid urbanization has caused significant land cover change (LCC) as well as changes in the land surface temperature (LST). However, the crucial land dynamic process, which could significantly contribute to the increase in LST and aggravation of the urban heat island (UHI) effect, remains poorly understood. Additionally, a strategy to optimize the most significant decreased land cover type in order to maximize the cooling effect is still lacking. Therefore, in this study, we selected the rapidly urbanizing and ‘hottest’ city in China, Fuzhou, as a case study. Two algorithms were selected to compare and obtain reliable LST data. A land use transfer matrix was used to detect critical contributions leading to the LST variations. The concept of cooling efficiency (CE) and the threshold value of efficiency (TVoE) are also proposed, defined, and calculated. The results show that LST values increased with increasing proportion of built-up land and sharply decreasing proportion of green space. Areas where LST differences exceed 4 °C cover 93% of the areas where green spaces decreased. Additionally, the LST variation is not only associated with the dominant land cover types but is also affected by the land cover transfer pattern and dynamics. Finally, we have calculated the TVoE of green space in Fuzhou city to be 4.55 ± 0.5 ha. This finding implies that when Fuzhou municipality implements urban/landscape planning, a green space area of 4.55 ± 0.5 ha is the most efficient to reduce the heat effect. This study extends the current understanding of LCC dynamics and LST variation. The concepts of the CE and TVoE are meaningful for landscape planning practice and can be used in other cases.     

The influence of small green space type and structure at the street level on urban heat island mitigation

The purpose of this study was to determine the types and structures of small green spaces (SGs) that effectively reduce air temperature in urban blocks. Six highly developed blocks in Seoul, South Korea served as the research sites for this study. Air temperature was measured at the street level with mobile loggers on clear summer days from August to September in 2012. The measurements were repeated three times a day for three days. By analyzing the spatial characteristics, SGs within the six blocks were categorized into the four major types: polygonal, linear, single, and mixed. The result revealed that the polygonal and mixed types of SGs showed simple linear regression at a significant level (p < 0.01). It indicated that the blocks’ urban heat island (UHI) mitigation (ΔT_Rmn) increased in a linear fashion when the area and volume of these two types of green spaces increased. The area and volume of a polygonal SG with mixed vegetation, over 300 m² and 2300 m³, respectively, lowered the ΔT_Rmn by 1 °C; SG with an area and volume of larger than 650 m² and 5000 m³, respectively, lowered the ΔT_Rmn by 2 °C. The results of this study will be useful to urban planners and designers for determine the types and structures of urban green spaces to optimize the cooling effect, as well as how such green spaces should be designed and distributed.     

Carbon sequestration of four urban parks in Rome

Urban parks form the largest proportion of public green spaces contributing to both physical and mental well-being of people living in urban areas. CO₂ sequestration capability of the vegetation developing in parks of four historical residences (Villa Pamphjli, Villa Ada Savoia, Villa Borghese and Villa Torlonia) in Rome and its economic value were analyzed. Villa Pamphjli and Villa Ada Savoia having a larger vegetation extension (165.04 ha and 134.33 ha, respectively), also had a larger total yearly CO₂ sequestration per hectare (CS) (780 MgCO₂ ha⁻¹ year⁻¹ and 998 MgCO₂ ha⁻¹ year⁻¹, respectively) than Villa Borghese (664 MgCO₂ ha⁻¹ year⁻¹) and Villa Torlonia (755 MgCO₂ ha⁻¹ year⁻¹), which had a lower vegetation extension (56.72 ha and 9.70 ha, respectively). CS was significantly correlated with leaf area index (LAI). The calculated CS for the four parks (3197 MgCO₂ ha⁻¹ year⁻¹), corresponding to 3.6% of the total greenhouse gas emissions of Rome for 2010, resulted in an annual economic value of $ 23537 /ha.     

Investigation of plant growth and flower performance on a semi-extensive green roof

Understanding of plant growth and flower performance is crucial for appropriate planting design. This study was aimed to understand characteristics of growth pattern and flower performance in green roof plants and how plant species diversity effect these characteristics. A semi-extensive green roof was installed in 2005 and 54 species plant species were planted in 10 cm and 20 cm of the substrate in Rotherham, UK. Thirty-two quadrats (50 cm × 50 cm) were set up through the combinations of plant species diversity (high and low), planting density (high and low). Percentage of coverage and height of each species were recorded at every month from February to November 2006 in these 32 quadrates. Flowering time of each species was studied every two weeks from February to November 2006. Flowering time was various from plants; some showed a very long flowering time, over five months whereas some finished flowering within two weeks. The growth characteristics of individual plant species over time were categorized into six patterns of coverage and vertical growth pattern. Spread of individual plants was larger in high diversity of plants than those in low diversity of plants. Number of flowering was higher and overall flowering term was longer in the quadrats of higher plant species diversity than those of lower plant diversity. However, these tendencies were affected strongly by the combination of species used. Therefore, it is important to be aware of individual plant growth characteristics such as plant size, growth pattern and flower performance for planting design.     

Bird song diversity influences young people's appreciation of urban landscapes

Increased losses of green areas in cities reduce people's experience of flora and fauna. Earlier studies have shown that biodiversity has benefits for urban inhabitants but the influence of animal sounds on people's experience of green space is poorly known. A sample of young urban people (N = 227) rated their reactions – positive or negative – to three bird song combinations: House Sparrow (Passer domesticus), Willow Warbler (Phylloscopus trochilus), 7 spp. i.e. Willow Warbler, Chaffinch (Fringilla coelebs), Blue Tit (Cyanistes caeruleus), Great Tit (Parus major), European Robin (Erithacus rubecula), Common Blackbird (Turdus merula), Great Spotted Woodpecker (Dendrocopos major), three urban settings (residential areas with varying amount of greenery) and nine combinations of song and setting. Bird song was generally considered positive and singing by several species was more highly rated than singing by a single species. On average, urban settings combined with bird song were more highly appreciated than the settings alone and even more so where there was singing by several species rather than just one. We conclude that our data support the idea that bird song contributes to positive values associated with urban green space. Urban planners should consider preserving a variety of habitats in cities for hosting a diversity of birds and thereby boost conservation of songbird diversity and recreational experiences for urban people.     

Reduction of chilling injury in ‘Tommy Atkins’ mangoes during ripening

Studies were conducted to investigate how harvest maturity influence fruit ripening processes to alleviate chilling injury (CI) in mangoes (cv. Tommy Atkins). Fruit at three stages of maturity, immature (M1), half-mature (M2) and mature (M3) were stored for 18 days at 5 °C and then at 1 or 3 days at 20 °C. M1 fruit succumbed to CI after 18 days at 5 °C, with symptoms increasing in severity upon warming. Low C₂H₄ production, poor colour development, minor changes to fruit composition, insipid flavour and poor aroma revealed that fruit ripening was insufficient to reduce CI compared to M2 and M3 fruits. M2 and M3 fruits had higher C₂H₄ production rates than M1 fruit and ripened normally with acceptable flavour and aroma after 18 days at 5 °C and 3 days at 20 °C. While M3 fruit had no CI symptoms, they were overripe and fruit decay incidence was 26.6%, compared to M2 fruit which had no decay, a trace of CI symptoms and possessed the best overall quality.     

Density,diversity and richness of woody plants in urban green spaces: A case study in Chennai metropolitan city

A tree diversity inventory was carried out in urban green spaces (UGSs) of Chennai metropolitan city, India. This inventory aims to study the diversity, density and richness of trees in UGSs of Chennai. A total of one hundred 10 m × 10 m (total 1 ha) plots were laid to reveal tree diversity and richness of UGSs. Trees with ≥10 cm girths at breast height (gbh) were inventoried. We recorded 45 species in 42 genera and 21 families. Caesalpiniaceae and Fabaceae each with 6 species dominated the study area followed by Arecaceae (3). Density and stand basal area of the present study were 500 stems ha^?1 and 64.16 m², respectively. Most of the inventoried trees were native (31 species) and deciduous (28 species). Fabaceae and Caesalpiniaceae dominated the present study area in terms of stand basal area and density. The Shannon diversity index and evenness of study area were 2.79 and 0.73, respectively. The most important species and families based on species important value index (IVI) and family important value index were Albizia saman, Polyalthia longifolia and Azadirachta indica; Fabaceae, Caesalpiniaceae and Annonaceae respectively. We find Chennai's urban forest is relatively superior to many urban forests of the world in terms of stand basal area and species richness. Results emphasize the importance of enhancement of urban green spaces in Chennai metropolitan city.     

Particulate matter pollution capture by leaves of seventeen living wall species with special reference to rail-traffic at a metropolitan station

Atmospheric Particulate Matter (PM) constitutes a considerable fraction of urban air pollution, and urban greening is a potential method of mitigating this pollution. The value of living wall systems has received scant attention in this respect. This study examined the inter-species variation of particulate capture by leaves of seventeen plant species present in a living wall at New Street railway station, Birmingham, UK. The densities of different size fractions of particulate pollutants (PM₁, PM_2.5 and PM₁₀) on 20 leaves per species were quantified using an Environmental Scanning Electron Microscope (ESEM) and ImageJ image-analysis software. The overall ability of plant leaves to remove PM from air was quantified using PM density and LAI (Leaf Area Index); any inter-species variations were identified using one-way Anova followed by Tukey’s pairwise comparison. This study demonstrates a considerable potential for living wall plants to remove particulate pollutants from the atmosphere. PM capture levels on leaves of different plant species were significantly different for all particle size fractions (P < 0.001). Smaller-leaved Buxus sempervirens L., Hebe albicans Cockayne, Thymus vulgaris L. and Hebe x youngii Metcalf showed significantly higher capture levels for all PM size fractions. PM densities on adaxial surfaces of the leaves were significantly higher compared to abaxial surfaces in the majority of the species studied (t-test, P < 0.05). According to EDX (Energy Dispersive X-ray) analysis, a wide spectrum of elements were captured by the leaves of the living wall plants, which were mainly typical railway exhaust particles and soil dust. Smaller leaves, and hairy and waxy leaf surfaces, appear to be leaf traits facilitating removal of PM from the air, and hence a collection of species which share these characters would probably optimize the benefit of living wall systems as atmospheric PM filters.     

Quality assessment of three warm-season turfgrasses growing in different substrate depths on shallow green roof systems

In an effort to increase the accessibility and functionality of shallow green roof systems, the ability of warm-season grasses to provide acceptable growth needs to be further investigated. In the current study, which was conducted during 2011 and 2012, three warm-season grasses (hybrid bermudagrass, Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt-Davy ‘MiniVerde’; seashore paspalum, Paspalum vaginatum Swartz ‘Platinum TE’ and zoysiagrass, Zoysia japonica Steud. ‘Zenith’) were established in outdoor lysimeters. The lysimeters were equipped with all necessary green roof layers placed below a coarse-textured substrate that comprised pumice, thermally treated attapulgite clay, peat, compost and zeolite. Half of the lysimeters had a substrate depth of 15 cm, while the other half had a substrate depth of 7.5 cm. Irrigation was applied at crop evapotranspiration (ET_c). Measurements included determination of substrate moisture content, green turf cover (GTC) and leaf stomatal resistance. Significant differences were observed in the values of GTC among the three turfgrass species and the two substrate depths. Zoysiagrass exhibited the best adaptation at the lower depths of shallow green roof systems. At 15 cm substrate depth, zoysiagrass managed to sustain green coverage for the two study periods. In addition, it was the only turfgrass species that managed to perform well at the substrate depth of 7.5 cm. Seashore paspalum exhibited limited green cover at both substrate depths, while hybrid bermudagrass could provide acceptable green coverage only at 15 cm substrate depth.     

Can trail spatial attributes predict trail use level in urban forest park? An examination integrating GPS data and space syntax theory

Understanding users’ spatial distribution in forest park is crucial for providing visitors with quality recreation experiences and for park planning and management. Utilizing users’ spatial distribution data, this study aims at investigating associations between trail use level and trail spatial attributes, through examining two large urban forest parks (Gongqing forest park and Paotaiwan forest park) in Shanghai, China. Users’ spatial distribution was measured utilizing GPS trackers with the interval of 10 seconds. This study conceptualizes trail spatial attributes as trail metric attributes and trail configurational attributes. Trail metric attributes include trail mean distance to gates, length, width and level of enclosure, which are calculated based on park map and on-site observation. We computed trail configurational attributes utilizing space syntax theory, which comprise measures of global integration, control, and connectivity. Trail connection with features/facilities, visual connection with water and shading are included as covariate variables. In total, we obtained 134 valid samples in Gongqing forest park and 210 valid samples in Paotaiwan forest park for analysis. Multivariate regression analyses indicate that when involving covariate variables, consistently in both parks, a greater trail usage is significantly related to trail shorter mean distance to park gate, trail width wider than 3 meters, higher global integration and higher control values. Collectively, these four trail spatial attributes explained 31.7 % (p < 0.001) and 27.3 % (p < 0.001) of the variances in trail use level in Gongqing forest park and Paotaiwan forest park. These findings provide direct implications to park designers and managers for providing visitors with different desirable social conditions, and ultimately improve users’ experiences and satisfactions.     

Analysis of greenhouse gas emissions from ornamental plant production: A nursery level approach

The focus of the work is to define a methodology to evaluate greenhouse gas (GHG) emissions for the nursery industry, comparing two different plant production systems (field- and container-grown plants) and assessing different scenarios for the reduction of the emissions. The Life Cycle Assessment (LCA) methodology, with the “from cradle to gate” approach, was used. The analysis revealed that the total emission of CO₂eq is higher in container cultivations than in field cultivations, with emissions ranging between 26.1 and 34.7 Mg ha^?1 year^?1 for the former, and between 2.3 and 6.6 Mg ha^?1 year^?1 for the latter; greenhouse horticultural crops emit 2.2–10.3 Mg ha^?1 year^?1 of CO₂eq and arable crop emissions were measured as 6.2 Mg ha^?1 year^?1 of CO₂eq.Different scenarios for the reduction of GHG emission were tested and a 15.5% reduction of GHG emission was achieved. Two of the scenarios applied – 50% recycled water usage (scenario 1) and 10% of green waste recovery for substrates (scenario 3) – are already in use in nursery farms.