The value of vegetation cover for ecosystem services in the suburban context

Latin-American cities can be characterized by dynamic processes of urbanization that encroach upon the natural and semi-natural surrounding landscapes. Our study presents the effects of landscape development, transformed from semi-natural conditions into a mostly disperse suburban settlement. We explore the impact that this transformation has had on this context by three ecosystem services that regulate rainwater runoff, enhance microclimate conditions and help to improve air quality by monitoring vegetation cover. We have designed a spatio-temporal hierarchical analysis which employs remote sensing techniques to capture the structural changes of this landscape over long, medium and short term scales on two spatial levels. This methodological approach was tested in the Metropolitan Area of Santiago (MAS) as case study area. Despite of the increase in impervious surfaces due to urban processes, there has also been an increase in vegetation cover, which has led to an improvement in the provision of the above-mentioned ecosystem services. Hence, if diverse urbanization processes continue and they are coupled with an increase in vegetation cover, the provision of ecosystem services could also expand. This phenomenon can be observed in some areas, where public and private green spaces are created and maintained. Our data analyses give evidence that certain types of suburban areas which increase the share of vegetation cover can provide daily ecological benefits for urban neighborhoods, and beyond, for adjacent areas. Moreover, suburban development can successfully provide ecological benefits to citizens. Such processes can only be ecologically sustainable if the composition of vegetation is well-adapted to the regional climatic conditions.     

The effects of urban greenway environment on recreational activities in tropical high-density Singapore: A computer vision approach

The urban greenway has been increasingly recognised as an important type of green infrastructure especially for land-scarce, densely-populated cities to efficiently provide their residents with continuous public spaces close to nature for recreation. Nevertheless, empirical studies on urban greenways and their recreational use rarely focus on high-density environment. Moreover, most research endeavours in this field are also largely confined to the subtropical climate, whereas much of the world’s future urban growth is projected to occur in the form of high-density mega-cities in much of tropical South and Southeast Asia. In view of these gaps, this study proposes a new approach that employs Computer Vision tools to examine the effects of the greenway’s physical environment on recreational activities, taking tropical Singapore as the test bed. The semantic segmentation model, PSPNet and the action detection model, ACAM are adapted and applied in conjunction with geographical information system tools to measure the greenway’s physical environment and people’s recreational activity at the human scale, and analyse their relationships. The result reveals a pattern that sees the clustering of different types of recreational activities at different time periods. It also reveals the relationships between recreational activities and specific environmental features, which were observed to have influenced the overall spatial distributions of the recreational activities. The finding also corroborates the design strategies for Singapore’s future urban greenways and offers a reference for engaging community groups to participate in the maintenance of urban greenways.     

A method to quantify infection and colonization of holm oak (Quercus ilex) roots by Phytophthora cinnamomi

ABSTRACT: Phytophthora cinnamomi Rands. is an important root rot pathogen widely distributed in the north hemisphere, with a large host range. Among others diseases, it is known to be a principal factor in the decline of holm oak and cork oak, the most important tree species in the "dehesa" ecosystem of south-western Spain. Previously, the focus of studies on P. cinnamomi and holm oak have been on molecular tools for identification, functional responses of the host, together with other physiological and morphological host variables. However, a microscopic index to describe the degree of infection and colonization in the plant tissues has not yet been developed. A colonization or infection index would be a useful tool for studies that examine differences between individuals subjected to different treatments or to individuals belonging to different breeding accessions, together with their specific responses to the pathogen. This work presents a methodology based on the capture and digital treatment of microscopic images, using simple and accessible software, together with a range of variables that quantify the infection and colonization process.     

Public acceptance of restrictions imposed on recreational activities in the peri-urban Nature Reserve Sihlwald, Switzerland

The peri-urban Nature Reserve Sihlwald is an important part of the recreational green belt in the vicinity of the city of Zürich (Switzerland). This contribution is an inquiry of the reaction of forest users towards restrictions that will be imposed on past time activities in the future. A research method developed in social psychology (Theory of Planned Behaviour) is applied to test whether behaviour intentions with regard to imposed restrictions are adhered to by the visitors or not, and how this is to be explained. The acceptance of various past time activities between different forest user groups is looked at in order to predict conflicts and achieve adequate regulations well in advance. The empirical results of applying the Theory of Planned Behaviour model favour a support of collective self-obligation among user groups to increase the acceptance of restrictions in the Nature Reserve Sihlwald.     

A spatially-explicit method to assess the dry deposition of air pollution by urban forests in the city of Florence,Italy

Urban forests (UF) provide a range of important ecosystem services (ES) for human well-being. Relevant ES delivered by UF include urban temperature regulation, runoff mitigation, noise reduction, recreation, and air purification. In this study the potential of air pollution removal by UF in the city of Florence (Italy) was investigated. Two main air pollutants were considered – particulate matter (PM₁₀) and tropospheric ozone (O₃) – with the aim of providing a methodological framework for mapping air pollutant removal by UF and assessing the percent removal of air pollutant.The distribution of UF was mapped by high spatial resolution remote sensing data and classified into seven forest categories. The Leaf Area Index (LAI) was estimated spatially using a regression model between in-field LAI survey and Airborne Laser Scanning data and it was found to be in good linear agreement with estimates from ground-based measurements (R² = 0.88 and RMSE% = 11%). We applied pollution deposition equations by using pollution concentrations measured at urban monitoring stations and then estimated the pollutant removal potential of the UF: annual O₃ and PM₁₀ removal accounted for 77.9 t and 171.3 t, respectively. O₃ and PM₁₀ removal rates by evergreen broadleaves (16.1 and 27.3 g/m²), conifers (10.9 and 28.5 g/m²), and mixed evergreen species (15.8 and 31.7 g/m²) were higher than by deciduous broadleaf stands (4.1 and 10 g/m²). However, deciduous forests exhibited the largest total removal due to the high percentage of tree cover within the city. The present study confirms that UF play an important role in air purification in Mediterranean cities as they can remove monthly up to 5% of O₃ and 13% of PM₁₀.     

Analysing recreational values and management effects in an urban forest with the visitor-employed photography method

Urban woodland management usually requires trade-offs between biodiversity conservation and promotion of recreational values. Preference studies have shown that people in general prefer semi-open forests with little undergrowth rather than unmanaged forests with dense understory and an abundance of dead wood. In this study the visitor employed photography (VEP) method was used to evaluate visitors’ perceptions of an urban forest. Volunteers were given cameras and asked to take pictures of the places that they liked and disliked the most along a trail with varied forest vegetation in a near-urban recreational area in Gothenburg, Sweden. The survey was conducted on two occasions, in April and September. Photo content in combination with the participants’ comments in their photo-logs was analysed with particular focus on features related to understory density, dead wood and visible human impact. The analyses of photo content suggested that the main differences in the participants’ preferences were between natural and human-made objects or landscapes. Pictures of natural objects were mostly classified as “liked”, while “disliked” was dominant among the pictures of human impact. Future VEP studies in urban woodlands should preferably include participants with a wider span in age and background than in the present study. The photo and analysis procedure could be changed, depending on local key-issues regarding management or conservation planning. This study has shown that the visitor employed photography method can be used as a quantitative method to evaluate perceptions about forest vegetation and management in urban woodlands, and could serve as a valuable complement to conventional methods in preference research.     

How different ethno-cultural groups value urban forests and its implications for managing urban nature in a multicultural landscape: A systematic review of the literature

Understanding how different ethno-cultural groups value urban nature is important to understand the role of ethno-cultural diversity in urban ecosystem management. Based on a systematic literature review, this paper summarizes the empirical evidence on how different ethno-cultural groups use, perceive, prefer, and assign meaning to urban nature. I use the urban forest, defined here as all the trees in a city, as a proxy to understand this process. The 31 studies reviewed here differ widely in their lines of inquiry, research methods, urban natural setting, and conceptualizations of ethno-cultural identity. Most studies take place in the US and Europe, where the most common definition of an ethno-culturally diverse group is a person of non-European/non-White background. Most studies focus on what these groups like about a particular urban natural setting, such as an urban park; and whether they like more or less trees in a specific context (e.g. urban park). These groups usually prefer passive and social uses of urban natural areas, and more manicured/functional natural landscapes with less trees. The most common meanings associated with urban natural settings dominated by trees are social interaction and integration. The most common explanations on why these differences occur involve theories on socio-economic marginality, collectivist vs. individualist cultures, urban vs. rural lifestyles, and landscapes of origin. Future research on the topic will benefit by differentiating race from ethnicity, capturing intra-ethnic variation, capturing immigrant identities, exploring the different social, cultural, and economic factors that influence values and/or preferences, and focusing on concrete aspects of urban nature, such as urban forests.     

Using contingent valuation to estimate the willingness of tourists to pay for urban forests: A study in Savannah, Georgia

This study estimated the monetary value of urban forests’ non-priced benefits to tourists. Data collected by a face-to-face self-administered survey of urban tourists in Savannah, Georgia, USA were used to estimate tourists’ willingness to pay (WTP) for urban forests by the contingent valuation method. Individual WTP was found higher among tourists with graduate school education. Results suggested that WTP for urban forests also increased significantly with income and destination loyalty of the tourists. Estimated mean and median WTP values were $11.25 (95% confidence interval: $7.34, $15.16) and $2.10 (95% confidence interval: $1.38, $2.82), respectively. Based on the estimated mean WTP, annual value of urban forests to tourists in Savanna in 2009 ranged from a minimum of $81 million to a maximum of $167 million with a 95% confidence interval. The annual value was $11.55 million (95% confidence interval: $7.59 million, $15.51 million) based on the estimated median WTP and assuming at least 50% of the tourists in Savannah would pay the median amount. As the mean was greatly influenced by extreme WTP values in the data, the annual value based on the median value was a more conservative estimate.     

Assessing urban recreational open spaces for the elderly: A case of three Indian cities

Many studies have highlighted the numerous benefits of access to inclusive public open spaces globally, focusing on various age groups. However, there exists a knowledge gap in understanding the needs of elderly users of urban Indian recreational open spaces that impact their usage behaviour, specifically regarding design and amenities provision. This study assesses the perceived accessibility and usability of an open space as an effect of its design features and tests it for the quality and availability of the age-specific amenities provided. A study of 51 recreational open spaces across three Indian cities of Mumbai, Bengaluru and Chennai was undertaken to evaluate their performance and age appropriateness, using multivariate analysis methods for derived empirical evidences. The findings indicate a considerable deficit in basic entry convenience and movement in public open spaces for people with movement difficulties and the shortfall of age-specific amenities. The outcome of the study highlighted the high positive impact of amenities provision and universal design features of a recreational open space on the perceived ‘Attractiveness’ of the open space, causing greater usage by the elderly. Backed with supporting empirical evidences, incorporation of universal design with barrier-free concepts while designing and developing recreational open spaces is strongly recommended for the Indian context.     

The social and economic value of cultural ecosystem services provided by urban forests in North America: A review and suggestions for future research

With the majority of the world’s human population now living in cities, urban forests provide an increasingly important range of ecosystem services, from improved air quality and climate change adaptation to better public health outcomes and increased tourism revenues. The importance of these ecosystem services in urban environments, and the central role that cities play in the lives of people around the world, have motivated various attempts to quantify the value of ecosystem services provided by urban forests. This paper reviews existing research in the fields of urban forestry, economics, sociology, and health on the value of urban ecosystem services, with a focus on cultural services, a category of ecosystem services that is of key importance to human well-being but that has suffered from a lack of empirical research. The review identified 38 studies that examined the value of mixed vegetation, 31 studies that examined the value of trees, and 43 studies that examined the value of green spaces. Psychological health is the most-studied ecosystem service category, with most research in this area focusing on the services of mixed vegetation. Social health, community economic development, and tourism are the least-studied, with most research in these areas focusing on mixed vegetation and trees. Multiple metrics were used to quantify the value of urban greenery within each ecosystem service category but only 11 metrics were assigned a monetary value. Gaps in the literature that present strong opportunities for future research include: the value of urban forests for improving social health, equitable access to ecosystem services, the impact of urban forests on community economic development, and economic valuation and green exposure metrics. We hope that this review stimulates future research in the areas highlighted and that municipalities consider including evaluations of a broad range of ecosystem services during land use planning and budgeting processes.     

Learning from the past to predict the future: using archaeological findings and GPS data to quantify reindeer sensitivity to anthropogenic disturbance in Norway

Norwegian wild reindeer Rangifer tarandus tarandus are divided into 23 virtually isolated populations, primarily due to the abandonment of traditional migration and movement corridors caused by the development of infrastructures. By conducting a nation-wide, interdisciplinary pre-post study on a temporal scale spanning centuries, we modelled current reindeer movements with respect to archaeological findings to quantify long-term changes in area use related to anthropogenic disturbance. The location of 3,113 pitfall traps and hunting blinds, built 600–2000 years ago and used until 350–400 years ago, testified the location of traditional movement corridors. Current movement routes were delineated using Brownian Bridge Movement Models based on 147 reindeer GPS-monitored during 10 years. Using Path Analysis we quantified direct, indirect and total effects of different infrastructures within multiple scales (1, 5, and 10 km-radius buffers) on the current probability of use of ancient movement corridors. Tourist cabins and roads had the strongest long-term direct effects at most scales: 1 tourist cabin and 1 km road within a 1 km-radius buffer would lead, respectively, to complete area abandonment, and to a 46 % decrease in the probability of use. Power lines and private cabins had significant indirect effects on area use through their effect on roads, while hiking trails and, in particular, hydroelectric dams had highly variable effects, not significant at a nation-wide scale. Finally, we provide a flexible tool to estimate the potential long-term direct and cumulative effects of different types of infrastructures at the desired spatial scale to be used for the development of future sustainable land management plans.     

Managing the potential for outdoor recreation: Adequate mapping and measuring of accessibility to urban recreational landscapes

Following the increasing public health concerns related to physical inactivity in the population, the relationship between outdoor recreation and public health has been increasingly acknowledged over the last decades. To improve public health, planners and policy-makers aim to provide good accessibility to recreational landscapes to facilitate outdoor recreational activity. At the same time, they are facing development pressure due to urban growth. In order for planners and policy-makers to secure people access to urban and near urban recreational areas, there is a need to map and measure access in a way that is adequate as a basis for decision-making in planning and design processes. Access is often defined as distance, or proximity, from residents’ homes to recreational areas. This paper explores different ways to map and measure distance to recreational areas, and aims to provide better decision support for planners and decision-makers. Moss municipality in Norway serves as a case study. We begin by addressing the meaning of the term ‘recreational landscape’ and how the choice of definition affects the results when mapping recreational areas. We also discuss who we are measuring distance for, and how different user groups will have different thresholds or critical distances affecting their frequency of visits to a recreational area. Last, we explore different methods for measuring distance within a GIS environment. The paper shows how the purpose of the analysis must be decisive when defining recreational landscapes and choosing methods for measuring access to recreational landscape, in order to provide valuable input to planners and policy-makers aiming at enhancing the possibility for outdoor recreation for people.     

Urbanization pressures on the natural forests in Turkey: An overview

Forests used to be the main field of interest for rural communities, but now they attract the attention of urbanites too. The forest–public relationship is important as forests protect water resources, preserve the soil and increase its productivity, provide positive effects on climate and health in general, and can be used for recreation and tourist purposes. This study aims at assessing how the current rapid urbanization process in Turkey affects forests. Urban requirements such as biomass for heating, education facilities, settlements, recreation, tourism and employment exert various pressures on the forest. In this study we assessed these pressures and suggest that forest legislations should be developed to respond to expectations of urbanites from forests, new recreation areas should be developed and urbanites’ interest in and knowledge of the forests should be increased, where all social groups including the forestry authority should work together.     

OUTENIQUA — A computer model to simulate succession in the mixed evergreen forests of the southern Cape,South Africa

A succession model for mixed evergreen forests of the southern Cape, South Africa, called OUTENIQUA, was developed based on one for subtropical rain forest in New South Wales, Australia. The model simulates the regeneration, growth and mortality on a 0.04 ha plot using an individual-tree based modeling approach to forest succession. The OUTENIQUA model was tested on its ability to simulate species dynamics of the forest stand used for its development, as well as on independent data from a neighboring stand and not used for the model derivation. The model is used as a research tool to summarize published and unpublished knowledge on the southern Cape forests and to highlight aspects where knowledge is insufficient. The development of the model represents a test of an individual-tree gap model as a simulation tool for use in management and directing research in subtropical and tropical forests.     

Similar spaces,different usage : A comparative study on how residents in the capitals of Finland and Denmark use cemeteries as recreational landscapes

Several studies from the Nordic countries show that cemeteries not only fulfil an important societal function as places for the disposal of bodily remains; they are also recreational landscapes that people visit to reflect, experience nature or perhaps go for a walk with the dog. In this comparative study, based on PPGIS data collected between 2018 and 2020 from residents in Copenhagen (Denmark) and Helsinki (Finland), we explored the extent to which residents use urban cemeteries as everyday recreational landscapes. We also assessed users’ characteristics and the values they attached to the cemeteries. The results show that several of Copenhagen’s cemeteries were actively used for recreation, while those in Helsinki were used much less frequently for this purpose. Of the total 7276 mapped visiting points in Copenhagen, 16.5% were located within cemeteries, compared with 1.9% of the 4298 mapped visiting points in Helsinki, hence conclusions from Helsinki should be drawn with caution. Physical activity and experiencing nature were the most common values attached to cemeteries in Copenhagen, whereas social interaction, spirituality and tranquillity were most common for Helsinki cemeteries. The results also revealed that younger Danes were particularly inclined to use cemeteries for social interactions, physical activity and spirituality and tranquillity. In the discussion, we elaborate on spatial differences between the cases, such as the availability of other green spaces, the size of cemeteries or people living in proximity to a cemetery, as well as on differences in policies and practices, including how Copenhagen stands out in actively promoting municipal cemeteries as recreational landscapes.     

Managing the middle ground: forests in the transition zone between cities and remote areas

In many parts of the world there are extensive landscapes where forests and people strongly intermingle, notably in the suburbs and exurbs of cities. This landscape of transitional forest generally receives limited attention from policy makers and researchers who tend to be rooted in traditions centered on either urban planning or management of natural resources in rural areas. The transitional forest is on the periphery of both perspectives, but it is a large area that provides numerous important values (biodiversity, ecosystem function, forest products, and amenities) to the people that live in them and their neighboring cities. Here we argue for increased attention to transitional forests, identify major challenges, and suggest changes to planning and management practices needed to ensure that the values of these forests are sustained.     

Epiphyte communities in Mediterranean fragmented forests: importance of the fragment size and the surrounding matrix

Context

Mediterranean forests have been fragmented intensively over time, thereby yielding small and isolated forest remnants. They host a rich variety of epiphytes, which may be affected by landscape structure. Previous studies have analyzed the influence of habitat quality on these epiphytic communities, but there is little knowledge of the effects of other fragment features.

Objectives

We evaluated the impacts of forest loss and fragmentation on epiphytic communities (lichens and bryophytes) at plot and fragment scales after controlling the variation in forest structure and management.

Methods

We considered 40 fragments of dense oak forests in a human-modified landscape. We quantified their spatial attributes (size and shape), the quality of the surrounding matrix and the forest stand structure. We modeled community traits, and the presence and abundance of species at fragment and plot scales.

Results

Fragment size, shape, and the quality of the surrounding matrix were key factors that affected epiphytic richness and diversity. Larger and more regularly shaped fragments hosted the richest and most diverse communities, possibly offering a larger core area and thus favoring the entry of typical forest species. A high-contrast matrix was only favorable in small fragments, probably allowing the arrival of propagules. The species-level response was highly variable.

Conclusions

Landscape structure provides powerful explanations of the richness and diversity losses among epiphytes. Forest management should ensure the retention of the largest possible continuous forests. The management strategy of the matrix will depend on the conservation goal, since we observed different effects related with quality and fragment size.

     

Three objectives of historical ecology: the case of litter collecting in Central European forests

Short- and long-term patterns of net ecosystem carbon balance (NECB) for small, relatively uniform forest stands have been examined in detail, but the same is not true for landscapes, especially those with heterogeneous disturbance histories. In this paper, we explore the effect of two contrasting types of disturbances (i.e., fire and tree harvest) on landscape level NECB by using an ecosystem process model that explicitly accounts for changes in carbon (C) stores as a function of disturbance regimes. The latter were defined by the average disturbance interval, the regularity of the disturbance interval (i.e., random, based on a Poisson frequency distribution, or regular), the amount of C removed by the disturbance (i.e., severity), and the relative abundance of stands in the landscape with unique disturbance histories. We used the model to create over 300 hypothetical landscapes, each with a different disturbance regime, by simulating up to 200 unique stand histories and averaging their total C stores. Mean NECB and its year-to-year variability was computed by calculating the difference in mean total C stores from one year to the next. Results indicated that landscape C stores were higher for random than for regular disturbance intervals, and increased as the mean disturbance interval increased and as the disturbance severity decreased. For example, C storage was reduced by 58% when the fire interval was shortened from 250 years to 100 years. Average landscape NECB was not significantly different than zero for any of the simulated landscapes. Year-to-year variability in landscape NECB, however, was related to the landscape disturbance regime; increasing with disturbance severity and frequency, and higher for random versus regular disturbance intervals. We conclude that landscape C stores of forest systems can be predicted using the concept of disturbance regimes, a result that may be a useful for adjusting estimates of C storage to broad scales that are solely based on physiological processes.     

A scale-sensitive connectivity analysis to identify ecological networks and conservation value in river networks

Existing methods for connectivity analysis still encounter difficulties in explaining functional relationships between network structure and ecological patterns over larger territories or complex structures like dendritic river networks. We propose a method that addresses the problem of scale and resolution in the connectivity analysis of dendritic network structures, illustrated here for the re-colonization of the French Loire river basin by the European otter. The ecological niche factor approach is applied to infer favourable habitat in the river network based on large scale data of land use and hydro-morphology of river segments for the entire river basin. These analyses identified the stressors to the riparian zone of channel straightening, urbanisation and forest fragmentation as the principal factors explaining otter occurrence. Using this estimate of habitat favourability, we used the Integral Index of Connectivity to quantify habitat availability and connectivity in the dendritic river network. When we calculate the integral index of connectivity over different spatial extents by constraining network distances, the scale-sensitivity of the network’s connectivity emerges. Accounting for high mobility by entering larger network distances in the analysis identifies conservation networks and priorities mainly in downstream parts of the river basin, whereas with smaller network distances, more restricted high quality areas in central and upstream parts are highlighted. The presented approach performed better than distribution modelling approaches in explaining species occurrence over the river network and confirms the crucial aspect of connectivity in otter re-colonization.