A multiscale assessment of the diversity of New Zealand’s nursery trees

Nurseries play an important role providing trees for a variety of managed environments including urban forests. The diversity of urban forests and forest restoration projects are influenced by nursery species availability, and as such, there is a need to better understand tree species diversity at nurseries. We collected tree species lists from 75 nurseries throughout New Zealand, which were used to describe species richness (alpha diversity) and to examine similarity in the composition of native and non-native species assemblages among nurseries (beta diversity) at three spatial scales: island, region, city. Together, the nurseries grew 863 species, 174 of which were native to New Zealand, from 312 genera and 130 families. Nurseries grew significantly more non-native species (μ = 63.5, σ = 60.6) than native species on average (μ = 31.7, σ = 22.7) (t = 2.99, df = 48.45, p = 0.004). Beta diversity for native and non-native tree species were only significantly different at the scale of cities or regions, not at the larger scale of islands. Few species were grown in all cities or all regions and the majority of those that were common were native species. In contrast, non-native species dominated the unique species at all spatial scales, (i.e., species uniquely grown in one city, region, or island). By quantifying tree species diversity in New Zealand’s nurseries, this research provides a basis to better understand the influence that nurseries have on urban and peri-urban tree diversity, and ultimately how that diversity impacts resilience and the provision of ecosystem services.     

A bird’s eye view: using circuit theory to study urban landscape connectivity for birds

Context

Connectivity is fundamental to understanding how landscape form influences ecological function. However, uncertainties persist due to the difficulty and expense of gathering empirical data to drive or to validate connectivity models, especially in urban areas, where relationships are multifaceted and the habitat matrix cannot be considered to be binary.

Objectives

This research used circuit theory to model urban bird flows (i.e. ‘current’), and compared results to observed abundance. The aims were to explore the ability of this approach to predict wildlife flows and to test relationships between modelled connectivity and variation in abundance.

Methods

Circuitscape was used to model functional connectivity in Bedford, Luton/Dunstable, and Milton Keynes, UK, for great tits (Parus major) and blue tits (Cyanistes caeruleus), drawing parameters from published studies of woodland bird flows in urban environments. Model performance was then tested against observed abundance data.

Results

Modelled current showed a weak yet positive agreement with combined abundance for P. major and C. caeruleus. Weaker correlations were found for other woodland species, suggesting the approach may be expandable if re-parameterised.

Conclusions

Trees provide suitable habitat for urban woodland bird species, but their location in large, contiguous patches and corridors along barriers also facilitates connectivity networks throughout the urban matrix. Urban connectivity studies are well-served by the advantages of circuit theory approaches, and benefit from the empirical study of wildlife flows in these landscapes to parameterise this type of modelling more explicitly. Such results can prove informative and beneficial in designing urban green space and new developments.

     

Memory and resilience: A two-pronged approach to natural spaces in Colombia’s transition to a peaceful society

The analysis of spontaneous environmental initiatives undertaken by individuals and communities in cases of conflicts has led to a growing research field in social science, according to which the community-based stewardship of nature seems to conduce to the resilience of co-evolved social-ecological systems. In Colombia, where no such research exists so far, the conflict which officially ended in November 2016 has led to massive internal migration due to forced displacement, as well as to widespread degradation of the environment. Based on evidence provided by case studies of top-down and bottom-up living memorials and urban agriculture initiatives, the article explores the potential of urban greening in the process of memorialisation and in generating new social cohesion, as well as better living conditions in urban areas. It analyses cases both where the conflict has taken place and in the cities where refugees have settled, in order to explore avenues for public policies in post conflict Colombia. The author concludes that greening initiatives offer manifold, so far overlooked, opportunities to restoring social and ecological resilience in urban areas and thus contribute to a lasting peace in Colombia.     

A landscape vulnerability framework for identifying integrated conservation and adaptation pathways to climate change: the case of Madagascar’s spiny forest

Context

Integrated conservation decision-making frameworks that help to design or adjust practices that are cognisant of environmental change and adaptation are urgently needed.

Objective

We demonstrate how a landscape vulnerability framework combining sensitivity, adaptive capacity, and exposure to climate change framed along two main axes of concern can help to identify potential strategies for conservation and adaptation decision-making, using a landscape in Madagascar’s spiny forest as a case-study.

Methods

To apply such a vulnerability landscape assessment, we inferred the sensitivity of habitats using temporal and spatial botanical data-sets, including the use of fossil pollen data and vegetation surveys. For understanding adaptive capacity, we analysed existing spatial maps (reflecting anthropogenic stressors) showing the degree of habitat connectivity, matrix quality and protected area coverage for the different habitats in the landscape. Lastly, for understanding exposures, we used climate change predictions in Madagascar, together with a digital elevation model.

Results

The fossil pollen data showed how sensitive arid-adapted species were to past climate changes, especially the conditions between 1000 and 500 cal yr BP. The spatial analysis then helped locate habitats on the two-dimensional axes of concern integrating sensitivity, adaptive capacity and climate change exposure. By identifying resistant, resilient, susceptible, and sensitive habitats to climate change in the landscape under study, we identify very different approaches to integrate conservation and adaptation strategies in contrasting habitats.

Conclusion

This framework, illustrated through a case study, provides easy guidance for identifying potential integrated conservation and adaptation strategies, taking into account aspects of climate vulnerability and conservation capacity.

     

Planting free trees on private property: understanding urban residents’ motivations and hesitations

In order to meet comprehensive planting goals, tree-planting campaigns must plant on private properties, in residential front and backyards. Successful engagement in these kinds of neighborhood plantings requires an understanding of residents' decision making. Through surveys with past recipients of free 1″-caliper trees, past neighborhood leaders of tree-planting recruiting, and door-to-door canvassing in a pilot neighborhood, this study shows the top factors for accepting free trees and main reasons for declining. Surveys asked past tree recipients their main motivations for accepting a free tree, and three reasons rose to the top: trees provide beauty, trees help the environment, and trees keep people healthy. Top barriers for declining a free tree included not desiring more trees than they had, concerns about maintenance, and a language barrier. These results can inform tree-planting campaigns and tree-focused organizations in order to improve messaging and neighborhood engagement – all to ensure that more trees are planted and canopy is increased.     

Healing gardens in children’s hospitals: Reflections on benefits,preferences and design from visitors’ books

There is increasing interest in the use of healing gardens in healthcare settings to provide therapeutic benefits. However it is not yet well understood how people who spend time in these gardens use these spaces, and whether the intended benefits are experienced. This paper evaluates visitor feedback about healing gardens at the Lady Cilento Children’s Hospital in Brisbane, Australia, to gain insight into end-user experiences compared with existing literature about experiences of healing gardens and natural contexts. We have coded and analysed unsolicited comments left in visitors’ books over a period of four weeks immediately after the hospital was opened. Several themes have been identified relating to reasons for which people access the healing gardens; benefits they perceive from spending time in these spaces; and features and aspects of the gardens that are most appreciated. We conclude that the gardens at the Lady Cilento Children’s Hospital provide emotional respite to visitors, through appreciation of the views, being able to have time out, being in nature, restorative experiences, and access to outdoor air. The visitor feedback suggests that the original intention of the garden design has been largely successful, and provides insight into particular aspects of the garden design that are critical to enhancing visitor benefits.     

Inequity in nature’s contributions to people in Ōtautahi/ Christchurch: A low-density post-earthquake city

Nature’s contributions to people (NCP) include the regulating, material, and non-material benefits of urban vegetation that improve well-being. It is increasingly important to plan cities that provide multiple types of NCP equitably to all residents of the city. However, due to historical legacies and planning policies, it is common for the most socially and economically vulnerable urban residents to suffer reduced access to the benefits of urban ecosystems. Previous studies of urban NCP have drawn attention to inequity in one or several types of NCP, but few have analysed a broad range. Here we analysed inequity in nine diverse forms of urban NCP across an index of economic and social vulnerability designed specifically to characterise vulnerability to environmental pressures. Furthermore, we used spatial analysis to map co-variance in vulnerability and a composite indicator of urban NCP, thus highlighting priority regions for future investments in green infrastructure. We applied this approach to the city of Christchurch/ Ōtautahi in Aotearoa/ New Zealand, which provides a valuable case study due to its multicultural population and recent history of widespread damage and regeneration following the 2011 earthquake. Overall, the distribution of urban NCP is inequitable to the disadvantage of more vulnerable residents. Residents of more vulnerable neighbourhoods experienced reduced provision of carbon stock, runoff retention, air quality enhancement, shade, educational green space, public outdoor space accessibility, private green space, and bird biodiversity contributions. Conversely, more vulnerable neighbourhoods had greater provision of erosion mitigation (although negligible in magnitude). The wide range of indicators used and assessed in response to vulnerability, coupled with an assessment of the type of vegetation cover (i.e. grass, tall trees) provides greater insights into how inequities in urban NCP can be addressed in future redevelopment.     

The changing landscape of wildfire: burn pattern trends and implications for California’s yellow pine and mixed conifer forests

Purpose

Wildfire spatial patterns drive ecological processes including vegetation succession and wildlife community dynamics. Such patterns may be changing due to fire suppression policies and climate change, making characterization of trends in post-fire mosaics important for understanding and managing fire-prone ecosystems.

Methods

For wildfires in California’s yellow pine and mixed-conifer forests, spatial pattern trends of two components of the post-fire severity matrix were assessed for 1984–2015: (1) unchanged or very low-severity and (2) high-severity, which represent remnant forest and stand-replacing fire, respectively. Trends were evaluated for metrics of total and proportional burned area, shape complexity, aggregation, and core area. Additionally, comparisons were made between management units where fire suppression is commonly practiced and those with a history of managing wildfire for ecological/resource benefits.

Results

Unchanged or very low-severity area per fire decreased proportionally through time, and became increasingly fragmented. High-severity area and core area increased on average across most of California, with the high-severity component also becoming simpler in shape in the Sierra Nevada. Compared to suppression units, managed wildfire units lack an increase in high-severity area, have less aggregated post-fire mosaics, and more high-severity spatial complexity.

Conclusions

Documented changes in severity patterns have cascading ecological effects including increased vegetation type conversion risk, habitat availability shifts, and remnant forest fragmentation. These changes likely benefit early-seral-associated species at the expense of mature closed-canopy forest-associated species. Managed wildfire appears to moderate some effects of fire suppression, and may help buy time for ecosystems and managers to respond to a changing climate.

     

Users’ recreation choices and setting preferences for trails in urban forests in Nanjing,China

With increased demand for outdoor recreational spaces, it is imperative to understand the experience of recreational hikers. This study explored users’ recreation choices and behavior-based setting preferences for certain trails in one forest park. Using on-site intercept surveys, a total of 1019 samples were collected from users of hiking trails and greenways in Purple Mountain Forest Park, Nanjing, China. The results from multiple regressions revealed that visitors’ recreation choices for trail settings, companions, and activities were associated with personal attributes, usage patterns, visitor motivations, and their preferences for the trail’s landscape attributes. The findings provide insights for the design and maintenance of trail settings in forest parks to satisfy the needs of various recreational hikers.     

Stress-resistant trees are more common in urban than rural forests: A case study of Cleveland,Ohio’s natural parks

Natural parks are comprised of preserved forested natural areas that are undergoing natural ecological processes. These areas can offer a refuge for local biodiversity and contribute substantially to ecosystem services in both rural areas with relatively low population densities, as well as high-density urban areas. Forested natural parks located in urban areas should experience more stressful environmental conditions than nearby rural areas, yet we know relatively little about how urbanization impacts tree communities within these important natural habitats. To better understand the impact of urbanization on forests, we investigated the species composition, abundance, and diversity of midstory and canopy trees as well as tree seedlings in urban and rural natural parks in and around Cleveland, Ohio. We found that both urban and rural natural parks have similar tree abundance, but midstory and canopy trees as well as tree seedling communities in the urban natural parks included higher abundances of stress-tolerant species compared to rural parks. In addition, this pattern was driven by changes in native tree species, as we observed low abundance of invasive species. More stress-resistant native species in urban areas include Quercus rubra and Prunus serotina, in contrast to rural natural parks which are dominated by Acer spp. and Fagus grandifolia. Lastly, we show that urban and rural natural parks have similar species diversity within plots, but we found higher variation in community composition among urban natural parks compared to among rural parks. Furthermore, Q. rubra and P. serotina were significantly larger in rural natural parks, indicating that both environmental stress and successional stage could drive compositional differences. Thus, we show that urbanization can have unexpected effects on plant community composition and diversity. Our study refutes the idea that these are degraded habitats, highlights the need to conserve them, and suggests that characterization of local variation in self-assembled urban tree communities will provide the most accurate picture of their management needs and potential ecosystem services.     

A review of the concept ‘management’ in relation to urban landscapes and green spaces: Toward a holistic understanding

The management of urban landscapes concerns existing urban open spaces such as public parks, playgrounds and residential green spaces. It involves many different actors and organizations and its practice is of importance for the sustainable development of cities. As a research field, it needs further theoretical development and common definitions. For example, the central term ‘management’ is seldom defined in the relevant literature regarding an urban landscape context, and public participation in management processes is unusual. This paper introduces urban landscape management as an overarching concept that brings together knowledge about management of urban landscapes from fields such as urban forestry, park management and landscape planning. Based on a literature review, a common understanding of management in an urban landscape context is proposed, including organizational and strategic aspects of managerial activities. Our approach is that urban landscapes are ultimately managed to provide user benefits. Urban landscape management can be viewed as a complex process that includes a number of different actors, elements and relationships, mutually affecting each other. This view supports future studies of urban landscape management and its role in sustainable urban development.     

Visitors’ heterogeneous preferences for urban park management: The case of a city park in Oulu,Finland

Utilizing survey data collected using a combined travel cost – conditional behavior method, the aim of this study was to analyze the heterogeneity of preferences among the residents of a city in Finland for the services of an urban park and its stream network. More specifically, by analyzing different behavioral responses to potential changes in ecological, cultural, and commercial services, we identified different groups of visitors to the park with a latent class model. A notable result regarding the demand for services in different classes was that low-income people valued the park more than high-income respondents, making improvements in the park’s recreational potential a successful social project. We found two latent classes, the main distinguishing factor of which was the preferences associated with increasing the number of events in the park. Adding events did not increase the benefits for the first class, but for the second class it did. In relation to class membership, if visitors usually visited the park alone or if they walked or cycled to the park, this increased the likelihood of belonging to a particular visitor group. In addition, we assessed how a possible increase in services affected the recreational value of the urban park for the city’s residents. We found that both the total and net value for different urban groups depended on three factors, i.e., the number of visits, the recreational value of a visit, and the proportion of people in each visitor group. We also used the results of the study to assess the profitability of a construction and management project in the park and found that the project was socially very profitable. Although our study examined a specific park in Finland, its results could also potentially be used when planning the management of other urban parks.     

Spatiotemporal patterns,relationships, and drivers of China’s agricultural ecosystem services from 1980 to 2010: a multiscale analysis

Context

During the past three decades, China’s agroecosystem has undergone dramatic alterations because of changes in climatic and management factors, which threatened agricultural sustainability.

Objectives

We investigated how climatic and management factors affected agricultural ecosystem services (AES).

Methods

We adopted the GIS-based Environmental Policy Integrated Climate (EPIC) model to simulate the five critical AES: food production, soil organic carbon (SOC), nitrate leaching, water erosion, and wind erosion from 1980 to 2010 and used a partial least square regression model to quantify the contributions of the drivers of the variation in the AES on the main grain-producing area (MGPA), climatic zone, and national scales.

Results

On the MGPA scale, SOC exhibited no obvious change and food production increased, whereas the negative environmental effects largely increased. The MGPA is important to ensure the safety of China’s food supply. At the climatic zone scale, food production and SOC increased, water erosion in the tropical-subtropical monsoonal zone and water and wind erosion in the temperate monsoonal zone decreased, whereas N leaching, water erosion, and wind erosion increased in other climate zones. At the national scale, food production, SOC, N leaching, and wind erosion increased, whereas water erosion decreased. The crop cultivated area played a major role in the effect on food production and SOC. The dominant factors for N leaching, water erosion, and wind erosion varied with crop type and study scales.

Conclusions

Adjustment of agricultural management measures is vital and possible to minimize the tradeoffs, increase the synergies among agro ecosystem services, and promote adaptation to the changing climate.

     

Rectifying I: three point and continuous fit of the spatial autocorrelation metric,Moran’s I,to ideal form

Landscape Ecology - Interpreting spatial autocorrelation is complicated by differences in data type, spatial conformation, and contiguity definitions. Though lacking consistent meaning,...