Ecosystem services of collectively managed urban gardens : exploring factors affecting synergies and trade-offs at the site level

Collective management of urban green space is being acknowledged and promoted. The need to understand productivity and potential trade-offs between co-occurring ecosystem services arising from collectively managed pockets of green space is pivotal to the design and promotion of both productive urban areas and effective stakeholder participation in their management. Quantitative assessments of ecosystem service production were obtained from detailed site surveys at ten examples of collectively managed urban gardens in Greater Manchester, UK. Correlation analyses demonstrated high levels of synergy between ecological (biodiversity) and social (learning and well-being) benefits related to such spaces. Trade-offs were highly mediated by site size and design, resulting in a tension between increasing site area and the co-management of ecosystem services. By highlighting synergies, trade-offs and the significance of site area, the results offer insight into the spatially sensitive nature of ecosystem services arising from multi-functional collectively managed urban gardens

Monitoring British Upland Ecosystems With the Use of Landscape Structure as an Indicator for State-and-Transition Models

Remote sensing and landscape ecology concepts can provide a useful framework for state-and-transition models (STM) in order to quantify thresholds at different scales, and provide useful information for scientists, land managers, and conservationists in relation to resilience management. The overall aim of this research was to develop a spatially explicit STM to quantify thresholds based on the scale of disturbance processes impacting a grazing system. Specific objectives were to develop a conceptual STM framework for upland grazing ecosystems, to quantify spatial dynamics of stable and degraded pastures, and to assess threshold occurrence. Color aerial photography from Armboth Fell in the English Lake District National Park (United Kingdom) was classified into bare rock, dwarf shrub heath (DSH), and grassland/degraded wet heath (GDWH) in four pastures with different degrees of grazing pressure. Vegetation communities from these pastures were combined with soils, climate, and landform data to create a conceptual STM framework. Each pasture was sampled with 2-ha plots to quantify DSH and GDWH spatial structure. The proposed STM consisted of two reference and three alternative states. Low–grazing-pressure areas showed significantly higher percentage of DSH cover with larger contiguous patches and lower patch density than high–grazing-pressure areas. Breakpoints, considered to be thresholds, in mean patch area were identified in our data when DSH percentage cover was  77%. The present study has shown the value of a robust, reliable, and repeatable approach to identify landscape dynamics and integrate it with field data to inform a conceptual STM framework for upland grazing ecosystems. It also demonstrates the importance of selecting scales relevant to the predominant disturbance process to test for threshold occurrence, and how this approach can be integrated with current assessment methods for resilience management

Site-specific factors in the production of local urban ecosystem services : a case study of community-managed green space

Pockets of green space in cities can provide important ecosystem services for urban residents. As naturalistic spaces in urban areas become increasingly sparse, communities are beginning to co-manage existing incidental pockets of land towards the creation of communal natural resources. Such green commons can be productive in terms of ecosystem services through targeted management such as in the case of urban agriculture. Although some work has been done to explore the motives behind and potential benefits of informal green space management, further research is required to understand those characteristics of site management and community input which contribute to the enhancement of site-specific ecosystem service production. A case study of ten examples of community-managed green space was undertaken to evaluate the contributory factors relating to site character and management which influenced productivity as defined by the cumulative provision of four urban-relevant ecosystem services. The analysis revealed that the level of community involvement, measured as intensity of volunteer hours, was highly instrumental in the productivity of sites. Food production also proved to be catalytic for the enhancement of ecosystem services whereas extent of vegetative cover and increasing site size were, counter-intuitively, detrimental to overall site productivity. The study therefore supports the promotion of participatory approaches to the management of ecosystems services in urban areas, particularly those which take small-scale urban agriculture as a primary practice