Suchergebnisse

Infrastructure for observing local human-environment interactions / Brent Yarnal [and others] -- Theory: computing with knowledge to represent and share understanding / Mark Gahegan, William Pike, Junyan Luo -- Infrastructure for collaboration / William Pike, Alan MacEachren, Brent Yarnal -- Representing and reasoning with conceptual understanding / Ola Ahlqvist, Chaoqing Yu -- Establishing vulnerability observatory networks to coordinate the collection and analysis of comparable data / Colin Polsky, Rob Neff, Brent Yarnal -- Comparative assessment of human-environment landscape change / John Harrington, Jr. [and others] -- Landsat mapping of local landscape change: the satellite-era context / Rachel M.K. Headley [and others] -- Assessing local vulnerabilities: methodological approaches and regional contexts / Colin Polsky [and others].

This presentation will present the SETER project. For the last twenty years, different research units participating in this project have been developing research activities on socio-ecological systems aiming at understanding relationships between agriculture and biodiversity, policies and landscapes dynamics, watershed management, ecosystem management and health risk, etc. At the same time, diverse schools of thought have developed theories and frameworks to analyse the dynamics and management of socio-ecological systems (Resilience,Vulnerability, Political ecology). The objective of this project is to assess the relevance and the complementarities of these theoretical frameworks by applying and testing them in the case of four empirical research case studies (Wetlands of the Rhone river delta, Locust control in Sahelian region, Multiple uses of Sahelian ecosystems, Management of Bemisia-phytovirus risk.) The lessons from this project will also provide the basis for new conceptualisations of socio-ecological systems dynamics and management. During summer 2009 senior researchers (Lance Gunderson, Allyson Quinlan, Colin Polsky, Marco Janssen, Paul Robbins, Nancy Peluso, Tom Bassett, Tor Benjaminssen) were hosted in Montpellier (France) for a common stay during which they interacted among them and with the participating units in Montpellier. Each case study was analysed from a different angle leading to progress in the understanding of the dynamics and management of the socio-ecological system under study. The different view points were discussed. This paper will present the preliminary results of this scientific dialog. (Texte intégral)

Abstract
Residential landscapes are essential to the sustainability of large areas of the United States. However, spatial and temporal variation across multiple domains complicates developing policies to balance these systems' environmental, economic, and equity dimensions. We conducted multidisciplinary studies in the Baltimore, MD, USA, metropolitan area to identify locations (hotspots) or times (hot moments) with a disproportionate influence on nitrogen export, a widespread environmental concern. Results showed high variation in the inherent vulnerability/sensitivity of individual parcels to cause environmental damage and in the knowledge and practices of individual managers. To the extent that hotspots are the result of management choices by homeowners, there are straightforward approaches to improve outcomes, e.g. fertilizer restrictions and incentives to reduce fertilizer use. If, however, hotspots arise from the configuration and inherent characteristics of parcels and neighborhoods, efforts to improve outcomes may involve more intensive and complex interventions, such as conversion to alternative ecosystem types.

Although ecosystem services have been intensively examined in certain domains (e.g., forests and wetlands), little research has assessed ecosystem services for the most dominant landscape type in urban ecosystems-namely, residential yards. In this paper, we report findings of a cross-site survey of homeowners in six U.S. cities to 1) examine how residents subjectively value various ecosystem services, 2) explore distinctive dimensions of those values, and 3) test the urban homogenization hypothesis. This hypothesis posits that urbanization leads to similarities in the social-ecological dynamics across cities in diverse biomes. By extension, the thesis suggests that residents' ecosystem service priorities for residential landscapes will be similar regardless of whether residents live in the humid East or the arid West, or the warm South or the cold North. Results underscored that cultural services were of utmost importance, particularly anthropocentric values including aesthetics, low-maintenance, and personal enjoyment. Using factor analyses, distinctive dimensions of residents' values were found to partially align with the Millennium Ecosystem Assessment's categories (provisioning, regulating, supporting, and cultural). Finally, residents' ecosystem service priorities exhibited significant homogenization across regions. In particular, the traditional lawn aesthetic (neat, green, weed-free yards) was similarly important across residents of diverse U.S. cities. Only a few exceptions were found across different environmental and social contexts; for example, cooling effects were more important in the warm South, where residents also valued aesthetics more than those in the North, where low-maintenance yards were a greater priority. ; MacroSystems Biology Program in the Emerging Frontiers Division of the Biological Sciences Directorate at the National Science Foundation (NSF) [EF-1065548, 1065737, 1065740, 1065741, 1065772, 1065785, 1065831, 121238320]; NSFNational Science Foundation (NSF) [DEB-0423476, SES-0951366]; Phoenix [BCS-1026865]; Plum Island (Boston) [OCE-1058747]; Cedar Creek (Minneapolis-St Paul) [DEB-0620652]; Florida Coastal Everglades (Miami) [DBI-0620409] ; This work was supported by the MacroSystems Biology Program in the Emerging Frontiers Division of the Biological Sciences Directorate at the National Science Foundation (NSF) under grants EF-1065548, 1065737, 1065740, 1065741, 1065772, 1065785, 1065831, 121238320. The work arose from research funded by grants from the NSF Long-Term Ecological Research Program supporting work in Baltimore (DEB-0423476), Phoenix (BCS-1026865), Plum Island (Boston) (OCE-1058747), Cedar Creek (Minneapolis-St Paul) (DEB-0620652), and Florida Coastal Everglades (Miami) (DBI-0620409). This research was also supported by the NSF-funded Decision Center for a Desert City II: Urban Climate Adaptation (SES-0951366). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of NSF. ; Public domain authored by a U.S. government employee

The urban heat island (UHI) is a well-documented pattern of warming in cities relative to rural areas. Most UHI research utilizes remote sensing methods at large scales, or climate sensors in single cities surrounded by standardized land cover. Relatively few studies have explored continental-scale climatic patterns within common urban microenvironments such as residential landscapes that may affect human comfort. We tested the urban homogenization hypothesis which states that structure and function in cities exhibit ecological "sameness" across diverse regions relative to the native ecosystems they replaced. We deployed portable micrometeorological sensors to compare air temperature and humidity in residential yards and native landscapes across six U.S. cities that span a range of climates (Phoenix, AZ; Los Angeles, CA; Minneapolis-St. Paul, MN; Boston, MA; Baltimore, MD; and Miami, FL). Microclimate in residential ecosystems was more similar among cities than among native ecosystems, particularly during the calm morning hours. Maximum regional actual evapotranspiration (AET) was related to the morning residential microclimate effect. Residential yards in cities with maximum AET < 50-65 cm/year (Phoenix and Los Angeles) were generally cooler and more humid than nearby native shrublands during summer mornings, while yards in cities above this threshold were generally warmer (Baltimore and Miami) and drier (Miami) than native forests. On average, temperature and absolute humidity were similar to 6 % less variable among residential ecosystems than among native ecosystems from diverse regions. These data suggest that common residential land cover and structural characteristics lead to microclimatic convergence across diverse regions at the continental scale. ; Macrosystems Biology Program at NSF [EF-1065548, 1065737, 1065740, 1065741, 1065772, 1065785, 1065831, 1241960, 121238320]; Earth Systems Modeling program at NSF [EF-1049251]; NSF Long-term Ecological Research Program in Baltimore (BES LTER) [DEB-0423476]; NSF Long-term Ecological Research Program in Phoenix (CAP LTER) [BCS-1026865]; NSF Long-term Ecological Research Program in Plum Island (PIE LTER Boston) [OCE-1058747, 1238212]; NSF Long-term Ecological Research Program in Cedar Creek (CDR LTER, Minneapolis-St Paul) [DEB-1234162]; NSF Long-term Ecological Research Program in Florida Coastal Everglades (FCE LTER, Miami) [DBI-0620409] ; We are grateful to numerous technical staff, students, and volunteers who assisted with microclimate data collection, including Erin Barton, Matthew Camba, Emma Dixon, La'Shaye Ervin, Caitlin Holmes, Richard McHorney, Miguel Morgan, Joseph Rittenhouse, Anna Royar, Jehane Samaha, Sydney Schiffner, Julea Shaw, Anissa Vega, Elisabeth Ward, and Megan Wheeler. We also thank Darrel Jenerette for reviewing an earlier draft of this manuscript. This project was supported by several collaborative grants from the Macrosystems Biology Program at NSF (EF-1065548, 1065737, 1065740, 1065741, 1065772, 1065785, 1065831, 1241960, and 121238320), and by the Earth Systems Modeling program at NSF (EF-1049251). This work was also supported in part by the NSF Long-term Ecological Research Program in Baltimore (BES LTER, DEB-0423476), Phoenix (CAP LTER, BCS-1026865), Plum Island (PIE LTER Boston; OCE-1058747 and 1238212), Cedar Creek (CDR LTER, Minneapolis-St Paul; DEB-1234162), and Florida Coastal Everglades (FCE LTER, Miami; DBI-0620409). ; Public domain authored by a U.S. government employee