ABSTRACT. A growing body of work has emphasized the importance of residential areas to the overall green infrastructure of cities and recognizes that outcomes related to these areas are best studied using a social-ecological approach. We conducted vegetation surveys to evaluate yard practices that relate to the state of the yard vegetation, including species diversity and abundance, vegetation structure, and the percent of green area of yards versus paved areas, at the Río Piedras watershed within the San Juan metropolitan area. We used concomitant social household surveys to evaluate the association of social-economic and demographic factors at the household scale with these vegetation characteristics, as well as with landscape-level characteristics related to urban morphology and elevation. Our results for this tropical site were consistent with studies elsewhere in that a greater number of social factors at the household scale were more important in explaining the traits related to how green the yards were. On the other hand, we failed to detect the so-called luxury effect on urban vegetation encountered at many sites. Instead, we found consistent vegetation associations with the age of the residents, housing ownership, and, most importantly, with yard size. We have discussed the potential reasons for these discrepancies and the potential consequences of the human-natural links at the household scale to the future dynamics of this portion of the green infrastructure within this urban watershed.

ABSTRACT. Green spaces within residential areas provide important contributions to the sustainability of urban systems. Therefore, studying the characteristics of these areas has become a research priority in cities worldwide. This project evaluated various aspects of the plant biodiversity of residential yards (i.e., front yards and back yards within the Río Piedras watershed in the San Juan metropolitan area of Puerto Rico). Our work included gathering information on vegetation composition and abundance of woody species (i.e., trees, shrubs, palms, ferns) and large herbs (>2 m height), species origin (native vs. introduced), and species uses (ornamental, food, and medicinal plants). A total of 424 yards were surveyed within an area of 187,191 m². We found 383 woody species, with shrubs being the most abundant plant habitat. As expected, residential yards hosted a disproportionate amount of introduced species (69.5%). The most common shrub species were all non-native ornamentals, whereas the most common tree species included food trees as well as ornamental plants and two native species. Front yards hosted more ornamental species per unit area than backyards, while the latter had more food plants. The high amount of introduced species may present a challenge in terms of implementation of plant conservation initiatives if there is no clear definition of urban conservation goals. On the other hand, the high frequency of yards containing food plants may facilitate the development of residential initiatives that could provide future adaptive capacity to food shortages.

Attitudes toward urban residential trees and awareness of their ecosystem services and disservices may play an important role in management decisions of private residential green spaces with important consequences to urban sustainability. In 2011, 397 household surveys were conducted in six locations of the Río Piedras Watershed (San Juan, Puerto Rico) to evaluate residents' attitudes toward residential and neighborhood trees and their association with household socio-demographic factors, how awareness of services and disservices relate to the spatial proximity of trees (home versus neighborhood), and whether attitudes are associated with yard management (tree abundance). Most residents self-reported positive attitudes toward trees in general and these appeared to be more frequent than self-reported negative attitudes. Respondents recognized more tree services (emphasizing shade, lower temperature, food, and ornamental/aesthetics) and fewer disservices (emphasizing maintenance hardship, property damage, and power line obstruction). Not all tree services and disservices were equally recognized, and differences in the spatial context of trees and residents may contribute to the variation in residents' awareness of tree ecosystem services or disservices. Variation in positive attitudes partially explained the current variation in yard tree abundance, along with residents' age, housing tenure, yard size, and watershed location. Results have direct implications for urban forest planning and management in residential contexts.Sustainability 2020, 12, 117 2 of 21 feature of green infrastructure and urban forestry management strategies are incorporated into green infrastructure planning due to the commonality of the two approaches [9]. It is generally accepted that these green networks, and trees specifically, can provide a variety of ecosystem services that directly or indirectly impact human well-being in urban socio-ecological systems [10,11]. On the other hand, green spaces may inadvertently cause perceived or realized disservices that may affect human well-being (i.e., structural damage to private or public infrastructure, sources of pollen allergens) [12] if not planned adequately. Managing for ecosystem disservices may facilitate the optimization of outcomes for well-being rather than just managing ecosystem services alone [13]. One possibility is that the interplay between perceived services and disservices of green infrastructure within urban spaces could also be influencing management decisions about these spaces and changing them over time [13][14][15]. If so, urban planning with sustainability as a goal must address the links between human attitudes and behaviors toward green spaces and how these factors may influence the planning, development, and management of urban green infrastructure [16][17][18][19].Residential green infrastructure has earned visibility as an important component of urban landscapes for its potential to provide multiple ecosystem services. Green infrastructure in the form of residential ...

ABSTRACT. Appraising the social-ecological processes influencing the inflow, transformation, and storage of materials and energy in urban ecosystems requires scientific attention. This appraisal can provide an important tool for assessing the sustainability of cities. Socioeconomic activities are mostly responsible for these fluxes, which are well manifested in the household unit. Human behavior associated with cultural traditions, belief systems, knowledge, and lifestyles are important drivers controlling the transfer of materials throughout the urban environment. Within this context, we explored three aspects of household consumption and waste disposal activities along the Río Piedras Watershed in the San Juan metropolitan area of Puerto Rico. These included: the source of food consumed by residents, recycling activities, and trends in connection to the municipality's sewerage system. We randomly interviewed 440 households at 6 sites along the watershed. We also conducted analysis to estimate accessibility to commercial food services for residents in the study areas. Our surveys revealed that nearly all interviewed households (~97%) consumed products from supermarkets. In neighborhoods of the upper portion of the watershed, where residential density is low with large areas of vegetative cover, more than 60% of residents consumed food items cultivated in their yards. Less than 36% of residents in the in densely urbanized parts of the lower portion of the watershed consumed items from their yards. Accessibility to commercial stores for food consumption contrasted among study sites. Recycling activities were mostly carried out by residents in the lower portion of the watershed, with better access to recycling programs provided by the municipality. The surveys also revealed that only 4 to 17% of residences in the upper watershed are connected to the sewerage system whereas the large majority uses septic tanks for septic water disposal. For these residents wastewater from house maintenance is disposed of directly into the environment. In the lower portion of the watershed all residents were connected to the sewerage system. Our study suggests there is a need to understand human behavioral attitudes in the acquirement and processing of resources, as a tool to generate informed-based strategies promoting sustainable consumption and disposal patterns.

No abstract