There are a large number of contributors to BES, including senior scientists, post-doctoral researchers, undergraduates, and even high school students. Their activities are presented below, divided into the Core Areas for urban LTER research, and ending with the Core Activity of engagement, especially through education. Some of the published papers explaining the methods and approaches, and recent results are cited. These can be found in the publication list of the BES website here: http://beslter.org/pubs_browser.asp
This post is complementary to two earlier ones, focusing on the goals of BES (https://besdirector.blogspot.com/2017/01/bes-annual-report-2017-part-1-what-have.html), and the theory motivating our research (http://besdirector.blogspot.com/2017/01/bes-annual-report-2017-part-2-what-is.html).
- Primary Production– BES measures parameters that support understanding the growth of dominant plants in terrestrial and stream environments. Woody plant biomass and change over time are assessed via extensive and intensive sampling. The i-Tree-Eco model is used to quantify woody plant production every five years based on 195 randomly located plots (Nowak et al. 2013). Eight intensively measured permanent plots combine assessment of vegetation and soil biogeochemistry (Groffman et al. 2006). The RHESSys model simulates coupled ecosystem primary production, hydrology, and nutrient cycling (Band et al. 2001; Tague and Band 2004). The primary production by stream biofilms and the effects of pharmaceutical contaminants on that production is investigated (Rosi-Marshall et al. 2013).
- Population Studies– Population studies and biodiversity assessments are a component of BES research. The organisms were chosen to satisfy specific criteria: sentinels for human health (mosquitoes), invasion of exotics (trees and herbaceous plants, mosquitoes, aquatic invertebrates), impact of pollutants and contaminants (aquatic biofilms); transformers of organic matter in soil nutrient cycles (earthworms); landscape integrators (birds); and predominant structuring elements (trees). Therefore, populations of birds (Rega et al. 2015), soil invertebrates, such as earthworms and isopods, are measured in both long-term and short term studies (Szlavecz et al. 2006, 2011, Pickett et al. 2011, Parker and Nilon 2012, Parker et al. 2014). Aquatic invertebrates are quantified in streams and in constructed stormwater detention ponds (Sokol et al. 2015). Plant populations are assessed in the 195 randomly located i-Tree permanent plots, which are sampled in all land uses (Nowak 2012). Plant population studies include experiments in vacant lots and measurements in residential lawns (Johnson et al. 2015), and assessments of alpha versus beta diversity along gradients of management intensity (Swan et al. 2015). The populations of introduced disease vectors are measured relative to their habitat and food web relationships along the urban-rural gradient and in neighborhoods of contrasting social-demographic characteristics (LaDeau et al. 2013).
- Movement of Organic Matter– Soil organic matter is assessed in Baltimore soils, including forests and lawns. Organic matter dynamics are also included in the studies of streams ecosystems (Kaushal et al. 2014), including assessment of stream burial which alters metabolism (Beaulieu et al. 2014). The input and dynamics of organic matter in streams is examined (Martinez et al. 2014). The effects of dissolved organic carbon on stream water quality has been examined (Duan 2014). Intercity comparisons of decomposition include work in Baltimore (Yesilonis et al. 2014). Several of the focal groups in the biotic population studies are important in decomposition of organic matter in soil (Szlavecz et al. 2011).
- Movement of Inorganic Matter– Inorganic nutrients and nutrient pollutants are routinely measured in BES watershed and stream research. Nitrate, phosphate, and particulates are key pollutants in metropolitan streams, and in the receiving waters of the Chesapeake Bay (Groffman et al. 2004; Kaushal et al. 2011). Nitrate and chloride are also drinking water pollutants. Nutrient processing data are collected in the permanent plots, in streams, and in riparian zones. Decades of road salt application have been assessed by historical analysis and now are complemented by on-going measurements of chloride concentration in Baltimore region streams, including those draining into the region’s reservoirs (Kaushal et al. 2005). Heavy metal contamination of soils is measured because those elements have implications for both public health and soil nutrient processing (Yesilonis et al. 2008; Schwarz et al. 2012). A flux tower on a suburban edge of the city measures a variety of inorganic compounds and physical conditions connecting soils and atmosphere (Chun et al. 2014).
- Disturbance Patterns– Disturbances, detected as pulsed structural alterations in ecosystems and landscapes of the Baltimore region, appear in long-term data on the geomorphology of stream channels, the alteration of forest cover, and the mortality of trees in permanent plots and coarse-scale vegetation surveys. Extreme climatic events are exposed as disturbances in long-term data sets on stream flow and nutrient loading. More subtle press disturbances include invasion of novel exotic species, and differential alteration of forest regeneration along urban-rural contrasts. Disturbances also take the form of social presses and pulses, such as shifting economic investment and disinvestment, migration of racial groups and social classes, and policy interventions such as the court-ordered retrofitting of Baltimore’s sanitary sewers. An integrated urban research program such as BES must account for both biophysical and social disturbance (Grimm et al., forthcoming 2017).
- Land Use/Land Cover Change– The National Land Cover Database is now available to provide coarse scale (30-m resolution; 16 categories) land cover information for Baltimore allowing the project to explore land cover/land use changes over time and to compare with other regions in the United States. However, the high degree of heterogeneity characteristic in cities, older suburbs, and in any urban area that has experienced parcel-level vegetation change, changes in occupancy and density, and shifts in use of industrial and commercial lands, requires more detailed characterization. A first step has been developing a sub-meter land cover mapping suitable for parcel analysis and as input for the patch-based HERCULES classification, which combines biophysically and socially generated cover elements to differentiate patches (Cadenasso et al. 2007). This results in a highly refined set of classes, currently being used to quantify “signatures” of urban cover in Baltimore to allow for temporal and inter-city comparisons. Forest patch change continues to be analyzed based on new remote imagery (Zhou et al. 2011). Fine scale assessments of land cover are being used to clarify the nature of shading both to improve patch discrimination and to provide data on insolation and shading of surfaces and buildings. Land use/cover change is being quantified at the level of suburban subdivision, using data on transacted price of home sales, as well as size and density of subdivisions (Irwin et al. 2014, Zhang et al. 2016). These are compared to distance from urban core, the different regulatory contexts of various counties in metropolitan Baltimore, and the nature of adjacent stormwater infrastructure. Lifestyle information is being extracted and mapped based on market segmentation data (Grove et al. 2015).
- Land Use/Land Cover Effects– The ecological effects of land use/land cover are being explored as a driver of Urban Heat Island effects by measuring land surface temperature relative to the census block geography of Baltimore (Zhou et al. 2011, Huang et al. 2011). Additional work focuses on the relationship of “hotspots” of land surface temperature to impervious and built land covers to assess the role of spatially explicit configuration of trees and buildings on UHI heterogeneity. Land cover heterogeneity is being explored relative to stream flow and chemistry, biodiversity in yards and vacant lots, and biogeochemical processes in urban forest fragments and lawns.
- Human-Natural Feedback– Feedbacks are best assessed through temporal changes following design and management interventions, policy shifts, and external disturbances. Activities to assess the fedbacks between social and ecological patterns and processes employ both extensive and intensive sampling frameworks that can be applied at multiple scales. The long term field-based sampling represents diverse urban landuses (e.g., i-Tree; stream gages). The high-resolution landcover mapping is being analyzed relative to the biogeochemical processes and social features including both demographic and lifestyle or consuption-based models. The 3000-household telephone survey, referenced by address and latitude/longitude, assesses environmental knowledge, attitudes, activities, and social involvement with the resident’s neighborhood in order to facilitate integration with biophysical measurements and social and economic census data. The role of environmentally active institutions is assessed via inventory and network analysis of stewardship organizations. A new theoretical structure for following human-natural causality through temporal sequences of intervention and response in a heterogeneous matrix is being explored.