18 research outputs found
Spatial Targeting of Agricultural Support Measures: Indicator-Based Assessment of Coverages and Leakages
This article evaluates the targeting strategy of a national-level program in Mexico that distributed agricultural support based on seven criteria that prioritized poor smallholder farming communities at high risk
of cropland failure. The findings highlight the continued lack of financial support for smallholder agriculture in Mexico, despite program rules and priority statements that stress the vulnerability of this sector. The article also illustrates the important role of spatial targeting in better aligning agricultural support payments with stated policy priorities
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Urban edge trees: Urban form and meteorology drive elemental carbon deposition to canopies and soils
Article asserts that urban tree canopies are a significant sink for atmospheric elemental carbon (EC)--and air pollutant that is a powerful climate-forcing agent and threat to human health. The authors' findings indicate that complex configurations of roads, buildings, and vegetation produce “urban edge trees” that contribute to heterogeneous EC deposition patterns across urban systems, with implications for greenspace planning
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The value of hydrologic information for watershed management programs: The case of CamboriĂş, Brazil
Article explores the value of hydrologic modeling and monitoring with respect to two dimensions: scientific credibility and use of generated knowledge in the design, implementation, and evaluation of the watershed management program in the CamboriĂş watershed, Brazil
Shower Thoughts: Why Scientists Should Spend More Time in the Rain
Stormwater is a vital resource and dynamic driver of terrestrial ecosystem processes. However, processes controlling interactions during and shortly after storms are often poorly seen and poorly sensed when direct observations are substituted with technological ones. We discuss how human observations complement technological ones and the benefits of scientists spending more time in the storm. Human observation can reveal ephemeral storm-related phenomena such as biogeochemical hot moments, organismal responses, and sedimentary processes that can then be explored in greater resolution using sensors and virtual experiments. Storm-related phenomena trigger lasting, oversized impacts on hydrologic and biogeochemical processes, organismal traits or functions, and ecosystem services at all scales. We provide examples of phenomena in forests, across disciplines and scales, that have been overlooked in past research to inspire mindful, holistic observation of ecosystems during storms. We conclude that technological observations alone are insufficient to trace the process complexity and unpredictability of fleeting biogeochemical or ecological events without the shower thoughts produced by scientists\u27 human sensory and cognitive systems during storms
Sustainable Science? Reducing the Carbon Impact of Scientific Mega-Meetings
This article uses 9 years of annual meeting attendance data from the Ecological Society of American and the Association of American Geographers to assess the efficacy of two additional solutions: 1) alternate large national meetings that require significant air travel with smaller regional meetings that do not; and 2) incorporate geography into the meeting location selection process
Sustainable Science? Reducing the Carbon Impact of Scientific Mega-Meetings
This article uses 9 years of annual meeting attendance data from the Ecological Society of American and the Association of American Geographers to assess the efficacy of two additional solutions: 1) alternate large national meetings that require significant air travel with smaller regional meetings that do not; and 2) incorporate geography into the meeting location selection process
A Low-Cost GPS-Based Protocol to Create High-Resolution Digital Elevation Models for Remote Mountain Areas
This article describes the use of a low-cost GPS-based protocol to construct a high-resolution digital elevation model for a rugged, remote mountain site in the northern Peruvian Andes
Black carbon in urban soils: land use and climate drive variation at the surface
Abstract Background Black carbon (BC) encompasses a range of carbonaceous materials––including soot, char, and charcoal––derived from the incomplete combustion of fossil fuels and biomass. Urban soils can become enriched in BC due to proximity to these combustion sources. We conducted a literature review of BC in urban soils globally and found 26 studies reporting BC and total organic carbon (TOC) content collected to a maximum of 578 cm depth in urban soils across 35 cities and 10 countries. We recorded data on city, climate, and land use/land cover characteristics to examine drivers of BC content and contribution to TOC in soil. Results All studies were conducted in the northern hemisphere, with 68% of the data points collected in China and the United States. Surface samples (0–20 cm) accounted for 62% of samples in the dataset. Therefore, we focused our analysis on 0–10 cm and 10–20 cm depths. Urban soil BC content ranged from 0–124 mg/g (median = 3 mg/g) at 0–10 cm and from 0–53 mg/g (median = 2.8 mg/g) at 10–20 cm depth. The median proportional contribution of BC to TOC was 23% and 15% at 0–10 cm and 10–20 cm, respectively. Surface soils sampled in industrial land use and near roads had the highest BC contents and proportions, whereas samples from residential sites had among the lowest. Soil BC content decreased with mean annual soil temperature. Conclusions Our review indicates that BC comprises a major fraction (nearly one quarter) of the TOC in urban surface soils, yet sampling bias towards the surface could hide the potential for BC storage at depth. Land use emerged as an importer driver of soil BC contents and proportions, whereas land cover effects remain uncertain. Warmer and wetter soils were found to have lower soil BC than cooler and drier soils, differences that likely reflect soil BC loss mechanisms. Additional research on urban soil BC at depth and from diverse climates is critical to better understand the role of cities in the global carbon cycle
Ambient urban N deposition drives increased biomass and total plant N in two native prairie grass species in the U.S. Southern Great Plains.
Remnants of native tallgrass prairie experience elevated atmospheric nitrogen (N) deposition in urban areas, with potential effects on species traits that are important for N cycling and species composition. We quantified bulk (primarily wet) inorganic N (NH4+-N + NO3--N) deposition at six sites along an urban development gradient (6-64% urban) in the Dallas-Fort Worth metropolitan area from April 2014 to October 2015. In addition, we conducted a phytometer experiment with two common native prairie bunchgrass species--one well studied (Schizachyrium scoparium) and one little studied (Nasella leucotricha)--to investigate ambient N deposition effects on plant biomass and tissue quality. Bulk inorganic N deposition ranged from 6.1-9.9 kg ha-1 yr-1, peaked in spring, and did not vary consistently with proportion of urban land within 10 km of the sites. Total (wet + dry) inorganic N deposition estimated using bulk deposition measured in this study and modeled dry deposition was 12.9-18.2 kg ha-1 yr-1. Although the two plant species studied differ in photosynthetic pathway, biomass, and tissue N, they exhibited a maximum 2-3-fold and 2-4-fold increase in total biomass and total plant N, respectively, with 1.6-fold higher bulk N deposition. In addition, our findings indicate that while native prairie grasses may exhibit a positive biomass response to increased N deposition up to ~18 kg ha-1 yr-1, total inorganic N deposition is well above the estimated critical load for herbaceous plant species richness in the tallgrass prairie of the Great Plains ecoregion and thus may negatively affect these plant communities