Carbon budget alteration due to landcover–landuse change in wetlands: the case of afforestation in the Lower Delta of the Paraná River marshes (Argentina)

The objective of this work was to analyse the effects on carbon budget caused by the replacement of freshwater marshes by salicaceae plantations at ecosystem and regional scales, in the Lower Delta of the Paraná River in Argentina. Biomass and net aboveground primary productivity were estimated for one of the main species planted in the delta, Salix babylonica var. sacramenta, and for the dominant species of the marshes that are most widespread in the study area, Scirpus giganteus and Schoenoplectus californicus. Soil organic carbon was also estimated. Afforestation and marshes were mapped based on the digital classification of Landsat imagery. Aboveground biomass stored by afforestation is higher than by marshes (113.4 Mg/ha vs. around 10 Mg/ha). Nevertheless, soil organic matter accumulation is 10‐fold higher in the marshes. A huge amount of carbon is released into the atmosphere when marshes are converted to forest due to change from a wetland to a terrestrial condition.     

Relationships between landforms,soils and vegetation in the River Plate coastal plain,Argentina

The River Plate coastal plain is a 160‐km‐long, 3–10‐km‐wide strip, located to <5 m a.s.l. on the right bank of the estuary. It is formed by sediments and landforms generated by the littoral transport and marine ingressions and regressions during the Holocene. The coastal plain faces heavy pressures from Buenos Aires Metropolitan Area, with about 13 million inhabitants, industrial, mining and rural activities. Here, we analyse the relations existing between landforms, soils and vegetation. Despite the anthropogenic influence, the natural landscape is more or less preserved in some areas, such as patches of the southernmost gallery forest in the world in natural levees, the xerophytic forests located in well‐drained soils of beach ridges and other units such as Inland and Coastal Mudflats with wetland soils and vegetation, Tidal Flats with contrasting soils and plant communities among others.     

Spatial dependence and heterogeneity in the location processes of new high‐tech firms in Nanjing,China

Drawing upon township‐level data on high‐tech firms of Nanjing, China, this paper adopts a spatial econometric approach to examining the existence of spatial dependence and heterogeneity in the location processes of high‐tech firms. The results show that some locational determinants of neighbouring townships exert significant impacts on the attractiveness of a certain township for high‐tech firms. Besides, the marginal effects of some locational determinants are found to vary across space. In general, these results point to the need to account for both inter‐territorial spillovers and cross‐spatial variance in the investigation of factors that influence high‐tech firm location.     

Associations between evaporative cooling and dust‐mite allergens,endotoxins, and β‐(1 → 3)‐d‐glucans in house dust: A study of low‐income homes

Recent work suggests that evaporative coolers increase the level and diversity of bioaerosols, but this association remains understudied in low‐income homes. We conducted a cross‐sectional study of metropolitan, low‐income homes in Utah with evaporative coolers (n = 20) and central air conditioners (n = 28). Dust samples (N = 147) were collected from four locations in each home and analyzed for dust‐mite allergens Der p1 and Der f1, endotoxins, and β‐(1 → 3)‐d ‐glucans. In all sample locations combined, Der p1 or Der f1 was significantly higher in evaporative cooler versus central air conditioning homes (OR = 2.29, 95% CI = 1.05‐4.98). Endotoxin concentration was significantly higher in evaporative cooler versus central air conditioning homes in furniture (geometric mean (GM) = 8.05 vs 2.85 EU/mg, P < .01) and all samples combined (GM = 3.60 vs 1.29 EU/mg, P = .03). β‐(1 → 3)‐d ‐glucan concentration and surface loads were significantly higher in evaporative cooler versus central air conditioning homes in all four sample locations and all samples combined (P < .01). Our study suggests that low‐income, evaporative cooled homes have higher levels of immunologically important bioaerosols than central air‐conditioned homes in dry climates, warranting studies on health implications and other exposed populations.