Temporal Trends In Occurrence Research Articles

Effectiveness of the system of protected areas of Lombardy (Northern Italy) in preserving breeding birds

SummaryNetworks of protected areas (PAs) where human activities are allowed at different degrees are fundamental to ensure the long-term conservation of biological diversity and ecological processes. However, studies aimed at assessing their effectiveness, focusing on several species simultaneously are scarce. We assessed the effectiveness of the system of protected areas (PAs) of Lombardy, Northern Italy, in conserving bird populations by comparing the changes from 1992 to 2013 in the occurrence of 54 breeding bird species censused in areas classified in different protection categories, namely Nature Reserves (NRs), areas designed predominantly for the protection of nature; Regional Parks (RPs), naturally valuable areas where human activities, including intensive agriculture, are allowed; and non-protected areas (NPAs). Overall, occurrence of common birds increased in Lombardy in the last 20 years and farmland and long-distance migrants (LDMs), which suffered sharp declines at a continental scale, showed stable and increasing trends, respectively. These trends were, however, the balance between those of species whose occurrence markedly increased, and those of species that dramatically declined. Species occurred more often in PAs than in NPAs, while temporal trends in occurrence were significantly more positive in RPs than in both NRs and NPAs. Hence, PAs seemed effective in preserving common bird communities. Occurrence of woodland and short-distance migrant species was higher in PAs than in NPAs, while occurrence of farmland species and LDMs was similar in all protection categories. PAs of Lombardy appear therefore effective only in protecting some categories of birds. Farmland and LDM birds would benefit more from ecologically sustainable land-use policies aiming at improving agro-ecosystem biodiversity than from protected areas.

Spatial and temporal trends in occurrence of emerging and legacy contaminants in the Lower Columbia River 2008–2010

The Lower Columbia River in Oregon and Washington, USA, is an important resource for aquatic and terrestrial organisms, agriculture, and commerce. An 86-mile stretch of the river was sampled over a 3year period in order to determine the spatial and temporal trends in the occurrence and concentration of water-borne organic contaminants. Sampling occurred at 10 sites along this stretch and at 1 site on the Willamette River using the semipermeable membrane device (SPMD) and the polar organic chemical integrative sampler (POCIS) passive samplers. Contaminant profiles followed the predicted trends of lower numbers of detections and associated concentrations in the rural areas to higher numbers and concentrations at the more urbanized sites. Industrial chemicals, plasticizers, and PAHs were present at the highest concentrations. Differences in concentrations between sampling periods were related to the amount of rainfall during the sampling period. In general, water concentrations of wastewater-related contaminants decreased and concentrations of legacy contaminants slightly increased with increasing rainfall amounts.