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Background and aims To find out how N-saturated forests can return to an N-limited state, we examined the recovery of biotic N sinks under decreasing N supply. Methods . We studied a 40-year-old experiment in Pinus sylvestris forest, with control plots, N0, three N treatments, N1-N3, of which N3 was stopped after 20 years, allowing observation of recovery. Results In N3, the N concentration in foliage was still slightly elevated, but the N uptake capacity of ectomycorrhizal (ECM) roots in N3 was no longer lower than in N0. Per area the amount of a biomarker for fungi, here mainly attributed ECM, was higher in N3 and N0 than in N1 and N2. Retention of labeled 15 NH 4 + by the soil was greater in the control (99 %) and N3 (86 %), than in N1 (45 %) and N2 (29 %); we ascribe these differences to biotic retention because cation exchange capacity did not vary. Gross N mineralisation and retention of N correlated, negatively and positively, respectively, with abundance of ECM fungal biomarker. Conclusions . The results suggest a key role for ECM fungi in regulating the N cycle. We propose, in accordance with plant C allocation theory, that recovery is driven by increased tree below-ground C allocation to ECM roots and fungi.

Plant growth in boreal forests is commonly limited by a low supply of nitrogen, a condition that may be aggravated by high tree below-ground allocation of carbon to ectomycorrhizal (ECM) fungi and associated microorganisms. These in turn immobilise N and reduce its availability to plants as boreal ecosystems develop. Here, we studied a boreal forest ecosystem chronosequence created by new land rising out of the sea due to iso-static rebound along the coast of northern Sweden. We used height over the ocean to estimate ecosystem age and examined its relationship to soil microbial community structure and the gross turnover of N. The youngest soils develop with meadows by the coast, followed by a zone of N2-fixing alder trees, and primary boreal conifer forest on ground up to 560 years old. The young soils in meadows contained little organic matter and microbial biomass per unit area. Nitrogen was turned over at low rates when expressed per area (m2), but specific rates (per gram soil carbon (C)) were the highest found along the transect. In the zone with alder, the amounts of soil C and microbial biomass were much higher (bacterial biomass had doubled and fungal biomass quadrupled). Rates of gross N mineralisation (expressed on an area basis) were highest, but the retention of added labelled NH4 þ was lowest in this soil as compared to other ages. The alder zone also had the largest extractable pools of inorganic N in soil and highest N % in plant foliage. In the older conifer forest ecosystems the amounts of soil C and N, as well as biomass of both bacteria and fungi increased. Data on organic matter 14C suggested that the largest input of recently fixed plant C occurred in the younger coniferous forest ecosystems. With increasing ecosystem age, the ratio of microbial C to total soil C was constant, whereas the ratio of microbial N to total soil N increased and gross N mineralization declined. Simultaneously, plant foliar N % decreased and the natural abundance of 15N in the soil increased. More specifically, the difference in d15N between plant foliage and soil increased, which is related to relatively greater retention of 15N relative to 14N by ECM fungi as N is taken up from the soil and some N is transferred to the plant host. In the conifer forest, where these changes were greatest, we found increased fungal biomass in the F- and H-horizons of the mor-layer, in which ECM fungi are known to dominate (the uppermost horizon with litter and moss is dominated by saprotrophic fungi). Hence, we propose that the decreasing availability of N to the plants and the subsequent decline in plant production in ageing boreal forests is linked to high tree belowground C allocation to ECM fungi, a strong microbial sink for available soil N

Globalisation strongly influences social, environmental and economic resources, especially in those territories characterised by a historical dependency on a single industry, as in the case of mining. Our study aimed to envision possible future development paths for the mining city of Gällivare, in Northern Sweden, using a participatory approach. Four different transformative narratives were developed depicting a wide range of choices along an ideal anthropocentric-wild gradient. Through applying complementary methodologies for social-ecological system assessment (e.g., Q-methodology, ARDI approach), the expected social, economic and environmental impacts of the scenarios were explored. Results highlight the conflicting demands on natural resources in Northern Sweden and provides a deeper understanding of different perceptions and potential societal acceptance of each scenario from local and nonlocal stakeholder. This paper contributes to local discussions on future development in the area as well as to methodological advancements by providing a framework for the creation of a participative decision-making arena in similar transformative contexts.

Patient experience is an important component of the overall medical encounter. This paper explores how patient experience is measured and its role in radiology, including its impact on clinical outcomes and reimbursement. Although typically applied to safety and clinical outcomes, quality improvement methodology can also be used to drive improvement efforts centered on patient experience. Applying an established framework for patient-centered care to radiology, this paper provides a number of examples of projects that are likely to yield significant improvement in patient satisfaction measures.

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