197 research outputs found
Teaching and Learning Issues in the Disciplines: Leisure Studies
This report is submitted to the Higher Education Academy (HEA) on behalf of the Leisure Studies Association (LSA). The LSA aims to foster research in Leisure Studies; to promote interest in Leisure Studies and advance education in this field; to encourage debate through publications, and an international journal Leisure Studies; to stimulate the exchange of ideas on contemporary leisure issues; to disseminate knowledge of Leisure Studies to create the conditions for better-informed decisions by policy makers. The LSA is a member society of the Academy of Social Sciences
Sensitivity of stomatal conductance to soil moisture: Implications for tropospheric ozone
Abstract. Soil moisture and water stress play a pivotal role in regulating stomatal
behaviour of plants; however, in the last decade, the role of water
availability has often been neglected in atmospheric chemistry modelling
studies as well as in integrated risk assessments, despite the fact that
plants remove a large amount of atmospheric compounds from the lower
troposphere through stomata. The main aim of this study is to evaluate, within the chemistry transport
model CHIMERE, the effect of soil water limitation on stomatal conductance
and assess the resulting changes in atmospheric chemistry testing various
hypotheses of water uptake by plants in the rooting zone. Results highlight how dry deposition significantly declines when soil
moisture is used to regulate the stomatal opening, mainly in the semi-arid
environments: in particular, over Europe the amount of ozone removed by dry
deposition in one year without considering any soil water limitation to
stomatal conductance is about 8.5 TgO3, while using a dynamic layer
that ensures that plants maximize the water uptake from soil, we found a
reduction of about 10 % in the amount of ozone removed by dry deposition
(∼ 7.7 TgO3). Although dry deposition occurs from the top of canopy to
ground level, it affects the concentration of gases remaining in the lower
atmosphere, with a significant impact on ozone concentration (up to 4 ppb)
extending from the surface to the upper troposphere (up to 650 hPa). Our results shed light on the importance of improving the parameterizations
of processes occurring at plant level (i.e. from the soil to the canopy) as
they have significant implications for concentration of gases in the lower
troposphere and resulting risk assessments for vegetation or human health
Saffron: A multitask neuroprotective agent for retinal degenerative diseases
Both age related macular degeneration (AMD) and light induced retinal damage share the common major role played by oxidative stress in the induction/progression of degenerative events. Light damaged (LD) rats have been widely used as a convenient model to gain insight into the mechanisms of degenerative disease, to enucleate relevant steps and to test neuroprotectants. Among them, saffron has been shown to ameliorate degenerative processes and to regulate many genes and protective pathways. Saffron has been also tested in AMD patients. We extended our analysis to a possible additional effect regulated by saffron and compared in AMD patients a pure antioxidant treatment (Lutein/zeaxanthin) with saffron treatment. Methods: Animal model. Sprague-Dawley (SD) adult rats, raised at 5 lux, were exposed to 1000 lux for 24 h and then either immediately sacrificed or placed back at 5 lux for 7 days recovery period. A group of animals was treated with saffron. We performed in the animal model: (1) SDS-PAGE analysis; (2) Western Blotting (3) Enzyme activity assay (4) Immunolabelling; in AMD patients: a longitudinal open-label study 29 (+/- 5) months in two groups of patients: lutein/zeaxanthin (19) and saffron (23) treated. Visual function was tested every 8 months by ERG recordings in addition to clinical examination. Results: Enzymatic activity of MMP-3 is reduced in LD saffron treated retinas and is comparable to control as it is MMP-3 expression. LD treated retinas do not present "rosettes" and microglia activation and migration is highly reduced. Visual function remains stable in saffron treated AMD patients while deteriorates in the lutein/zeaxanthin group. Conclusion: Our results provide evidence of an additional way of action of saffron treatment confirming the complex nature of neuroprotective activities of its chemical components. Accordingly, long term follow-up in AMD patients reveals an added value of saffron supplementation treatment compared to classical antioxidant protocol
The Floodplain Woods of Tuscany
The contraction of lowland forests throughout Europe began in remote times and then intensified strongly with land reclamation by agriculture and urbanization during the first half of the last century. We present a map of the Floodplain Woods of Tuscany on a scale of 1:300,000 as a synthesis of that built at the scale of 1:10,000 and the methods used to obtain it. Nearly 90% of the patches contain habitats of concern to conservation, according to the Habitat Directive. The Tuscan Floodplain Woods remained prevalent in coastal areas, where some levels of protection are guaranteed by the presence of several protected areas, whereas they have practically vanished in the other parts of the regional territory. The resulting patches are very small and distant from each other, so only in-depth management of all potential floodplain forest areas, taking into consideration patches for their regeneration, can be useful to assure their conservation
Effects of climate, soil, structure and management on functional traits in forest understory
Many studies explored how the observed pattern of plant functional traits
(PFTs) may be influenced by environmental variables. However, studies on
forest ecosystems including also stand structure and management are lacking.
A first attempt to test the relative effect of variables related to the latter
groups, together with climate and soil gradients, on the community weighted
mean (CWM) values of PFTs was performed on forest understory in Italy.
The Level I biodiversity dataset (extensive CONECOFOR network) has
been used, based on a probabilistic sampling design, by 201 sites on a representative
16 x 16 km systematic grid. Following a harmonized protocol (ICP Forests,
BioSoil-Biodiversity project) 29 explanatory variables were recorded and
four plots 10x10 m have been surveyed for vascular specific cover, on each site.
Variance partitioning was used to identify the relative role of climatic, soil,
structural and management variables on the CWM values of specific leaf area
(SLA), plant height (H) and seed mass (SM). Redundancy analysis was used to
assess the relation between traits and variables.
The combination of the selected variables explained the variation of H (34.3%)
better than SLA (14.9%) and SM (11.1%). Climate alone, and in combination with
other variables, demonstrated to explain the largest proportion of the variation for
H (29.5%) and SM (9.3%); however, also structure and soil showed a relevant role.
Forest management (9.9%) and structure (5.4%) were the main drivers for SLA.
Considering a gradient of increasing temperature, aridity and nutrient
availability, we detected plant understory communities with higher mean values
of H and SM. High-SLA communities appeared in forests characterized
by a larger amount of deadwood.In forest understory vegetation, the PFTs pattern is linked to a complex
combination of variables. Not only climate and soil, but also forest structure
and management played a role, suggesting the importance of taking into
account such parameters in future research, at larger spatial scale including
different Country-level policies. The variation of SLA, H and SM is controlled
by different variables, making no obvious any attempt to predict the effects
of climate and land-use changes on understory functional signature
On the tracks of Nitrogen deposition effects on temperate forests at their southern European range - an observational study from Italy
We studied forest monitoring data collected at permanent plots in Italy over the period 2000\u20132009 to identify the possible impact of nitrogen (N) deposition on soil chemistry, tree nutrition and growth. Average N throughfall (N-NO3+N-NH4) ranged between 4 and 29 kg ha 1 yr 1, with Critical Loads (CLs) for nutrient N exceeded at several sites. Evidence is consistent in pointing out effects of N deposition on soil and tree nutrition: topsoil exchangeable base cations (BCE) and pH decreased with increasing N deposition, and foliar nutrient N ratios (especially N : P and N : K) increased. Comparison between bulk openfield and throughfall data suggested possible canopy uptake of N, levelling out for bulk deposition >4\u20136 kg ha 1 yr 1. Partial Least Square (PLS) regression revealed that - although stand and meteorological variables explained the largest portion of variance in relative basal area increment (BAIrel 2000\u20132009) - N-related predictors (topsoil BCE, C : N, pH; foliar N-ratios; N deposition) nearly always improved the BAIrel model in terms of variance explained (from 78.2 to 93.5%) and error (from 2.98 to 1.50%). N deposition was the strongest predictor even when stand, management and atmosphere-related variables (meteorology and tropospheric ozone) were accounted for. The maximal annual response of BAIrel was estimated at 0.074\u20130.085% for every additional kgN. This corresponds to an annual maximal relative increase of 0.13\u20130.14% of carbon sequestered in the above-ground woody biomass for every additional kgN, i.e. a median value of 159 kgC per kgN ha 1 yr 1 (range:
50\u2013504 kgC per kgN, depending on the site). Positive growth response occurred also at sites where signals of possible, perhaps recent N saturation were detected. This may suggest a time lag for detrimental N effects, but also that, under continuous high N input, the reported positive growth response may be not sustainable in the long-term
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