53,791 research outputs found
Creating value(s) by integrating local and extra-local resources in cereal production in the Swiss Alps
This paper explores the long-term prospect of alternative, local food initiatives, taking a particular interest in the development of the embedded local values, understood as economic as well as cultural values. Analysing the case of a cooperative of mountain cereal farmers in Switzerland, we show that sustaining local values-based quality is a dynamic process of linking local and extra-local resources. Our results first show the importance of both proximity and place in constructing the ‘local’ by the cooperative. Second, product flow, knowledge and information exchange, quality control, and innovation are governed by both horizontal and vertical relationships between local and extra-local resources, and these multiple relationships build trust in the network and beyond. This, thirdly, enables the cooperative to continuously reproduce its values by weaving them into a cycle of quality creation. We conclude that we need to understand the characteristic values-based quality of the cooperative’s products as the result of a recurring cycle of local and extra-local knowledge creation and resource exchange
Extending a geo-catalogue with matching capabilities
To achieve semantic interoperability, geo-spatial applications need to be equipped with tools able to understand user terminology that is typically different from the one enforced by standards. In this paper we summarize our experience in providing a semantic extension to the geo-catalogue of the Autonomous Province of Trento (PAT) in Italy. The semantic extension is based on the adoption of the S-Match semantic matching tool and on the use of a specifically designed faceted ontology codifying domain specific knowledge. We also briefly report our experience in the integration of the ontology with the geo-spatial ontology GeoWordNet
Local adaptation with high gene flow: temperature parameters drive adaptation to altitude in the common frog (Rana temporaria)
Both environmental and genetic influences can result in phenotypic variation. Quantifying the relative contributions of local adaptation and phenotypic plasticity to phenotypes is key to understanding the effect of environmental variation on populations. Identifying the selective pressures that drive divergence is an important, but often lacking, next step. High gene flow between high- and low-altitude common frog (Rana temporaria) breeding sites has previously been demonstrated in Scotland. The aim of this study was to assess whether local adaptation occurs in the face of high gene flow and to identify potential environmental selection pressures that drive adaptation. Phenotypic variation in larval traits was quantified in R. temporaria from paired high- and low-altitude sites using three common temperature treatments. Local adaptation was assessed using QST–FST analyses, and quantitative phenotypic divergence was related to environmental parameters using Mantel tests. Although evidence of local adaptation was found for all traits measured, only variation in larval period and growth rate was consistent with adaptation to altitude. Moreover, this was only evident in the three mountains with the highest high-altitude sites. This variation was correlated with mean summer and winter temperatures, suggesting that temperature parameters are potentially strong selective pressures maintaining local adaptation, despite high gene flow
Campylopus, a modern and successful genus!?
Campylopus with nearly 200 revised species is one of the largest genera of mosses in the world and has extremely broad geographical, altitudinal and ecological ranges. Factors to be considered for the rich speciation are 1) the enormous anatomical plasticity of the structure of the costa, 2) the ability for vegetative propagation utilizing different methods, and 3) the special twist mechanism of the cygneous setae. Phytogeographical interpretations of present ranges of species of Campylopus lead to the conclusion that this genus is of Gondwanalandic origin. Most of the species seem to be cool temperate in origin. They have adapted to dry habitats in the Mesozoic and invaded the tropical mountains during the Tertiary, accompanied by rich speciation. This is supported by the physiology of these species. According to preliminary gas exchange measurements, tropical montane species do not differ from temperate species, and are not able to stand climatic conditions of the tropical lowland rainforests; a relatively young habitat for bryophytes. A cladistic analysis of the infrageneric categories of Campylopus using phytogeographical evaluations of apomorphic character states shows that the section Homalocarpus seems to be the most primitive and the subgenera Campylopidulum and Thysanomitrion the most derived
Beta-diversity of Central European forests decreases along an elevational gradient due to the variation in local community assembly processes
Beta-diversity has been repeatedly shown to decline with increasing
elevation, but the causes of this pattern remain unclear, partly because they
are confounded by coincident variation in alpha- and gamma-diversity. We used
8,795 forest vegetation-plot records from the Czech National Phytosociological
Database to compare the observed patterns of beta diversity to null-model
expectations (beta-deviation) controlling for the effects of alpha- and
gamma-diversity. We tested whether \b{eta}-diversity patterns along a 1,200 m
elevation gradient exclusively depend on the effect of varying species pool
size, or also on the variation of the magnitude of community assembly
mechanisms determining the distribution of species across communities (e.g.,
environmental filtering, dispersal limitation). The null model we used is a
novel extension of an existing null-model designed for presence/absence data
and was specifically designed to disrupt the effect of community assembly
mechanisms, while retaining some key features of observed communities such as
average species richness and species abundance distribution. Analyses were
replicated in ten subregions with comparable elevation ranges. Beta-diversity
declined along the elevation gradient due to a decrease in gamma-diversity,
which was steeper than the decrease in alpha-diversity. This pattern persisted
after controlling for alpha- and gamma-diversity variation, and the results
were robust when different resampling schemes and diversity metrics were used.
We conclude that in temperate forests the pattern of decreasing beta-diversity
with elevation does not exclusively depend on variation in species pool size,
as has been hypothesized, but also on variation in community assembly
mechanisms. The results were consistent across resampling schemes and diversity
measures, thus supporting the use of vegetation plot databases for
understanding...Comment: Accepted version 25 pages, 5 figures, 1 tabl
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