1,231 research outputs found

    Land degradation means a loss of management options

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    This essay approaches land degradation by targeting its ultimate thermodynamic causes, rather than its immediate environmental consequences. The objective is to make some propositions that could help understand the essence of the process, and contribute to a theoretical framework to be developed. These propositions are: 1. Human populations are an ecosystem component, not an external driver. 2. Coupled Human and Natural Systems (CHANS) tend to increase their overall complexity over time. CHANS complexity cannot feasibly be managed. 3. CHANS are made up of two types of subsystems, a consuming Foreland (FL) consisting of the human population, and a producing Backland (BL) in its environment. 4. The FL maintains its order at the expense of simplifying the BL, which becomes an entropy sink. This is the essence of ecological degradation, which is inherent to CHANS persistence. 5. Land degradation is an ecological state, not a landscape type. Hence it should be assessed within a complete range of states of ecological maturity. 6. Land use creates degradation proportional to the simplification of the ecosystems involved. Such degradation can be defined as a decrease in exergy, and results in loss of management options. Three associated corollaries are: a) A more effective target may be to regulate rather than attempt to eliminate land degradation; b) Monitoring ecological degradation trajectories may be more effective than assessing land degradation states; c) Land degradation can be decreased by maximizing the potential for interconversion between land uses.This work was supported by the European Commission under the DeSurvey IP [FP6 Integrated Project contract no. 003950], the European Space Agency under the DesertWatch Extension project [DUE contract no. 18487/04/I-LG] and Tragsatec (Grupo Tragsa) [contract no. 25.604]

    Piedra philosophal

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    Copia digital. Valladolid : Junta de Castilla y LeĂłn. ConsejerĂ­a de Cultura y Turismo, 2009-2010Port con orla tip

    Mediterranean Landscape Re-Greening at the Expense of South American Agricultural Expansion

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    The stabling of livestock farming implies changes in both local ecosystems (regeneration of forest stands via reduced grazing) and those located thousands of kilometers away (deforestation to produce grain for feeding livestock). Despite their importance, these externalities are poorly known. Here we evaluated how the intensification and confinement of livestock in Spain has affected forest surface changes there and in South America, the largest provider of soybeans for animal feed to the European Union. For this purpose, we have used Spanish soybean import data from Brazil, Paraguay and Argentina and a land condition map of Spain. The area of secondary forest in Spain that has regenerated as a result of livestock stabling has been ~7000 kha for the decade 2000–2010. In the same period, 1220 kha of high value South American ecosystems (e.g. Chaco dry Forest, Amazonian rainforest or Cerrado) have been deforested. While these figures may offer a favorable interpretation of the current industrial livestock production, it is not possible to speak of compensation when comparing the destruction of well-structured ecosystems, such as primary South American forests, with the creation of secondary forest landscapes in Spain, which are also prone to wildfires. Our results highlight how evaluating land use change policies at a national or regional level is an incomplete exercise in our highly telecoupled and globalized world.This study was funded by the European Research Council grant agreement nº 647038 (BIODESERT). FTM acknowledges support from Generalitat Valenciana (CIDEGENT/2018/041)

    TĂ­tulo: Tractatus de spe et charitate.

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    Colofón.Sign.: A-Z\p8\s, 2A-2I\p8\s.Port. con esc. de la compañía de Jesús y orla tip

    TĂ­tulo: Tractatus de Fide Divina.

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    Sign.: [calderón]>84884<.Port. con orla tip. y esc. de la Compañia de Jesus

    TĂ­tulo: Tractatus de fide divina.

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    Sign.: A-Z\p8\s, 2A-2F\p8\s.Errores de pag., de p. 429 pasa a 440, de p. 449 pasa a 446.Port. con orla tip.Port. con esc. xil. de la Compañía de Jesús

    Abrupt fragmentation thresholds of eight zonal forest types in mainland Spain

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    This study quantifies patchiness of eight types of zonal forests in three biogeographic regions of mainland Spain (Atlantic, Alpine and Mediterranean) which together occupy 1,726,578 ha. Their dominant species and European Habitat Type codes (EU Directive 92/43 EEC) are: Fagus sylvatica (9120, 9130 and 9150), Quercus robur and Q. pyrenaica (9230), Q. suber (9330), Pinus uncinata (9430), P. nigra ssp. salzmannii (9530) and P. pinea (subset of 9540). We applied the Korcak’s exponent B, which describes a hyperbolic relationship between the cumulative frequency of the number of patches and their sizes. The objectives were: 1) detect possible patch size intervals in which B varies significantly, explicitly identifying area thresholds, and 2) contribute to development of a robust forest mass fragmentation indicator. Exponent B was found by segmented regression analysis. The vector data were extracted from a filtered version of the Spanish Forest Map 1:50,000 (1997–2006). After validating the procedure by applying it to a previously published dataset, we found that in all cases the patch size range could be split into two significant intervals around relatively small threshold areas of 27–101 ha. In the one on the left, the rate at which relatively large patches become less abundant was always very slow (B = 0.017–0.094). After this threshold had been passed, the rate increased abruptly (B = 1.100–2.590). Both this high fragmentation and its lack of parsimony were unexpected in zonal forest types. General interpretations converge to the coexistence of forest patches of different ages due to human pressure events.This work was supported by Tragsatec (Grupo Tragsa) [contract numbers 39.916 and 38.454]; and the Spanish National R&D&I Plan (including ERDF funds) [grant number CGL2016-78075-P]

    Consistency of expert product reviews: an application to wine guides

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    Purpose. The purpose of this study is to examine the internal consistency of wine guides by comparing the judgements of experts who taste and review wines. It further classifies the wines into categories to establish whether expert reviews of similar wines are coherent. Design/methodology/approach. Sentiment analysis based on natural language processing techniques was used to compare quantitative and qualitative reviews between experts. In addition, a finite mixture model was used to classify wines into categories to analyse internal consistency between ratings. Findings. The results for a sample of more than 200,000 Wine Enthusiast ratings reveal significant differences between the experts’ reviews, which shows that there are no standard criteria for reviewing the wines included in the guide. Originality. Wine guides are amongst the most widely used marketing resources in the wine industry. They provide a signal to consumers about the quality of wines, guiding their purchase decisions, whilst also influencing the reputation of brands and the performance of the companies producing these wines. Thus, the main contribution of this study is to improve comparisons of the assessments by wine guide experts in relation to the wines they taste. This analysis will make it possible to verify their effectiveness as a source of information for consumers and will allow wine producers to make more accurate assessments of the potential impact of experts on their performance

    A dataset with complete geographic distributions of eight zonal monospecific forest types in mainland Spain

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    Distribution area and surface are both parameters of paramount importance for habitat management, monitoring and conservation. Here we present the distribution of eight zonal forest types of mainland Spain that are consistent with the Habitat Types (HT) listed in Annex I of the European Union Habitats Directive 92/43 EC. Their dominant species and HT codes are Fagus sylvatica (9120, 9130 and 9150), Quercus robur and Q. pyrenaica (9230), Q. suber (9330), Pinus uncinata (9430), P. nigra ssp. salzmannii (9530) and P. pinea (subset of 9540). These distributions are based on tesserae from the 1:50,000 Spanish Forest Map and are the result of sorting assisted by supplementary databases. The distributions are presented as vector coverages, and provide three information levels of increasing detail: geographic distribution, basic forest type and structural forest patch. Two R scripts are also included with the dataset. They implement a segmented regression approach to investigate forest fragmentation on these or other patch-like data.Tragsatec (Grupo Tragsa) funded this research through the following projects: Climatic Regionalization and Ecosystem Fragmentation (Contract No. 39.916) and Methods to Estimate Rates of Change of Occupied Surface of Forest and Shrubland Habitat Types within their Respective Distribution Ranges (Contract No. 38.454)

    NPG–TRIS Thermal Storage System. Quantification of the Limiting Processes: Sublimation and Water’s Adsorption

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    The NPG–TRIS binary system (NPG = (CH3)2C(CH2OH)2 = 2,2-dimetyl-1,3-propanodiol; TRIS = NH2C(CH2OH)3 = 2-Amino-2-(hydroxymethyl)-1,3-propanediol) was intensively investigated as a thermal energy storage system, due to the reversibility of its phase transitions and their associated energy. An adapted methodology was applied to precisely quantify its sublimation tendency. Relevant thermochemical data were revisited and evaluated using some specific experimental procedures. We also determined that the widely accepted requirement of working in an inert atmosphere to avoid deviations due to hygroscopicity is not necessary. Nevertheless, to take advantage of the energetic properties of the NPG–TRIS system, closed containers will be required to avoid NPG losses, due to its quantitatively determined high sublimation tendency.This study was financially supported by the Basque Government (IT1301-19, IT1364-19) and through the Elkartek18 R&D program, by the University of the Basque Country UPV/EHU (GIU19/019), and by the Ministry of Science and Innovation of Spain (PID2019-106644GB-I00
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