13 research outputs found

    Modelo bioético para el análisis de la habitabilidad en la vivienda

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    La habitabilidad se refiere a estas configuraciones del espacio edificado, y se expresa en las diferentes escalas y entornos que el ser humano ha creado para su desarrollo como especie.La habitabilidad, en palabras de Macías, es “la capacidad de los espacios construidos para satisfacer las necesidades objetivas y subjetivas de los individuos, en estrecha relación con los ambientes socioculturales y naturales hacia la mejora de la calidad de vida”. (De Hoyos Martínez, et al., 2014)El ser humano ha modificado la configuración del espacio que lo rodea a lo largo de la historia, con el fin de hacer del mundo un lugar habitable, adaptándolo para proveerse de sitios para vivir, descansar, transitar, en fin, para realizar todas sus actividades cotidianas. Dichas modificaciones tienen lugar en las diversas escalas del espacio construido, entre los que se encuentran la vivienda, el barrio y la ciudad, y que, según Paola Coppola (2004), varían de acuerdo con las características socio-territoriales dentro de las que son creadas

    Mature stand developmental stage has ceased to constitute the most suitable habitat for the capercaillie in the Augustów Forest, Poland

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    Abstract Background Forest management affects the habitat conditions for many forest-dwelling species. Among them, the capercaillie (Tetrao urogallus) is a rare forest grouse inhabiting old, mature forests. We compared the structure of forest habitat among 9 active and 9 abandoned leks in the Augustów Forest (North-Eastern Poland), within a radius of 1 km of the leks, defined as the Key Areas for the capercaillie in lowland temperate forest. Habitat measurements were conducted on 1779 circular plots. Assessments made on all plots related to 13 habitat variables measured or noted in the field, including stand structure, canopy closure, stand developmental stage, percentage of Scots pine (Pinus sylvestris), soil fertility and soil moisture, the share of undergrowth, the cover of shrubs, the cover of bilberry (Vaccinium sp.), and the presence of certain habitat elements important to the capercaillie. Results To compare the still-occupied and the abandoned KAs for the capercaillie, a logistic regression model was developed. The variables best explaining differences between these two categories were: the occurrence of undergrowth layers, canopy closure in the second canopy layer, and stand age. According to the model, with the increase of the shrub-layer cover as well as the density of trees, the probability of the presence of the capercaillie decreased. The capercaillie in the area of the Augustów Forest occupy mainly dry and poor, middle-aged, pine-dominated forests, with a moderate extent of stand canopy closure and only weakly-developed layers of undergrowth. Conclusions The filling-in of mature stands with sub-canopy trees and shrubs (the process which is stimulated by climate change and site eutrophication) causes structural changes, which are unfavourable to the capercaillie. This might explain why in the course of the recent decades the capercaillie has abandoned the oldest stands, distinguished by the presence of bigger shares of undergrowth. The capercaillie has shifted to younger stands, which reveal a lesser extent of canopy closure and a more limited development of understorey vegetation

    Supplementary data

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    This data file contains tree quantities and basal area sums in 50mm-wide classes of diameter at breast height (dbh), given separately for (a) all live, ingrowth and outgrowth trees, (b) 8 major woodland community types, (c) 5 research plots, (d) 57 separate community patches, (e) 7 subsequent measurement censuses, and (f) 11 tree species. Additionally, community patch areas are given

    Sheltered or suppressed? Tree regeneration in unmanaged European forests

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    Tree regeneration is a key demographic process influencing long-term forest dynamics. It is driven by climate, disturbances, biotic factors and their interactions. Thus, predictions of tree regeneration are challenging due to complex feedbacks along the wide climatic gradients covered by most tree species. The stress gradient hypothesis (SGH) provides a framework for assessing such feedbacks across species ranges, suggesting that competition between trees is more frequent under favourable conditions, whereas reduced competition (i.e. positive interactions) is more likely under climatic stress. Moreover, tree life-history strategies (LHS) may shed light on how and whether the SGH explains regeneration of different tree species. To address these topics, we developed statistical models based on >50,000 recruitment events observed for 24 tree species in an extensive permanent plot network (6540 plots from 299 unmanaged European temperate, boreal and subalpine forests) covering a wide climatic gradient. We found that the effects of Leaf Area Index (as a proxy for competition) on tree recruitment changed along climatic gradients but in a species-specific manner. Competition predominates, with its intensity decreasing under stressful conditions for most species, as predicted by the SGH. However, positive interactions were only evident for a few species. Additionally, the ability of the SGH to explain patterns of competition and positive interactions across the gradients differed among species, with some differences and exceptions that may be related to varying LHS. Synthesis. Our study shows that competition between trees toward climatic stress decreases systematically but depends on species stress tolerance to climate and shade. These findings explain within- and between-species differences in tree recruitment patterns in European temperate forests. Moreover, our findings imply that projections of forest dynamics along wide climatic gradients and under climate change must accommodate both competition and positive interactions, as they strongly affect rates of community turnover

    Multi-decade tree mortality in temperate old-growth forests of Europe and North America

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    Aim: Old-growth, mesic temperate forests are often assumed to be structured by gap-phase processes, resulting in quasi-equilibrial long-term dynamics. This assumption influences management focused on simulation of natural disturbance dynamics and is embedded in most models of forest successional dynamics. We use multi-decade monitoring of permanent plots in old-growth forests to assess demographic assumptions directly with respect to tree mortality rates. Location: Sixteen sites in mesic, temperate old-growth forests in eastern North America and Europe with multi-decade monitoring. Time period: Variable across sites, spanning c. 20%78 years from 1936 to 2014. Major taxa studied: Tree species of late-successional, cool-temperate forests of Europe and eastern North America. Methods: We calculated and compared the annualized mortality rates (m), with confidence intervals, by species, size class and measurement interval, for tree species of sufficient abundance. Results: Retrospective analysis shows dynamic and diverse demographic properties across populations and sites. Stand-scale mortality rates of 0.7%2.5%/ year average higher than previous estimates for old-growth temperate forests. Variations among species, over time and among size classes, suggest that gap-phase models are inadequate to explain stand dynamics, implying instead that rare disturbance events of moderate severity have long-lasting effects in old-growth forests and that indirect anthropogenic influences affect old-growth, unlogged forests. Main conclusions: Multi-decade baseline data, essential for understanding community assembly and long-term dynamics in these %slow systems,% are rare and poorly integrated. Our analysis demonstrates the value of the few long-term, %legacy% data sets. Results suggest that differences in life history interact with complex disturbance histories, resulting in non-equilibrial dynamics in old-growth temperate tree communities, and that changes in disturbance patterns through anthropogenic climate change might, there%fore, be an important driver of ecosystem change

    Multi‐decade tree mortality in temperate old‐growth forests of Europe and North America: Non‐equilibrial dynamics and species‐individualistic response to disturbance

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    Aim: Old-growth, mesic temperate forests are often assumed to be structured by gap-phase processes, resulting in quasi-equilibrial long-term dynamics. This assumption influences management focused on simulation of natural disturbance dynamics and is embedded in most models of forest successional dynamics. We use multi-decade monitoring of permanent plots in old-growth forests to assess demographic assumptions directly with respect to tree mortality rates. Location: Sixteen sites in mesic, temperate old-growth forests in eastern North America and Europe with multi-decade monitoring. Time period: Variable across sites, spanning c. 20%78 years from 1936 to 2014. Major taxa studied: Tree species of late-successional, cool-temperate forests of Europe and eastern North America. Methods: We calculated and compared the annualized mortality rates (m), with confidence intervals, by species, size class and measurement interval, for tree species of sufficient abundance. Results: Retrospective analysis shows dynamic and diverse demographic properties across populations and sites. Stand-scale mortality rates of 0.7%2.5%/ year average higher than previous estimates for old-growth temperate forests. Variations among species, over time and among size classes, suggest that gap-phase models are inadequate to explain stand dynamics, implying instead that rare disturbance events of moderate severity have long-lasting effects in old-growth forests and that indirect anthropogenic influences affect old-growth, unlogged forests. Main conclusions: Multi-decade baseline data, essential for understanding community assembly and long-term dynamics in these %slow systems,% are rare and poorly integrated. Our analysis demonstrates the value of the few long-term, %legacy% data sets. Results suggest that differences in life history interact with complex disturbance histories, resulting in non-equilibrial dynamics in old-growth temperate tree communities, and that changes in disturbance patterns through anthropogenic climate change might, there%fore, be an important driver of ecosystem change
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