63 research outputs found

    Landmænds opfattelser af natur og aktuel naturkvalitet på bedriften. Cross cutting rapport for CC3

    Get PDF
    Landmanden er en væsentlig aktør i forhold til at udvikle og forbedre natur og landskabskvaliteter på de økologiske bedrifter. Spørgsmålet er imidlertid, om der er en sammenhæng mellem den måde landmanden opfatter værdier i natur og landskab på, den måde han handler og forvalter i forhold til disse værdier, og så den naturkvalitet han set udfra en biologisk synsvinkel har på sin bedrift. Det spørgsmål blev der arbejdet med i en cross cutting øvelse i projektet Naturkvalitet i økologisk jordbrug

    Strong microsite control of seedling recruitment in tundra

    Get PDF
    The inclusion of environmental variation in studies of recruitment is a prerequisite for realistic predictions of the responses of vegetation to a changing environment. We investigated how seedling recruitment is affected by seed availability and microsite quality along a steep environmental gradient in dry tundra. A survey of natural seed rain and seedling density in vegetation was combined with observations of the establishment of 14 species after sowing into intact or disturbed vegetation. Although seed rain density was closely correlated with natural seedling establishment, the experimental seed addition showed that the microsite environment was even more important. For all species, seedling emergence peaked at the productive end of the gradient, irrespective of the adult niches realized. Disturbance promoted recruitment at all positions along the environmental gradient, not just at high productivity. Early seedling emergence constituted the main temporal bottleneck in recruitment for all species. Surprisingly, winter mortality was highest at what appeared to be the most benign end of the gradient. The results highlight that seedling recruitment patterns are largely determined by the earliest stages in seedling emergence, which again are closely linked to microsite quality. A fuller understanding of microsite effects on recruitment with implications for plant community assembly and vegetation change is provided

    Female labour market outcomes and the impact of maternity leave policies

    Get PDF
    ABSTRACT: This paper shows how family policies aimed at reconciling the pressures of family and work generate substantial variation in labour market outcomes across developed countries. We use a life-cycle model of female labour supply and savings behaviour, calibrated to the US economy, to assess the effect of introducing to the US a maternity leave policy similar to Scandinavian-type policies. We focus on the impact on gender differences in participation and in wages. We distinguish between the effect of the job protection offered by maternity leave and the effect of income replacement. Job protection leads to substantial increases in participation of mothers with children under 6, but with little long term effects. The effects on wages are minimal, with negative selection effects offsetting the reduced human capital depreciation. Income replacement has a limited impact on participation or wages.Virginia Sánchez-Marcos thanks the Spanish Ministry of Science and Technology for Grant ECO2009-09614 and RecerCaixa for financial support

    European Vegetation Archive (EVA): An integrated database of European vegetation plots

    Get PDF
    © 2016 International Association for Vegetation Science. The European Vegetation Archive (EVA) is a centralized database of European vegetation plots developed by the IAVS Working Group European Vegetation Survey. It has been in development since 2012 and first made available for use in research projects in 2014. It stores copies of national and regional vegetation- plot databases on a single software platform. Data storage in EVA does not affect on-going independent development of the contributing databases, which remain the property of the data contributors. EVA uses a prototype of the database management software TURBOVEG 3 developed for joint management of multiple databases that use different species lists. This is facilitated by the SynBioSys Taxon Database, a system of taxon names and concepts used in the individual European databases and their corresponding names on a unified list of European flora. TURBOVEG 3 also includes procedures for handling data requests, selections and provisions according to the approved EVA Data Property and Governance Rules. By 30 June 2015, 61 databases from all European regions have joined EVA, contributing in total 1 027 376 vegetation plots, 82% of them with geographic coordinates, from 57 countries. EVA provides a unique data source for large-scale analyses of European vegetation diversity both for fundamental research and nature conservation applications. Updated information on EVA is available online at http://euroveg.org/eva-database

    Birth Order and the Intrahousehold Allocation of Time and Education

    No full text
    This paper develops a model of intrahousehold allocation with endogenous fertility, which captures the relationship between birth order and investment in children. It shows that a birth order effect in intrahouse hold allocation can arise even without assumptions about parental preferences for specific birth orders of children or genetic endowments varying by birth order. The important contribution is that fertility is treated as endogenous, a possibility that other models of intrahousehold allocation have ignored. The implications of the model are that children with higher birth orders (that is, who are born later) have an advantage over siblings with lower birth orders, and that parents who are inequality-averse will not have more than one child. The model furthermore shows that not taking account of the endogeneity of fertility when analyzing intrahousehold allocation may seriously bias the results. The effects of a child's birth order on its human capital accumulation are analyzed using a longitudinal data set from the Philippines that covers a very long period. We examine the effects of birth order on both number of hours in school during education and completed education. The results for both are consistent with the predictions of the model. © 2004 President and Fellows of Harvard College and the Massachusetts Institute of Technology.

    Naturkvalitet og biodiversitet

    No full text
    Oversigt over betydningen af Økologisk jordbrug for natur og biodiversite
    corecore