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Ajouter le résultat dans votre panierThe effects of landscape complexity on arable weed species diversity in organic and conventional farming / Indra Roschewitz in Journal of applied ecology, 42 ([01/01/2005])
Titre : The effects of landscape complexity on arable weed species diversity in organic and conventional farming Type de document : Imprimé Auteurs : Indra Roschewitz (1976-) ; Doreen Gabriel (1976-) ; Teja Tscharntke (1952-) ; Carsten Thies Année de publication : 2005 Article en page(s) : 873-882 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Malherbologie
[CBNPMP-Thématique] Messicole
[CBNPMP-Thématique] Science du paysage, division de l'espace en individualités, éléments du paysageRésumé : There is growing concern about declining species diversity in agro-ecosystems caused by agricultural intensification at the field and landscape scales. Species diversity of arable weeds is classically related to local abiotic factors and resource conditions. It is believed to be enhanced by organic farming but the surrounding landscape may also be important. This study assessed the ruderal vegetation, seed bank and seed rain in 24 winter wheat fields to examine the relative importance of organic vs. conventional farming and landscape complexity for weed species diversity. Diversity was partitioned into its additive components: alpha, beta and gamma diversity. Percentage arable land in a circular landscape sector of 1-km radius around each study site was used as an indicator of landscape complexity. Weed species diversity in the vegetation, seed rain and seed bank was higher in organic than in conventional fields. Increasing landscape complexity enhanced species diversity more strongly in the vegetation of conventional than organic fields, to the extent that diversity was similar in both farming systems when the landscape was complex. Species diversity of the seed bank was increased by landscape complexity irrespective of farming system. Overall diversity was largely determined by the high heterogeneity between and within the fields (beta diversity). Only in very few cases could higher weed species diversity in complex landscapes and/or organic farming be related to species dependence on landscape or farming system. Synthesis and applications. Local weed species diversity was influenced by both landscape complexity and farming system. Species diversity under organic farming systems was clearly higher in simple landscapes. Conventional vegetation reached similar diversity levels when the surrounding landscape was complex through the presence of refugia for weed populations. Consequently, agri-environment schemes designed to preserve and enhance biodiversity should not only consider the management of single fields but also of the surrounding landscape.
Lien pérenne : DOI : 10.1111/j.1365-2664.2005.01072.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=141297
in Journal of applied ecology > 42 [01/01/2005] . - 873-882Roschewitz, Indra (1976-), Gabriel, Doreen (1976-), Tscharntke, Teja (1952-), Thies, Carsten 2005 The effects of landscape complexity on arable weed species diversity in organic and conventional farming. Journal of applied ecology, 42: 873-882.Documents numériques
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Titre : Effects of ski piste preparation on alpine vegetation Type de document : Imprimé Auteurs : Sonja Wipf ; Christian Rixen (1969-) ; Markus Fischer ; Bernhard Schmid ; Veronika Stoeckli Année de publication : 2005 Article en page(s) : 303-316 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Etude d'aménagement, étude d'impact, actions anthropiques et leur impact
[CBNPMP-Thématique] RevégétalisationNote de contenu : 1 Ski resorts increasingly affect alpine ecosystems through enlargement of ski pistes, machine-grading of ski piste areas and increasing use of artificial snow. 2 In 12 Swiss alpine ski resorts, we investigated the effects of ski piste management on vegetation structure and composition using a pairwise design of 38 plots on ski pistes and 38 adjacent plots off-piste. 3 Plots on ski pistes had lower species richness and productivity, and lower abundance and cover of woody plants and early flowering species, than reference plots. Plots on machine-graded pistes had higher indicator values for nutrients and light, and lower vegetation cover, productivity, species diversity and abundance of early flowering and woody plants. Time since machine-grading did not mitigate the impacts of machine-grading, even for those plots where revegetation had been attempted by sowing. 4 The longer artificial snow had been used on ski pistes (2–15 years), the higher the moisture and nutrient indicator values. Longer use also affected species composition by increasing the abundance of woody plants, snowbed species and late-flowering species, and decreasing wind-edge species. 5 Synthesis and applications. All types of ski piste management cause deviations from the natural structure and composition of alpine vegetation, and lead to lower plant species diversity. Machine-grading causes particularly severe and lasting impacts on alpine vegetation, which are mitigated neither by time nor by revegetation measures. The impacts of artificial snow increase with the period of time since it was first applied to ski piste vegetation. Extensive machine-grading and snow production should be avoided, especially in areas where nutrient and water input are a concern. Ski pistes should not be established in areas where the alpine vegetation has a high conservation value.
Lien pérenne : DOI : 10.1111/j.1365-2664.2005.01011.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=148162
in Journal of applied ecology > 42 [01/01/2005] . - 303-316Wipf, Sonja, Rixen, Christian (1969-), Fischer, Markus, Schmid, Bernhard, Stoeckli, Veronika 2005 Effects of ski piste preparation on alpine vegetation. Journal of applied ecology, 42: 303-316.Documents numériques
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Titre : Evaluation of the ecological restoration potential of plant communities in Norway spruce plantations using a life-trait based approach Type de document : Imprimé Auteurs : Bruno Hérault ; Olivier Honnay ; Daniel Thoen Année de publication : 2005 Article en page(s) : 536-545 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Restauration des écosystèmes
[CBNPMP-Thématique] RevégétalisationMots-clés : Picea abies Note de contenu : 1.In Europe, intensively managed coniferous plantations rarely achieve similar natureconservation functions as deciduous woodlands. The ability to identify coniferous plan-tations that might be successfully converted to deciduous woodland is a key goal in for-est management. The herbaceous plant community composition of mature plantationsmay be an accurate selection criterion for stands that are most suitable for initiating theconversion process to deciduous forest.2.The herbaceous plant communities in Norway spruce plantations were analysedusing a functional group approach. The analysis was conducted in three steps: (i) iden-tification of emergent groups (EG) by multivariate classification; (ii) comparison of EGabundance between coniferous and deciduous stands (i.e. the target communities);(iii) partitioning the variation in EG abundance in coniferous plantations between forestmanagement, local environmental and regional variables.3.Seven EG were identified: two core forest groups (short geophytes and zoochoreousperennials), two groups from open habitats (annuals and helophytes) and three mixedgroups (anemochoreous perennials, graminoids and short perennials).4.Among the core forest groups, short geophytes were severely under-represented inplantations (because of their low dispersal abilities and specific habitat requirements)while zoochoreous perennials were slightly more abundant (because of their gooddispersal and competitive abilities).5.Regional variables largely influenced the abundance of core-forest EG. Restoration ofcommunities rich in zoochoreous perennials is far easier than restoring short geophyte-rich communities because of the different colonization abilities of these EG.6.Forest management variables were of secondary importance for the restorationpotential of plantations. Because generalist EG were favoured by low stand densities,forest practitioners should avoid large thinning operations.7.Local environmental variables played a minor role in determining EG abundance.However, short geophytes preferred rather high soil pH values and were thereforenegatively affected by acidification caused by coniferous litter.8.Synthesis and applications.The performance of short geophytes is the key to conversionsuccess of Norway spruce plantations to deciduous forest. Stands located on base-richsoils and in landscapes with high forest connectivity are the most appropriate candidatesfor initiating the conversion process. For other types of stands, future work should explorethe possibility of restoring other land-use types, such as annually mown meadows. Lien pérenne : DOI : 10.1111/j.1365-2664.2005.01048.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=148187
in Journal of applied ecology > 42 [01/01/2005] . - 536-545Hérault, Bruno, Honnay, Olivier, Thoen, Daniel 2005 Evaluation of the ecological restoration potential of plant communities in Norway spruce plantations using a life-trait based approach. Journal of applied ecology, 42: 536-545.Documents numériques
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