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Conservatoire botanique national des Pyrénées et de Midi-Pyrénées

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Impact of invasive plants on the species richness, diversity and composition of invaded communities / Martin Hejda in Journal of ecology, 97 (2009) 

Public Citation [article]  inJournal of ecology > 97 (2009) . - 393-403 Titre : Impact of invasive plants on the species richness, diversity and composition of invaded communities Type de document : Imprimé Auteurs : Martin Hejda ; Petr Pyšek ; Vojtěch Jarošík (1958-2013) Année de publication : 2009 Article en page(s) : 393-403 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Plantes subspontanées, naturalisées, envahissantes Résumé : 1 Much attention has been paid to negative effects of alien species on resident communities but studies that quantify community-level effects of a number of invasive plants are scarce. We address this issue by assessing the impact of 13 species invasive in the Czech Republic on a wide range of plant communities. 2 Vegetation in invaded and uninvaded plots with similar site conditions was sampled. All species of vascular plants were recorded, their covers were estimated and used as importance values for calculating the Shannon diversity index H′, evenness J and Sørensen index of similarity between invaded and uninvaded vegetation. 3 With the exception of two invasive species, species richness, diversity and evenness were reduced in invaded plots. Species exhibiting the greatest impact reduced species numbers per plot and the total number of species recorded in the communities sampled by almost 90%. A strong reduction of species number at the plot scale resulted in a marked reduction in the total species number at the landscape scale, and in less similarity between invaded and uninvaded vegetation. The decrease in species richness in invaded compared to uninvaded plots is largely driven by the identity of the invading species, whereas the major determinants of the decrease in Shannon diversity and evenness are the cover and height of invading species, and differences between height and cover of invading and dominant native species, independent of species identity. 4 Synthesis. Management decisions based on impact need to distinguish between invasive species, as their effects on diversity and composition of resident vegetation differ largely. Tall invading species capable of forming populations with the cover markedly greater than that of native dominant species exert the most severe effects on species diversity and evenness. Since a strong impact on the community scale is associated with reduction in species diversity at higher scales, invaders with a high impact represent a serious hazard to the landscape. Identifiant : DOI : 10.1111/j.1365-2745.2009.01480.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=154073 Hejda, M., Pyšek, P., Jarošík, V., 2009 . Impact of invasive plants on the species richness, diversity and composition of invaded communities. Journal of ecology, 97: 393-403.

Documents numériques

Article (2009) URL

Local adaptation occurs along altitudinal gradient despite the existence of gene flow in the alpine plant species Festuca eskia / Héloïse Gonzalo-Turpin in Journal of ecology, 97 (2009) 

Public Citation [article]  inJournal of ecology > 97 (2009) . - 742-751 Titre : Local adaptation occurs along altitudinal gradient despite the existence of gene flow in the alpine plant species Festuca eskia Type de document : Numérique Auteurs : Héloïse Gonzalo-Turpin (1981-) ; Laurent Hazard Année de publication : 2009 Article en page(s) : 742-751 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Flux de gènes [CBNPMP-Thématique] Changement climatique [CBNPMP-Géographique] Pyrénées Mots-clés : Festuca eskia Ramond ex DC. Résumé : 1 Alpine plant species are particularly vulnerable to climate change. Therefore, estimating the adaptive potential of alpine species is of vital importance for determining their future viability. In alpine plants, adaptive potential depends on (i) altitudinal genetic differentiation among populations, combined with gene flow along an altitudinal gradient; (ii) phenotypic plasticity for the traits under selection and (iii) co-gradient variation between genetic and environmental influences on these traits. 2 The adaptive potential of Festuca eskia Ramond (Poaceae), a perennial alpine grass common in the Pyrenean Mountains, was examined in this study. A reciprocal transplant experiment involving 180 individuals along three altitudinal gradients (from 1500 to 2500 m) was established, and survival, functional and reproductive traits were recorded. In addition, four neutral sequence-tagged site and simple sequence repeat molecular markers were chosen to estimate gene flow among populations. 3 Genetic differentiation attributable to selection was detected in all traits between populations along the altitudinal gradient despite the existence of restricted gene flow. For traits directly related to fitness, local altitudinal adaptation was clearly evident. The patterns of local adaptation suggested that selection patterns differed along an altitudinal gradient. Selection for reproductive output was predominant at low altitudes, whereas differential survivorship was observed at higher altitudes. 4 Genetic differentiation with increasing altitude resulted in reduced plant stature and reproductive output but increased specific leaf area (SLA). This increased SLA at higher altitude is interpreted as a resource acquisition strategy. 5 Phenotypic plasticity was seen in all traits at the population level. Evidence of co-gradient variation between genetic differentiation and plastic response was found for all traits except SLA, suggesting that adaptive phenotypic plasticity operates in F. eskia. 6 Synthesis. Local adaptation occurs in F. eskia. It involves different adaptive traits according to the altitude. Such differentiation occurs at a small scale along altitudinal gradients despite the existence of gene flow and phenotypic plasticity. The coexistence of genetic differentiation, gene flow and phenotypic plasticity along altitudinal gradients provides an adaptive potential for F. eskia to successfully adapt to climate change. Identifiant : DOI : 10.1111/j.1365-2745.2009.01509.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=156348 Gonzalo-Turpin, H., Hazard, L., 2009 . Local adaptation occurs along altitudinal gradient despite the existence of gene flow in the alpine plant species Festuca eskia. Journal of ecology, 97: 742-751.

Documents numériques

Article (2009) URL