Changes in the silver fir forest vegetation 50 years after cessation of active management

Knowledge of the vegetation and the monitoring of its changes in preserved areas is an essential part of effective conservation policy and management. The aim of this study was to assess the effectiveness of traditional methods of conservation of silver fir forests. The study analyses the changes in the structure and species composition of a temperate forest excluded from the commercial silvicultural management for 50 years, and since then protected as a nature reserve. The study is based on a comparative analysis of phytosociological reléves made on permanent plots in 1961, 1982, 1994 and 2011. PCA and ecological indicator values were analyzed, as well as characteristic species based on an indicator value (IndVal) index. Results revealed significant and dynamic changes in the forest structure and composition. The mixed coniferous-broadleaved forest with Abies alba and diverse ground flora, considered in the 1960s as valuable and worthy of conservation, was found to have been anthropogenically transformed and unstable. Significant reduction in the human impact was followed by spontaneous regeneration of oak–hornbeam forest. However, the directional process of changes in vegetation was modified by such silvicultural treatments as selective cutting of trees and gap creation, all intended for silver fir maintenance. The results show that Carpinus betulus effectively outcompeted Pinus sylvestris, Picea abies, Quercus robur and A. alba. Changes in the forest overstory and understory caused temporal changes in the habitat conditions reflected in changes in the ground vegetation composition. The proportion of light-demanding and oligotrophic species significantly decreased, while the contribution of species with a wide ecological amplitude, i.e. more shade-tolerant and nutrient-demanding – increased. The share of A. alba was reduced. Species defined in this study as most valuable, should be actively protected, or selection of conservation targets should be re-evaluated

PlantID – DNA-based identification of multiple medicinal plants in complex mixtures

Background An efficient method for the identification of medicinal plant products is now a priority as the global demand increases. This study aims to develop a DNA-based method for the identification and authentication of plant species that can be implemented in the industry to aid compliance with regulations, based upon the economically important Hypericum perforatum L. (St John’s Wort or Guan ye Lian Qiao). Methods The ITS regions of several Hypericum species were analysed to identify the most divergent regions and PCR primers were designed to anneal specifically to these regions in the different Hypericum species. Candidate primers were selected such that the amplicon produced by each species-specific reaction differed in size. The use of fluorescently labelled primers enabled these products to be resolved by capillary electrophoresis. Results Four closely related Hypericum species were detected simultaneously and independently in one reaction. Each species could be identified individually and in any combination. The introduction of three more closely related species to the test had no effect on the results. Highly processed commercial plant material was identified, despite the potential complications of DNA degradation in such samples. Conclusion This technique can detect the presence of an expected plant material and adulterant materials in one reaction. The method could be simply applied to other medicinal plants and their problem adulterants

Mangroves v1.0: a new taxonomic tool to characterize mangroves. The case of South east Indian and Sri Lankan mangroves and potential application to African mangroves

In this paper we present an innovative tool for plant identification conceived to reinforce the national capacity building in taxonomy. We introduce Mangroves v1.0, built up on a species identification system called IDAO (Identification Assistée par Ordinateur). This software allows the identification of 50 mangroves species of South East India and Sri Lanka, with the perspective to adjust and extend to other of the world. This software provides and facilitates dissemination of scientific and traditional knowledge. Corollary, it appears as a good support to training, research and development actions and its applications, from awareness to practical management of trees and the ecosystem, could benefit African mangroves and contribute to their renewed interest. (Résumé d'auteur

Featured Herbarium: BUT—The Friesner Herbarium of Butler University

Feature written by Rebecca Dolan on the BUT—The Friesner Herbarium of Butler University in the Vasculum

DigR : how to model root system in its environment? 1 - the model

Many models already exist through literature dealing with root system representation, among which pure structure models such as Root Typ (Pagès 2004), SimRoot (Lynch 1997), AmapSim (Jourdan 1997); diffusion PDE models (Bastian 2008; Bonneu 2009) and structure/function that are rather scarce and recent (Dupuy 2010)may be aroused. Nevertheless in these studies, root architecture modeling was not carried out at organ level including environmental influence and not designed for integration into a whole plant characterization. We propose here a multidisciplinary study on root system from field observations, architectural analysis, formal and mathematical modeling and finally software simulation. Each speciality is individually investigated through an integrative and coherent approach that leads to a generic model (DigR) and its software simulator that is designed for further integration into a global structure/function plant model. DigR model is based on three main key points: (i) independent root type identification (ii) architectural analysis and modeling of root system at plant level; (iii) root architecture setup indexed on root length. Architecture analysis (Barthelemy 2007) applied to root system (Atger 1994) leads to root type organisation for each species. Roots belonging to a particular type share dynamical and morphological characteristics. Root architectural setup consists in topological features as apical growth, lateral branching, senescence and death, and geometrical features as secondary growth and axes spatial positioning. These features are modeled in DigR through 23 parameters whose values can evolve as a function of length position along the root axes for each root type. Topology rules apical growth speed, delayed growth, death and self pruning probabilities. Branching is characterized by spacing and mixture of lateral root types. Geometry rules root diameter increase, branching and growth directions (including local deviations and global reorientation). DigR simulator provides a user interface to input parameter values specific to each species. It is integrated into the Xplo environment (Taugourdeau 2010). Its internal multi-scale memory representation is ready for dynamical 3D visualization, statistical analysis and saving to standard formats (MTG(Godin 2007), Obj,). DigR is simulated in a quasiparallel computing algorithm and may be used either as a standalone application or integrated in other simulation platforms. This will allow further implementation of functional - structural interactions during growth simulation. The software is distributed under free LGPL license and is dedicated both to biologists and modelers. Shown applications (fig. 1) mimic the diversity of root systems and emphasize the genericity of the model according to different sets of parameter values. Examples (fig. 2) prove that additional knowledge may be plugged to DigR to simulate root plasticity facing environmental constraints. Further work will be carried out to apply DigR to various species and to connect DigR to biophysical soil models (Gérard 2008; Zhang et al. 2002); to aerial part models (Barczi 2008); to ecophysiological models (Mathieu 2009, Bornhoffen 2007); and finally to mix this pure descriptive model to a PDE model that handles fine root diffuse modelling (Bonneu 2009). (Texte intégral

In and out of Madagascar : dispersal to peripheral islands, insular speciation and diversification of Indian Ocean daisy trees (Psiadia, Asteraceae)

This study was supported by the European Union’s HOTSPOTS Training Network (MEST-2005-020561)Madagascar is surrounded by archipelagos varying widely in origin, age and structure. Although small and geologically young, these archipelagos have accumulated disproportionate numbers of unique lineages in comparison to Madagascar, highlighting the role of waif-dispersal and rapid in situ diversification processes in generating endemic biodiversity. We reconstruct the evolutionary and biogeographical history of the genus Psiadia (Asteraceae), a plant genus with near equal numbers of species in Madagascar and surrounding islands. Analyzing patterns and processes of diversification, we explain species accumulation on peripheral islands and aim to offer new insights on the origin and potential causes for diversification in the Madagascar and Indian Ocean Islands biodiversity hotspot. Our results provide support for an African origin of the group, with strong support for non-monophyly. Colonization of the Mascarenes took place by two evolutionary distinct lineages from Madagascar, via two independent dispersal events, each unique for their spatial and temporal properties. Significant shifts in diversification rate followed regional expansion, resulting in co-occurring and phenotypically convergent species on high-elevation volcanic slopes. Like other endemic island lineages, Psiadia have been highly successful in dispersing to and radiating on isolated oceanic islands, typified by high habitat diversity and dynamic ecosystems fuelled by continued geological activity. Results stress the important biogeographical role for Rodrigues in serving as an outlying stepping stone from which regional colonization took place. We discuss how isolated volcanic islands contribute to regional diversity by generating substantial numbers of endemic species on short temporal scales. Factors pertaining to the mode and tempo of archipelago formation and its geographical isolation strongly govern evolutionary pathways available for species diversification, and the potential for successful diversification of dispersed lineages, therefore, appears highly dependent on the timing of arrival, as habitat and resource properties change dramatically over the course of oceanic island evolution.Publisher PDFPeer reviewe

Assembling the Tree of Life in Europe (AToLE)

A network of scientists under the umbrella of 'Assembling the Tree of Life in Europe (AToLE)' seeks funding under the FP7-Theme: Cooperation - Environment (including Climate Change and Biodiversity Conservation) programme of the European Commission.
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