Search results for "Montane ecology"

Carbon and Oxygen Isotope Signals from the Callovian–Oxfordian in French Sedimentary Basins

2013

3 pages; International audience; High-resolution carbon and oxygen isotope data from the Paris Basin and the Subalpine Basin (France) are available in a precise biostratigraphic framework for the Callovian-Oxfordian stages. A biostratigraphically well-constrained δ13C curve, derived from bulk carbonates in the Paris Basin and the Subalpine Basin, is provided in order to document carbon-cycle evolution and to serve as a chemostratigraphic reference for the Callovian-Oxfordian in the Tethyan domain. Sea-temperature reconstructions, using diagenetically screened belemnite and oyster data, reveal major climate perturbations at the Middle-Late Jurassic transition.

Coupling agent-based with equation-based models to study spatially explicit megapopulation dynamics

2018

International audience; The incorporation of the spatial heterogeneity of real landscapes into population dynamics remains extremely difficult. We propose combining equation-based modelling (EBM) and agent-based modelling (ABM) to overcome the difficulties classically encountered. ABM facilitates the description of entities that act according to specific rules evolving on various scales. However, a large number of entities may lead to computational difficulties (e.g., for populations of small mammals, such as voles, that can exceed millions of individuals). Here, EBM handles age-structured population growth, and ABM represents the spreading of voles on large scales. Simulations applied to t…

Syntaxonomy and biogeography of the Irano‐Turanian mires and springs

2021

Aims: To develop the first comprehensive syntaxonomic classification for patchy montane mire and spring vegetation across the Irano-Turanian phytogeographical region in Iran, Tajikistan and Kyrgyzstan and to explore the effects of the main environmental and geographic gradients on their distribution. Location: Alborz Mountain range (Iran), Pamir-Alai Mountains (Tajikistan) and Tian Shan Mountains (Kyrgyzstan); total area of about 3,000,000 km2. Methods: A database of 1,015 vegetation relevés including a total of 675 vascular and bryophyte taxa was established, covering the large mountains ranges of the Irano-Turanian regions in Iran, Tajikistan and Kyrgyzstan, at altitude ranging from 1,300…

Responses of above- and below-ground fungal symbionts to cessation of mowing in subalpine grassland

2017

Abstract The cessation of mowing in subalpine grasslands promotes the dominance of Festuca paniculata leading to the reduction in plant diversity. Moreover, it affects positively the abundance of Epichloe sp. inhabiting F. paniculata leaves and negatively the soil density of arbuscular mycorrhizal fungi (AMF). We explored how the cessation of mowing influences root AMF communities in F. paniculata and the neighboring plants, and Epichloe sp alkaloids. Thirteen AMF operational taxonomical units were found. The neighboring plants affected positively the abundances of Aalpin and GLOM_7 whereas the interaction plant/management type influenced significantly Claroide_1 , GLOM_1 and GLOM_7 . The N…

Thuoux and Saint-Pierre d’Argençon Sections (Subalpine Basin, Southeastern France): Case Studies of Ammonite Biostratigraphy for the Potential Candid…

2014

The Thuoux and Saint-Pierre d’Argencon sections (Subalpine Basin, southeastern France) display a thick silty–clayey sedimentation with abundant and diversified ammonite faunas, free of detectable hiatuses. The Callovian–Oxfordian boundary is biostratigraphically located between the Lamberti and the Mariae zones or, more precisely, between the Lamberti Subzone (paucicostatum horizon) and the Scarburgense Subzone (thuouxensis horizon). The mixing of Boreal–Sub-Boreal Cardioceratinae and Sub-Mediterranean–Tethyan Hecticoceratinae, Peltoceratinae, and Perisphinctinae in this basin allows reliable worldwide correlations that enhance the choice of the Thuoux and Saint-Pierre d’Argencon sections a…

Syntaxonomy, diversity and distribution of the vegetation of rock crevices, clefts and ledges in the colline and montane belts of Central Pamir-Alai …

2021

Mountain areas are very often considered to be biodiversity hotspots. Rocks are one of the most unique habitats and serve as a suitable biotope for many endemic and specialized plant species. Here we present the results of the vegetation studies conducted in central and eastern Pamir-Alai and the south-western Tian Shan mountains in 2013‒2019. Based on 334 phytosociological relevés we propose a synopsis of the rock communities of the montane and colline zones of eastern Middle Asia. As a result of our research, we distinguish 17 communities defined into five groups of petrophytic vegetation within the Caricion koshewnikowii alliance. We describe 11 new associations: Feruletum bucharicae, Sc…

Reply to the comment of Zimmermann et al. (2010) on “Spatial throughfall heterogeneity in a montane rain forest in Ecuador: Extent, temporal stabilit…

2010

Vegetation of rock crevices of the montane and colline zones in the Pamir-Alai and Tian Shan Mts in Tajikistan (Middle Asia)

2014

The paper presents the results of phytosociological research conducted on the vegetation of rock habitats in the montane and colline zones of the Pamir-Alai Mountains (Tajikistan). During field surveys done in 2010–2013, 122 phytosociological releves were sampled. Plant species were recorded according to the Braun-Blanquet cover-abundance scale. The vegetation studies were carried out generally in the western Pamir-Alai and south-western Tian Shan Mts, especially in the Zeravshan, Hissar, Hazratishoh, Darvaz, Rushan, Turkestan, Kuramin and Vanch ranges. A synopsis of the rock communities of the montane and colline zones in Tajikistan is proposed. The collected material presents most of the …

Will nutrient cycles in a tropical montane forest in Ecuador be affected by a changing element composition of rainfall?

2009

isotracer: An R package for the analysis of tracer addition experiments

2021

AbstractTracer addition experiments, particularly using isotopic tracers, are becoming increasingly important in a variety of studies aiming at characterizing the flows of molecules or nutrients at different levels of biological organization, from the cellular and tissue levels, to the organismal and ecosystem levels.We present an approach based on Hidden Markov Models (HMM) to estimate nutrient flow parameters across a network, and its implementation in the R package isotracer.The isotracer package is capable of handling a variety of tracer study designs, including continuous tracer drips, pulse experiments, and pulse-chase experiments. It can also take into account tracer decay when radio…