Search results for " Ecosystem"

Novel virocell metabolic potential revealed in agricultural soils by virus-enriched soil metagenome analysis

2021

International audience; Viruses are now recognized as important players in microbial dynamics and biogeochemical cycles in the oceans. Yet, compared with aquatic ecosystems, virus discovery in terrestrial ecosystems has been challenging partly due to the inherent complexity of soils. To expand our understanding of soil viruses and their putative contributions to soil microbial processes, we analysed metagenomes of community-level virus-enriched suspensions by tangential flow filtration obtained from two French agricultural soils. We found viral sequences representing a total of 239 viral operational taxonomic units that corresponded to 29.5% of the mapping reads in the metagenomic datasets.…

Understorey plant and soil responses to disturbance and increased nitrogen in boreal forests

2009

Question: How do N fertilization and disturbance affect the understorey vegetation, microbial properties and soil nutrient concentration in boreal forests? Location: Kuusamo (66°22′N; 29°18′E) and Oulu (65°02′N; 25°47′E) in northern Finland. Methods: We conducted a fully factorial experiment with three factors: site (two levels), N fertilization (four levels) and disturbance (two levels). We measured treatment effects on understorey biomass, vegetation structure, and plant, soil and microbial N and C concentrations. Results: The understorey biomass was not affected by fertilization either in the control or in the disturbance treatment. Fertilization reduced the biomass of deciduous Vacciniu…

Top predators, mesopredators and their prey: interference ecosystems along bioclimatic productivity gradients

2010

1. The Mesopredator Release Hypothesis (MRH) suggests that top predator suppression of mesopredators is a key ecosystem function with cascading impacts on herbivore prey, but it remains to be shown that this top-down cascade impacts the large-scale structure of ecosystems. 2. The Exploitation Ecosystems Hypothesis (EEH) predicts that regional ecosystem structures are determined by top-down exploitation and bottom-up productivity. In contrast to MRH, EEH assumes that interference among predators has a negligible impact on the structure of ecosystems with three trophic levels. 3. We use the recolonization of a top predator in a three-level boreal ecosystem as a natural experiment to test if l…

Retrieval and assessment of CO2 uptake by mediterranean ecosystems using remote sensing and

2014

Photosynthesis is a process by which carbon and energy enter ecosystems. The knowledge of where,when, and how carbon dioxide (CO2) is exchanged between terrestrial ecosystems and atmosphere is crucial to close the Earth's carbon budget and predict feedbacks in a likely warming climate. Gross photosynthesis (uptake of CO2) by vegetation is responsible for the gross primary production (GPP) of the ecosystem. Normally GPP refers to the sum of the photosynthesis by all leaves measured at the ecosystem scale. John Monteith proposed in 1972 a simple approach that has become the paradigm for understanding GPP. It considers GPP as proportional to the incident short wave radiation (PAR), the fractio…

Ecological indicators – Schrödinger Ratio

2008

Impact of trace metals from past mining on the aquatic ecosystem: a multi-proxy approach in the Morvan (France).

2014

10 pages; International audience; This study seeks to determine to what extent trace metals resulting from past mining activities are transferred to the aquatic ecosystem, and whether such trace metals still exert deleterious effects on biota. Concentrations of Cd, Cu, Pb and Zn were measured in streambed sediments, transplanted bryophytes and wild brown trout. This study was conducted at two scales: (i) the entire Morvan Regional Nature Park and (ii) three small watersheds selected for their degree of contamination, based on the presence or absence of past mining sites. The overall quality of streambed sediments was assessed using Sediment Quality Indices (SQIs). According to these standar…

Botanical excursions in central and Western Sicily - Field Guide For the 60th IAVS Symposium

2017

La partecipazione ad un business ecosystem: implicazioni per la nozione di successo

2020

L’obiettivo del capitolo è offrire un’introduzione alla letteratura sugli ecosistemi aziendali e discutere critica-mente la tematica del successo e della misurazione delle performance del business ecosystem e degli attori che vi partecipano. A tale scopo, il capitolo è strutturato come segue. Il paragrafo 2 focalizza l’attenzione sulla definizione di business ecosystem. I paragrafi 3, 4 e 5 spiegano, rispettivamente, perché nasce un business ecosystem, chi sono gli attori e quali sono le strutture sottese agli ecosistemi aziendali. Il paragrafo 6 discute la misurazione delle performance del business ecosystem focalizzando l’attenzione sui seguenti aspetti: (a) indicatori di performance a li…

Offshore Assets in the Transition from ‘Traditional Business Practice’ to ‘Connected Business Eco-systems’

2020

In many industrial sectors we have already begun to see how new business ecosystems gradually emerge turning the traditional business practices upside down. Particularly within relatively conventional sectors, such as upstream oil and gas (O&G) and land-based process industry, we expect to see substantial changes in the years to come. In this paper, we elaborate on principal challenges related to major structural changes and core technology platforms for the oil industry identifying critical features and elaborating on emerging operational principles. This is based on a critical review of latest industry conditions and practices that are targeted towards the creation of new business models …

Biogenic habitat shifts under long-term ocean acidification show nonlinear community responses and unbalanced functions of associated invertebrates

2019

Este artículo contiene 8 páginas, 4 figuras.