Impact of grazing, resource availability and light on prokaryotic growth and diversity in the oligotrophic surface global ocean.

Environ Microbiol

Departamento de Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain.

Published: April 2019

The impact of grazing, resource competition and light on prokaryotic growth and taxonomic composition in subtropical and tropical surface waters were studied through 10 microcosm experiments conducted between 30°N and 30°S in the Atlantic, Pacific and Indian oceans. Under natural sunlight conditions, significant changes in taxonomic composition were only observed after the reduction of grazing by sample filtration in combination with a decrease in resource competition by sample dilution. Sunlight exposure significantly reduced prokaryote growth (11 ± 6%) and community richness (14 ± 4%) compared to continuous darkness but did not significantly change community composition. The largest growth inhibition after sunlight exposure occurred at locations showing deep mixed layers. The reduction of grazing had an expected and significant positive effect on growth, but caused a significant decrease in community richness (16 ± 6%), suggesting that the coexistence of many different OTUs is partly promoted by the presence of predators. Dilution of the grazer-free prokaryotic community significantly enhanced growth at the level of community, but consistently and sharply reduced the abundance of Prochlorococcus and SAR11 populations. The decline of these oligotrophic bacterial taxa following an increase in resource availability is consistent with their high specialization for exploiting the limited resources available in the oligotrophic warm ocean.

Download full-text PDF

Source
http://dx.doi.org/10.1111/1462-2920.14581DOI Listing

Publication Analysis

Top Keywords

impact grazing
8
grazing resource
8
resource availability
8
light prokaryotic
8
prokaryotic growth
8
resource competition
8
taxonomic composition
8
reduction grazing
8
sunlight exposure
8
community richness
8

Similar Publications

Assessing learning, behaviour, and stress level in goats while testing a virtual fencing training protocol.

Animal

December 2024

Venn Research Association for the Promotion of Virtual Fencing in Tyrol and the Alpine region. Brixnerstraße 1, 6020 Innsbruck, Austria.

Virtual fencing (VF) is a modern fencing technology using Global Positioning System-enabled collars which emit acoustic signals and, if the animal does not respond, electric pulses. Studies with cattle indicate successful learning and no distinct negative impact on the animals' behaviours and stress level. However, the number of studies testing VF with goats is relatively small.

View Article and Find Full Text PDF

Supporting rotational grazing systems with virtual fencing: paddock transitions, beef heifer performance, and stress response.

Animal

December 2024

Department of Crop Sciences, Grassland Science, Georg-August-University Göttingen, Von-Siebold-Strasse 8, 37075 Göttingen, Germany; Centre for Biodiversity and Sustainable Land Use, Büsgenweg 1, 37075 Göttingen, Germany.

Animal welfare is integral to sustainable livestock production, and pasture access for cattle is known to enhance welfare. Despite positive welfare impacts, high labour requirements hinder the adoption of sustainable grazing practices such as rotational stocking management. Virtual fencing (VF) is an innovative technology for simplified, less laborious grazing management and remote animal monitoring, potentially facilitating the expansion of sustainable livestock production.

View Article and Find Full Text PDF

Grazing Intensity Modifies Soil Microbial Diversity and Their Co-Occurrence Networks in an Alpine Steppe, Central Tibet.

Microorganisms

January 2025

Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.

Grazing intensity is one of the crucial anthropogenic activities on alpine grasslands. However, how grazing intensity affects soil microorganism diversities and their co-occurrence networks in alpine steppe remains uncertain. We carried out a controlled grazing experiment (null grazing, CK; moderate grazing, MG; and heavy grazing, HG) on a typical alpine steppe in the Lhasa River Basin, Central Tibet, China.

View Article and Find Full Text PDF

Grazing-Induced Habitat Degradation: Challenges to Giant Panda Survival Resulting from Declining Bamboo and Soil Quality.

Animals (Basel)

January 2025

Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China.

Grazing is the primary human-induced disturbance affecting giant panda () habitats and has a severe impact on the long-term sustainability of the giant panda population. To address the lack of quantitative studies on grazing's impact on habitat quality, we selected China's most heavily grazed giant panda nature reserve. Utilizing the Maxent model and stoichiometric analysis, we investigated habitat quality degradation caused by grazing and quantified changes in bamboo nutritional quality and soil physicochemical properties.

View Article and Find Full Text PDF

Background: Cystic echinococcosis is a parasitic cyclo-zoonotic disease caused by the taeniid Echinococcus and causes significant economic losses in livestock production, yet its impact is often overlooked and under estimated.

Methods: This study investigated the risk factors and economic impact of cystic echinococcosis in livestock, in Uganda's pastoral and agro-pastoral communities. In the study, 14,937 livestock were examined at selected slaughterhouses in Moroto, Kumi, Luwero and Nakasongola districts from March 2019 to February 2020.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!