9 research outputs found

    Patterns of macroinvertebrate production and energy flow in headwater streams of the Brazilian Savanna

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    Secondary production estimates are an important element of ecosystem ecology because they facilitate quantification of the roles of consumers in material and energy cycling. We estimated production and resource consumption of stream macroinvertebrates, along with stream metabolism and organic matter storage in 3 relatively undisturbed Savanna headwater streams in southeastern Brazil. We measured production of benthic macroinvertebrates and reach-scale metabolism from October 2015 to September 2016. Mean annual values of gross primary production and ecosystem respiration varied from 0.06 to 0.22 and 3.96 to 23.76 g O2 m−2 d−1, respectively, reflecting net heterotrophic conditions. Total secondary production ranged from 11.0 to 13.5 g ash-free dry mass m−2 y−1. Gatherers, shredders, and predators were the most important contributors to production, ranging from 11 to 30%, 21 to 39%, and 20 to 49% of total production, respectively, and detrital pathways accounted for most energy flow. Shredders only ingested 3.4 to 8.1% of total available food resources, suggesting that food resource availability does not limit production in these streams. To our knowledge, this study provides the first quantification of energy flow patterns in Brazilian Savanna streams using secondary production estimates and is one of the few measuring growth rates and secondary production of macroinvertebrates with short generation times under field conditions in tropical streams. Furthermore, this study is one of the few to link stream metabolism and organic matter storage to secondary production. Our results will help to understand reference conditions in the poorly studied streams of a region particularly threatened by human activities and potentially elsewhere in tropical systems

    FreshLanDiv: A Global Database of Freshwater Biodiversity Across Different Land Uses

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    International audienceMotivation Freshwater ecosystems have been heavily impacted by land‐use changes, but data syntheses on these impacts are still limited. Here, we compiled a global database encompassing 241 studies with species abundance data (from multiple biological groups and geographic locations) across sites with different land‐use categories. This compilation will be useful for addressing questions regarding land‐use change and its impact on freshwater biodiversity. Main Types of Variables Contained The database includes metadata of each study, sites location, sample methods, sample time, land‐use category and abundance of each taxon. Spatial Location and Grain The database contains data from across the globe, with 85% of the sites having well‐defined geographical coordinates. Major Taxa and Level of Measurement The database covers all major freshwater biological groups including algae, macrophytes, zooplankton, macroinvertebrates, fish and amphibians
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