Diversity of diatoms, benthic macroinvertebrates, and fish varies in response to different environmental correlates in Arctic rivers across North America

Abstract

1. Climate change poses a significant threat to Arctic freshwater biodiversity, but impacts depend upon the strength of organism response to climate-related drivers. Currently, there is insufficient knowledge about Arctic freshwater biodiversity patterns to guide assessment, prediction, and management of biodiversity change.2. As part of the Circumpolar Biodiversity Monitoring Program's first freshwater assessment, we evaluated diversity of diatoms, benthic macroinvertebrates, and fish in North American Arctic rivers. Alpha diversity was assessed in relation to temperature, water chemistry, bedrock geology, and glaciation history to identify important environmental correlates. Biotic composition was compared among groups to evaluate response to environmental gradients.3. Macroinvertebrate α-diversity declined strongly with increasing latitude from 48°N to 82°N, whereas diatom and fish diversity peaked around 70°N without a clear latitudinal decline. Macroinvertebrate diversity was significantly positively related to air temperature. Diatom diversity was related to bedrock geology and temperature, whereas fish diversity was related to glaciation history. Fish and macroinvertebrate assemblages differed between sites in western Canada,where invertebrate composition was more variable, and Alaska, where fish composition was more variable. In sites with both diatom and macroinvertebrate data, diatom composition was distinct in Alaska, where richness was highest in former glacial refugia. Macroinvertebrate composition was distinct in lowest-latitude eastern and high-latitude western Canadian sites where temperature was highest. 5. Temperature, precipitation, geology, calcium, and substrate size were important environmental correlates for diatoms and macroinvertebrates, although the relative importance of each correlate differed. Diatom taxa were most strongly

Temperature and spatial connectivity drive patterns in freshwater macroinvertebrate diversity across the Arctic

“…Benthic macroinvertebrates are an ideal organism group to assess the long‐term ecological effects of climate change on Arctic freshwater diversity because they provide time‐integrated responses to environmental conditions, including those induced by landscape‐level changes in vegetation and hydrology (Brown et al., 2018; Resh, 2008), and different taxa have varied levels of dispersal capability (Medeiros et al., 2020; Sarremejane et al., 2020). Moreover, benthic macroinvertebrate diversity, composition, and species distribution patterns have been shown to reflect temperature gradients in the Arctic (Culp et al., 2019; Lento et al., 2020; Medeiros et al., 2020) and alpine regions (Brighenti et al., 2019; Khamis et al., 2014; Niedrist & Füreder, 2021). Investigations of biodiversity in Arctic freshwater benthic macroinvertebrates have found strong associations between community composition and physical and chemical environmental drivers at different spatial scales, although these studies have largely focused on ecosystem‐specific assessments within relatively small regions of the Arctic (e.g., Johnson & Goedkoop, 2002; Lento et al., 2013; Tolonen et al., 2016).…”

Synecological response of desert spring benthic prokaryotes and macroinvertebrates to Sierra Nevada roof pendant-derived calcium

“…As cells attach and settle in the system, endogenous nutrient cycling is increased, promoting the development of metabolically diverse assemblages and enhances trophic interactions [84,89] . Calcium may also be important for structuring BMI communities, as observed in other aquatic systems [90,91] , although most studies do not address mechanisms for this relationship. We propose that Ca 2+ may structure these BMI communities indirectly through trophic interactions with microbial bio lms (as discussed below) or directly by in uencing BMI physiology.…”

Arctic freshwater biodiversity: Establishing baselines, trends, and drivers of ecological change

“…In the fifth regional paper, Lento et al. (2022) evaluate drivers of diversity of diatoms, benthic macroinvertebrates, and fish in North American Arctic rivers. This paper shows that α diversity of benthic macroinvertebrates at the basin scale declines more strongly with increasing latitude than does diversity of diatoms or fish.…”