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This dataset contains species abundance data of epilithic diatoms collected from the Upper Kuparuk River, Alaska (USA), spanning from 1997 to 2022. The dataset is part of a long-term study aimed at understanding the ecological impacts of phosphorus enrichment in Arctic freshwater ecosystems. Samples were collected annually from both phosphorus-fertilized and reference reaches of the river to assess the influence of nutrient enrichment on diatom community composition. The dataset includes detailed records of diatom species identified and their relative abundances in the phosphorus reach only. Analyses of this dataset using permutational multivariate analysis of variance (PERMANOVA) and Redundancy Analysis (RDA) revealed significant shifts in diatom communities attributable to phosphorus enrichment. Indicator Species Analysis identified key diatom species that are reliable indicators of phosphorus-enriched conditions. This dataset provides valuable insights into the long-term responses of diatom communities to nutrient enrichment and the ecological interactions with mosses that colonized the fertilized reach. It serves as an important resource for researchers studying nutrient dynamics, ecological monitoring, and the impacts of climate change on Arctic freshwater systems.
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Biogeochemical responses over 37 years to manipulation of phosphorus concentrations in an Arctic river: The Upper Kuparuk River Experiment
Abstract The climate of the Arctic region is changing rapidly, with important implications for permafrost, vegetation communities, and transport of solutes by streams and rivers to the Arctic Ocean. While research on Arctic streams and rivers has accelerated in recent years, long‐term records are relatively rare compared to temperate and tropical regions. We began monitoring the upper Kuparuk River in 1983 as part of a long‐term, low‐level, whole‐season phosphorus enrichment of a 4–6 km experimental reach, which was subsequently incorporated into the Arctic Long‐Term Ecological Research (Arctic LTER) programme. The phosphorus enrichment phase of the Upper Kuparuk River Experiment (UKRE) ran continuously for 34 seasons, fundamentally altering the community structure and function of the Fertilized reach. The objectives of this paper are to (a) update observations of the environmental conditions in the Kuparuk River region as revealed by long‐term, catchment‐level monitoring, (b) compare long‐term trends in biogeochemical characteristics of phosphorus‐enriched and reference reaches of the Kuparuk River, and (c) report results from a new ‘ReFertilization’ experiment. During the UKRE, temperature and discharge did not change significantly, though precipitation increased slightly. However, the UKRE revealed unexpected community state changes attributable to phosphorus enrichment (e.g., appearance of colonizing bryophytes) and long‐term legacy effects of these state changes after cessation of the phosphorus enrichment. The UKRE also revealed important biogeochemical trends (e.g., increased nitrate flux and benthic C:N, decreased DOP flux). The decrease in DOP is particularly notable in that this may be a pan‐Arctic trend related to permafrost thaw and exposure to new sources of iron that reduce phosphorus mobility to streams and rivers. The trends revealed by the UKRE would have been difficult or impossible to identify without long‐term, catchment level research and may have important influences on connections between Arctic headwater catchments and downstream receiving waters, including the Arctic Ocean.
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- Award ID(s):
- 1637459
- PAR ID:
- 10385577
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Hydrological Processes
- Volume:
- 35
- Issue:
- 3
- ISSN:
- 0885-6087
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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