In:
Biogeosciences, Copernicus GmbH, Vol. 18, No. 8 ( 2021-04-27), p. 2649-2662
Abstract:
Abstract. Unraveling the environmental controls influencing Arctic tundra
productivity is paramount for advancing our predictive understanding of the
causes and consequences of warming in tundra ecosystems and associated
land–atmosphere feedbacks. This study focuses on aquatic emergent tundra
plants, which dominate productivity and methane fluxes in the Arctic coastal
plain of Alaska. In particular, we assessed how environmental nutrient
availability influences production of biomass and greenness in the dominant
aquatic tundra species: Arctophila fulva and Carex aquatilis. We sampled a total of 17 sites distributed across
the Barrow Peninsula and Atqasuk, Alaska, following a nutrient gradient that
ranged from sites with thermokarst slumping or urban runoff to sites with
relatively low nutrient inputs. Employing a multivariate analysis, we
explained the relationship of soil and water nutrients to plant leaf macro-
and micro-nutrients. Specifically, we identified soil phosphorus as the main
limiting nutrient factor given that it was the principal driver of
aboveground biomass (R2=0.34, p=0.002) and normalized difference
vegetation index (NDVI) (R2=0.47, p=0.002) in both species.
Plot-level spectral NDVI was a good predictor of leaf P content for both
species. We found long-term increases in N, P and Ca in C. aquatilis based on historical
leaf nutrient data from the 1970s of our study area. This study highlights the
importance of nutrient pools and mobilization between terrestrial–aquatic
systems and their potential influence on productivity and land–atmosphere
carbon balance. In addition, aquatic plant NDVI spectral responses to
nutrients can serve as landscape hot-spot and hot-moment indicators of
landscape biogeochemical heterogeneity associated with permafrost
degradation, nutrient leaching and availability.
Type of Medium:
Online Resource
ISSN:
1726-4189
DOI:
10.5194/bg-18-2649-2021
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2021
detail.hit.zdb_id:
2158181-2
