Alterations to sediment nutrient deposition and transport along a six reservoir sequence

Abstract. Litterfall is one of the major pathways connecting above- and below-ground processes. The effects of climate and land-use change on carbon (C) and nutrient inputs by litterfall are poorly known. We quantified and analyzed annual patterns of C and nutrient deposition via litterfall in natural forests and agroforestry systems along the unique elevation gradient of Mt. Kilimanjaro. Tree litter in three natural (lower montane, Ocotea and Podocarpus forests), two sustainably used (homegardens) and one intensively managed (shaded coffee plantation) ecosystems was collected on a biweekly basis from May 2012 to July 2013. Leaves, branches and remaining residues were separated and analyzed for C and nutrient contents. The annual pattern of litterfall was closely related to rainfall seasonality, exhibiting a large peak towards the end of the dry season (August–October). This peak decreased at higher elevations with decreasing rainfall seasonality. Macronutrients (N, P, K) in leaf litter increased at mid elevation (2100 m a.s.l.) and with land-use intensity. Carbon content and micronutrients (Al, Fe, Mn, Na) however, were unaffected or decreased with land-use intensity. While leaf litterfall decreased with elevation, total annual input was independent of climate. Compared to natural forests, the nutrient cycles in agroforestry ecosystems were accelerated by fertilization and the associated changes in dominant tree species.

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Effect of Nitrogen Availability on Oat Grain Growth and Nutrient Deposition

Acta Agriculturae Scandinavica Section B - Soil & Plant Science ◽

10.1080/09064710127622 ◽

2001 ◽

Vol 51 (3) ◽

pp. 106-112 ◽

Cited By ~ 2

Author(s):

Roy M. Peterson ◽

Victor V. Rendig

Keyword(s):

Grain Growth ◽

Nitrogen Availability ◽

Nutrient Deposition

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Phosphorus supply affects long-term carbon accumulation in mid-latitude ombrotrophic peatlands

Communications Earth & Environment ◽

10.1038/s43247-021-00316-2 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Daniel N. Schillereff ◽

Richard C. Chiverrell ◽

Jenny K. Sjöström ◽

Malin E. Kylander ◽

John F. Boyle ◽

...

Keyword(s):

Carbon Sink ◽

Threshold Effect ◽

Carbon Accumulation ◽

Ecosystem Productivity ◽

Microbial Decomposition ◽

Nutrient Deposition ◽

Carbon Burial ◽

Carbon Store ◽

Post Industrial

AbstractOmbrotrophic peatlands are a globally important carbon store and depend on atmospheric nutrient deposition to balance ecosystem productivity and microbial decomposition. Human activities have increased atmospheric nutrient fluxes, but the impacts of variability in phosphorus supply on carbon sequestration in ombrotrophic peatlands are unclear. Here, we synthesise phosphorus, nitrogen and carbon stoichiometric data in the surface and deeper layers of mid-latitude Sphagnum-dominated peatlands across Europe, North America and Chile. We find that long-term elevated phosphorus deposition and accumulation strongly correlate with increased organic matter decomposition and lower carbon accumulation in the catotelm. This contrasts with literature that finds short-term increases in phosphorus supply stimulates rapid carbon accumulation, suggesting phosphorus deposition imposes a threshold effect on net ecosystem productivity and carbon burial. We suggest phosphorus supply is an important, but overlooked, factor governing long-term carbon storage in ombrotrophic peatlands, raising the prospect that post-industrial phosphorus deposition may degrade this carbon sink.

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Alpine limnology of the Rocky Mountains of Canada and the USA in the context of environmental change

Environmental Reviews ◽

10.1139/er-2017-0046 ◽

2018 ◽

Vol 26 (3) ◽

pp. 231-238 ◽

Cited By ~ 1

Author(s):

Laura E. Redmond

Keyword(s):

Climate Change ◽

Rocky Mountains ◽

Multiple Stressors ◽

Ultra Violet ◽

Future Climate Change ◽

Monitoring Methods ◽

Freshwater Biodiversity ◽

Nutrient Deposition ◽

Alpine Regions ◽

The Usa

The cumulative impacts of multiple environmental and anthropogenic stressors on freshwater biodiversity have been studied in systems across the globe. The magnitude of multiple interdependent stressors on alpine systems may lead to increased primary productivity and jeopardize these unique communities. In this review, the consequences of individual stressors on alpine lake and pond ecology are synthesized, as well as the cumulative and potentially synergistic or antagonistic effects of multiple stressors. Beside temperature variability, other stressors reviewed include ultra violet (UV) radiation, organic pollutants, nutrient deposition, and biological invasions. Each stressor was evaluated individually and in combination with increasing water temperatures. In alpine environments, climatic warming is anticipated to increase with elevation, therefore amplifying the effects of temperature-related responses. The purpose of this review is to highlight the ecological effects of climate change on alpine lakes and ponds in the Rocky Mountains of North America and fill knowledge gaps between disciplines of aquatic studies. This work underscores that to better understand and face the overall effects of climate change on alpine biota, investigations must continue to assess the compounded impacts of multiple stressors. Emphasis must be put on the standardization of monitoring methods across alpine regions to aid in consistent trend and prediction analysis within the context of both current and future climate change.

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