The effect of canopy exchange on input of base cations in a subalpine spruce plantation during the growth season

From 1989 to 1996, ion deposition in precipitation, throughfall, and stemflow were measured under a deciduous and a coniferous stand, located in the Lake Clair Watershed, during the growing and the dormant seasons. During the growing season, throughfall deposition under both stands was significantly depleted in H+ and NH4+ compared with wet deposition, and a significant uptake of NO3- was observed under the coniferous canopy. Deposition of Ca2+, Mg2+, K+, Na+, Cl-, and SO42- was significantly higher in the throughfall than in the wet precipitation. During the growing season, the coniferous stand was more efficient in retaining nitrogen (NH4+ and NO3-), while H+ was more intensively retained in the deciduous stand. Significant interactions between precipitation and forest canopies were also observed during the dormant season: throughfall depositions of Ca2+, Mg2+, K+, Na+, and Cl- were significantly higher than wet precipitation under both canopies, while throughfall SO42- was significantly enriched only under the coniferous stand. Using a Na+ ratio method, foliar leaching was found mostly responsible for the throughfall enrichment on a full-year basis in both stands, with values averaging 61, 73, and 96% of the total throughfall fluxes for Ca2+, Mg2+, and K+, respectively. Under both stands, net canopy exchange (NCE) of base cations, expressed on a monthly basis, were correlated to water volume and to H+ and SO42- deposition. Multiple regression models including wet SO42- deposition and an estimate of dry S deposition, explained up to 88% (Ca2+ in the coniferous stand) of the variance in base cation NCE under both stands.

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COMPARISON OF DRY DEPOSITION AND CANOPY EXCHANGE OF BASE CATIONS IN TEMPERATE HARDWOOD FORESTS IN FLANDERS AND CHILE

Gayana Botánica ◽

10.4067/s0717-66432003000100003 ◽

2003 ◽

Vol 60 (1) ◽

Cited By ~ 6

Author(s):

Jeroen Staelens ◽

An De Schrijver ◽

Carlos Oyarzún ◽

Noël Lust

Keyword(s):

Dry Deposition ◽

Base Cations ◽

Hardwood Forests ◽

Canopy Exchange

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Evaluation of deposition fluxes in two mountain Norway spruce stands with different densities using the extended Canopy Budget Model

Journal of Forest Science ◽

10.17221/39/2012-jfs ◽

2013 ◽

Vol 59 (No. 2) ◽

pp. 72-86 ◽

Cited By ~ 2

Author(s):

I. Drápelová

Keyword(s):

Dry Deposition ◽

Inorganic Nitrogen ◽

Base Cations ◽

Stand Density ◽

Mountain Forest ◽

Deposition Fluxes ◽

Budget Model ◽

Canopy Exchange ◽

Spruce Stands ◽

Canopy Budget Model

The field study in a mountain forest at Bílý Kříž provides a comparison of element fluxes for two adjacent forest spruce stands of the same age (29 years in 2005) but with different stem densities. During five years (2001–2005), bulk and throughfall precipitation was sampled and analysed. Total deposition, dry deposition and canopy exchange fluxes were evaluated on the basis of the Canopy Budget Model. Highly significant differences in base cations, dissolved organic carbon, SO42−, F−, and Cl− throughfall concentrations were found between the sparser and denser spruce stands.  Throughfall, dry deposition and canopy exchange fluxes were also influenced by stand density. Annual throughfall fluxes of inorganic nitrogen were within 11.9–17.8 kg N·ha–1·yr–1 on the sparser plot and within 15.4–20.6 kg N·ha–1·yr–1 on the denser plot; annual throughfall fluxes of sulphur were within 15.3–20.3 kg S·ha–1·yr–1 on the sparser plot and within 20.7–27.7 kg S·ha–1·yr–1on the denser plot. The critical load for nitrogen (11.2 kg N·ha–1·yr–1) was exceeded on both plots in all evaluated years 2002–2005.  Total annual inorganic nitrogen deposition was higher by up to 37.5% (in 2002) on the denser plot than on the sparser one.

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Bulk deposition of base cations in a subalpine natural forest landscape estimated by canopy budget model: A focus on the forest edge canopy

10.22541/au.163332401.13759958/v1 ◽

2021 ◽

Author(s):

Siyi Tan ◽

Dong Qing ◽

Xiangyin Ni ◽

kai Yue ◽

Shu Liao ◽

...

Keyword(s):

Base Cations ◽

Base Cation ◽

Forest Edge ◽

Natural Forest ◽

Subalpine Forest ◽

Budget Model ◽

Canopy Exchange ◽

Closed Canopy ◽

Canopy Budget Model ◽

Throughfall Deposition

Calculations of base cation inputs of loads in forest edge canopies are rare, although forest edge canopies play a paradoxical role in the effective capture of atmospheric deposition. Throughfall deposition and canopy exchange of base cations were studied with a continuous throughfall investigation under a natural forest edge and a closed canopy in a subalpine forest over a period of 2 years. Compared with precipitation, the concentration of base cations in the throughfall of both canopies was enriched as expected, but the enrichment level in the forest edge was less than that in the closed canopy. Moreover, the throughfall deposition of base cation fluxes in the closed canopy (35.19 kg ha-1 y-1) was slightly higher than that in the forest edge canopy (33.50 kg ha-1 y-1). Seasonally, the base cation input in the rainy season was 2.32–2.70 times higher than that in the snowy season in throughfall in forest edge canopy and the closed canopy. Furthermore, the canopy budget model suggested that the direction and magnitude of canopy exchange and dry deposition controlled the net throughfall fluxes (NTF) of base cations, and obvious differences could be observed between the canopy and seasonal scales. Compared with other elements, K and Mg leached from the main canopy exchange process, while Ca was absorbed by both canopy types in the annual NTF. These results highlight the spatial variability of base cation chemical characteristics, enhance cognitive the deposition of nutrients and regulatory factors in different forest landscapes, preferably guide the formulation forest ecological management strategies.

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Modelling the Effects of Acid Deposition: Estimation of Long-Term Water Quality Responses in Forested Catchments in Finland

Hydrology Research ◽

10.2166/nh.1988.0008 ◽

1988 ◽

Vol 19 (2) ◽

pp. 99-120 ◽

Cited By ~ 17

Author(s):

A. Lepistö ◽

P. G. Whitehead ◽

C. Neal ◽

B. J. Cosby

Keyword(s):

Water Quality ◽

Surface Water ◽

Base Cations ◽

Surface Water Quality ◽

Mineral Weathering ◽

Co2 Solubility ◽

Forested Catchments ◽

Deposition Rates ◽

Magic Model

A modelling study has been undertaken to investigate long-term changes in surface water quality in two contrasting forested catchments; Yli-Knuutila, with high concentrations of base cations and sulphate, in southern Finland; and organically rich, acid Liuhapuro in eastern Finland. The MAGIC model is based on the assumption that certain chemical processes (anion retention, cation exchange, primary mineral weathering, aluminium dissolution and CO2 solubility) in catchment soils are likely keys to the responses of surface water quality to acidic deposition. The model was applied for the first time to an organically rich catchment with high quantities of humic substances. The historical reconstruction of water quality at Yli-Knuutila indicates that the catchment surface waters have lost about 90 μeq l−1 of alkalinity in 140 years, which is about 60% of their preacidification alkalinity. The model reproduces the declining pH levels of recent decades as indicated by paleoecological analysis. Stream acidity trends are investigated assuming two scenarios for future deposition. Assuming deposition rates are maintained in the future at 1984 levels, the model indicates that stream pH is likely to continue to decline below presently measured levels. A 50% reduction in deposition rates would likely result in an increase in pH and alkalinity of the stream, although not to estimated preacidification levels. Because of the high load of organic acids to the Liuhapuro stream it has been acid before atmospheric pollution; a decline of 0.2 pH-units was estimated with increasing leaching of base cations from the soil despite the partial pH buffering of the system by organic compounds.

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Soil and Stream Water Chemistry During Spring Snowmelt

Hydrology Research ◽

10.2166/nh.1992.0002 ◽

1992 ◽

Vol 23 (1) ◽

pp. 13-26 ◽

Cited By ~ 11

Author(s):

W. H. Hendershot ◽

L. Mendes ◽

H. Lalande ◽

F. Courchesne ◽

S. Savoie

Keyword(s):

Stream Water ◽

Base Cations ◽

Stream Chemistry ◽

Stream Water Chemistry ◽

The Matrix ◽

Adsorption Desorption ◽

The Relationship ◽

Best Fit ◽

Spring Snowmelt ◽

Over Time

In order to determine how water flowpath controls stream chemistry, we studied both soil and stream water during spring snowmelt, 1985. Soil solution concentrations of base cations were relatively constant over time indicating that cation exchange was controlling cation concentrations. Similarly SO4 adsorption-desorption or precipitation-dissolution reactions with the matrix were controlling its concentrations. On the other hand, NO3 appeared to be controlled by uptake by plants or microorganisms or by denitrification since their concentrations in the soil fell abruptly as snowmelt proceeded. Dissolved Al and pH varied vertically in the soil profile and their pattern in the stream indicated clearly the importance of water flowpath on stream chemistry. Although Al increased as pH decreased, the relationship does not appear to be controlled by gibbsite. The best fit of calculated dissolved inorganic Al was obtained using AlOHSO4 with a solubility less than that of pure crystalline jurbanite.

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Current, steady-state and historical weathering rates of base cations at two forest sites in northern and southern Sweden: a comparison of three methods

Biogeosciences ◽

10.5194/bg-17-281-2020 ◽

2020 ◽

Vol 17 (2) ◽

pp. 281-304 ◽

Cited By ~ 1

Author(s):

Sophie Casetou-Gustafson ◽

Harald Grip ◽

Stephen Hillier ◽

Sune Linder ◽

Bengt A. Olsson ◽

...

Keyword(s):

Steady State ◽

Soil Depth ◽

Base Cations ◽

Base Cation ◽

Mineral Weathering ◽

Soil Horizon ◽

Soil Horizons ◽

Weathering Rate ◽

Weathering Rates ◽

Forest Sites

Abstract. Reliable and accurate methods for estimating soil mineral weathering rates are required tools in evaluating the sustainability of increased harvesting of forest biomass and assessments of critical loads of acidity. A variety of methods that differ in concept, temporal and spatial scale, and data requirements are available for measuring weathering rates. In this study, causes of discrepancies in weathering rates between methods were analysed and were classified as being either conceptual (inevitable) or random. The release rates of base cations (BCs; Ca, Mg, K, Na) by weathering were estimated in podzolised glacial tills at two experimental forest sites, Asa and Flakaliden, in southern and northern Sweden, respectively. Three different methods were used: (i) historical weathering since deglaciation estimated by the depletion method, using Zr as the assumed inert reference; (ii) steady-state weathering rate estimated with the PROFILE model, based on quantitative analysis of soil mineralogy; and (iii) BC budget at stand scale, using measured deposition, leaching and changes in base cation stocks in biomass and soil over a period of 12 years. In the 0–50 cm soil horizon historical weathering of BCs was 10.6 and 34.1 mmolc m−2 yr−1, at Asa and Flakaliden, respectively. Corresponding values of PROFILE weathering rates were 37.1 and 42.7 mmolc m−2 yr−1. The PROFILE results indicated that steady-state weathering rate increased with soil depth as a function of exposed mineral surface area, reaching a maximum rate at 80 cm (Asa) and 60 cm (Flakaliden). In contrast, the depletion method indicated that the largest postglacial losses were in upper soil horizons, particularly at Flakaliden. With the exception of Mg and Ca in shallow soil horizons, PROFILE produced higher weathering rates than the depletion method, particularly of K and Na in deeper soil horizons. The lower weathering rates of the depletion method were partly explained by natural and anthropogenic variability in Zr gradients. The base cation budget approach produced significantly higher weathering rates of BCs, 134.6 mmolc m−2 yr−1 at Asa and 73.2 mmolc m−2 yr−1 at Flakaliden, due to high rates estimated for the nutrient elements Ca, Mg and K, whereas weathering rates were lower and similar to those for the depletion method (6.6 and 2.2 mmolc m−2 yr−1 at Asa and Flakaliden). The large discrepancy in weathering rates for Ca, Mg and K between the base cation budget approach and the other methods suggests additional sources for tree uptake in the soil not captured by measurements.

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