Effects of grassland afforestation on exchangeable soil and soil solution aluminium

Soil Research ◽  
2001 ◽  
Vol 39 (5) ◽  
pp. 1003 ◽  
Author(s):  
M. L. Adams ◽  
M. R. Davis ◽  
K. J. Powell

The impact of land use change from grassland to conifer forest on the aluminium (Al) concentrations in soils and soil solutions was examined. Soils from grassland were compared with those from adjoining 15–19-year old forest stands at 3 contrasting pairs of sites in South Island, New Zealand. The site pairs were on a terrace [Pinus nigra/P. ponderosa, and grassland (CP)], and a hill slope [Pseudotsuga menziesii and grassland (CF)] in the Craigieburn range, Canterbury, and a hill slope in the Lammerlaw Range, Otago [P. radiata and grassland (LP)]. The sites had never been cultivated or fertilised, and for each pair the forest and grassland were similar in terms of soil and topography. The 1 M KCl exchangeable and 0.02 M CaCl 2 extractable Al levels at 0–10 cm were higher in forest than in grassland topsoil at CP and LP (P < 0.01). In soil solutions there was a trend for both ‘reactive Al’ and Al bound in labile organic complexes to be higher in forest soil at all sites, but site-pair differences were only significant at LP, and only for ‘reactive Al’. The increase in ‘reactive Al’ at this site was linked to the low pH and low base saturation. The ratios of exchangeable and soil solution Ca 2+ and Mg 2+ to ‘reactive Al’ were substantially lower in forest than grassland soils at all sites. Aluminium complexation capacity (Al-CC) values at all sites were higher in forest soil solutions than in grassland soil solutions. For the grassland and forest sites at LP, the Al-CC correlated strongly with the amount of soluble fulvic and humic matter present, as estimated from soil solution UV absorbance at 250 nm. In soils with the lowest percentage base saturation and buffering capacity (LP), afforestation of pastoral grassland with Pinus radiata significantly reduced soil pH and base cation levels, while increasing both soil and soil solution Al concentrations. Under such conditions (base saturation <20%), the increase in ‘reactive Al’ concentrations in soil solutions under fast growing conifer tree species may be sufficient to affect Mg uptake.

1992 ◽  
Vol 22 (6) ◽  
pp. 893-904 ◽  
Author(s):  
J.D. Joslin ◽  
M.H. Wolfe

The decline of red spruce (Picearubens Sarg.) at high elevations in eastern North America has been linked in time and space with exposure to acidic cloud water. To investigate the belowground effects of a cloud water deposition gradient between two mature red spruce stands on the summit of Whitetop Mountain, Virginia, the chemistries of precipitation, throughfall, and soil solution were monitored over a 2-year period, and fine-root distributions were characterized. Deposition of water, sulfate, nitrate, and ammonium in throughfall and stemflow was from 15 to 55% greater at the site with greater exposure to cloud water deposition (high cloud site), depending upon the particular ion and year. Soil solution nitrate concentrations were highly variable over time, and base cation, Al, and H ion concentrations were highly correlated with nitrate in both organic and mineral horizons at both sites. Soil solution nitrate, base cation, Al, and H ion concentrations were two to six times greater during periods of low soil moisture in the summer–autumn of 1987 and 1988 than during the remainder of the study period. In the mineral soil solutions, the high cloud site had significantly higher (p < 0.001) concentrations of nitrate and Al, and significantly lower (p < 0.05) Ca:Al and Mg:Al ratios. The high cloud stand also had shallower root systems, with fine-root biomass less than 40% of that of the low cloud stand (p < 0.05) at all depths greater than 18 cm. Soil solutions collected from below 15 cm at the high cloud site had a mean Ca:Al ratio less than 0.5 and Al concentrations that during dry periods, frequently approached or exceeded the literature values for the toxicity threshold for red spruce root growth. Restricted root development in the high cloud stand was apparently the result of this unfavorable chemical environment.


1996 ◽  
Vol 26 (4) ◽  
pp. 696-709 ◽  
Author(s):  
Paul A. Arp ◽  
Tõnu Oja ◽  
Marius Marsh

A steady-state mass-balance model was used to calculate critical loads of S and N deposition for maintaining acceptable long-term acidity levels within upland forests in southern Ontario. Preliminary estimates about critical S and N loads were obtained using existing information about soils, vegetation and atmospheric ion deposition from 12 forest sites, all located within provincial parks or conservation areas. The following were considered: wet atmospheric deposition of all major cations and anions; availability for plant uptake of N, Ca, Mg, and K in the rooting space of each soil; nutrient uptake and storage in the growing woody biomass of the forest stands; estimates of soil weathering; and mean annual air temperature, precipitation, and evapotranspiration. From this, regional isopleth maps were generated to depict the following: (1) current deposition patterns; (2) critical acidification loads and their current exceedances (or nonexceedances) for two acidification effects criteria for soil solutions, namely (i) acceptable Al concentrations ([Al]leach,crit) and (ii) acceptable Al to base cation concentration ratios ([Al]/[BC]leach,crit); (3) critical N-eutrophication loads and their current exceedances for acceptable levels of NO3-N concentrations in soil solutions ([NO3-N]leach,crit). It was found that the northern part of the study area (part of the Canadian Shield) is currently subjected to atmospheric S and N deposition in excess of critical loads, with [Al]leach,crit set at 0.02 mequiv./L or [Al]/[BC]leach,crirt set at 0.15 equiv./equiv. This sensitivity to acid precipitation is, as calculated, primarily due to shallow and weathering-resistant soils and soil parent materials (mostly granitic). The middle portion of the study area is calculated to receive N slightly in excess of the N eutrophication limit, when [NO3-N]leach,crit is set at 0.1 mequiv./L. Considerable co-deposition of base cations (Ca, Mg, K) in the middle and southern part of the study area alleviates some of the atmospheric acidification stress. This stress is further neutralized by the soils and bedrock of this region (predominantly calcareous).


1994 ◽  
Vol 24 (3) ◽  
pp. 609-617 ◽  
Author(s):  
W.H. Hendershot ◽  
F. Courchesne

Forest fertilization has been adopted as the primary means of controlling sugar maple (Acersaccharum Marsh.) dieback in southern Quebec. Following foliar analysis, treatments containing appropriate mixtures of K, Ca, Mg, and (or) P have been used on commercial sugar groves. This study was undertaken to identify the impact of base cation additions on nutrient cycling in a sugar maple stand in the Lower Laurentians, Quebec, and to quantify the amounts of added nutrients that were retained in the stand or lost by leaching. In 1988, six 40 × 40 m plots were established; three were kept as controls and the other three received a mixture of 500 kg•ha−1 of K2SO4, 250 kg•ha−1 of Ca,Mg(CO3)2 and 250 kg•ha−1 of CaCO3 applied as fine particulate matter in June 1989. Soil solutions were collected weekly during the spring and fall from October 1988 until November 1992. Soil solution chemistry indicated that there was increased biocycling of both K and Mg as a result of the treatment. The application of appropriate mixtures of base cation will improve the fertility of the soils and decrease nutrient imbalances. The amount of added material lost from the rooting zone was a small proportion of the amount added: over a 4-year period following treatment only 12.1, 9.5, and 1.4% of added Ca, Mg, and K were lost, respectively.


2003 ◽  
Vol 33 (8) ◽  
pp. 1544-1556 ◽  
Author(s):  
Shaun A Watmough ◽  
Peter J Dillon

We calculated critical loads of acidity (S and S + N separately) for seven forested catchments in south-central Ontario, using a critical threshold designed to maintain the Ca/Al molar ratio above 1.0 or the base cation (BC; Ca + Mg + K) to Al molar ratio above 10 in soil solution. Critical loads are ~10–50% lower using the BC/Al ratio compared with the Ca/Al ratio, and harvesting greatly increases forest sensitivity to acid deposition. If forests are harvested, critical load calculations indicate that further reductions in S and N bulk deposition are required to maintain the BC/Al ratio in soil solution above 10, but reductions in S deposition are only mandatory for three of the seven catchments. However, S export exceeds inputs in bulk deposition by 40–100%. Our study indicates that setting the critical threshold of BC/Al at 10 may not maintain soil base saturation above 20%, and that N export is unpredictable at current deposition levels. We calculate that SO4 leaching (and therefore deposition) must be reduced by between 10 and 74% to maintain healthy, productive forests in catchments that are harvested. More reliable estimates of base cation removals during harvest, minimum Ca leaching losses from soils that can occur without affecting forest productivity, and critical limits for soil base saturation are needed to improve these critical load estimates.


Author(s):  
Giuliana Zanchi ◽  
Klas Lucander ◽  
Veronika Kronnäs ◽  
Martin Erlandsson Lampa ◽  
Cecilia Akselsson

AbstractThe study investigated the effects of forest residue extraction on tree growth and base cations concentrations in soil water under different climatic conditions in Sweden. For this purpose, the dynamic model ForSAFE was used to compare the effects of whole-tree harvesting and stem harvesting on tree biomass and the soil solution over time at 6 different forest sites. The study confirmed the results from experimental sites showing a temporary reduction of base cation concentration in the soil solution for a period of 20–30 years after whole-tree harvesting. The model showed that this was mainly caused by the reduced inputs of organic material after residue extraction and thereby reduced nutrient mineralisation in the soil. The model results also showed that whole-tree harvesting can affect tree growth at nitrogen-poor forest sites, such as the ones in northern Sweden, due to the decrease of nitrogen availability after residue removal. Possible ways of reducing this impact could be to compensate the losses with fertilisation or extract residue without foliage in areas of Sweden with low nitrogen deposition. The study highlighted the need to better understand the medium- and long-term effects of whole-tree harvesting on tree growth, since the results suggested that reduced tree growth after whole-tree harvesting could be only temporary. However, these results do not account for prolonged extraction of forest residues that could progressively deplete nutrient pools and lead to permanent effects on tree growth.


Author(s):  
S.E. Rudov ◽  
◽  
V.Ya. Shapiro ◽  
O.I. Grigoreva ◽  
I.V. Grigorev ◽  
...  

In the Russian Federation logging operations are traditionally carried out in winter. This is due to the predominance of areas with swamped and water-logged (class III and IV) soils in the forest fund, where work of forestry equipment is difficult, and sometimes impossible in the warm season. The work of logging companies in the forests of the cryolithozone, characterized by a sharply continental climate, with severe frosts in winter, is hampered by the fact that forest machines are not recommended to operate at temperatures below –40 °C due to the high probability of breaking of metal structures and hydraulic system. At the same time, in the warm season, most of the cutting areas on cryosolic soils become difficult to pass for heavy forest machines. It turns out that the convenient period for logging in the forests of the cryolithozone is quite small. This results in the need of work in the so-called off-season period, when the air temperature becomes positive, and the thawing processes of the soil top layer begin. The same applies to the logging companies not operating in the conditions of cryosolic soils, for instance, in the Leningrad, Novgorod, Pskov, Vologda regions, etc. The observed climate warming has led to a significant reduction in the sustained period of winter logging. Frequent temperature transitions around 0 °C in winter, autumn and spring necessitate to work during the off-season too, while cutting areas thaw. In bad seasonal and climatic conditions, which primarily include off-season periods in general and permafrost in particular, it is very difficult to take into account in mathematical models features of soil freezing and thawing and their effect on the destruction nature. The article shows that the development of long-term predictive models of indicators of cyclic interaction between the skidding system and forest soil in adverse climatic conditions of off-season logging operations in order to improve their reliability requires rapid adjustment of the calculated parameters based on the actual experimental data at a given step of the cycles.


2020 ◽  
Vol 17 (2) ◽  
pp. 281-304 ◽  
Author(s):  
Sophie Casetou-Gustafson ◽  
Harald Grip ◽  
Stephen Hillier ◽  
Sune Linder ◽  
Bengt A. Olsson ◽  
...  

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.


1989 ◽  
Vol 69 (3) ◽  
pp. 611-627 ◽  
Author(s):  
D. R. COOTE ◽  
S. SHAH SINGH ◽  
C. WANG

Acid rain and N fertilizers both contribute to soil acidity, but no method has been available to compare their relative impacts. A simple model (SOLACID) is presented to assess quantitatively the acidifying effects of precipitation and N fertilizers on agricultural soils. Acid rain has been treated as a dilute solution of NH4NO3, (NH4)2SO4 and associated acids. Soil and plant pathways are considered for [Formula: see text], [Formula: see text]and [Formula: see text] by way of leaching, gaseous losses from microbial reduction, plant uptake and removal, and organic immobilization and mineralization. Leaching of [Formula: see text] was the factor to which the model was most sensitive. A relationship between base saturation and base cation leaching is described. Field data reported from 21 treatments at six experimental sites were used to test the model, which provided reliable estimates of final pH (r2 = 0.92**) and of changes in base saturation (r2 = 0.86**). Compared with previously published methods, the model provided the best estimates of lime requirements as computed from field measurements (r2 = 0.87**). Key words: Ammonia, sulfate, leaching, nitrification


2013 ◽  
Vol 10 (3) ◽  
pp. 1365-1377 ◽  
Author(s):  
M. O. Rappe-George ◽  
A. I. Gärdenäs ◽  
D. B. Kleja

Abstract. Addition of mineral nitrogen (N) can alter the concentration and quality of dissolved organic matter (DOM) in forest soils. The aim of this study was to assess the effect of long-term mineral N addition on soil solution concentration of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) in Stråsan experimental forest (Norway spruce) in central Sweden. N was added yearly at two levels of intensity and duration: the N1 treatment represented a lower intensity but a longer duration (43 yr) of N addition than the shorter N2 treatment (24 yr). N additions were terminated in the N2 treatment in 1991. The N treatments began in 1967 when the spruce stands were 9 yr old. Soil solution in the forest floor O, and soil mineral B, horizons were sampled during the growing seasons of 1995 and 2009. Tension and non-tension lysimeters were installed in the O horizon (n = 6), and tension lysimeters were installed in the underlying B horizon (n = 4): soil solution was sampled at two-week intervals. Although tree growth and O horizon carbon (C) and N stock increased in treatments N1 and N2, the concentration of DOC in O horizon leachates was similar in both N treatments and control. This suggests an inhibitory direct effect of N addition on O horizon DOC. Elevated DON and nitrate in O horizon leachates in the ongoing N1 treatment indicated a move towards N saturation. In B horizon leachates, the N1 treatment approximately doubled leachate concentrations of DOC and DON. DON returned to control levels, but DOC remained elevated in B horizon leachates in N2 plots nineteen years after termination of N addition. We propose three possible explanations for the increased DOC in mineral soil: (i) the result of decomposition of a larger amount of root litter, either directly producing DOC or (ii) indirectly via priming of old SOM, and/or (iii) a suppression of extracellular oxidative enzymes.


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