Seed banks in five boreal forest stands originating between 1810 and 1963

1982 ◽  
Vol 60 (9) ◽  
pp. 1815-1821 ◽  
Author(s):  
Anders Granström
Keyword(s):  
Boreal Forest ◽  
Plant Species ◽  
Mineral Soil ◽  
Coniferous Forest ◽  
Soil Samples ◽  
Distribution Data ◽  
Forest Stands ◽  
Humus Layer ◽  
Seed Content ◽  
Organic Horizons

The viable seed content of soil samples from five coniferous forest stands in northern Sweden, aged 16–169 years, was determined by means of germination trials. The soil samples were separated into five fractions: three organic horizons and two mineral soil horizons. Seedlings of 15 phanerogam species emerged, representing densities of 239–763 seeds/m2 in the soils from the different stands. The depth distributions of the seeds varied with both plant species and forest stand. Most seeds were found at various depths in the humus layer, but in one stand an appreciable seed density of Luzula pilosa was present in the mineral soil. Most of the seedlings belonged to plant species present in the vegetation or with good means of dispersal. The depth distribution data, however, suggest that Luzula pilosa in particular may have a persistent seed bank. The role of persistent seeds in the vegetational composition of the boreal forest is discussed.

Soil acidity in 1970 and 1989 in a coniferous forest in southwest Finland

1998 ◽  
Vol 78 (3) ◽  
pp. 477-479 ◽  
Author(s):  
C. J. Westman ◽  
S. Jauhiainen
Keyword(s):  
Key Words ◽  
Soil Ph ◽  
Soil Acidity ◽  
Mineral Soil ◽  
Coniferous Forest ◽  
Soil Layers ◽  
Water Suspension ◽  
Ph Values ◽  
Humus Layer ◽  
Repeated Sampling

Forest soil pH in southwest Finland was measured with identical sampling and analysing methods in 1970 and 1989. The acidity of the organic humus layer increased significantly as pH values measured on water and on salt suspensions decreased between the two sampling dates. For the mineral soil layers, no unambiguous trend was found. pH values measured on salt suspension tended to be unchanged or lower, while pH on water suspension in some soil layers were even higher in 1989 than in 1970. Key words: pH, repeated sampling

scholarly journals Radiocarbon Dating of Soil Organic Matter Fractions in Andosols in Northern Ecuador

Radiocarbon ◽  
2006 ◽  
Vol 48 (3) ◽  
pp. 337-353 ◽  
Author(s):  
Femke H Tonneijck ◽  
Johannes van der Plicht ◽  
Boris Jansen ◽  
Jacobus M Verstraten ◽  
Henry Hooghiemstra
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Soil Organic Matter ◽  
Forest Floor ◽  
Radiocarbon Dating ◽  
Mineral Soil ◽  
Soil Samples ◽  
Acid Extraction ◽  
Independent Evidence ◽  
Organic Horizons

Volcanic ash soils (Andosols) may offer great opportunities for paleoecological studies, as suggested by their characteristic accumulation of organic matter (OM). However, understanding of the chronostratigraphy of soil organic matter (SOM) is required. Therefore, radiocarbon dating of SOM is necessary, but unfortunately not straightforward. Dating of fractions of SOM obtained by alkali-acid extraction is promising, but which fraction (humic acid or humin) renders the most accurate 14C dates is still subject to debate. To determine which fraction should be used for 14C dating of Andosols and to evaluate if the chronostratigraphy of SOM is suitable for paleoecological research, we measured 14C ages of both fractions and related calibrated ages to soil depth for Andosols in northern Ecuador. We compared the time frames covered by the Andosols with those of peat sequences nearby to provide independent evidence. Humic acid (HA) was significantly older than humin, except for the mineral soil samples just beneath a forest floor (organic horizons), where the opposite was true. In peat sections, 14C ages of HA and humin were equally accurate. In the soils, calibrated ages increased significantly with increasing depth. Age inversions and homogenization were not observed at the applied sampling distances. We conclude that in Andosols lacking a thick organic horizon, dating of HA renders the most accurate results, since humin was contaminated by roots. On the other hand, in mineral soil samples just beneath a forest floor, humin ages were more accurate because HA was then contaminated by younger HA illuviated from the organic horizons. Overall, the chronostratigraphy of SOM in the studied Andosols appears to be suitable for paleoecological research.

Dung longevity influences the fate of endozoochorically dispersed seeds in forest ecosystems

Botany ◽  
2011 ◽  
Vol 89 (11) ◽  
pp. 779-785 ◽  
Author(s):  
Bogdan Jaroszewicz ◽  
Ewa Pirożnikow
Keyword(s):  
Plant Species ◽  
Deciduous Forest ◽  
Coniferous Forest ◽  
Light Availability ◽  
European Bison ◽  
Plant Establishment ◽  
Seed Content ◽  
Closed Canopy ◽  
Seedling Germination ◽  
Forest Habitats

Many studies show large discrepancies between the potential (studied in the greenhouse) and realized (studied in the field) effects of endozoochory. The influence of environmental conditions on the fate of endozoochorically dispersed seeds and subsequent plant establishment is still not well understood. We addressed this issue by studying the viable seed content of the dung of European bison ( Bison bonasus L.) by means of seedling germination in the greenhouse and in two forest habitats in Białowieża Primeval Forest. The number of seedlings and the number of plant species that emerged from 1 L of feces were positively correlated with dung longevity. Generative shoots were produced by plants only in coniferous forest. Their number was positively correlated with dung longevity and with light availability. Germination of seeds from bison feces was higher in coniferous forest than in deciduous forest but did not differ between open- and closed-canopy plots within the same habitat. We conclude that (i) seed germination and plant establishment after endozoochorous dispersal is influenced by dung longevity; (ii) the number of generative shoots produced by endozoochorously dispersed plants is influenced by dung longevity and light availability; (iii) seeds of some plant species, present in dung, stay viable for at least 3 years.

Foraging ecology of black-backed woodpeckers (Picoides arcticus) in unburned eastern boreal forest stands

2010 ◽  
Vol 40 (5) ◽  
pp. 991-999 ◽  
Author(s):  
Junior A. Tremblay ◽  
Jacques Ibarzabal ◽  
Jean-Pierre L. Savard
Keyword(s):  
Boreal Forest ◽  
Foraging Ecology ◽  
Radio Telemetry ◽  
Woody Debris ◽  
Continuous Production ◽  
Coniferous Forest ◽  
Insect Outbreaks ◽  
Forest Stands ◽  
Picoides Arcticus ◽  
Downed Woody Debris

Managed coniferous forest dominates much of the black-backed woodpecker’s ( Picoides arcticus Swainson) breeding range. Despite this, little is known about the fine-scale foraging behaviour of this focal species in unburned managed forest stands in the absence of insect outbreaks. To investigate the foraging substrates used in such a habitat, we employed radio-telemetry to track a total of 27 black-backed woodpeckers. During two successive summers (2005–2006), 279 foraging observations were recorded, most of which were on dying trees, snags, and downed woody debris. Individuals frequently foraged by excavation, suggesting that in the absence of insect outbreaks the black-backed woodpecker forages mainly by drilling. The majority of foraging events occurred on recently dead snags with a mean dbh (±SE) of 18.3 ± 0.4 cm. Our results suggest that in unburned boreal forest stands, substrate diameter and decay class are important predictors of suitable foraging substrates for black-backed woodpeckers. We suggest that conservation efforts aimed at maintaining this dead-wood dependent cavity nesting species within the landscape, should endeavour to maintain 100 ha patches of old-growth coniferous forest. This would ensure the continuous production of a sufficient quantity of recently dead or dying trees to meet the foraging needs of this species.

Nitrogen cycling in undisturbed and manipulated boreal forest

1982 ◽  
Vol 296 (1082) ◽  
pp. 419-425 ◽  
Keyword(s):  
Boreal Forest ◽  
Boreal Forests ◽  
Forest Canopy ◽  
Mineral Soil ◽  
Terrestrial Ecosystems ◽  
Ecosystem Functions ◽  
Managed Forests ◽  
Available N ◽  
Humus Layer

Like most forests and several other natural terrestrial ecosystems, the boreal forest accumulates N in biomass and soil organic matter, even although measured rates of biological N 2 fixation are normally low. The accumulation of N is disrupted if the forest canopy is removed by natural causes (fire, wind-felling or insect outbreaks) or by cutting. During the period after such a ‘catastrophe’ (in fact a common event in boreal forests, considered in a long-term perspective), the accumulation is discontinued or even changed into a loss of N from the site. Some losses are caused directly by fire or, in managed forests, by removal of biomass. These losses are usually small, except with whole-tree utilization. Nitrogen losses associated with nitrification processes (both leaching and denitrification) may be more serious on a cleared area, where uptake by vegetation is inconsiderable for some period. Nitrate formation may then take place both in the humus layer (the mor) and in the mineral soil, although the pH may be well below 4.5 in the mor layer. Scarcity of available N in the soil is a common cause of slow growth. Effects of fertilization on ecosystem functions are discussed.

Recovery of 15N-labelled nitrate applied to a small upland boreal forest catchment

2000 ◽  
Vol 30 (7) ◽  
pp. 1165-1177 ◽  
Author(s):  
Sébastien Lamontagne ◽  
Sherry L Schiff ◽  
Richard J Elgood
Keyword(s):  
Boreal Forest ◽  
Pinus Banksiana ◽  
Mineral Soil ◽  
N Recovery ◽  
Short Term ◽  
Organic Horizons ◽  
Balance Analysis ◽  
Second Year ◽  
Forest Island ◽  
Forest Islands

Nitrate labelled with 15N was added for 2 years to a small Boreal Shield forested catchment to evaluate where new nitrogen (N) inputs are stored in this system in the short term. The landscape in the study catchment is a mosaic of Pinus banksiana Lamb. - Picea mariana (Mill.) BSP "forest islands" surrounded by "pillows" of lichens, mosses, and grasses on exposed bedrock surfaces. After the second year of N addition, 10% of the added 15N was found in aboveground biomass, 27% in organic horizons, 6% in forest island mineral soil, 3% in "soil" underneath pillows, and 16% was lost through runoff. Despite covering a smaller proportion of the catchment and having only slightly larger N stocks, forest islands stored more 15N (31%) than pillows (15%). Preferential routing of water towards forest islands and a greater potential for biotic and abiotic N immobilization are hypothesized to favor N retention in forest islands. Thirty-eight percent of the 15N could not be accounted for. The comparison of a mass-balance analysis with the 15N recovery suggests a missing sink for the 15N in forest islands, possibly woody detritus. In the short term (~2 years), organic horizons are the main sinks for elevated N inputs in the boreal forest.

Effects of clear-cutting on the composition of bacterial populations of northern spruce forest soil

1977 ◽  
Vol 23 (2) ◽  
pp. 131-138 ◽  
Author(s):  
Seppo Niemelä ◽  
Veronica Sundman
Keyword(s):  
Forest Soil ◽  
Heterotrophic Bacteria ◽  
Mineral Soil ◽  
Coniferous Forest ◽  
Soil Layer ◽  
Population Characteristics ◽  
Short Term ◽  
Biochemical Tests ◽  
Clear Cutting ◽  
Humus Layer

This paper concerns the microbiological part of an investigation, the goal of which is to describe the biological changes in coniferous forest soil upon clear-cutting in a northern (66°20′ N) moraine area where reforestation after clear-cutting had been met with difficulty. The zoological part of the work has been published elsewhere. Clear-cut sites of increasing age (4, 7, and 13 years) were investigated and compared with a forest area where no cutting of timber had been done for 120 years.A total of 684 random isolates of heterotrophic bacteria from pooled samples of the sites investigated were passed through 36 biochemical tests. The data were condensed by the aid of factor analysis, and a comparison of the populations was based on squared Euclidean distances between population centroids in a seven-dimensional factor space.The most marked population changes followed a course in which frequencies of some population characteristics became increasingly different until 7 years after clear-cutting, with regression towards the control clearly evident after 13 years. Disturbances of shorter duration were also relatively common, with maximal changes observed in the 4-year samples, and with a complete recovery after 7 years.The mineral soil populations seemed to undergo greater changes than the humus populations.The most distinct changes believed to be due to clear-cutting were the short-term relative increase of organisms producing acid from sucrose and dissolving CaHPO4, and a long-term increase of lipolytic and caseolytic, rhamnose-negative organisms; both in the mineral soil layer. In the humus layer, a short-term increase of lipolytic and of rhamnose-positive organisms seemed to take place.

The effects of simulated acid precipitation in the surface horizons of two eastern Canadian forest Podzol soils

1987 ◽  
Vol 17 (9) ◽  
pp. 1138-1143 ◽  
Author(s):  
D. J. Thacker ◽  
G. K. Rutherford ◽  
G.W. Vanloon
Keyword(s):  
Mineral Soil ◽  
Acid Precipitation ◽  
Exchange Capacity ◽  
Soil Core ◽  
X Ray Diffraction ◽  
Total N ◽  
Organic C ◽  
Podzolic Soils ◽  
Humus Layer ◽  
Organic Horizons

Undisturbed 18-cm soil cores of the L, F, H, Ae, and upper Bhf horizons of Ferro-Humic Podzols from the Turkey Lake Watershed (Ontario) and Montmorency Forest (Quebec) were treated in the laboratory with 10 m of simulated acid precipitation at pH 5.7, 3.5, and 2.0 over approximately 1 year. Leachate samples were collected from the bottom of the humus layer and the bottom of the soil core and the soils were analyzed at the completion of leaching. The soils from the two sites behaved similarly. Anion concentrations in the leachates adjusted to input levels after approximately 2 m of simulated rainfall. Leaching generally produced an initial flush of cations followed by lower concentrations. The pH 2.0 treatment caused major changes in some soil properties; the pH 3.5 and 5.7 treatment had a more modest effect. Base saturation was markedly reduced following the pH 2.0 treatment, slightly reduced following the pH 3.5 treatment, and slightly increased following the distilled water treatment. Cation exchange capacity was reduced only in the organic horizons receiving pH 2.0 treatment. Organic C, total N, and C/N ratios showed no changes on acidification. Leaching of Fe and Al was only substantial with the pH 2.0 treatment and much more Al than Fe was mobilized. Bicarbonate – extractable P in the mineral soil was doubled by the pH 2.0 treatment compared with the other treatments. X-ray diffraction of clays indicated a loss of hydroxyaluminum interlayers with increasing acidity, which is a stage in the acidic transformation of micaceous to smectite-like materials in Podzolic soils.

Sorption of niobium on boreal forest soil

2015 ◽  
Vol 103 (12) ◽  
Author(s):  
Mervi Söderlund ◽  
Martti Hakanen ◽  
Jukka Lehto
Keyword(s):  
Boreal Forest ◽  
Forest Soil ◽  
Mass Distribution ◽  
Mineral Soil ◽  
Distribution Coefficients ◽  
Soil Samples ◽  
Deep Forest

AbstractThe sorption of niobium (Nb) was investigated on humus and mineral soil samples taken from various depths of a four-metre deep forest soil pit on Olkiluoto Island, southwestern Finland. Mass distribution coefficients,

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