scholarly journals The fluxes and distribution of molybdenum in a mountainous fir forest in two hydrological years

2019 ◽  
Keyword(s):  
Dry Deposition ◽  
Hydrological Cycle ◽  
Mineral Soil ◽  
Sedimentary Rocks ◽  
Soil Layers ◽  
Clay Concentration ◽  
Tree Canopies ◽  
Standing Trees ◽  
Mo Content ◽  
Throughfall Deposition

<p>The distribution, stocks and fluxes of Mo were examined in a mountainous fir forest in Greece in two hydrological years. In both years, the fluxes of Mo in throughfall were lower than those in bulk deposition implying Mo retention and probably uptake by tree canopies. The Mo concentration was appreciable in soil solution but its fluxes were lower than those in throughfall. The Mo fluxes in both bulk and throughfall deposition were higher than those in litterfall, a finding that stresses the importance of the hydrological cycle for this metal. The Mo concentration in the older twigs in the standing trees were higher than the current year ones most probably due to the existence of dry deposition. The concentrations of total Mo in soils reflected the nature of the sedimentary rocks underlying the soil and increased with depth following the clay concentration gradient. The available (oxalate extractable) Mo in soils ranged from 3% to 14% of the total Mo. In terms of the stocks of Mo, the soil had by far the highest values in both total and available Mo. The needs of the fir plants for Mo uptake are covered by the available Mo in the mineral soil layers, whereas the Mo content in the organic horizon may not be adequate for this purpose.</p>

scholarly journals The distribution and variability of heavy metals in a mountainous fir forest ecosystem in two hydrological years

2018 ◽  
Vol 20 (2) ◽  
pp. 188-197 ◽  
Keyword(s):  
Heavy Metals ◽  
Forest Ecosystem ◽  
Dry Deposition ◽  
Hydrological Cycle ◽  
Mineral Soil ◽  
The Other ◽  
Ground Vegetation ◽  
Soil Layers ◽  
The Past ◽  
Standing Trees

The concentrations (for two hydrological years) of the heavy metals As, Cd, Cr, Ni and Pb as well as the isotopic 206Pb/207Pb composition in soil layers were studied in a remote mountainous Bulgarian fir (Abies borisii regis) forest in central Greece. The concentrations of metals in the hydrological cycle (bulk deposition and throughfall) were lower than the respective ones in the past in Europe, especially for Pb. In the litterfall consisting of mosses, lichens, insect frass and pollen the concentrations of all heavy metals were found far higher than those in the needle litterfall. An evidence of dry deposition was that all metals had higher concentrations in older needles than the young ones with the exception of Ni. Ni also had the highest concentration in the trunk wood, whereas all the other metals had a very low one. It is highly probable that Ni has an internal cycle within the fir trees. In all compartments of the standing trees the order of concentrations was Ni>Pb>Cr>Cd>As. The concentrations of metals in the ground vegetation were low with the exception of Cd, Cr and Ni in ferns. The concentrations of metals in the FH horizon and mineral soil followed the order Cr>Ni>Pb>As>Cd, whereas in the L layer Ni had the highest value. Despite the remoteness of the fir forest, the percentages of anthropogenic Pb in the soil reached an appreciable 41% in the FH horizon and lowered to 2% in the 20-40 cm layers.

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 Dynamic of nitrogen and dissolved organic carbon in an alpine forested catchment: atmospheric deposition and soil solution trends

2019 ◽  
Vol 34 ◽  
pp. 41-66 ◽  
Author(s):  
Raffaella Balestrini ◽  
Carlo Andrea Delconte ◽  
Andrea Buffagni ◽  
Alessio Fumagalli ◽  
Michele Freppaz ◽  
...  
Keyword(s):  
Soil Solution ◽  
Forest Ecosystem ◽  
Forest Floor ◽  
Mineral Soil ◽  
Chemical Species ◽  
Organic N ◽  
Seasonal Temperature ◽  
Inorganic N ◽  
Forest Floor Leachates ◽  
Throughfall Deposition

A number of studies have reported decreasing trends of acidifying and N deposition inputs to forest areas throughout Europe and the USA in recent decades. There is a need to assess the responses of the ecosystem to declining atmospheric pollution by monitoring the variations of chemical species in the various compartments of the forest ecosystem on a long temporal scale. In this study, we report on patterns and trends in throughfall deposition concentrations of inorganic N, dissolved organic N (DON) and C (DOC) over a 20-year (1995–2015) period in the LTER site -Val Masino (1190 m a.s.l.), a spruce forest, in the Central Italian Alps. The same chemical species were studied in the litter floor leachates and mineral soil solution, at three different depths (15, 40 and 70 cm), over a 10-year period (2005–2015). Inorganic N concentration was drastically reduced as throughfall and litter floor leachates percolated through the topsoil, where the measured mean values (2 µeq L-1) were much lower than the critical limits established for coniferous stands (14 µeq L-1). The seasonal temperature dependence of throughfall DOC and DON concentration suggests that the microbial community living on the needles was the main source of dissolved organic matter. Most of DOC and DON infiltrating from the litter floor were retained in the mineral soil. The rainfall amount was the only climatic factor exerting a control on DOC and N compounds in throughfall and forest floor leachates over a decadal period. Concentration of SO4 and NO3 declined by 50% and 26% respectively in throughfall deposition. Trends of NO3 and SO4 in forest floor leachates and mineral soil solution mirrored declining depositions. No trends in both DON and DOC concentration and in DOC/DON ratio in soil solutions were observed. These outcomes suggest that the declining NO3 and SO4 atmospheric inputs did not influence the dynamic of DON and DOC in the Val Masino forest. The results of this study are particularly relevant, as they are based on a comprehensive survey of all the main compartments of the forest ecosystem. Moreover, this kind of long-term research has rarely been carried out in the Alpine region.

Viable seed populations by soil depth and potential site recolonization after disturbance

1977 ◽  
Vol 55 (18) ◽  
pp. 2408-2412 ◽  
Author(s):  
Janice M. Moore ◽  
Ross W. Wein
Keyword(s):  
Soil Depth ◽  
Seedling Emergence ◽  
Mineral Soil ◽  
Organic Soil ◽  
Viable Seed ◽  
Soil Layers ◽  
Forest Experiment Station ◽  
Viable Seeds ◽  
Study Sites ◽  
Germination Experiment

Seedling emergence from organic and mineral soil layers was measured for nine study sites at the Acadia Forest Experiment Station near Fredericton, New Brunswick. The number of viable seeds showed a decrease from deciduous-dominated forest, to conifer-dominated forest, to organic soil study sites. Viable seed number varied from 3400/m2 for a deciduous-dominated forest study site to zero for a bog study site. Most seeds germinated from the upper organic soil layers of all study sites and were predominantly Rubus strigosus Michx. After the germination experiment, ungerminated seeds, which showed no viability by the tetrazolium test, were separated from the soil. These seeds were almost entirely Betula spp. and seed numbers were as high as 4200–9400/m2 for a deciduous-dominated forest. The applicability of the results to differing types of postdisturbance revegetation is discussed.

Roles of clay layers in rainfall-runoff processes in a serpentinite headwater catchment

2020 ◽  
Author(s):  
Takahiko Yoshino ◽  
Shin'ya Katsura
Keyword(s):  
Water Flow ◽  
Groundwater Level ◽  
Mineral Soil ◽  
High Water ◽  
Organic Soil ◽  
Rainfall Runoff ◽  
Soil Layers ◽  
Clay Layers ◽  
Headwater Catchment

&lt;p&gt;Rainfall-runoff processes in a headwater catchment have been typically explained by water flow in permeable soil layers (comprised of organic soil layers and mineral soil layers produced by weathering of bedrock) overlying less permeable layers (i.e., bedrock). In a catchment where mineral soils are characterized by clayey materials (e.g., mudstone, slate, and serpentine catchment), it is possible that mineral soil layers function substantially as less permeable layers because of a low permeability of clayey materials. However, roles of clay layers in rainfall-runoff processes in such a headwater catchment are not fully understood. In this study, we conducted detailed hydrological, hydrochemical, and thermal observations in a serpentinite headwater catchment (2.12 ha) in Hokkaido, Northern Japan, where mineral soil layers consisting of thick clay layers (thickness: approximately 1.5 m) produced by weathering of the serpentinite bedrock underlies organic soil layers (thickness: approximately 0.4 m). Saturated hydraulic conductivity (Ks) and water retention curve of these two layers were also measured in a laboratory. The observation results demonstrated that groundwater was formed perennially in the organic soil layers and clay layers. The groundwater level within the organic soil layers and specific discharge of the catchment showed rapid and flashy change in response to rainfall. In contrast, the groundwater level within the clay layers showed slow and small change. Temperature of the groundwater and stream water suggested that water from the depth of the organic soil layers contributed to streamflow. The electric conductivity (EC) of the groundwater in the clay layers was very high, ranging from 321 to 380 &amp;#181;S cm&amp;#713;&amp;#185;. On the other hand, the EC of soil water (unsaturated water stored in the organic soil layers) was relatively low, ranging from 98 to 214 &amp;#181;S cm&amp;#713;&amp;#185;. Hydrograph separation using EC showed that contribution of water emerging from the clay layers to the total streamflow ranged from 31 to 76% in low to high flow periods. Temporal variation in the total head, measured using tensiometers installed at four depths at the ridge of the catchment, indicated that in wet periods when the groundwater level in the organic soil layers was high, water flow from the organic soil layers to the clay layers occurred, whereas, in dry periods, water flow from the clay layers into the organic soil layers occurred. The laboratory measurements showed that the organic soil layers had high Ks (10&amp;#713;&amp;#178; cm s&amp;#713;&amp;#185;) and low water-holding capacity, whereas the clay layers had low Ks (10&amp;#713;&amp;#8308; cm s&amp;#713;&amp;#185;) and high water-holding capacity. It can be concluded from these results that clay layers play two roles: (1) forming perched groundwater table and lateral flow on the clay layers (the role of less permeable layers) and (2) supplying water into the organic soil layers in the dry periods (the role of water supplier).&lt;/p&gt;

scholarly journals Soil Layers Matter: Vertical Stratification of Root-Associated Fungal Assemblages in Temperate Forests Reveals Differences in Habitat Colonization

2021 ◽  
Vol 9 (10) ◽  
pp. 2131
Author(s):  
Anis Mahmud Khokon ◽  
Dominik Schneider ◽  
Rolf Daniel ◽  
Andrea Polle
Keyword(s):  
Regional Differences ◽  
Temperate Forests ◽  
Mineral Soil ◽  
Niche Partitioning ◽  
Organic Layer ◽  
Habitat Conditions ◽  
Saprotrophic Fungi ◽  
Soil Layers ◽  
Habitat Colonization ◽  
Phylogenetic Signature

Ectomycorrhizal and saprotrophic fungi play pivotal roles in ecosystem functioning. Here, we studied the vertical differentiation of root-associated fungi (RAF) in temperate forests. We analysed RAF assemblages in the organic and mineral soil from 150 experimental forest plots across three biogeographic regions spanning a distance of about 800 km. Saprotrophic RAF showed the highest richness in organic and symbiotrophic RAF in mineral soil. Symbiotrophic RAF exhibited higher relative abundances than saprotrophic fungi in both soil layers. Beta-diversity of RAF was mainly due to turnover between organic and mineral soil and showed regional differences for symbiotrophic and saprotrophic fungi. Regional differences were also found for different phylogenetic levels, i.e., fungal orders and indicator species in the organic and mineral soil, supporting that habitat conditions strongly influence differentiation of RAF assemblages. Important exceptions were fungal orders that occurred irrespective of the habitat conditions in distinct soil layers across the biogeographic gradient: Russulales and Cantharellales (ectomycorrhizal fungi) were enriched in RAF assemblages in mineral soil, whereas saprotrophic Polyporales and Sordariales and ectomycorrhizal Boletales were enriched in RAF assemblages in the organic layer. These results underpin a phylogenetic signature for niche partitioning at the rank of fungal orders and suggest that RAF assembly entails two strategies encompassing flexible and territorial habitat colonization by different fungal taxa.

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