Fungal sporocarp mediated losses of Ca, Fe, K, Mg, Mn, N, P, and Zn from conifer logs in the early stages of decomposition

1994 ◽  
Vol 24 (9) ◽  
pp. 1883-1893 ◽  
Author(s):  
Mark E. Harmon ◽  
Jay Sexton ◽  
Bruce A. Caldwell ◽  
Steve E. Carpenter
Keyword(s):  
Fungal Species ◽  
Critical Element ◽  
Conifer Species ◽  
Fair Proportion ◽  
Element Ratios ◽  
Early Stages

The export of mass and nutrients associated with the formation of fungal sporocarps during the first 7 years of decomposition of logs of four conifer species (Abiesamabilis Dougl. ex Forbes, Pseudotsugamenziesii (Mirb.) Franco, Thujaplicata D. Don, and Tsugaheterophylla (Raf.) Sarg.) was investigated in western Oregon. Abundance of the most common fungal species, Naematolomacapnoides (Fr.:Fr.) P. Kumm, differed significantly with log species; the fungus was most abundant on Abies and least abundant on Thuja. Fungi increased concentrations of N, K, and P over those found in associated logs by as much as 38, 115, and 136 times, respectively. Thus, a fair proportion of the initial N (0.9–2.9%), K (1.8–4.5%), and P (1.9–6.6%) was transported out of logs via sporocarps at a time when immobilization would have been predicted from critical element ratios (e.g., C/N).

scholarly journals Contrasting conifer species productivity in relation to soil carbon, nitrogen and phosphorus stoichiometry of British Columbia perhumid rainforests

2020 ◽  
Vol 17 (5) ◽  
pp. 1247-1260
Author(s):  
John Marty Kranabetter ◽  
Ariana Sholinder ◽  
Louise de Montigny
Keyword(s):  
Forest Floor ◽  
Mineral Soil ◽  
Basal Area ◽  
Picea Sitchensis ◽  
P Availability ◽  
Growth Responses ◽  
Conifer Species ◽  
Effective Measure ◽  
Element Ratios ◽  
Wide Range

Abstract. Temperate rainforest soils of the Pacific Northwest are often carbon (C) rich and encompass a wide range of fertility, reflecting varying nitrogen (N) and phosphorus (P) availability. Soil resource stoichiometry (C : N : P) may provide an effective measure of site nutrient status and help refine species-dependent patterns in forest productivity across edaphic gradients. We determined mineral soil and forest floor nutrient concentrations across very wet (perhumid) rainforest sites of southwestern Vancouver Island (Canada) and employed soil element ratios as covariates in a long-term planting density trial to test their utility in defining basal area growth response of four conifer species. There were strong positive correlations in mineral soil C, N, and organic P (Po) concentrations and close alignment in C : N and C : Po both among and between substrates. Stand basal area after 5 decades was best reflected by mineral soil and forest floor C : N, but in either case included a significant species–soil interaction. The conifers with ectomycorrhizal fungi had diverging growth responses displaying either competitive (Picea sitchensis) or stress-tolerant (Tsuga heterophylla, Pseudotsuga menziesii) attributes, in contrast to a more generalist response by an arbuscular mycorrhizal tree (Thuja plicata). Despite the consistent patterns in organic matter quality, we found no evidence for increased foliar P concentrations with declining element ratios (C : Po or C : Ptotal) as we did for N. The often high C : Po ratios (as much as 3000) of these soils may reflect a stronger immobilization sink for P than N, which, along with ongoing sorption of PO4-, could limit the utility of C : Po or N : Po to adequately reflect P supply. The dynamics and availability of soil P to trees, particularly as Po, deserves greater attention, as many perhumid rainforests were co-limited by N and P, or, in some stands, possibly P alone.

scholarly journals Soil carbon, nitrogen and phosphorus stoichiometry (C : N : P) in relation to conifer species productivity and nutrition across British Columbia perhumid rainforests

2019 ◽  
Author(s):  
John Marty Kranabetter ◽  
Ariana Sholinder ◽  
Louise de Montigny
Keyword(s):  
Organic Matter ◽  
Mineral Soil ◽  
Basal Area ◽  
Picea Sitchensis ◽  
P Availability ◽  
Growth Responses ◽  
Conifer Species ◽  
Soil C ◽  
Element Ratios ◽  
Wide Range

Abstract. Temperate rainforest soils of the Pacific Northwest are often carbon (C) rich and encompass a wide range in fertility reflecting varying nitrogen (N) and phosphorus (P) availability. Soil resource stoichiometry (C : N : P) may provide an effective measure of site nutrient status and help refine species-dependent patterns in forest productivity across edaphic gradients. We described the nature of soil organic matter for mineral soil and forest floor substrates across very wet (perhumid) rainforest sites of southwestern Vancouver Island (Canada), and employed soil element ratios as covariates in a long-term planting density trial to test their utility in defining basal area growth response of four conifer species. There were strong positive correlations in mineral soil C, N and organic P (Po) concentrations, and close alignment in C : N and C : Po both among and between substrates. Stand basal area after five decades was best reflected by soil C : N but included a significant species-soil interaction. The conifers with ectomycorrhizal fungi had diverging growth responses displaying either competitive (Picea sitchensis) or stress-tolerant (Tsuga heterophylla, Pseudotsuga menziesii) attributes, in contrast to a more generalist response by an arbuscular mycorrhizal tree (Thuja plicata). Despite the consistent patterns in organic matter quality we found no evidence via foliar nutrition for increased P availability with declining element ratios as we did for N. The often high C : Po ratios (as much as 3000) of these soils may reflect a stronger immobilization sink for P than N, which, along with ongoing sorption of PO4−, could limit the utility of C : Po or N : Po to adequately reflect P supply. The dynamics and availability of soil P to trees, particularly as Po, deserves greater attention as many perhumid rainforests were co-limited by N and P, or, in some stands, possibly P alone.

Spherulitic crystal growth in the prodissoconch larval of Crassostrea virginica

1983 ◽  
Vol 41 ◽  
pp. 518-519
Author(s):  
George G. Cocks ◽  
Louis Leibovitz ◽  
DoSuk D. Lee
Keyword(s):  
Crystal Structure ◽  
Crassostrea Virginica ◽  
Crystal Orientation ◽  
Developmental Changes ◽  
Gastrula Stage ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Stages Of Growth ◽  
Early Stages ◽  
Initial Deposition

Our understanding of the structure and the formation of inorganic minerals in the bivalve shells has been considerably advanced by the use of electron microscope. However, very little is known about the ultrastructure of valves in the larval stage of the oysters. The present study examines the developmental changes which occur between the time of conception to the early stages of Dissoconch in the Crassostrea virginica(Gmelin), focusing on the initial deposition of inorganic crystals by the oysters.The spawning was induced by elevating the temperature of the seawater where the adult oysters were conditioned. The eggs and sperm were collected separately, then immediately mixed for the fertilizations to occur. Fertilized animals were kept in the incubator where various stages of development were stopped and observed. The detailed analysis of the early stages of growth showed that CaCO3 crystals(aragonite), with orthorhombic crystal structure, are deposited as early as gastrula stage(Figuresla-b). The next stage in development, the prodissoconch, revealed that the crystal orientation is in the form of spherulites.

Formation of Dislocation Channels in Neutron Irradiated Molybdenum

1972 ◽  
Vol 30 ◽  
pp. 672-673
Author(s):  
S. Mahajan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ambient Temperature ◽  
Room Temperature ◽  
Channel Formation ◽  
Early Stages ◽  
Transmission Electron ◽  
Three Stages ◽  
Two Stages ◽  
Polycrystalline Molybdenum

The evolution of dislocation channels in irradiated metals during deformation can be envisaged to occur in three stages: (i) formation of embryonic cluster free regions, (ii) growth of these regions into microscopically observable channels and (iii) termination of their growth due to the accumulation of dislocation damage. The first two stages are particularly intriguing, and we have attempted to follow the early stages of channel formation in polycrystalline molybdenum, irradiated to 5×1019 n. cm−2 (E > 1 Mev) at the reactor ambient temperature (∼ 60°C), using transmission electron microscopy. The irradiated samples were strained, at room temperature, up to the macroscopic yield point.Figure 1 illustrates the early stages of channel formation. The observations suggest that the cluster free regions, such as A, B and C, form in isolated packets, which could subsequently link-up to evolve a channel.

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