The influence of nutrients on fungal growth, productivity, and sporulation during leaf breakdown in streams

1995 ◽  
Vol 73 (S1) ◽  
pp. 1361-1369 ◽  
Author(s):  
Keller Suberkropp
Keyword(s):  
Growth Rates ◽  
Fungal Biomass ◽  
Fungal Growth ◽  
Aquatic Hyphomycetes ◽  
Acetate Incorporation ◽  
Yellow Poplar ◽  
Leaf Breakdown ◽  
Leaf Surfaces ◽  
Good Agreement ◽  
Growth And Reproduction

In streams, aquatic hyphomycetes degrade leaf litter and transform it into a more suitable resource for invertebrate detritivores. Previous studies have demonstrated that fungi comprise a major portion of the microbial biomass associated with decomposing leaves and that inputs of leaves in the autumn reduce the concentration of soluble phosphorus in the water. These observations indicate that fungi obtain inorganic nutrients from the water passing over leaf surfaces. However, very little is known concerning the effects of nutrients on the activity of the fungi growing within leaves. To examine this question, I determined fungal biomass (from ergosterol concentrations) and sporulation rates during the breakdown of yellow poplar (Liriodendron tulipifera) leaves in three streams that differed in water chemistry. I also estimated instantaneous growth rates by measuring rates of [14C]acetate incorporation into ergosterol and calculated fungal productivity from growth rates and biomass. Growth rates and productivity determined by this method showed good agreement with values calculated from changes in fungal biomass during early stages of leaf breakdown for two of the streams examined. Highest concentrations of fungal biomass and greatest fungal activity occurred in the stream with the highest concentrations of nutrients. However, differences in total fungal production and biomass were not as great as were differences among sporulation rates in the three streams suggesting that fungal allocation of resources to growth and reproduction can vary depending on nutrient availability. Key words: aquatic hyphomycetes, ergosterol, leaf breakdown, nutrients, fungal productivity, streams.

Estimation of fungal growth rates in soil using 14C-acetate incorporation into ergosterol

2001 ◽  
Vol 33 (14) ◽  
pp. 2011-2018 ◽  
Author(s):  
Erland Bååth
Keyword(s):  
Growth Rates ◽  
Fungal Growth ◽  
Acetate Incorporation

Acetate Incorporation into Ergosterol to Determine Fungal Growth Rates and Production

2005 ◽  
pp. 197-202 ◽  
Author(s):  
Keller Suberkropp ◽  
Mark O. Gessner
Keyword(s):  
Growth Rates ◽  
Fungal Growth ◽  
Acetate Incorporation

scholarly journals Fungal Growth, Production, and Sporulation during Leaf Decomposition in Two Streams

2001 ◽  
Vol 67 (11) ◽  
pp. 5063-5068 ◽  
Author(s):  
Keller Suberkropp
Keyword(s):  
Fungal Biomass ◽  
Fungal Growth ◽  
Quercus Alba ◽  
White Oak ◽  
Decomposition Rates ◽  
Yellow Poplar ◽  
Low Concentrations ◽  
Growth Production ◽  
Oak Leaves ◽  
Poplar Leaves

ABSTRACT I examined the activity of fungi associated with yellow poplar (Liriodendron tulipifera) and white oak (Quercus alba) leaves in two streams that differed in pH and alkalinity (a hardwater stream [pH 8.0] and a softwater stream [pH 6.7]) and contained low concentrations of dissolved nitrogen (<35 μg liter−1) and phosphorus (<3 μg liter−1). The leaves of each species decomposed faster in the hardwater stream (decomposition rates, 0.010 and 0.007 day−1 for yellow poplar and oak, respectively) than in the softwater stream (decomposition rates, 0.005 and 0.004 day−1 for yellow poplar and oak, respectively). However, within each stream, the rates of decomposition of the leaves of the two species were not significantly different. During the decomposition of leaves, the fungal biomasses determined from ergosterol concentrations, the production rates determined from rates of incorporation of [14C]acetate into ergosterol, and the sporulation rates associated with leaves were dynamic, typically increasing to maxima and then declining. The maximum rates of fungal production and sporulation associated with yellow poplar leaves were greater than the corresponding rates associated with white oak leaves in the hardwater stream but not in the softwater stream. The maximum rates of fungal production associated with the leaves of the two species were higher in the hardwater stream (5.8 mg g−1 day−1 on yellow poplar leaves and 3.1 mg g−1 day−1 on oak leaves) than in the softwater stream (1.6 mg g−1day−1 on yellow poplar leaves and 0.9 mg g−1day−1 on oak leaves), suggesting that effects of water chemistry other than the N and P concentrations, such as pH or alkalinity, may be important in regulating fungal activity in streams. In contrast, the amount of fungal biomass (as determined from ergosterol concentrations) on yellow poplar leaves was greater in the softwater stream (12.8% of detrital mass) than in the hardwater stream (9.6% of detrital mass). This appeared to be due to the decreased amount of fungal biomass that was converted to conidia and released from the leaf detritus in the softwater stream.

Measurement of growth rates for single crystals and pressed tablets of CuSO4.5 H2O on a rotating disc

1989 ◽  
Vol 54 (11) ◽  
pp. 2951-2961 ◽  
Author(s):  
Miloslav Karel ◽  
Jaroslav Nývlt
Keyword(s):  
Growth Rate ◽  
Single Crystal ◽  
Single Crystals ◽  
Growth Rates ◽  
Diffusion Coefficients ◽  
Preferred Orientation ◽  
Rotating Disc ◽  
Dissolution Rates ◽  
Rates Of Growth ◽  
Good Agreement

Measured growth and dissolution rates of single crystals and tablets were used to calculate the overall linear rates of growth and dissolution of CuSO4.5 H2O crystals. The growth rate for the tablet is by 20% higher than that calculated for the single crystal. It has been concluded that this difference is due to a preferred orientation of crystal faces on the tablet surface. Calculated diffusion coefficients and thicknesses of the diffusion and hydrodynamic layers in the vicinity of the growing or dissolving crystal are in good agreement with published values.

Fungal richness does not buffer the effects of streams salinization on litter decomposition

2021 ◽  
Vol 57 ◽  
pp. 5
Author(s):  
Janine Pereira da Silva ◽  
Aingeru Martínez ◽  
Ana Lúcia Gonçalves ◽  
Felix Bärlocher ◽  
Cristina Canhoto
Keyword(s):  
Mass Loss ◽  
Litter Decomposition ◽  
Fungal Biomass ◽  
Fungal Species ◽  
Aquatic Hyphomycetes ◽  
Negative Effects ◽  
Stream Functioning ◽  
Induced Changes ◽  
Sporulation Rate ◽  
The Impact

Freshwater salinization is a world-wide phenomenon threatening stream communities and ecosystem functioning. In these systems, litter decomposition is a main ecosystem-level process where fungi (aquatic hyphomycetes) play a central role linking basal resource and higher levels of food-web. The current study evaluated the impact of aquatic hyphomycete richness on leaf litter decomposition when subjected to salinization. In a microcosm study, we analysed leaf mass loss, fungal biomass, respiration and sporulation rate by fungal assemblages at three levels of species richness (1, 4, 8 species) and three levels of salinity (0, 8, 16 g NaCl L‑1). Mass loss and sporulation rate were depressed at 8 and 16 g NaCl L‑1, while fungal biomass and respiration were only negatively affected at 16 g L‑1. A richness effect was only observed on sporulation rates, with the maximum values found in assemblages of 4 species. In all cases, the negative effects of high levels of salinization on the four tested variables superimposed the potential buffer capacity of fungal richness. The study suggests functional redundancy among the fungal species even at elevated salt stress conditions which may guarantee stream functioning at extreme levels of salinity. Nonetheless, it also points to the possible importance of salt induced changes on fungal diversity and identity in salinized streams able to induce bottom-up effects in the food webs.

Effects of symbiotic bacteria and tree chemistry on the growth and reproduction of bark beetle fungal symbionts

2009 ◽  
Vol 39 (6) ◽  
pp. 1133-1147 ◽  
Author(s):  
A.S. Adams ◽  
C.R. Currie ◽  
Y. Cardoza ◽  
K.D. Klepzig ◽  
K.F. Raffa
Keyword(s):  
Bark Beetles ◽  
Fungal Growth ◽  
Physical Separation ◽  
Ips Grandicollis ◽  
Symbiotic Fungi ◽  
Host Relationships ◽  
Bacteria And Fungi ◽  
Ophiostoma Montium ◽  
Bacterial Volatiles ◽  
Growth And Reproduction

Bark beetles are associated with diverse assemblages of microorganisms, many of which affect their interactions with host plants and natural enemies. We tested how bacterial associates of three bark beetles with various types of host relationships affect growth and reproduction of their symbiotic fungi. Fungi were exposed to volatiles from bacteria in an arena that imposed physical separation but shared airspace. We also exposed fungi to vapors of the host compound, α-pinene, and to combinations of bacterial volatiles and α-pinene. Bacterial volatiles commonly stimulated growth of Leptographium procerum (W.B. Kendr.) M.J. Wingf. and Grosmannia clavigera (Rob.-Jeffr. & R.W. Davidson) Zipfel, Z.W. de Beer & Wingf., which are symbiotic fungi of Dendroctonus valens LeConte and Dendroctonus ponderosae Hopkins, respectively. They less commonly stimulated growth of Ophiostoma ips (Rumbold) Nannf., which is associated with Ips grandicollis Eichhoff. Some bacteria inhibited L. procerum, Ophiostoma montium (Rumbold) von Arx (another associate of D. ponderosae), and O. ips. Bacteria greatly stimulated spore production of symbionts of D. valens and D. ponderosae. α-Pinene strongly affected some of these relationships, causing amplification, reduction, or reversal of the interactions among the bacteria and fungi. Our results show that some bacteria associated with bark beetles directly affect fungal symbionts and interact with tree chemistry to affect fungal growth and sporulation. The strongest effects were induced by bacteria associated with beetles adapted to attacking living trees with vigorous defenses, and on fungal reproductive structures.

scholarly journals Determining Diversity of Freshwater Fungi on Decaying Leaves: Comparison of Traditional and Molecular Approaches

2003 ◽  
Vol 69 (5) ◽  
pp. 2548-2554 ◽  
Author(s):  
Liliya G. Nikolcheva ◽  
Amanda M. Cockshutt ◽  
Felix Bärlocher
Keyword(s):  
Species Richness ◽  
Fungal Biomass ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Rflp Analysis ◽  
Fungal Species ◽  
Aquatic Hyphomycetes ◽  
Molecular Techniques ◽  
Red Maple ◽  
Molecular Approaches ◽  
Community Evenness

ABSTRACT Traditional microscope-based estimates of species richness of aquatic hyphomycetes depend upon the ability of the species in the community to sporulate. Molecular techniques which detect DNA from all stages of the life cycle could potentially circumvent the problems associated with traditional methods. Leaf disks from red maple, alder, linden, beech, and oak as well as birch wood sticks were submerged in a stream in southeastern Canada for 7, 14, and 28 days. Fungal biomass, estimated by the amount of ergosterol present, increased with time on all substrates. Alder, linden, and maple leaves were colonized earlier and accumulated the highest fungal biomass. Counts and identifications of released conidia suggested that fungal species richness increased, while community evenness decreased, with time (up to 11 species on day 28). Conidia of Articulospora tetracladia dominated. Modifications of two molecular methods—denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP) analysis—suggested that both species richness and community evenness decreased with time. The dominant ribotype matched that of A. tetracladia. Species richness estimates based on DGGE were consistently higher than those based on T-RFLP analysis and exceeded those based on spore identification on days 7 and 14. Since traditional and molecular techniques assess different aspects of the fungal organism, both are essential for a balanced view of fungal succession on leaves decaying in streams.

Effects of early drought and transplanting on the subsequent development of the tobacco plant

1968 ◽  
Vol 19 (1) ◽  
pp. 47 ◽  
Author(s):  
JM Hopkinson
Keyword(s):  
Growth Rates ◽  
Tobacco Plant ◽  
Subsequent Development ◽  
Leaf Expansion ◽  
Flower Initiation ◽  
Relative Growth Rates ◽  
Leaf Surfaces ◽  
Number Of Leaves ◽  
Net Assimilation ◽  
Short Time

Detailed studies were made of the growth of tobacco plants during and after the experimental imposition of water stresses similar to those of commercial hardening and transplanting. During water stress (due to root damage, drought, or both) all growth rates were depressed, but, a short time after the relief of stress, relative leaf expansion rates, net assimilation rates, and relative growth rates rose to higher values than were reached by untreated plants at comparable stages of development. As a result, all stressed plants rapidly recovered from their period of adverse conditions. The plants that had originally been subjected to the most severe treatments overhauled those that had suffered less and finally acquired the greatest total leaf areas and dry weights. The increase was due to: (1) a change in the distribution of leaf surfaces, which occurred when leaf initiation was retarded relative to leaf expansion and resulted in increased growth of the lower leaves; (2) a delay in flower initiation, which took place at a higher node, increased the number of leaves, and prolonged the period of vegetative growth.

scholarly journals Invertebrates, Fungal Biomass, and Leaf Breakdown in Pools and Riffles of Neotropical Streams

2017 ◽  
Vol 17 (1) ◽  
Author(s):  
Renato Tavares Martins ◽  
Lidimara Souza da Silveira ◽  
Marcos Pereira Lopes ◽  
Roberto Gama Alves
Keyword(s):  
Fungal Biomass ◽  
Leaf Breakdown ◽  
Neotropical Streams

Relationship between growth rate and undercooling in Pt-added Y1Ba2Cu3O7−x

1996 ◽  
Vol 11 (5) ◽  
pp. 1114-1119 ◽  
Author(s):  
A. Endo ◽  
H. S. Chauhan ◽  
Y. Nakamura ◽  
Y. Shiohara
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Parabolic Equation ◽  
Growth Rates ◽  
Crystal Size ◽  
Experimental Conditions ◽  
Seed Crystals ◽  
Cooling Method ◽  
Increasing Trend ◽  
Good Agreement

Y1Ba2Cu307−x (Y123) crystals were grown by two different methods, the constant undercooling solidification and the continual cooling method, with top seeding by Sm123 seed crystals in order to investigate a relationship between undercooling (ΔT) and a growth rate (R). The crystals of Y123 with a sharp faceted interface, which consisted of {100} and {001} faces, grew epitaxially from the seed. It was found that the growth rates of {100} face (Ra) and that of {001} face (Rc) showed an increasing trend with increasing ΔT, and Rc was faster than Ra within these experimental conditions, ΔT < 20 K. The relation between R and ΔT follows the parabolic equation, viz. Ra ∝ ΔT1.9 and Rc ∝ ΔT1.3 for {100} and {001} faces, respectively. The simulated crystal size using the R and ΔT relations obtained from the constant undercooling method showed good agreement with experimental data by the continual cooling.

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