Biomass and distribution patterns of conifer twig microepiphytes in a Douglas fir forest

Total cell volume estimates and species composition for twig microepiphytes are presented for four species of coniferous trees common in the Pacific Northwest. Fungal cell volumes per square centimetre were much greater on Pseudotsuga menziesii than on the other conifers sampled; population densities of algal cells were similar on all hosts. On P. menziesii, microbial populations build up as the twigs age, with total cell volumes at a maximum on 6- and 7-year-old twigs; thereafter total cell volumes decline as twig surface areas decline, although population densities remain high. When fungal cell volumes are expanded to tree and stand levels, estimates of 372 cm3/tree and 15 kg/ha are generated. These values are significant in comparison with estimated standing crops of epiphytic fungi on needles (30 kg/ha) and suggest that twig microepiphytes must be considered in any investigation on the role of epiphytes in nutrient cycling in coniferous forests.

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Needle microepiphytes in a Douglas fir canopy: biomass and distribution patterns

Canadian Journal of Botany ◽

10.1139/b79-124 ◽

1979 ◽

Vol 57 (9) ◽

pp. 1000-1007 ◽

Cited By ~ 22

Author(s):

George C. Carroll

Keyword(s):

Cell Volume ◽

Distribution Patterns ◽

Douglas Fir ◽

Total Cell ◽

Microbial Cell ◽

Microbial Cells ◽

Cutting Out ◽

Total Cell Volume ◽

Volume Estimates ◽

Cell Volumes

Distribution patterns and total cell-volume estimates for needle microepiphytes are presented for three strata in the canopy of a single old-growth Douglas fir tree. Microbial cell volume was estimated by photographing transverse sections of needles, tracing microbial profiles on Mylar film, cutting out the tracings, and determining the pooled trace weights from various zones of each needle section. Microbial cells are concentrated in the midrib groove and over the stomatal zones of individual needles. Microbial cell volume on the upper needle surfaces increases during the 1st year and declines in subsequent years. Cell volumes on the lower needle surfaces increase from the 1st to the 3rd year and decrease from the 3rd to the 4th year. An increase in microbial cell volume occurs on both upper and lower surfaces from year 7 to year 8. Total microbial cell volume in relation to available needle surface area is greatest in the lower canopy and decreases with increasing height in the canopy. The total volume of microbial cells on needles was estimated to be 1093 cm3 for the entire tree.

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Species-Specific Spatial and Temporal Distribution Patterns of Emigrating Juvenile Salmonids in the Pacific Northwest

Reviews in Fisheries Science ◽

10.1080/10641260903304487 ◽

2009 ◽

Vol 18 (1) ◽

pp. 40-64 ◽

Cited By ~ 4

Author(s):

David L. Smith ◽

John M. Nestler ◽

Gary E. Johnson ◽

R. Andrew Goodwin

Keyword(s):

Pacific Northwest ◽

Temporal Distribution ◽

Distribution Patterns ◽

Spatial And Temporal Distribution ◽

Juvenile Salmonids ◽

The Pacific ◽

Species Specific

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Trends in Occurrence, Distribution, and Population Densities of Plant-Parasitic Nematodes in the Pacific Northwest of the United States from 2012 to 2016

Plant Health Progress ◽

10.1094/php-11-18-0077-rs ◽

2019 ◽

Vol 20 (1) ◽

pp. 20-28 ◽

Cited By ~ 1

Author(s):

Inga A. Zasada ◽

Megan Kitner ◽

Catherine Wram ◽

Nadine Wade ◽

Russell E. Ingham ◽

...

Keyword(s):

United States ◽

Pacific Northwest ◽

Parasitic Nematode ◽

The United States ◽

Plant Parasitic Nematode ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Population Densities ◽

The Pacific ◽

Plant Parasitic

The Pacific Northwest (PNW) of the United States (Idaho, Oregon, and Washington) is a diverse agricultural production area with over 400 different commodities grown in the region. Plant-parasitic nematodes are a constraint to the production of many of these commodities. Soil sample data from 2012 to 2016 were obtained from nematode diagnostic laboratories in the region to assess trends in occurrence, population densities, and distribution of plant-parasitic nematodes in the PNW. A total of 38,022 unique data points were analyzed. The number of plant-parasitic nematode samples processed in the PNW by diagnostic laboratories has significantly increased from 2012 to 2016. Fifteen genera of plant-parasitic nematodes were identified by diagnostic laboratories, with 86% of the samples in the PNW containing at least one plant-parasitic nematode genus. These laboratories provide a valuable service to agriculture in the PNW. Additionally, they serve as a rich source of information on plant-parasitic nematode distribution, occurrence, and abundance that, when analyzed, provides an empirical basis upon which to interpret individual grower reports and make management recommendations.

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THE CHANGE IN OSMOTICALLY INACTIVE FRACTION PRODUCED BY CELL ACTIVATION

The Journal of General Physiology ◽

10.1085/jgp.32.1.43 ◽

1948 ◽

Vol 32 (1) ◽

pp. 43-51 ◽

Cited By ~ 12

Author(s):

Herbert Shapiro

Keyword(s):

Cell Volume ◽

Sea Urchin ◽

Cell Activation ◽

Sea Water ◽

Total Cell ◽

Respiratory Metabolism ◽

Arbacia Punctulata ◽

Mechanical Analogue ◽

Total Cell Volume ◽

Cell Volumes

1. Resting and activated eggs of the sea urchin Arbacia punctulata were swollen in hypotonic sea water (60, 70, 80, and 90 per cent), and allowed to attain equilibrium volumes (Figs. 1 and 2). 2. Both fertilized and unfertilized eggs obey the Boyle-van't-Hoff law, but the value for b, the "osmotically inactive fraction" or non-swellable volume, was different for the two, averaging in the cases studied 7.3 per cent for unfertilized and 27.4 per cent for fertilized. 3. On activation, the eggs of the sea urchin undergo a definite increase in total cell volume, of approximately 2.7 per cent. 4. Some evidence is adduced for the possibility that the alteration in cell volume and in o.i.f. may depend upon the species in question. 5. A parallelism between change in b and alteration of respiratory metabolism in Arbacia, Chaetopterus, and Arbacia fragments is pointed out. This requires further investigation in other species to establish generality. 6. Equations for the calculation of the point at which osmotic pressures and cell volumes are identical for unfertilized and fertilized eggs are included. 7. A mechanical analogue of the phenomena is introduced (Fig. 3).

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Effect of Foliarly Applied Spirotetramat on Reproduction of Heterodera avenae on Wheat Roots

Plant Disease ◽

10.1094/pdis-01-11-0017 ◽

2011 ◽

Vol 95 (8) ◽

pp. 983-989 ◽

Cited By ~ 22

Author(s):

R. W. Smiley ◽

J. M. Marshall ◽

G. P. Yan

Keyword(s):

Pacific Northwest ◽

Cyst Nematode ◽

Crop Rotations ◽

Cereal Crops ◽

Heterodera Avenae ◽

Single Application ◽

Population Densities ◽

Nematode Density ◽

Wheat Roots ◽

The Pacific

The cereal cyst nematode, Heterodera avenae, has the potential to reduce yields of cereal crops in the Pacific Northwest. Spirotetramat (Movento) is a foliar-applied insecticide with ambimobile translocation that reduces fecundity of sucking insects which feed on roots as well as foliage. Spirotetramat (88 g/ha) was applied to foliage during 2010 in two wheat fields infested by H. avenae near St. Anthony, ID and Palouse, WA. In Idaho, two applications at 2-week intervals during late spring to plants already exhibiting swollen white females reduced the postharvest density of H. avenae eggs plus juveniles by 35% (P = 0.03) compared to the nontreated control. In Washington, a single application before white females became apparent reduced the nematode density by 78% (P = 0.01). Grain yields and test weights were not significantly affected by application of spirotetramat at either location. In addition, symptomatic plants from the Idaho field were transplanted into greenhouse pots and treated with spirotetramat. One application (110 g/ha) reduced numbers of eggs plus juveniles/plant by 78% (P = 0.02). Spirotetramat effectively reduced H. avenae populations and warrants further evaluation as a substitute for crop rotations or long fallow periods that reduce nematode population densities in infested fields.

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