The effects of acid rain on nitrogen fixation in Western Washington coniferous forests

1977 ◽  
Vol 8 (1) ◽  
pp. 21-34
Author(s):  
Robert Denison ◽  
Bruce Caldwell ◽  
Bernard Bormann ◽  
Lindell Eldred ◽  
Cynthia Swanberg ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Acid Rain ◽  
Coniferous Forests ◽  
Western Washington

Impact of Simulated Acid Rains on Nitrogenase Activity in Peltigera Aphthosa and P. Polydactyla

1985 ◽  
Vol 17 (1) ◽  
pp. 27-31 ◽  
Author(s):  
R. P. Fritz-Sheridan
Keyword(s):  
Nitrogen Fixation ◽  
Acid Rain ◽  
North American ◽  
Nitrogenase Activity ◽  
Simulated Acid Rain ◽  
Complete Inhibition ◽  
Simulated Rain

AbstractTwo ubiquitous diazotrophic North American lichens, Peltigera aphthosa and P. polydaclyla, were subjected to simulated acid rain. Both lichens exhibited a 50% reduction in nitrogen fixation at pH 5, 80% reduction at pH 4 and complete inhibition at pH 2. Nitrogen fixation was zero after 20 days exposure to simulated rain at pH 3 and zero after fourdays at pH 2.

Mycophagy of red-backed voles in Oregon and Washington

1982 ◽  
Vol 60 (12) ◽  
pp. 3307-3315 ◽  
Author(s):  
Douglas C. Ure ◽  
Chris Maser
Keyword(s):  
Ectomycorrhizal Fungi ◽  
Stomach Contents ◽  
Green Plant ◽  
Cascade Range ◽  
Coniferous Forests ◽  
Fruiting Bodies ◽  
Plant Parts ◽  
Small Seed ◽  
Western Washington ◽  
Seed Crops

We analyzed stomach contents from two subspecies of Clethrionomys californicus and three subspecies of C. gapperi from coniferous forests of Oregon and western Washington. Seasonal diets were determined for each subspecies of C. californicus. Major foods eaten were the fruiting bodies of hypogeous ectomycorrhizal fungi, predominantly Gasteromycetes, and fruticose lichens, regardless of season. Fungus consumption partially depended on availability. When fungi became scarce, lichens were substituted. Other foods were important only during winter in Cascade Range. Clethrionomys gapperi from Washington consumed large quantities of conifer seed and green plant parts in midautumn. These materials were a small part of the diets of Oregon red-backed voles in midautumn, but this may relate to localized small seed crops. Dependence on ectomycorrhizal fungi by western red-backed voles probably accounts for the latter's disappearance from deforested sites.

Nodulation and nitrogen fixation by red alder and Sitka alder on coal mine spoils

1982 ◽  
Vol 12 (4) ◽  
pp. 992-997 ◽  
Author(s):  
Paul Heilman ◽  
Gorden Ekuan
Keyword(s):  
Nitrogen Fixation ◽  
Nitrogenase Activity ◽  
Douglas Fir ◽  
Tree Age ◽  
Fixed Nitrogen ◽  
Red Alder ◽  
Mine Spoils ◽  
Nodule Number ◽  
Western Washington ◽  
The Difference

Nodule number, nodule weight, and nitrogen fixation (nitrogenase activity by acetylene reduction) were determined for 3 years for red alder (Alnusrubra Bong.) and Sitka alder (Alnussinuata Reg. Rydb.) on three types of coal spoils in western Washington. Generally, the two species were similar in number and weight of nodules and in nitrogen-fixation rates when measured in June (these rates varied from 23 to 27 µmol•g−1•h−1). The type of coal spoil material influenced nodule number but not nodule weight. Topsoil covered subsoil had the highest number of nodules. Trees on unweathered subsoil had the lowest number, particularly for Sitka alder. Nodule weight (dry, ash free) varied from 68 kg•ha−1 for 5-year-old Sitka alder interplanted in a 1:1 mix with Douglas-fir (1790 alders•ha−1) to 188–200 kg•ha−1 for pure stands of both alder species at age 5 (5380 trees•ha−1). The difference in nodule weight between species was not significant. Both species fixed nitrogen at similar rates although in the last year of measurement red alder trees fixed 37% more nitrogen than Sitka alder. This difference was not significant, however. Nitrogen fixation per unit area depended on tree age and spacing, varying from 17 kg•ha−1•year−1 at age 3 with 1830 alders•ha−1 to 150 kg•ha−1•year−1 by both species at age 5 and a density of 5380 trees•ha−1. Fixation rates increased from age 3 to 5 years primarily because of increased nodule weight. Nitrogen fixation by the Sitka alder in mixture with Douglas-fir was relatively high and was encouraging for the concept of mixed plantings of these two species. However, response of Douglas-fir to mixed planting with Sitka alder has not been demonstrated.

Acid Rain meeting in Ottawa

1984 ◽  
Vol 18 (5) ◽  
pp. 157-158 ◽  
Author(s):  
Bette Hileman
Keyword(s):  
Acid Rain
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