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Competitive relations between Douglas-fir and Pacific madrone on shallow soils in a Mediterranean climate Competitive relations between Douglas-fir and Pacific madrone on shallow soils in a Mediterranean climate

A large area of Pacific Coast forests is characterized by shallow soil, with negligible rainfall in the growing season. This study explores water-seeking strategy on such a site. We studied availability of bedrock water and its effects on growth and ecophysiology of 11-yr-old planted Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) and sprouting Pacific madrone (Arbutus menziesii Pursh...
Authors
Zheng Q. Wang, M. Newton, J. C. Tappeiner

Sympatric occurrence of Eubranchiopoda in ephemeral pools: A comment Sympatric occurrence of Eubranchiopoda in ephemeral pools: A comment

Debrey et al. (1991) observed what they thought was the atypical occurrence of three species of Eubranchiopoda, each belonging to a different order in a vernal prairie pond in southeastern Wyoming. Co-occurrence of Eubranchiopoda in ephemeral pools is not unusual. Evidence of multi-species temporary pool communities is presented, along with a brief discussion of what may structure...
Authors
T. B. Graham

Effects of hydrology on zooplankton communities in high-mountain ponds, Mount Rainier National Park, USA Effects of hydrology on zooplankton communities in high-mountain ponds, Mount Rainier National Park, USA

Ten high-mountain ponds in Mount Rainier National Park, Washington State, were studied from ice-out in June through September1992 to investigate the influences of fluctuating pond volumes on zooplankton communities. All of the ponds were at maximum volume immediately after ice-out. The temporary pond with the shortest wet phase was inhabited by rotifer taxa with short generation times...
Authors
Scott Girdner, Gary L. Larson

Identification of kin structure among Guam rail founders: A comparison of pedigrees and DNA profiles Identification of kin structure among Guam rail founders: A comparison of pedigrees and DNA profiles

Kin structure among founders can have a significant effect on subsequent population structure. Here we use the correlation between DNA profile similarity and relatedness calculated from pedigrees to test hypotheses regarding kin structure among founders to the captive Guam rail (Rallus owstoni) population. Five different pedigrees were generated under the following hypotheses: (i)...
Authors
Susan M. Haig, J.D. Ballou, N.J. Casna

What we know and don't know about amphibian declines in the West What we know and don't know about amphibian declines in the West

The problem of declining amphibian species is thought to be particularly acute in western North America, but there are many gaps in our knowledge. Although several declines have been well-documented, other declines are anecdotal or hypothesized. Most documented declines are of ranid frogs or toads (Bufo). Species from montane habitats and those occurring in California have been best...
Authors
Paul Stephen Corn

Integrating limnological characteristics of high mountain lakes into the landscape of a natural area Integrating limnological characteristics of high mountain lakes into the landscape of a natural area

A general conceptual watershed-lake model of the complex interactions among climatic conditions, watershed location and characteristics, lake morphology, and fish predation was used to evaluate limnological characteristics of high mountain lakes. Our main hypothesis was that decreasing elevation in mountainous terrain corresponds to an increase in diversity of watershed size and lake...
Authors
Gary L. Larson, A. Wones, C. D. McIntire, B. Samora

Vertical distribution of a deep-water moss and associated epiphytes in Crater Lake, Oregon Vertical distribution of a deep-water moss and associated epiphytes in Crater Lake, Oregon

A one-person submersible was used to examine the vertical distribution of the deep-water moss Drepanocladus aduncus (Hedw.) Warnst in Crater Lake (Oregon). Living specimens were found attached to sediment and rocks at depths between 25 m and 140 m. Dense beds of the moss were observed at depths between 30 m and 80 m, a region that corresponded roughly to the zone of maximum primary...
Authors
C. D. McIntire, H.K. Phinney, Gary L. Larson, M.W. Buktenica

Biology of North American tortoises Biology of North American tortoises

Chelonians have fascinated people for centuries and have been the object of biological studies for nearly as long. Perhaps the long life span and harmless demeanor of most species contribute to their wide appeal. they also represent a link to the distant past because their characteristic shell separated this line of ectotherms from all other reptiles and all other animals in the age of...

Predation by dipteran larvae on fairy shrimp (Crustacea: Anostraca) in Utah rock pools Predation by dipteran larvae on fairy shrimp (Crustacea: Anostraca) in Utah rock pools

A series of experiments examined how ecological factors affect notonectid foraging success on fairy shrimp. Variation in pond depth over natural ranges had no direct effect on notonectid ability to capture fairy shrimp. Decreases in water clarity over natural ranges led to decreased notonectid ability to capture fairy shrimp. This corresponds with the observation that six weeks after the...
Authors
T. B. Graham
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