Recent comparative studies across sex-changing animals have found that the relative size and age at sex change are strikingly invariant. In particular, 91%–97% of the variation in size at sex change across species can be explained by the simple rule that individuals change sex when they reach 72% of their...
By emulating natural disturbances such as wildfire, managers hope to maintain biodiversity in managed forests. Leaving residual (live) trees in harvested areas is key to this strategy. However, the effectiveness of this approach is unknown. I surveyed songbirds in 176 stands in the Rocky Mountains of southeastern British Columbia, Canada,...
Although variations in insolation and emergent feedbacks among soil moisture,
vegetation, and soil cohesion are commonly invoked to explain topographic asymmetry that
depends on aspect, few studies have directly quantified the efficiency of regolith transport along
hillslopes of opposing aspect. We utilize meteoric ¹⁰Be concentrations in regolith (n = 74)...
This article presents a novel method combining ion irradiation, in-situ transmission electron microscopy (TEM), and microchemistry analysis before/after irradiation, which allows to examine same microstructural areas throughout ion irradiation. A 12 wt% Cr Ferritic/Martensitic steel (HT9) was irradiated in the TEM to 1.17 x 10(20) ions.m(-2) at 440 degrees C...
The quality of lumber and veneer recovered from logs of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is directly influenced by the maximum limb size attained on the crop tree. Because limb sizes are influenced by standdensity regimes, a need has arisen for quantitative tools that link a wide array of silvicultural...
The upper drainage of the John Day River system produces summer steelhead and spring chinook salmon. The fish are generally confined to the main stem and its tributaries above Prairie City. The spawning and rearing areas are comparatively free of undesirable fish species, but salmonid smolts migrating downstream must travel...
Clear Creek, tributary of North Fork John Day River, is a mountain stream located in the Blue Mountains of eastern Oregon. It joins Granite Creek about 1.5 miles below the old abandoned mining town of Granite. Gravel removed from Clear Creek by gold dredging activity was replaced in a 3.37-mile...
The project objectives were to determine the possibility of raising the subterranean water in adequate amounts by installation of an underground weir; to determine what type of structure would be most feasible; and to formulate a biological evaluation program if the first two objectives were accomplished. Tex Creek, tributary to...
A NE–SW-trending graben at Kap Dalton on the Blosseville Kyst contains an at least 600 m thick
succession of Eocene basalt lavas and sediments. The succession has been investigated by new field
work, geochemical analysis and radiometric dating by the ⁴⁰Ar-³⁹Ar incremental heating method.
The results show that the volcanic...