Clutch sizes and nests of tailed frogs from the Olympic Peninsula, Washington

In the summers 1995-1998, we sampled 168 streams (1,714 m of randomly selected 1-m bands) to determine distribution and abundance of stream amphibians in Olympic National Park, Washington. We found six nests (two in one stream) of the tailed frog, compared to only two nests with clutch sizes reported earlier for coastal regions. This represents only one nest per 286 m searched and one nest per 34 streams sampled. Tailed frogs occurred only in 94 (60%) of streams and, for these waters, we found one nest per 171 m searched or one nest per 20 streams sampled. The numbers of eggs for four masses (x = 48.3, range 40-55) were low but one single strand in a fifth nest had 96 eggs. One nest with 185 eggs likely represented communal egg deposition. Current evidence indicates a geographic trend with yearly clutches of relatively few eggs in coastal tailed frogs compared to biennial nesting with larger clutches for inland populations in the Rocky Mountain

Effect of Natural Zeolite Application on NitriteConcentrations in Rape (Brassica campestris L.) inPb-Contaminated Soils in Peri-Urban Areas

Peri-urban soils are polluted by lead (Pb) due to urban development in China. Natural zeolites have been widely used for remediating heavy metals in soils, but the effects of natural zeolite application on nitrite concentration in rape have not been studied. Pot experiments were carried out to investigate using a random complete block design. Zeolite application and Pb contaminants in soil caused significant decreases in nitrite concentrations in rape. Chlorophyll a (Chl-a), chlorophyll b (Chl-b), and chlorophyll a &thorn; b (Chl-a &thorn; b) in rape decreased as levels of Pb contamination increased. Pb contamination reduced the photosynthetic activity of rape, and appears to limit the transformation of nitrate to nitrite, but pose food risk. Zeolite application caused a significant increase in soil pH, with a variation range of 0.5. The increase in soil pH reduced nitrite accumulation in soil by enhancing activity of ammonia-oxidizing bacteria. The content of soil aggregates &gt;0.25 and &gt;2.00 mm all increased in response to the application of zeolite. Increases in soil aggregates could effectively control excessive release of nitrogen (N) accumulated in soils, which would reduce uptake of N by plants. These results indicate that the application of zeolite is an eco-friendly and effective way to improve the quality of rape growing in peri-urban areas.</p