Alpine disturbance studies: Olympic national park,USA

Measurements of downslope rock-creep, of the slow rate of plant establishment on alpine and subalpine road-cuts, and of the reduction in plant cover and plant production in two alpine plant communities, illustrate the degree of disturbance that can occur. The development of large trails or roads should not be permitted in areas of such active downslope rock movement, because of the natural rate of mass-wasting. If more people are to visit and enjoy the alpine communities, asphalt paths to confine their walking are desirable, for trampling experiments showed that plant cover and plant production were rapidly reduced in even one season of light use. Recovery during the following year was, however, quite rapid—especially in the snow-bank community. Different alpine and subalpine habitats have different sensitivities to disturbance, and any plans for increased human use must incorporate this kind of information.     

agr-Naphthaflavone as an Indicator in Iodometry

In my communication "Toxicity and the Chemical Properties of Ions" in the August 19th issue of Science, the ionic field was printed as p((1/2)) (p. 194, second column, third line from bottom). It should be r((1/2)), i.e. the reciprocal of the square of the ionic radius.