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<br />000116 <br /> <br />"However, special circumstances should also be considered. <br />Subnormal precipitation years serve to 'weed out' root <br />diseased trees, suppressed trees, and trees marginally <br />adapted to given sites. If the periodic 'thinning' func- <br />tion resulting from subnormal precipitation years is <br />eliminated, overstock and insect/disease problems associ- <br />ated with overstocking or with drought might occur. <br />However, localized sites which are under-stocked because of <br />shallow, rocky soils may be benefited by an increase in <br />stock. <br /> <br />"Some major specific effects can be expected to material- <br />ize. However, because of the complex nature of the envi- <br />ronmental matrix of soils, moisture, vegetation, yearly <br />climate, cycles of climatic change, and pathogens and <br />insects, it is not expected that conclusive data will be <br />developed from a 5- to 7-year pilot program. The effects <br />are: <br /> <br />"1. Since trees grow faster with a plentiful water <br />supply, it is expected that less severe attacks and less <br />mortality from pathogens such as dwarf mistletoe and <br />cytospora canker will occur under augmented condi ti ons <br />than under drought conditions. <br /> <br />"2. For the same reason, root and butt decay (F. annosus) <br />in fir will have less impact because fir growth-will <br />keep ahead of the pathogen. <br /> <br />"3. Tipmoth on eastside pine would be less severe due <br />to increased growth of the pine. <br /> <br />"4. Under augmented water supplies, a decrease in <br />losses from the pine reproduction weevil, Cylindrolop <br />turus eatoni, may be expected as a result of the less- <br />ened drought stress. <br /> <br />"The workshop group believes the normal insect and disease <br />monitoring will serve little purpose, since so many factors <br />other than precipitation augmentation can influence the <br />success of disease and insect attacks. Therefore, the most <br />effective monitoring and research program would be one that <br />concentrates on determining: (1) the success of the <br />augmentation, (2) the effect upon snowpacks under various <br />environmental complexes, and (3) the effects of different <br />climatic influences upon insect and disease incidence. <br /> <br />"Item 3 is a research recommendation that goes beyond the <br />impact of weather modification. It involves the basic <br />impact of all forms of climatic influence upon forest <br />diseases and insects. This encompasses microclimatic <br />influences which occur as a result of forest fires, the <br /> <br />19 <br />