While much is known about the parasitic interactions among animals, little is known about factors governing the parasitic interactions among higher plants. This study will focus on the water and nutrient relations between a parasite (mistletoe) and its host (juniper) under natural and experimentally modified environmentally modified environmental conditions in the field. The proposed study will test specific hypotheses relating to the water and nutrient fluxes between host and parasite, and should lead to new insights on the factors governing these interactions as well as to new insights on why this form of biological interaction might have evolved. As part of the approach, this study will utilize a new and powerful tool in the ecological sciences, stable isotope ratio analysis at natural abundance levels, to estimate long-term physiological performance of both host and parasite. Among the applied aspects of this study, mistletoes account for a significant decrease in timber productivity nationally and if we can get a better understanding of the factors governing host-parasite interactions we are more likely to achieve an understanding of how to control this serious pest to the lumber industry.//
