RIVERSIDE, California, Dec. 20 (TNSres) -- The University of California Riverside campus issued the following news: * * * Rake dead grass to increase flower power * * * California's native wildflowers are being smothered by layers of dead, invasive grasses. A new UC Riverside study shows that simply raking these layers can boost biodiversity and reduce fire danger. The study, published this week in Restoration Ecology, tested whether removing thatch -- dead leaves and debris -- could allow  more