George Strait has the most #1 hits at 57 and counting. Nobody else comes close. Conway Twitty actually had the most until 2006 with 55 #1 hits. The Beatles are the musical act with the most songs to reach No. 1 on the Billboard singles chart. Mariah Carey has 18 such #1 hits and Elvis Presley 17.
Primary succession begins on rock formations, such as volcanoes or mountains, or in a place with no organisms or soil. This creates conditions nearer optimum for vascular plant growth; pedogenesis or the formation of soil is the most important process.
Secondary succession. 1  begins on soil from which previous community has been removed (by fire, agriculture, etc.) 2  old field succession. 3  example sere: grass -> shrub -> trees -> oak hickory forest.  secondary succession can proceed much faster because the soil has been prepared by the previous community.