“…However, droughts and competition from grass probably only served to slow the invasion and growth of junipers in adjacent grasslands, since the trees are easily established during wet years Oohnsen 1962), especially where shade is present (Meagher 1943 ). Fire, occurring about every 10 to 30 years (Leopold 1924), kept the junipers restricted to shallow, rocky soils and rough topography (Arend 1950, Burkhardt and Tisdale 1969. For the last 70 years, however, heavy livestock grazing has reduced grass competition as well as fuel for fires.…”