The number of species on an island at which the arrival rate of new species equals the extinction rate of species already present is called the equilibrium species number. At this number, the species richness and the species composition . A. is constant; is constant B. is constant; can be variable C. can be variable; is constant D. can be variable; can be variable E. depends on the size of the island; is constant

they each offer a fresh glut of resources to the organisms that can arrive and exploit them. as individuals and new species continue to appear, they actively and passively alter the environment. competition for shared resources increases, local abiotic and biotic conditions shift, and the relative abundances of species change accordingly. the process is called ecological succession, and it is one of the earliest and most well-known concepts in ecology.