Question 10-19

　　Geographers say that what defines a place are four properties: soil, climate, altitude,

　　and aspect, or attitude to the Sun. Florida’s ancient scrub demonstrates this principle. Its

　　soil is pure silica, so barren it supports only lichens as ground cover.( It does, however,

　　sustain a sand-swimming lizard that cannot live where there is moisture or plant matter

　　(5) the soil.) Its climate, despite more than 50 inches of annual rainfall, is blistering desert

　　plant life it can sustain is only the xerophytic, the quintessentially dry. Its altitude is a

　　mere couple of hundred feet, but it is high ground on a peninsula elsewhere close to sea

　　level, and its drainage is so critical that a difference of inches in elevation can bring major

　　changes in its plant communities. Its aspect is flat, direct, brutal—and subtropical.

　　Florida’s surrounding lushness cannot impinge on its desert scrubbiness.

　　This does not sound like an attractive place. It does not look much like one either;

　　Shrubby little oaks, clumps of scraggly bushes, prickly pear, thorns, and tangles. “It appear

　　Said one early naturalist,” to desire to display the result of the misery through which it has

　　Passed and is passing.” By our narrow standards, scrub is not beautiful; neither does it meet

　　our selfish utilitarian needs. Even the name is an epithet, a synonym for the stunted, the

　　scruffy, the insignificant, what is beautiful about such a place?

　　The most important remaining patches of scrub lie along the Lake Wales Ridge, a chain of paleoislands running for a hundred miles down the center of Florida, in most places less than ten miles wide. It is relict seashore, tossed up millions of years ago when ocean levels

　　(20) were higher and the rest of the peninsula was submerged. That ancient emergence is

　　precisely what makes Lake Wales Ridge so precious: it has remained unsubmerged, its

　　ecosystems essentially undisturbed, since the Miocene era. As a result, it has gathered to

　　itself one of the largest collections of rare organisms in the world. Only about 75 plant

　　species survive there, but at least 30 of these are found nowhere else on Earth.