One of the more persistent misconceptions among younger scholars is the belief that civilization exists apart from nature rather than within it. Such distinctions are often useful for administrative purposes, but become increasingly difficult to maintain when examined across the scales of time addressed within this volume.

The civilizations of Ran have endured for periods measured not in centuries, but in geological eras. Across such spans, cities become ecosystems, transportation networks become migration corridors, industrial districts become habitats, and entire species adapt themselves to the conditions created by intelligent life. The distinction between natural and artificial environments, while occasionally useful, is seldom absolute.

This volume is not concerned primarily with the history, governance, achievements, or institutions of the Ran Empire and its predecessor cultures. Such subjects are addressed extensively elsewhere. Nevertheless, it would be impossible to discuss the ecology of the system without acknowledging the influence of civilizations whose presence has shaped environmental conditions for millions of years.

Many organisms described within these records depend upon settlements, agricultural systems, transportation corridors, industrial infrastructure, or archological complexes for their continued existence. Others have adapted to avoid them entirely. Countless species now occupy ecological niches created by civilization itself, while some environments once regarded as artificial have become indistinguishable from naturally occurring habitats.

The reader should therefore understand that references to cities, settlements, archologies, industrial zones, transportation networks, and inhabited regions are not departures from the purpose of this work. They are components of the ecological reality being examined. Where such systems influence the distribution, behavior, evolution, or survival of life, they shall be addressed accordingly.