Why and how to put the Ph back into the ecology PhD

The number of papers containing the words philosophy and ecology rises and declines sharply over about 25 years. Has philosophy fallen out of ecology, and should there be a revival?  Ecologists may use a variety of philosophical concepts and tools to strengthen the practice of their science. Philosophical tools and concepts may help ecologists: better understand the theory underlying their science; how to generalize their results; strengthen logical arguments; better answer questions at the interface of science and philosophy; and understand the ethical implications of their research.