Plant volatiles constitute about 1% of plant secondary metabolites; they act as a means for communication between plants, insects, and herbivores, moving freely through the atmosphere and soil.  Volatiles emitted into the atmosphere can serve to defend plants against herbivores and pathogens by their ability to either directly repel microbes and animals, or attract natural predators of attacking insects/herbivores.  These warning volatiles also induce the emission of similar defensive volatiles by neighboring plants.  Volatiles can also enhance a plants reproductive success by attracting pollinators and/or seed dispersers.  Volatiles emitted from roots can contribute to below ground defense in similar ways: acting as antimicrobial and antiherbivore substances, or attracting enemies of root feeding herbivores.  The presence of volatiles was also found to increase a plant’s ability to withstand injury from extreme temperature fluctuations, and enables continued photosynthesis even in temperature extremes.  The presence of volatiles, and abilities for plants to produce them, greatly increases plants resiliency to a variety of threats.