Parent material and relief define the initial state for soil development, regional climate, and potential biota, determine the rate at which chemical and biological transformations proceed, and time determines the reach of these processes and their expression in ecosystem, soil, vegetation, and animal component properties.
One notable project was his study of the Mendocino pygmy forest, a remarkable community of ericaceous and coniferous plant species whose stunted growth and grotesquely twisted morphology reveal a long and tortured struggle for survival on a 500,000-year-old marine terrace.
The University of California's Jenny Pygmy Forest Reserve is named in his honor and is found adjacent to Van Damme State Park.
Jenny applied fundamental soil science to the problems of the day when he wrote about "the rosy outlook that is sweeping the nation about converting biomass to alcohol and gasohol...We are promised construction of ingenious machines that will pick up all crop residues in the fields and leaf litter and humus in the forests.
Because of a possible climatic warm-up, we do not wish to accelerate humus oxidation and the concomitant flux of carbon dioxide from soil into the atmosphere.