Kerner was particularly active in the fields of phytogeography and phytosociology. He is known for his studies in the fields of meteorology, phytogeography and agricultural sciences. Grecescu was among the founders of research into floristics and phytogeography in Romania. He organised an international conference of invited speakers on "Taxonomy, Phytogeography and Evolution". Domin specialised in phytogeography, geobotany and plant taxonomy. He is largely remembered for his work in the fields of plant taxonomy and phytogeography. The term phytogeography itself suggests a broad meaning. His main scientific field was the new discipline of phytogeography. These patterns termed ecogeographical rules when applied to plants represent another area of phytogeography. Afterwards he did biosystematic research on "Acer" in the Laboratory of botanical systematics and phytogeography. She summarized her thinking in "The Phytogeography of Unglaciated Eastern United States and Its Interpretation". Von Humboldt advocated a quantitative approach to phytogeography that has characterized modern plant geography. Traditional phytogeography concerns itself largely with floristics and floristic classification, see floristic province. In phytogeography, concerned with the geographic distribution of plant species, floristic provinces are used. Phytogeography is part of a more general science known as biogeography.