id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
work_caj45ayvwzfnlgdexgw6xxmaqu	Estelle Levetin	Changing pollen types/concentrations/distribution in the United States: Fact or fiction?	2008.0	7	.pdf	application/pdf	6849	688	60	increased atmospheric levels of carbon dioxide have species in many countries, recorded through visual observations of fl owering and by airborne pollen. of increasing atmospheric carbon dioxide on plants and Research shows that increasing atmospheric carbon dioxide by about 200 ppm above ambient atmospheric levels on increased plant biomass, fl ower production, and pollen. that increasing carbon dioxide produces more fl owers. of increases in fl ower heads along with overall plant biomass in A. However, pollen production increased initially and then held steady as future carbon dioxide levels Overall, the change from historic to ambient levels increased pollen production by 132%, and the observed with only increasing carbon dioxide levels. responses to increased carbon dioxide levels, several true for plants that fl ower in spring and early summer, dioxide levels had greater biomass and increased pollen production. the phenology of many plants, with spring-fl owering species showing earlier fl owering.	./cache/work_caj45ayvwzfnlgdexgw6xxmaqu.pdf	./txt/work_caj45ayvwzfnlgdexgw6xxmaqu.txt