As the human population increases and more people are moving to urban areas, human activities are having a profound effect on urban ecosystems. Land use changes, fragmentation, and loss of habitat associated with urbanization have direct effects on biodiversity and ecosystem productivity. Human activities within urban environments also affect biogeochemical cycles, atmospheric chemistry, and local climate. The most commonly cited changes to the urban environment are increased temperature, carbon dioxide, and nitrogen deposition. These are all environmental factors that affect plant stoichiometry, growth, and allocation. Thus, these changes in the urban environment have the potential to affect plants in both complementary and conflicting ways. Changes in plant growth and tissue quality may then affect insect herbivore food choice and feeding habits.
Growth chamber experiments have been conducted to examine the effects of elevated nitrogen, temperature, and CO2 on various species of plants and herbivorous insects, but the results have been mixed and there is no clear consensus. The magnitude and direction of plant responses in these manipulations were highly dependent on species, and availability of other limiting resources such as water. To date, few studies have compared plant growth and herbivory in adjacent urban and rural areas to determine the effects of real world urban conditions on plants and insects. For my research project, I would like to examine plant responses to the urban environment in north Texas.