Establishment and persistence of common ragweed (Ambrosia artemisiifolia L.) in disturbed soil as a function of an urban–rural macro‐environment

Abstract

No data are available on whether rising carbon dioxide concentration [CO 2 ] or increased air temperature can alter the establishment and persistence of common ragweed (Ambrosia artemisiifolia L.) within a plant community following soil disturbance. To determine ragweed longevity, we exposed disturbed soil with a common seed bank population to an in situ temperature and [CO 2 ] gradient along an urban-rural transect beginning in early 2002. No other consistent differences in meteorological variables (e.g. wind speed, humidity, PAR, tropospheric ozone) as a function of urbanization were documented over the course of the study (2002)(2003)(2004)(2005). Above-ground measurements of biomass over this period demonstrated that ragweed along the transect responded to urban induced increases in [CO 2 ]/temperature with peak biomass being observed at this location by the end of 2003. However, by the Fall of 2004, and continuing through 2005, urban ragweed populations had dwindled to a few plants. The temporal decline in ragweed populations was not associated with increased disease, herbivory or autoallelopathy, but was part of a demographic reduction in the total number of annual plant species observed for the urban location. In a separate experiment, we showed that such a demographic shift is consistent with CO 2 /temperature induced increases in biomass and litter accumulation, with a subsequent reduction in germination/survival of annual plant species. Overall, these data indicate that [CO 2 ]/temperature differences associated with urbanization may increase initial ragweed productivity and pollen production, but suggest that long-term, multi-year persistence of ragweed in the urban macro-environment may be dependent on other factors.

Allergenic pollen season variations in the past two decades under changing climate in the United States

“…Population shifts and changes of land use in the proximity of the NAB counting stations may play an important role in determining the amount of airborne pollen collected at the corresponding stations (Haberle et al , 2014, Reid & Gamble, 2009, Ziska & Beggs, 2012). Because of the fertilizer effect of CO 2 in the atmosphere, increase of CO 2 level itself or combined with rising temperature has been reported to substantially influence pollen and spore production (English et al , 2009, Rogers et al , 2010, Ziska et al , 2009, Ziska et al , 2003, Ziska et al , 2007). Data describing these compounding factors (e.g., CO 2 level and land changes) are generally not available or very limited during the period of 1994–2010 for most of the NAB pollen stations.…”

The Pannonian plain as a source of Ambrosia pollen in the Balkans

“…The development of such an inventory could prove problematical. The presence of ragweed is dependent on soil disturbance (Ziska et al 2007) and so emission inventories require yearly updates due to changes to source characteristics. For instance, changes to land management techniques in agricultural areas, such as increasing the area under grassland, could alter the source strength by displacing ragweed populations.…”

Anthropogenic climate change and allergen exposure: The role of plant biology

“…[32][33][34][35][36][37][38][39][40] This might reflect the pernicious and ubiquitous nature of ragweed pollen. For example, results from the US National Health and Nutrition Examination Survey show that 26.2% of the US population has a positive skin test response to ragweed.…”

“…38 These data suggested that soil disturbance, in addition to any CO 2 /climate shift, played an essential role in maintaining ragweed populations in urban and suburban environments. 39 Recently, pollen data from the National Allergy Bureau in the United States and the Aerobiology Research Laboratories in Canada were analyzed to determine whether recent warming had resulted in a change in the duration of the ragweed pollen season in North America. 40 These data demonstrated that the duration of the ragweed pollen season has been increasing but only as a function of increasing latitude, which is consistent with differential global warming projected by the IPCC (Fig 1).…”