ESTUDIO DEMOGRÁFICO DE Emilia sonchifolia (ASTERACEAE) EN UNA FINCA CAFETERA DE ARMENIA, QUINDÍO, COLOMBIA / Demographic study of Emilia sonchifolia (Asteraceae) in a coffee farm in Armenia, Quindío, Colombia.

Se realizó un estudio con el fin de determinar la estructura demográfica de Emilia sonchifolia (L.) DC en una finca cafetera del Municipio de Armenia, Quindío, Colombia, donde se recolectaron datos durante cuatro semanas, en tres sitios: exterior, borde e interior del cultivo. Usando parámetros calculados a partir de los datos de campo, se construyó un modelo logístico para describir el comportamiento poblacional de E. sonchifolia en el tiempo. Se encontraron diferencias significativas en las variables: número de individuos por estado etario en el tiempo, porcentaje de mortalidad, tiempo de cambio del estado plántula a juvenil y de juvenil a adulto, número de hojas y de ramas; no se encontraron diferencias significativas en la densidad poblacional, número de inflorescencias e infrutescencias en los sitios de estudio. En general, se puede atribuir este comportamiento a la estrategia de reproducción r que sigue E. sonchifolia. Finalmente, las simulaciones hechas a partir del modelo logístico sugieren que la especie tiende a desaparecer si alguno de los estados etarios no está presente inicialmente; así, una alternativa plausible para el control sería su eliminación en el estado juvenil. Los resultados ofrecen alternativas con respecto al manejo de poblaciones de arvenses.

A research study was conducted to determine the demographic structure of Emilia sonchifolia L. in a coffee plantation in Armenia, Quindío, Colombia. Data were collected over a period of four weeks on three sites: inside, at the border and outside a coffee farm. A logistic population model was built to describe the population behavior of E. sonchifolia over time. Statiscally significant differences were found between: number of individuals per life stage in time, mortality rate, transition time from seedling to juvenile and from juvenile to adult; and number of leaves and branches. There was no evidence for statistically significant differences in population density or in number of inflorescences and fruits between study sites. In general, the observed behavior may be attributed to the r strategy used by this species. Finally, our results suggest the survival of the species is conditioned by the presence of all life stages at the beginning of each simulation based on the logistic model; so, a potential strategy for its controlling would require the removal during the juvenile stage. The considerations offer alternatives regarding weed population management.

Evaluation of the association of vegetation of allergenic plants and pollinosis with meteorological changes

PURPOSE: There are a number of reports suggesting that widespread propagation of weeds and high concentration of weed pollen have been contributed to climate change. We investigated the interrelationship between allergenic pollen concentration, allergic symptom and meteorological factor. METHODS: We collected data of pollen concentration and meteorological factors in 7 stations nationwide during between 1998 and 2012. We recruited total 297 allergic patients sensitized to weed pollens from each station, conducted a survey about allergic symptom, and calculated symptom index. We surveyed the vegetation area of ragweed and Japanese hop. Based on these data, we performed the long-term trend analysis (X11-ARIMA, autoregressive integrated moving average) on regional pollen concentration, and correlation analysis to investigate the interrelation between weed pollen concentration, allery symptom index and meteorological factor. We have also done regression analysis on vegetation area and maximal pollen concentration. RESULTS: Long-term trend analysis showed the increasing trend of pllen concentration in Seoul. Weed pollen concentration, allergy symptom index and each meteorological factor were not correlated significantly. Regression analysis revealed that increase of weed vegetation area results in increase of weed pollen concentration. Through this regression equation, we estimated the vegetation area that can product pollen concentration triggering allergenic risk. CONCLUSION: Meteorological factors, pollen concentration and allergic symptoms should be consistently assessed and the relationship between each factor should be analyzed, considering climate change. It is necessary to verify the equation for pollen estimation by vegetation area and set up a policy for vegetation control focused on the reduction of allergenic pollen.

Changes in Sensitization Rate to Weed Allergens in Children with Increased Weeds Pollen Counts in Seoul Metropolitan Area

The prevalence of allergic diseases in children has increased for several decades. We evaluated the correlation between pollen count of weeds and their sensitization rate in Seoul, 1997-2009. Airborne particles carrying allergens were collected daily from 3 stations around Seoul. Skin prick tests to pollen were performed on children with allergic diseases. Ragweed pollen gradually increased between 1999 and 2005, decreased after 2005 and plateaued until 2009 (peak counts, 67 in 2003, 145 in 2005 and 83 grains/m3/day in 2007). Japanese hop pollen increased between 2002 and 2009 (peak counts, 212 in 2006 and 492 grains/m3/day in 2009). Sensitization rates to weed pollen, especially ragweed and Japanese hop in children with allergic diseases, increased annually (ragweed, 2.2% in 2000 and 2.8% in 2002; Japanese hop, 1.4% in 2000 and 1.9% in 2002). The age for sensitization to pollen gradually became younger since 2000 (4 to 6 yr of age, 3.5% in 1997 and 6.2% in 2009; 7 to 9 yr of age, 4.2% in 1997 and 6.4% in 2009). In conclusion, sensitization rates for weed pollens increase in Korean children given increasing pollen counts of ragweed and Japanese hop.

Changes in Sensitization Rate to Weed Allergens in Children with Increased Weeds Pollen Counts in Seoul Metropolitan Area

The prevalence of allergic diseases in children has increased for several decades. We evaluated the correlation between pollen count of weeds and their sensitization rate in Seoul, 1997-2009. Airborne particles carrying allergens were collected daily from 3 stations around Seoul. Skin prick tests to pollen were performed on children with allergic diseases. Ragweed pollen gradually increased between 1999 and 2005, decreased after 2005 and plateaued until 2009 (peak counts, 67 in 2003, 145 in 2005 and 83 grains/m3/day in 2007). Japanese hop pollen increased between 2002 and 2009 (peak counts, 212 in 2006 and 492 grains/m3/day in 2009). Sensitization rates to weed pollen, especially ragweed and Japanese hop in children with allergic diseases, increased annually (ragweed, 2.2% in 2000 and 2.8% in 2002; Japanese hop, 1.4% in 2000 and 1.9% in 2002). The age for sensitization to pollen gradually became younger since 2000 (4 to 6 yr of age, 3.5% in 1997 and 6.2% in 2009; 7 to 9 yr of age, 4.2% in 1997 and 6.4% in 2009). In conclusion, sensitization rates for weed pollens increase in Korean children given increasing pollen counts of ragweed and Japanese hop.