Aeropalinología de la ciudad de Yerba Buena, provincia de Tucumán (Argentina). Aeropalinology of Yerba Buena city, province of Tucumán (Argentina)

Español. Durante los años 1999 - 2002 se llevó a cabo la primera caracterización aerobiológica de la ciudad de Yerba Buena. El muestreo atmosférico se realizó con un captador gravimétrico de tipo Durham. El análisis de las muestras permitió la identificación de 46 tipos polínicos. Los granos de polen más relevantes en el muestreo son de especies cultivadas como Cupressaceae, Morus sp., Broussonetia sp., Fraxinus sp., Liquidambar sp., Salix sp. y Pinus sp. Desde julio a octubre se obtuvo el mayor registro de polen atmosférico con el 70,84 % anual, con una predominancia de granos de polen de especies arbóreas, el 25,05 % de noviembre a abril con un aporte principalmente de granos de polen de especies herbáceas y el 3,57 % de mayo a junio sin contribuciones dominantes de algún tipo polínico. Se elaboró un calendario polínico basado en los 17 tipos de polen de mayor registro atmosférico y se lo comparó con calendarios polínicos obtenidos en ciudades del país. La floración en las Sierra del San Javier en Tucumán, es marcadamente estacional con una acumulación de más de 70% de las especies que florecen en el período primaveral. El muestreo continuado a lo largo de 3 años ha permitido observar que las variaciones polínicas estacionales de la atmósfera de la ciudad de Yerba Buena se hallan en relación con los factores fenológicos y meteorológicos propios de cada año. English. The first aerobiologic characterization of Yerba Buena city in Tucumán (Argentina) was carried out for the period 1999-2002 using a Durham gravimetric spore trap. The analysis of samples allowed the identification of 46 pollen types. The most outstanding pollen grains in these samples came from cultivated species such as Cupressaceae, Morus sp., Broussonetia sp., Fraxinus sp., Liquidambar sp., Salix sp.and Pinus sp. From July to October the largest atmospheric pollen records were obtained with 70,84% in arboreal species predominantly. From November to April, an important contribution of 25,05% in herbaceous species mainly, and with a 3,57% from May to June without observing predominant contribution of any pollen type. A pollen calendar based on the most frequent 17 pollen types, containing the largest atmospheric records, was elaborated. We compared the pollen calendar obtained with those of other cities in the country. Flowering in the Sierra San Javier at Tucumán is markedly seasonal with an accumulation of over 70% of the species that bloom in the spring period. Continuous sampling during 3 years has revealed that the seasonal pollen variation in the atmosphere of the city of Yerba Buena, is in connection with the phenological and meteorological factors characteristic of every year.

Pollen and Archaeology at Wetherill Mesa

Nine profiles of prehistoric cultural deposits at Wetherill Mesa, Mesa Verde National Park, Colorado, were analyzed for fossil pollen content. Relatively large numbers of corn (Zea) pollen occur in certain deposits of Mug House. In the alluvium retained behind low walls of two check-dams, the frequency of Zea is relatively low (.07%) but approximates the frequency of Zea pollen in soil of a garden on Chapin Mesa planted in Indian corn since 1919. Evidently, soil behind the prehistoric checkdams served as corn plots. The abundance of pollen resembling bee-weed (Cleome serrulata) suggests a more important role for the caper family in prehistoric time than would be inferred from its macrofossil record alone. The Cieome-type is common in prehistoric refuse and in human coprolite in the Four Corners area.Pollen content of matrix within a single archaeological site may vary, depending on the nature of the deposit. Although parts of their deposits overlap in time, the pollen content of (1) a trash slope, (2) a kiva, and (3) a work area within Mug House pueblo varies greatly, especially in economic pollen. Variation between profiles is reduced considerably when they are taken from the same type of deposit, that is, adjacent kivas or trash profiles.The hope that the fossil record would shed new light on the cause of abandonment of Mesa Verde was largely unrealized. The main stratigraphic event in the pollen sequence of the last 1000 years is a relative increase in juniper and pine pollen following abandonment 700 years ago. Ecologically, this rise can be explained as the result of secondary plant succession with first juniper and then pinyon invading fields when human disturbance ended. It may or may not reflect climatic change.