The dispersal of diaspores is a key process for successful reproduction, survival and evolution of plants. To model the dispersal of biological propagules (e.g., spores, pollen) it is necessary to measure their terminal velocity (Vt) in air. In this study, we used a new method based on video image analysis to measure Vt of spores of seven fern taxa. The average Vt of fern spores was 7.0 cm s−1, but varied among species from 1.6 to 11.3 cm s−1. Similar values were reported previously for airborne particles of mosses and seed plants. Spores of Danaea nodosa and Lophosoria quadripinnata had a lower Vt than other spores of similar size, perhaps owing to their surface ornamentation that increases their drag coefficient, or an air cavity, which diminishes their density. The reliability of the video image analysis method used here on fern spores was verified by comparing observed and theoretically calculated Vt of glass beads of known diameter and density. This method also allows the observation of spore behavior (e.g., rotation) as they move through the air. Because the method is relatively easy and inexpensive, it can promote future aerobiological research on other biological airborne particles as well.

Mexico is among the countries that are facing the greatest water stress, where factors such as climate change, contamination of surface water, groundwater sources, and inefficient management have limited the availability of water resources. Consequently, new supply sources need to be implemented. Rainwater harvesting systems (RHS) are viable and sustainable alternatives, the implementation of which primarily depends on identifying suitable sites and applying technologies that are appropriate for different users. This research used the Analytical Hierarchy Process (AHP) technique in a GIS environment to select the optimal sites for designing RHS, taking into account hydrological, biophysical, and socioeconomic criteria. After determining the ideal sites, the study presents proposals and costs for the design of an urban and rural RHS based on the characteristics of the region and the needs of the community. The findings show that implementing RHS in the study area can be a practical, economical, and efficient alternative for water resource management, since these projects are aimed at sustainability.

Se presentan datos relativos a la morfología de las esporas de 36 especies de helechos y tres licofitas presentes en la localidad de Río Malila, municipio de Molango de Escamilla, en el estado de Hidalgo, México. Los taxa estudiados corresponden a 27 géneros y 14 familias. Las esporas de Ctenitis equestris, Elaphoglossum obscurum, Pecluma sursumcurrens y Polystichum turrialbae se describen por primera vez. Las descripciones palinológicas se realizaron con base en observaciones de material fresco y con microscopía de luz y/o electrónica de barrido y se incluyen imágenes para cada uno de los taxa estudiados. Como resultado se elaboró una clave dicotómica para la identificación de las especies presentes en la zona a partir de sus esporas. El conocimiento palinológico de los helechos puede contribuir a resolver problemas taxonómicos del grupo, ayudar en el diagnóstico oportuno de poblaciones en riesgo y facilitar posteriores estudios aerobiológicos de las pteridofitas, desde la identificación de esporas presentes en el aire, la determinación de patrones fenológicos de comunidades, la dispersión de esporas en diferentes condiciones meteorológicas y ambientales, hasta su posible efecto en la salud de otros organismos.