RICHNESS, ABUNDANCE AND ORIENTATION OF Tillandsia IN SHRUBS OF THE MONTE REGION, IN LA RIOJA, ARGENTINA

VARELA R. O; TORRES, J. R

San Miguel de Tucumán

Jornada; THIRD JOINT MEETING OF THE BIOLOGY SOCIETIES OF ARGENTINA; 2015

Sociedades de Biología de Argentina

Tillandsia (Bromeliaceae) is the most diverse genus of vascular plants, in the Monte region of La Rioja, Argentina. This study analyzes the richness, abundance and orientation preference of Tillandsia in six shrub species in a sector of the Central Valley of La Rioja. The study area is located north of the Capayán River (29º 02? 52.2?S; 67º 27? 23.3?W; 1053 masl) in the Famatina Department. Sampling was conducted during September 2014 when the Tillandsia species are easily distinguishable. Six species of host plants were studied: Acacia gilliesii, Bulnesia retama, Larrea cuneifolia, Prosopis torquata, Tricomaria usillo and Zuccagnia punctata.Plants with the largest canopy size in each species (n = 20) were selected within an area of 1km2. Height and crown diameter for each host plant and the number of Tillandsia plants according to the cardinal direction (north / south) were recorded. A total of 656 Tillandsia plants belonging tof 10 species were counted in 120 host plants. In order of abundance they were: T. duratii (70%), T.aizoides (11%), T. pedicellata (9%), T. gilliesii (6%), T. myosura (2%), T. minutiflora, T. angulosa, T. capillaris, and T. castellanii (2% overall). The host plants with greatest richness and abundance were P. torquata (8 spp; 165 indiv.), A. gilliesii (7 spp; 216 indiv.),and B. retama (6 spp; 154 indiv.). The richness of Tillandsia was relatively similar between orientations, but the abundance was greater in the northern orientation. Tillandsia duratii was similarly abundant in the main hosts. The greater abundance and richness ofTillandsia was concentrated in host plants with heights of 2.5-4 m and a crown diameter of 2-7 m.