A new quantitative classification of ecological types in the bromeliad genus Tillandsia (Bromeliaceae) based on trichomes

Abstract

Using collection specimens, we measured the density and wing area of trichomes in 37 species of the bromeliad genus Tillandsia, specifically the abaxial proximal, abaxial distal, adaxial proximal and adaxial distal parts of the leaf. The product of the trichome "wing" area by the number of trichomes (means) produced a pure number (T) that was correlated to ecological features. The correlation was positive with respect to arid environments (xeric Tillands) and negative with respect to humid environments (mesic Tillands). Bulbous, and particularly myrmecophytic species and species with tanks, represented particular categories. Other intermediate types were identified based on the T number, totalling five ecological types. In comparison with other systems of ecological typification for Tillands and other Bromeliaceae, the present system offers measurable data whose analysis is reproducible.

Physiological responses of Tillandsia albida (Bromeliaceae) to long-term foliar metal application

“…used are the only source of water, then relatively low concentrations we applied to intact plants allowed uptake of water including metal ions (otherwise desiccation would occur). In line with this assumption, T. albida has high number of trichomes (mean value 40/mm 2 ) among 37 Tillandsia species investigated [36]. Secondly, tissue-absorbed Cd and Ni differed considerably, indicating that these metals rely on various uptake mechanisms.…”

Fog interception by Ball moss (<i>Tillandsia recurvata</i>)

“…Juvenile, vegetative specimens of T. recurvata were chosen because the trichomes of some bromeliads are reduced in frequency and dimension as the plant reaches the adult form (Stefano et al, 2008). This kind of specimens would represent the upper bound of water storage.…”

“…Atmospheric species of bromeliad colonize the tree canopy, rocks and even cable lines and therefore, the only water available to them is that detained on their surfaces and the atmospheric vapor available in the limit layer. The role of trichomes is very important for water detention; when the humidity content in the plant is low, the trichome wings are elevated and when moist, they are folded and stick to the leaf surface (Schmitt et al, 1989;Stefano et al, 2008). When the trichomes' wings are folded a reduction in the contact angle with rain or fog drops is possible and the runoff from the surface could be decreased.…”

Throughfall alterations by degree of Tillandsia usneoides cover in a southeastern US Quercus virginiana forest

“…However, ions which respond to an 365 epiphyte's ecophysiological activities (Table 1; Figure 3b-d,f) differed for our vascular epiphyte 366 species compared to the bryophytes and lichens most heavily studied in past research-probably 367 as a result of T. usneoides' direct exchange with entrained rain droplets through its trichome 368 scale anatomy Stefano et al 2008). Throughfall Mg 2+ and Ca 2+ 369 concentrations both increased with lichen and bryophyte presence (Lang et al 1976;Veneklaas 370 1990;Coxson 1991;Knops et al 1996;Oyarzún et al 2004), likely because Ca 2+ (and a large 371 portion of Mg 2+ ) is stored in an intercellular leachable position (e.g., Farmer et al 1991).…”

“…Since T. usneoides relies on moisture-related atmospheric exchange across its scales to uptake ionic nutrients(Alves et al 2008, Stefano et al 2008), we expected NO 3 -depletion to increase with smaller VPD classes under heavy epiphyte coverage. This was observed for bare to low epiphyte-laden canopy…”