Experimental evidence of an increased leaf production in Prosopis after removal of epiphytes (Tillandsia).

SORIA, N.; TORRES, C.; GALETTO, L.

FLORA

ELSEVIER GMBH

Año: 2014 vol. 209 p. 580 - 586

0367-2530

tThe production of new leaves of host trees can be affected by the presence of epiphytic species. Thisexperimental study was planned to evaluate the effects on the mean number of new leaves producedby Prosopis alba considering the factors site-disturbance, different epiphytes loads, and the respectivezones in the tree crown. The number of new leaves produced was counted manipulating branches withoriginally low and high loads of epiphytes at different crown zones, in 10 trees per site. The effect ofmanual removal of epiphytes on the leaf production of the hosts was analyzed by comparing branchresponses in short and medium periods of time (i.e., 6 months and 3 years, respectively). There were nosignificant differences when comparing the number of new leaves produced in the sampled trees at siteswith different human disturbance intensities. By contrast, significant differences were observed betweenboth epiphytic loads treatments and when comparing tree crown zones. Experimental results showeda higher subsequent host leaf production (>100%) in branches where epiphytes were experimentallyremoved, in comparison with branches with high load of epiphytes The number of new leaves producedin branches with naturally low loads of the epiphytes was higher than 1000% compared to branches withhigh Tillandsia loads. Finally, a higher significant production of new leaves was observed in the bottomcrown zone as compared with the middle and upper crown zones. Furthermore, this trend was confirmedconsidering a longer time-period (3 years) after experimental removal of epiphytes. A significant increase(>100%) was observed when comparing the production of new leaves between different periods aftertotal epiphyte removal. In consequence, Tillandsia species could be considered as "structural parasites"of Prosopis alba.