STRANGLER FIG ROOTING HABITS AND NUTRIENT RELATIONS IN THE LLANOS OF VENEZUELA

The strangler figs, Ficus pertusa and F. trigonata , are abundant in the seasonally flooded palm savanna (llanos intermedio) near Calabozo, Venezuela. The most common host tree for the hemiepiphytic figs is the palm Copernicia tectorum ; nearly half of the palms support either an epiphytic or a ground‐rooted fig. During their epiphytic stage the figs are rooted behind the palms' marcescent leaf bases. Material trapped behind the leaf bases is higher in organic matter, nitrogen, magnesium, and potassium than soil from the ground near the palms. The suggestion that nutrient availability to epiphytes is high is supported by the observation that concentrations of several nutrients, including N, P, and K, are significantly higher in epiphytic leaves than in tree leaves. Figs retain access to the epiphytic medium by producing upwardly growing (apogeotropic) roots that remain attached in the host palm's crown long after the fig has become firmly rooted in the ground. Although upward growing roots are expected to be more important in nutrient than water uptake, there are no obvious differences in the xylem anatomy of upward and downward growing fig roots. Terrestrial roots of fig trees are generally infected with vesicular‐arbuscular mycorrhizae, but the epiphytic roots of the same individuals are not infected.