EDGARDO I. GARRIDO-PEREZ1, GERHARD GEROLD1, MARIO UCAN-MAY2
1Institute of Geography, Goettingen University, Landscape Ecology, Germany
2Independent Contractor, Ejido Solferino, Quintana Roo, Mexico
It has been proposed that global change increases hurricane's frequency and liana abundance; and that lianas pull and break trees. Indeed, trees hosting live lianas should have a higher probability to be broken during hurricanes. We tested this when Hurricane Wilma stroke North Eastern Yucatan Peninsula (October 2005). There we have 6 pairs of 400m2 forest plots. We marked and identified all trees 14#143,16cm dbh and lianas 14#141cm diameter at ground level. Before the hurricane we cut the lianas in one plot of each pair. We located: three, two and one pair of plots in the 14#1455yr, 18yr, and 10yr-old stands respectively. For the 14#1455yr-old stands, the % of snapped"=trunk trees was smaller in the liana"=cut (4%, SD=0,21), than in uncut plots (7%, SD=2,17), suggesting that lianas ``helped'' the hurricane to snap trees. For the 18yr"=old stand, the hurricane snapped more trunks in the liana"=cut plots (averages: liana"=cut=8%; liana"=uncut=1,3% snapped trees), suggesting that lianas avoided tree"=snapping. The same occurred in the 10yr"=old stand (liana"=cut=9%; liana"=uncut=2,7% snapped"=trees). Liana"=cutting did not change the % of other damage types. For example, in the 14#1455yr"=old stands, the % of trees having only large branches remaining were: Liana"=cut=0,8% (SD=1,3), and liana"=uncut= 1,3% (SD=2,2). Dominant lianas were: Cydista spp and Arrabidaea spp (both soft"=bodied Bignoniaceae, in the 14#1455yr"=old stands), and Dalbergia glabra (heavy"=bodied Papilionoidae, in both, 18- and 10yr"=old stands). We suggest D. glabra individuals functioned as ``fixing"=cables'' avoiding snapping. Results suggest that liana"=cutting before logging may be not"=necessary and can be structurally detrimental in secondary forests in hurricane areas.
Keywords: Hurricanes, Liana-cut, Mexico, tree-snapping