| Summary: | Since 1960, when hurricane Adriana hit the region, no meteor had affected the coasts of Nayarit, in the Mexican Pacific. In October 1994, hurricane Rosa hit with winds of up to 160 km/h, affecting large mangrove areas. The most severe effects were exerted mainly on Laguncularia racemosa, followed by Avicennia germinans, and minimally on Rhizophora mangle. From the white mangrove, only 31,9 % of the trees remained standing with <10m of height and a DAP <10,8 cm. The largest effect of the hurricane was recorded in 39,9 % of the medium sized trees, which were bent and died later on. The oldest trees (28,1 %) were broken down by the force of the wind, due to the greater height (>11 m) and greater resistance because of the thickness of the trunks (>10,1 cm). In A. germinans, the biggest effect was recorded in the mature trees, since all of them suffered broken branches. In the whole lacunar system, L. racemosa presents a narrow and shallow radical system (90,7 and 30,9 cm) that makes it vulnerable to winds. The loss of wood due to the hurricane was variable: 35,0 m3/ha in the least affected site and up to 103,7 m3/ha in the mature forest. A large loss of propagules and plantules was also recorded in the forests. These events are frequent in the mangrove forests and can favor natural selection processes, which modulate succession and evolution of this vegetation along time.
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