Assessment of vegetation and soil conditions in restored mangroves interrupted by severe tropical typhoon 'Chan-hom' in the Philippines

Using a space-for-time substitution approach, we investigated the effects of a typhoon on the vegetation and soil development trajectories of monospecific stands of Rhizophora mucronata mangroves of different ages (6-, 8- 10-, 11-, 12-, 17-, 18- and 50-year stands). The vegetation and soil parameters were compared to a reference system comprised of mature, natural mangrove stands. Pre-typhoon measures of vegetation and soil parameters were compared with 1-mo, 7-mo and 9-mo post-typhoon. Prior to the occurrence of the typhoon, there were clear patterns of vegetation and soil development with age of the stands. The development trajectory was however interrupted by the occurrence of the typhoon. Severe damage was more apparent in older mangrove stands (11- and 18- year stands) with very low to no damage in the younger stands. The typhoon-impacted sites experienced a number of changes, including: complete defoliation; reduced living tree densities of 61-69 %; decreased above-ground biomass of 70-79 %; increased soil nutrient levels of 40-60 %; more waterlogged soils by at least 113 % and increased soil temperature of 8-10 A degrees C. Cumulative tree mortality, compounded by the lack of seedling recruits and unfavourable soil conditions may limit long-term recovery of the typhoon-impacted stands.