Typhoon effects on litterfall in a subtropical forest

Abstract

The litterfall in a subtropical broadleaf forest within the Fushan Experimental Forest in northeastern Taiwan was monitored for 9 years. Mean annual litterfall was very sensitive to typhoon frequency and intensity, ranging from 3 to 11 Mg·ha -1 ·year -1 . Litterfall was significantly higher in years with strong typhoons than in years without typhoons, and the number of strong typhoons explained 82% of interannual variation in litterfall. Nutrient-use efficiency (dry mass/nutrients in litterfall) was high for N, but low for P compared with other tropical forests. This result supports the idea that the study forest is P limited but not N limited. Nutrient loss via litterfall represents a large percentage of aboveground biomass, especially during years with strong typhoons (e.g., 19%-41%, 15%-40%, 5%-12%, for N, P, and K, respectively). Forests that experience infrequent wind disturbance (e.g., temperate or boreal forests) can gradually regain any lost nutrients prior to the next disturbance; this is different from the situation observed in the Fushan Experimental Forest. At Fu-shan the pattern of not responding to typhoons with a flush of new growth appears to be an adaptation to the frequency with which there are multiple typhoons affecting the forest in a single year. Nutrient loss in litterfall caused by frequent typhoon disturbances appears to limit tree growth and contributes to the very low canopy height of the Fushan Experimental Forest.Résumé : La chute de litière dans une forêt décidue subtropicale située dans la forêt expérimentale de Fushan dans le Nord-Est de Taiwan a été suivie pendant 9 ans. La chute annuelle moyenne de litière était très sensible à l'intensité et la fréquence des typhons, variant de 3 à 11 Mg·ha -1 ·an -1 . La chute de litière était significativement plus élevée lors des années avec de violents typhons que lors des années sans typhons. Le nombre de typhons violents expliquait 82 % de la variation inter annuelle dans la chute de litière. L'efficacité d'utilisation des nutriments (masse sèche/nutriments dans la chute de litière) était élevée pour N mais faible pour P comparativement à d'autres forêts tropicales. Ce résultat supporte l'idée que P est un facteur limitant dans la forêt sous étude mais que N ne l'est pas. La perte de nutriments via la chute de litière représente un important pourcentage de la biomasse épigée, particulièrement lors des années avec de violents typhons (p. ex. respectivement 19-41 %, 15-40 % et 5-12 % pour N, P et K). Les forêts qui ne sont pas fré-quemment soumises à des perturbations par le vent (p. ex. les forêts tempérées ou boréales) peuvent graduellement retrouver les nutriments perdus avant que survienne une autre perturbation; cela est différent de la situation observée dans la forêt expérimentale de Fushan. À Fu-shan, le fait de ne pas produire de nouvelles pousses à la suite d'un typhon semble être une adaptation à la fréquence avec laquelle de multiples typhons affectent la forêt au cours d'une même année. La perte de nutriments causée par de fréqu...

Enhanced annual litterfall production due to spring solar radiation in cool-temperate mixed forests of northern Hokkaido, Japan

“…2) in agreement with other studies (Xu et al, 2000;Lin et al, 2003;Saarsalmi et al, 2007;Li et al, 2010). The annual litterfall rate among the mixed forests ranged from 76 to 335 g DW m -2 year -1 , implying that variation in the litterfall rate exists even in forests of the same dominant species (Gairola et al, 2009 partly induced by human errors.…”

“…In addition, there was a significant positive correlation at the Dc site between the annual litterfall rate and the number of windy days during the growing season or autumn in the current year. These phenomena are easily understandable compared with the relationship between spring solar radiation and the annual litterfall rate, because several researches already reported that strong wind (Christensen, 1975;Lin et al, 2003) or low air temperature (Battaglia et al, 1998) enhances the litterfall rate.…”

“…It is necessary to examine how felled litters vary with climate inasmuch as previous litterfall studies have indicated that climate can significantly affect the forest litterfall. Typhoons (Lin et al, 2003), floods (Haase, 1999), temperature (Kouki and Hokkanen, 1992), precipitation (Hennessey et al, 1992;Pedersen and BilleHansen, 1999;Campanella and Bertiller, 2010), and a combination of temperature and precipitation (Saarsalmi et al, 2007) were proved to be significant factors regulating forest litterfall. But despite the increasing amount of research relative to litterfall dynamics in cool-temperate forests (Tripathi et al, 2006;Xu and Shibata, 2007;Watanabe et al, 2012), the influence of changing climate on the litterfall production has been largely ignored.…”

Responses of Soil Labile Organic Carbon to a Simulated Hurricane Disturbance in a Tropical Wet Forest

“…Mean soil MBC in the CTDD plots was significantly higher than in the control plots in every sampling week, except for the three weeks before the treatment and the 96th week after the treatment. A sudden deposition of massive hurricane-induced litterfall in various forests was shown to increase soil carbon input and the heterogeneity of the microenvironment for soil microbes [5], change soil C/N ratios [3,8], increase and then decrease competition for soil nutrients between soil microorganisms and plant species [23,57], and alter the biomass and biodiversity of litter invertebrates [14], all of which could be potential factors that might have jointly elevated soil MBC. These potential factors in the CTDD plots may lead to a persistent higher soil MBC in the CTDD plots.…”

“…Natural disturbances often deposit massive amounts of litterfall in forests, such as in the case of drought [1], wind [2], rainstorms [3], and ice storms [4]. Severe hurricane-force winds instantaneously…”