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Akio Hagihara - One of the best experts on this subject based on the ideXlab platform.

  • Stand structure, phenology and Litterfall dynamics of a subtropical mangrove Bruguiera gymnorrhiza
    Journal of Forestry Research, 2016
    Co-Authors: Md Kamruzzaman, Sahadev Sharma, Mouctar Kamara, Akio Hagihara
    Abstract:

    We evaluated the phenology and Litterfall dynamics of the mangrove Bruguiera gymnorrhiza (L.) Lamk along the Okukubi River, Okinawa Island, Japan. Over 3 years, this species showed the highest Litterfall of leaves and stipules in summer and the lowest Litterfall in winter. From Kendall’s coefficient of concordance, the monthly changes in leaf, stipule, and branch were strongly and significantly concordant among years. Leaf and stipule Litterfall could be governed by monthly maximum wind speed, monthly day length, and monthly mean air temperature. Branch Litterfall depended on monthly maximum wind speed and monthly rainfall, and increased exponentially with increasing monthly maximum wind speed. Mean total Litterfall was 11.8 Mg ha^−1 yr^−1, with the largest component being leaf Litterfall (65.8 %). Annual leaf Litterfall per plot was almost constant regardless of the tree density of the plot. Mean leaf longevity was 18 months. Flower and mature propagule Litterfall might be influenced by monthly mean air temperature, monthly day length and monthly mean air temperature. The average development periods from flower buds to flowers and flower buds to mature propagules were 1 and 8 months, respectively. Except for leaf and branch, all vegetative and reproductive organ Litterfall had clear annual cycles. B. gymnorrhiza showed a positive correlation between leaf production and reproductive organ production.

  • vegetative and reproductive phenology of the mangrove bruguiera gymnorrhiza l lam on okinawa island japan
    Trees-structure and Function, 2013
    Co-Authors: Md Kamruzzaman, Sahadev Sharma, Mouctar Kamara, Akio Hagihara
    Abstract:

    Vegetative and reproductive phenology of the subtropical mangrove Bruguiera gymnorrhiza was investigated at Manko Wetland, Okinawa Island, Japan. Phenology was assessed using Litterfall data over 4 years. Leaf and stipule Litterfall occurred throughout the year, with distinct seasonal patterns. Kendall’s coefficient of concordance, W, revealed that the monthly changes in leaf and stipule Litterfall were strongly and significantly concordant among years. Leaf Litterfall was linked to monthly day length and maximum wind speed, and stipule Litterfall was linked to monthly mean air temperature, monthly rainfall, and maximum wind speed. Branch Litterfall showed no clear monthly pattern, but tended to vary with monthly maximum wind speed. Mean leaf longevity was 19 months. Mean total Litterfall was 10.1 Mg ha−1 year−1, with the largest component being vegetative organs (58 %). Flower and propagule Litterfall were highest in autumn and summer, respectively, and lowest in winter. The W values revealed that, of the reproductive organs, only flower Litterfall had a significant monthly trend. Flower Litterfall was correlated with monthly mean air temperature and relative humidity. The average development periods from flower buds to flowers and from flowers to mature propagules were approximately 1 and 8 months, respectively. It took 9 months to produce mature propagules from flower buds. Except for branches, all vegetative and reproductive components of Litterfall had clear annual cycles.

  • Litterfall of three subtropical mangrove species in the family rhizophoraceae
    Journal of Oceanography, 2012
    Co-Authors: Md Kamruzzaman, A Rafiqul T M Hoque, Sahadev Sharma, Akio Hagihara
    Abstract:

    This study was conducted to evaluate and compare the Litterfall dynamics of three mangrove species in the family Rhizophoraceae: Rhizophora stylosa, Kandelia obovata, and Bruguiera gymnorrhiza, in Manko Wetland, Okinawa Island, Japan. Over 3 years, these species showed highest Litterfall of leaves and stipules in summer and the lowest Litterfall in winter. Litterfall of flowers and fruits peaked in July for R. stylosa, and in August and again in October–November for K. obovata. Litterfall of flower buds, flowers, and propagules occurred throughout the year for B. gymnorrhiza, but was highest in summer. Litterfall of propagules was highest in September and May for R. stylosa and K. obovata, respectively. Kendall’s coefficient of concordance revealed that the monthly changes for leaf, stipule, flower, and fruit Litterfalls of all the species were strongly and significantly concordant among the years. The conversion rate of flowers to propagules was 2.3 % in R. stylosa, 5.9 % in K. obovata, and 10.3 % in B. gymnorrhiza. Total annual Litterfall in R. stylosa was significantly different from K. obovata and B. gymnorrhiza; however, the latter two species showed no significant differences. Leaves contributed the most to the total Litterfall of all three species, and represented 58.4, 54.0, and 50.4 % of the total Litterfall for R. stylosa, K. obovata, and B. gymnorrhiza, respectively. Except for branches and flower bud primordia, all other components of Litterfall had clear annual cycles for all three species. Rhizophora stylosa and K. obovata showed a negative correlation between leaf production and reproductive organ production, but B. gymnorrhiza tended to increase leaf production with increasing reproductive organ production.

  • Litterfall dynamics in an overcrowded mangrove kandelia obovata s l yong stand over five years
    Estuarine Coastal and Shelf Science, 2012
    Co-Authors: Sahadev Sharma, A Rafiqul T M Hoque, Kangkuso Analuddin, Akio Hagihara
    Abstract:

    Abstract Organic matter fluxes into marginal wetland areas require to be quantified given their support for the detrital components. Following their study for 5 years in a mangrove ( Kandelia obovata ) stand near the northernmost limit of the species’ distribution in East Asia, leaf and stipule Litterfalls exhibited a clear monthly pattern, with maximum values in July and minimum values in February. In this region, mangroves experience a distinct seasonal climate characterised by low temperatures and frequent typhoons. Propagule Litterfall was largest in April and May, whereas no propagule Litterfall occurred in summer. Kendall’s coefficient of concordance revealed that the monthly trends of Litterfall did not significantly differ among years (branch, p p −2  yr −1 , of which leaf Litterfall constituted 49.3–67.9%. Higher annual total Litterfall was caused by high production of branch Litterfall during typhoons. Stipule Litterfall (an indicator of new-leaf flush) decreased with increasing levels of flower/fruit and propagule Litterfalls and mean annual leaf Litterfall per tree decreased with increasing tree density among plots. Annual leaf Litterfall per plot was almost constant regardless of tree density and mean leaf longevity was estimated to be 12.04 ± 0.04 month.

  • Biomass and aboveground net primary production in a subtropical mangrove stand of Kandelia obovata (S., L.) Yong at Manko Wetland, Okinawa, Japan
    Wetlands Ecology and Management, 2009
    Co-Authors: Md. Nabiul Islam Khan, Rempei Suwa, Akio Hagihara
    Abstract:

    Biomass and aboveground net primary production (ANPP) in a monospecific pioneer stand of a mangrove Kandelia obovata (S., L.) Yong were quantified. The estimated biomasses in leaves, branches, stems, roots, aboveground and total were 5.61 (3.68%), 28.8 (18.9%), 46.1 (30.2%), 71.8 (47.2%), 80.5 (52.8%) and 152 Mg ha^−1 (100%), respectively. Stem phytomass increment per tree was estimated using allometric relationships and stem analysis. Stem volume without bark of harvested trees showed a strong allometric relationship with D _0.1 ^2 H ( D _0.1, diameter at a height of one-tenth of tree height H ) ( R ^2 = 0.924). Annual stem volume increment per tree showed a strong allometric relationship with D _0.1 ^2 H ( R ^2 = 0.860). Litterfall rate ranges from 3.87 to 56.1 kg ha^−1 day^−1 for leaves and 0.177 to 46.2 kg ha^−1 day^−1 for branches. Seasonal changes of Litterfall rate were observed, which showed a peak during wet season (August–September). Total annual Litterfall was estimated as 10.6 Mg ha^−1 year^−1, in which 68.2% was contributed by the leaves. The ANPP in the K. obovata stand was 29.9–32.1 Mg ha^−1 year^−1, which is ca. 2.8–3.0 times of annual Litterfall. The growth efficiency (aboveground biomass increment/LAI) was 5.35–5.98 Mg ha^−1 year^−1. The low leaf longevity (9.3 months) and high growth efficiency of K. obovata makes it a highly productive mangrove species.

Leiming Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Overview of mercury dry deposition, Litterfall, and throughfall studies
    Atmospheric Chemistry and Physics, 2016
    Co-Authors: L. Paige Wright, Leiming Zhang, Frank J. Marsik
    Abstract:

    Abstract. The current knowledge concerning mercury dry deposition is reviewed, including dry-deposition algorithms used in chemical transport models (CTMs) and at monitoring sites and related deposition calculations, measurement methods and studies for quantifying dry deposition of gaseous oxidized mercury (GOM) and particulate bound mercury (PBM), and measurement studies of Litterfall and throughfall mercury. Measured median GOM plus PBM dry deposition in Asia (10.7 µg m−2 yr−1) is almost double that in North America (6.1 µg m−2 yr−1) due to the higher anthropogenic emissions in Asia. The measured mean GOM plus PBM dry deposition in Asia (22.7 µg m−2 yr−1), however, is less than that in North America (30.8 µg m−2 yr−1). The variations between the median and mean values reflect the influences that single extreme measurements can have on the mean of a data set. Measured median Litterfall and throughfall mercury are, respectively, 34.8 and 49.0 µg m−2 yr−1 in Asia, 12.8 and 16.3 µg m−2 yr−1 in Europe, and 11.9 and 7.0 µg m−2 yr−1 in North America. The corresponding measured mean Litterfall and throughfall mercury are, respectively, 42.8 and 43.5 µg m−2 yr−1 in Asia, 14.2 and 19.0 µg m−2 yr−1 in Europe, and 12.9 and 9.3 µg m−2 yr−1 in North America. The much higher Litterfall mercury than GOM plus PBM dry deposition suggests the important contribution of gaseous elemental mercy (GEM) to mercury dry deposition to vegetated canopies. Over all the regions, including the Amazon, dry deposition, estimated as the sum of Litterfall and throughfall minus open-field wet deposition, is more dominant than wet deposition for Hg deposition. Regardless of the measurement or modelling method used, a factor of 2 or larger uncertainties in GOM plus PBM dry deposition need to be kept in mind when using these numbers for mercury impact studies.

  • Litterfall mercury dry deposition in the eastern usa
    Environmental Pollution, 2012
    Co-Authors: Martin R. Risch, John F Dewild, David P Krabbenhoft, Randall K Kolka, Leiming Zhang
    Abstract:

    Mercury(Hg)inautumnLitterfallfrompredominatelydeciduousforestswasmeasuredin3yearsofsamples from 23 Mercury Deposition Network sites in 15 states across the eastern USA. Annual Litterfall Hg dry depositionwas significantly higher (median 12.3 micrograms per square meter (mg/m 2 ), range 3.5e23.4mg/ m 2 ) than annual Hg wet deposition (median 9.6mg/m 2 , range 4.4e19.7 mg/m 2 ). The mean ratio of dry towet Hg deposition was 1.3e1. The sum of dry and wet Hg deposition averaged 21 mg/m 2 per year and 55% was Litterfall dry deposition. Methylmercury was a median 0.8% of Hg in Litterfall and ranged from 0.6 to 1.5%. Annual Litterfall Hg and wet Hg deposition rates differed significantly and were weakly correlated. Litterfall Hg dry deposition differed among forest-cover types. This study demonstrated how annual Litterfall Hg dry deposition rates approximate the lower bound of annual Hg dry fluxes. Published by Elsevier Ltd.

Mengistu T Teramage - One of the best experts on this subject based on the ideXlab platform.

  • impact of forest thinning on the dynamics of Litterfall derived 137cs deposits in coniferous forest floor after fukushima accident
    Chemosphere, 2020
    Co-Authors: Yuichi Onda, Mengistu T Teramage, Hiroaki Kato
    Abstract:

    Abstract The effects of a 50% forest thinning intensity on Fukushima-derived 137Cs deposition by Litterfall and its discharge by runoff in hillslope coniferous forest were monitored using four Litterfall traps and a hillslope erosion plot. The observation was underway during the pre-and post-thinning periods. Results demonstrated that during the pre-thinning period a total 150 ± 13 g m−2 of Litterfall deposited about 924 ± 69 Bq m−2 of 137Cs. This accounts for 11% of the local 137Cs fallout recorded for the study site in the aftermath of the accident. After thinning, both Litterfall and 137Cs increased by more than six- and two-fold, respectively. This is possibly owing to the slow individual tree recovery rate assisted by the change on the running space provided by canopy openings, which can accelerate even the normal gust wind to gain damaging power on the unshielded mechanically injured parts of the contaminated residual trees. In both cases, Litterfall generally transferred about 37% (3 ± 0.2 kBq m−2) of the local 137Cs fallout onto the forest floor over the observation period. The eroded litter-associated 137Cs increased by about a factor of two after thinning, which only accounted for less than 1% of 137Cs deposited by Litterfall. This implies that the forest floor retains 137Cs and remains contaminated regardless of the size of the eroded litter material. But this could become a potential secondary contamination source for the downstream resources such as water bodies and villages, especially at the time of flooding, which in turn calls a serious attention in designing decontamination schemes.

  • the role of Litterfall in transferring fukushima derived radiocesium to a coniferous forest floor
    Science of The Total Environment, 2014
    Co-Authors: Mengistu T Teramage, Hiroaki Kato, Yuichi Onda, Takashi Gomi
    Abstract:

    Abstract The deposition of Fukushima-derived radiocesium via falling litter in a coniferous forest 180 km downwind immediately following the nuclear power plant accident was investigated. The Litterfall contribution to the transfer of radiocesium from the forest canopy to the forest floor was determined, and this pathway was compared with hydrological pathways. The results demonstrated that during the observation period, a total of approximately 5.5 kBq m − 2 of Fukushima-derived radiocesium was deposited on the forest floor through throughfall (53%), stemflow (2.3%) and Litterfall (45%) routes. The data revealed that the contributions of hydrological pathways became less important as time passed. However, the Litterfall route, which transferred approximately 31% (2.5 ± 0.6 kBq m − 2 ) of the local fallout within the observation period, continued depositing radiocesium onto the forest floor.

Robert A Congdon - One of the best experts on this subject based on the ideXlab platform.

  • ecosystem dynamics at disturbed and undisturbed sites in north queensland wet tropical rain forest iii nutrient returns to the forest floor through Litterfall
    Journal of Tropical Ecology, 1998
    Co-Authors: John L Herbohn, Robert A Congdon
    Abstract:

    The nutrient contents and accessions in Litterfall over a period of 3 y are reported for undisturbed areas and at two sites disturbed by selective harvesting in tropical rain forest in North Queensland, Australia. Mean concentrations (mg g(-1) dry weight) of nutrients in Litterfall ranged from 10 to 12 for nitrogen; 0.33 to 0.43 for phosphorus; 3.6 to 4.3 for potassium; 6.0 to 10.5 for calcium and 1.7 to 2.6 for magnesium. These concentrations are in the middle to lower part of the spectrum of values recorded for tropical forest. Accessions of nutrients in Litterfall (kg ha(-1) y(-1)) ranged from 59 to 64 N; 1.9 to 2.4 P; 20 to 24K; 34 to 63 Ca; and 9 to 16 Mg. These rates, particularly for IN and P, are among the lowest recorded for tropical forests. There were no consistent between-site differences in total nutrient accessions in small Litterfall. In terms of the contribution of Litterfall to the accessions of nutrients to the forest floor, this suggests that the logged sites have recovered from the effects of selective harvesting within 25 y. Nutrient accessions at each site were distinctly seasonal, with maximum accessions occurring in the late dry season to late in the wet season. Leaf-fall accounted for the largest proportion of nutrient accessions over the study period, although at certain times accessions in both reproductive material and wood were significant. A cyclone which crossed the coast near the study sites resulted in large nutrient accessions over a short period but had little effect on the total annual accession. A comparison with previous studies of Litterfall in Australian tropical rainforests indicates that nutrient return in Litterfall is directly related to soil fertility.

  • ecosystem dynamics at disturbed and undisturbed sites in north queensland wet tropical rain forest ii Litterfall
    Journal of Tropical Ecology, 1993
    Co-Authors: John L Herbohn, Robert A Congdon
    Abstract:

    Rates of Litterfall over a period of 3 y at one undisturbed site and two sites disturbed by selective harvesting are reported for a tropical rain forest area in North Queensland, Australia. Litterfall over a period of 18 months is also reported for a further undisturbed site in the same area. No significant differences were found in annual Litterfall between the sites, with annual Litterfall rates ranging from 5.0 to 6.0 t ha-1 y-1. These rates are considerably lower than those reported for other rain forest areas in Australia, and are within the lower ranges recorded for other tropical rain forests. Litterfall was found to be strongly seasonal at all sites with the maximum falls occurring from the end of the dry season to the end of the wet season. The between year variability of the sites was quite low, with the ratio of maximum to minimum production ranging from 1.05 to 1.20. The average percentages of leaves, wood and reproductive material in Litterfall were similar at each site. Leaves were the dominant component of Litterfall with the average proportion of the total Litterfall ranging from 72% to 76% over the study period at each of the four sites. At certain times, however, the fall of wood and reproductive material was quite significant, comprising as much as 71% and 34% of Litterfall respectively. A strong negative correlation was found between the fall of leaves and wood at all sites.

Tom Lewis - One of the best experts on this subject based on the ideXlab platform.

  • Temporal variations in Litterfall biomass input and nutrient return under long-term prescribed burning in a wet sclerophyll forest, Queensland, Australia.
    The Science of the total environment, 2019
    Co-Authors: Bushra Muqaddas, Tom Lewis
    Abstract:

    Abstract Litterfall helps maintaining nutrient return in forest ecosystems. However, the influence of long-term prescribed burning on the dynamics of Litterfall biomass and carbon (C) and nitrogen (N) cycling is poorly understood. A 39-year old prescribed burning field trial in a wet sclerophyll forest, southeast Queensland, Australia, was used to investigate the interactive effects of prescribed fire regimes and temporal variation on the quantity and quality of Litterfall and C and N return. Treatments included no burning (NB) since 1969, 2 yearly burning (2yrB; burned 19 times) and 4 yearly burning (4yrB; burned 9 times) since 1972. Litterfall was collected monthly on 32 occasions between 2011 and 2013. Significant temporal variation was observed in monthly and annual Litterfall biomass. Both burning treatments had lower monthly inputs of total Litterfall and leaf litter, mean annual cumulative litter biomass, litter C concentrations and C return via leaf litter, compared with the NB treatment. Most significant reductions in litter N concentrations and N return via litter were associated with 2yrB treatment. The 4yrB and the NB treatments did not differ significantly in terms of twig biomass, Litterfall C:N ratios and N return via leaf litter. Despite both long-term prescribed burning treatments negatively impacting C return to the soil by reducing the quantity and quality of litter inputs, previous studies at the site suggest no difference in 0–10 cm soil organic carbon levels between the 4yrB treatment and the unburnt treatment. Hence a longer period of prescribed burning at the 4yrB frequency is likely required before lower C return translates to differences in ecosystem productivity in this wet sclerophyll forest ecosystem. The 2yrB can potentially alter forest C and N cycling and net primary productivity, but these alterations are unlikely to be detected through short-term studies.