Through litter decomposition enormous amounts of carbon is emitted to the atmosphere. Numerous large-scale decomposition experiments have been conducted focusing on this fundamental soil process in order to understand the controls on the terrestrial carbon transfer to the atmosphere. However, previous studies were mostly based on site-specific litter and methodologies, adding major uncertainty to syntheses, comparisons and meta-analyses across different experiments and sites. In the TeaComposition initiative, the potential litter decomposition is investigated by using standardized substrates (Rooibos and Green tea) for comparison of litter mass loss at 336 sites (ranging from -9 to +26 °C MAT and from 60 to 3113 mm MAP) across different ecosystems. In this study we tested the effect of climate (temperature and moisture), litter type and land-use on early stage decomposition (3 months) across nine biomes. We show that litter quality was the predominant controlling factor in early stage litter decomposition, which explained about 65% of the variability in litter decomposition at a global scale. The effect of climate, on the other hand, was not litter specific and explained <0.5% of the variation for Green tea and 5% for Rooibos tea, and was of significance only under unfavorable decomposition conditions (i.e. xeric versus mesic environments). When the data were aggregated at the biome scale, climate played a significant role on decomposition of both litter types (explaining 64% of the variation for Green tea and 72% for Rooibos tea). No significant effect of land-use on early stage litter decomposition was noted within the temperate biome. Our results indicate that multiple drivers are affecting early stage litter mass loss with litter quality being dominant. In order to be able to quantify the relative importance of the different drivers over time, long-term studies combined with experimental trials are needed.

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The impact of temporal variations in seed supply on rates of seed removal by rodents (Apodemus speciosus and Eothenomys andersoni) was examined to demonstrate that seed predation on Aesculus turbinata can depend on the seed abundance of other dominant tree species. The impact of seasonal variation in Fagus crenata seed fall was examined, in particular. Research was undertaken in two sites within the Kanumazawa Riparian Research Forest in Japan. Seed production of the three tree species (A. turbinata, F. crenata and Quercus mongolica) was recorded annually from 1992 to 1998 in the long-term monitoring plot. In each of the 3 years (1995-97), the fate of approximately 100 seeds of A. turbinata were monitored under each of the five mature trees in the short-term plot. The seed success of A. turbinata varied greatly among the 7 years of the study. Both A. turbinata seed survival and seedling emergence were particularly low during the F. crenata mast year and among the lowest in the 7-year observation period. No such trend was observed when Q. mongolica massively fruited. Only in 1996 were more seeds initially destroyed (60%) than cached. Seed predation was the predominantly source of seed mortality, accounting for between 93 and 100% of seed death. Although the fate of all seeds was not known, the proportion of seeds that germinated was low, ranging from only 1 to 3% with over 80% of seeds suffering predation in most years. In 1995, the rate of A. turbinata seed removal suddenly decreased in October despite an abundance of seeds. Rodents exhibited a strong, consistent preference to F, crenata seeds over A. turbinata and this preference increased as F. crenata seed became more abundant. results indicate that there was no clear relationship between rodent abundance and any of the seed fall measures, although their populations increased rapidly in the summer following F. crenata masting.

Abstract. Aesculus turbinata is a tree species with large seeds (6.2 g mean dry weight). We studied the demography of its seeds and seedlings in a temperate deciduous forest in northern Japan to elucidate the ecological significance of large seeds with special reference to herbivory and secondary dispersal. Both seed and seedling stages suffered greatly from herbivores. Seedling herbivory was important judged from experiments with shoot clipping and hypogeal cotyledon removal. However, some seedlings survived through re‐sprouting after herbivory. Survival rate and percentage resprouting seedlings were lower than those with remaining cotyledons, though seedling size was not affected. This suggests that stored resources in hypogeal cotyledons are working as a kind of ‘risk hedge’ against severe aboveground shoot clipping experienced by A. turbinata. The spatial distribution of seedlings was expanded via seed scatter‐hoarding by rodents. Seedling survival rate was higher within canopy gaps than under closed canopy, indicating that canopy gaps are safe sites for establishment, and was negatively correlated with seedling density. Therefore, secondary seed dispersal in this species seems to be effective in ‘finding’ safe sites and in ‘escaping’ density‐dependent mortality. The large seeds and seedlings of A. turbinata are attractive to herbivores, but the high resistance of seedlings to herbivory due to large reserves and the effective secondary dispersal appear to mitigate these disadvantages.

This data paper reports tree census data collected in a network of 34 forest sites in Japan. This is the largest forest data set freely available in Japan to date. The network is a part of the Monitoring Sites 1000 Project launched by the Ministry of the Environment, Japan. It covers subarctic to subtropical climate zones and the four major forest types in Japan. Forty-two permanent plots, usually 1 ha in size, were established in old-growth or secondary natural forests. Censuses of woody species ‡15 cm girth at breast height were conducted every year or once during 2004 to 2009. The data provide species abundance, survivorship and stem girth growth of 52,534 individuals of 334 tree and liana species. The censuses adopted common census protocol, which provide good opportunities for meta-analyses and comparative studies among forests. The data have been used for ecological studies as well as for the biodiversity reports published by the Ministry of the Environment.