Home-field Advantage Hypothesis Research Articles

No home‐field advantage in litter decomposition from the desert to temperate forest

Abstract Litter decomposition rates are determined by the interplay of climate, decomposer organisms and litter quality. It has been suggested that the decomposer community may be locally adapted to litter quality, providing a home‐field advantage (HFA) resulting in accelerated decomposition of local compared to non‐local litter, after accounting for decomposition differences due to litter quality and the functional capacity of microorganisms. Although widely tested in forests, this hypothesis remains controversial and lacks support of its generality across climates. We therefore tested the HFA hypothesis for litter decomposition in four contrasting ecosystems along an extensive climatic gradient in Chile, using a translocation experiment involving litter from 20 species. In addition to comparing mass loss, we adopted a novel way to disentangle decomposer effects from climate effects, based on loss rates of elements that are actively released from the litter by decomposers during its breakdown versus elements that are simply leached by precipitation. We used the ratios of nitrogen and potassium losses (N/K loss) and phosphorus and potassium losses (P/K loss) to unravel the relative role of microbial breakdown (N and P loss) versus physical leaching (K loss) along the climate gradient. Thus, at each site, we tested whether litter mass loss, N/K loss and P/K loss presented an additional loss due to a HFA for local compared to non‐local litter. Across a wide range of environments and litter types, our findings unequivocally contradicted the HFA hypothesis. We observed no significantly positive HFA along the gradient; however, litter quality and the general ability of the decomposer community influenced litter decomposition much more strongly than origin or location of the litter. Our study questions the applicability of the HFA for litter decomposition and calls for more studies that include a large range of climatic conditions to understand the context‐dependency of HFA. Read the free Plain Language Summary for this article on the Journal blog.

Comparison of leaf litter decomposition and microbial decomposer communities in fringe and riverine mangroves in French Guiana

Mangroves are highly productive and changing forests located in the intertidal zone of tropical regions. Leaf litter decomposition represents a substantial part of their carbon sink abilities. Little is known about the potential effect of climate change on this key process of ecosystem functioning. This study compared leaf litter microbial decay between fringe and riverine Avicennia germinans stands. A direct and reciprocal transplant experiment using litterbags was setup in French Guiana to test 3 hypotheses: (i) the activities and abundance of microbial decomposers are lowest in the fringe mangroves due to exposure to saline water and tidal immersion; (ii) for these reasons, litter decomposes faster in riverine stands; and (iii) according to the home-field advantage hypothesis, litter decomposes more rapidly in the environment from which it originates. Remaining litter masses, abundance of litter microbial community (phospholipid fatty acid signatures (PLFA)), and their functional capability (enzyme activities and Biolog) were assessed. Litter directly transplanted in riverine stands showed higher enzymatic activity (+ 77%), catabolic diversity (+ 10%), and microbial biomass (+ 60%) than litter transplanted directly in fringe stands. In contrast, both riverine and fringe derived litter showed faster decay at the fringe (14% mass loss) than riverine site (4% mass loss) between 30 and 45 days. Here, environmental conditions associated with different distances from the sea such as salinity and inundation regimes, rather than microbial features are suggested as main factors affecting decomposition process. Expected sea level rise in the coastal Guianas may therefore modify the mangroves productivity in the coming decades.

Absence of a home-field advantage within a short-rotation arable cropping system

AimsThe home-field advantage (HFA) hypothesis predicts faster decomposition of plant residues in home soil compared to soils with different plants (away), and has been demonstrated in forest and grassland ecosystems. It remains unclear if this legacy effect applies to crop residue decomposition in arable crop rotations. Such knowledge could improve our understanding of decomposition dynamics in arable soils and may allow optimisation of crop residue amendments in arable systems by cleverly combining crop-residue rotations with crop rotations to increase the amount of residue-derived C persisting in soil.MethodsWe tested the HFA hypothesis in a reciprocal transplant experiment with mesh bags containing wheat and oilseed rape residues in soils at three stages of a short-rotation cropping system. Subsets of mesh bags were retrieved monthly for six months to determine residue decomposition rates, concomitantly measuring soil available N, microbial community structure (phospholipid fatty acid analysis), and microbial activity (Tea Bag Index protocol) to assess how plants may influence litter decomposition rates via alterations to soil biochemical properties and microbial communities.ResultsThe residues decomposed at similar rates at all rotational stages. Thorough data investigation using several statistical approaches revealed no HFA within the crop rotation. Soil microbial community structures were similar at all rotational stages.ConclusionsWe attribute the absence of an HFA to the shortness of the rotation and soil disturbance involved in intensive agricultural practices. It is therefore unlikely that appreciable benefits could be obtained in short conventionally managed arable rotations by introducing a crop-residue rotation.

Litter breakdown of invasive alien plant species in a pond environment: Rapid decomposition of Solidago canadensis may alter resource dynamics

Alien plant invasions of riparian zones can trigger bottom-up effects on freshwater ecosystems through changes in leaf litter supply. Riparian zones of ponds are often invaded by alien species, and although these habitats are common, the effect of invasive alien species on ponds has rarely been studied. We performed a leaf litter experiment in a pond and compared within- and between-species variation in the breakdown rates of three native species (Alnus glutinosa, Phragmites australis and Typha angustifolia) and two aggressive alien invaders of riparian zones (Fallopia japonica and Solidago canadensis). The litter of S. canadensis decomposed faster than the litter of the other plants; more than 50 % of the S. canadensis biomass decomposed within a week. This contradicts the home-field advantage hypothesis, and we argue that the quality rather than the origin of litter might be the key factor driving breakdown rates. We also reported considerable intra-specific variation; old leaves (collected in spring after a partial aerial breakdown on stems) decomposed two to seven times slower than senescent leaves (collected in autumn just after abscission). The continuous seasonal supply of leaves of different quality into freshwaters may be disrupted by terrestrial invasions, especially if an invader forms monoculture stands and produces a highly palatable litter, as is the case with S. canadensis. This may fundamentally alter the resource dynamics in the pond environment through a rapid depletion of litter mass before the next litterfall.

Litter decomposition: Little evidence of the “home-field advantage” in a mountain forest in Italy

We tested the “home-field advantage” hypothesis, i.e., that leaves decay faster under the parent tree species in European beech, Douglas fir, and Turkey oak stands in a mountain forest in Italy. The fate of leaves in buried litterbags was monitored for one year to document their carbon (C) and nitrogen (N) dynamics, chemical structure, and associated microbial community.The three litter types lost C continuously at a similar rate, regardless of the species they were buried under. On the other hand, the N losses varied among litter types, and beech even gained a small but significant amount of N in the first 3–6 months. Differences between the litters were evident in the alkyl region of the nuclear magnetic resonance spectra and smaller in the aromatic and aryl acids regions. By the end of the experiment, all litters had lost substantial quantities of carbohydrates, lignin, proteins, and lipids, particularly oak litter. The richness and diversity of bacterial and fungal communities increased with time. Litter type had the greatest impact on microbial community composition in the first months of decomposition; afterwards, the stand type had a greater influence on the assemblage of decomposer microorganisms.Overall, this study provides little evidence in support of the home-field advantage hypothesis, which could be valid only for oak. Instead, our findings indicate that the chemical composition of litter is the main factor affecting the early stages of litter decomposition. Tree species and soil properties within the stand play an important role in the advanced stages of decomposition since these factors control the assemblage and functions of the soil microbial community.

Home-field advantage of CWD decomposition in subtropical forests varied by field sites

Previous studies have found that home-field advantage (HFA) appears to be widespread in the decomposition of litter, but few studies have examined HFA in the decomposition of coarse woody debris (CWD) in forest ecosystems. To test the HFA hypothesis for CWD decomposition, we quantified the respiration of CWD (RCWD) for different tree species over a two-year study period. We used a dynamic chamber method to monitor RCWD over time in two reciprocal translocation field experiments by placing CWD of the same decay stage from three tree species into two different forest types. The three species used were Cryptomeria japonica (CR), Platycarya strobilacea (PL) and Acer davidii (AC); the two forest types were broadleaf forest (home field for PL and AC; visiting field for CR) and coniferous forest (home field for CR; visiting field for PL and AC). We also characterized the microbial community of each CWD and the soil underneath as well as the control soil without CWD influence by the method of phospholipid fatty acids (PLFAs). We found that the RCWD of PL and AC in the HF were significantly higher than that in the VF, while the opposite was true for the RCWD of CR. Soil microbial community affected CWD microbial community, especially for the bacteria component, with field site explaining 17.4% of the total variation in CWD microbial community. Our results suggest that the difference in CWD decomposition between home and visiting field was directly explained by the difference in soil microbial community between home and visiting field, which may be attributed to the differences in soil nutrient and litter quality between the two field sites (forest types).

Establishment of mixed plantations of Pinus sylvestris var. mongolica and Populus × xiaozhuanica may not be appropriate: evidence from litter decomposition

Abstract Aims Mongolian pine (Pinus sylvestris var. mongolica) and Xiaozhuan poplar (Populus × xiaozhuanica) are two predominant afforestation tree species in the semi-arid sandy lands of northeast China, which are characterized by poor soil nutrients. Plant litter decomposition plays a critical role in regulating nutrient cycling in terrestrial ecosystems. Admixture of broadleaf litter to conifer litter is expected to improve litter decomposition and soil fertility, and thus productivity. However, the effects on the decomposition of litter mixture of the above two tree species are not well understood. Therefore, it is essential to assess the decomposition performance of litter mixture with the aim of improving forest nutrient management and the establishment of mixed plantation. Appropriate forest management practice is critical for the sustainability of site productivity in plantation forests. Methods We conducted a field litterbag decomposition transplant experiment for single pine litter, single poplar litter and their mixture in a pine stand, a poplar stand and an adjacent grassland for 16 months in the Keerqin Sandy Lands, northeast China. Important Findings After 16 months of incubation, there remained significantly more litter mass of pine (73.8%) than of poplar (67.2%). The mass remaining was positively correlated with litter carbon (C):nitrogen (N), C:phosphorus (P) and lignin:N ratios, and negatively with litter N and P concentrations, which suggests that initial litter chemical properties were an important factor affecting litter decay. Generally, net N and P immobilizations were observed during decomposition. This indicates that litter decomposition in this area was N-limited as N was progressively immobilized, and then tended to induce P limitation. Thus, we strongly recommend prohibiting litter harvesting by local residents to maintain soil fertility in this nutrient-poor area. Our results do not support the home-field advantage hypothesis, as illustrated by the fact that, in most cases, mass loss of litter from native habitat was comparable to that in transplanted habitats during decomposition. Furthermore, a dominant additive effect was detected, indicating that the establishment of mixed plantation may not be appropriate for these two species.

Home-Field Advantage in Wood Decomposition Is Mainly Mediated by Fungal Community Shifts at "Home" Versus "Away".

The home-field advantage (HFA) hypothesis has been used intensively to study leaf litter decomposition in various ecosystems. However, the HFA in woody substrates is still unexplored. Here, we reanalyzed and integrated existing datasets on various groups of microorganisms collected from natural deadwood of two temperate trees, Fagus sylvatica and Picea abies, from forests in which one or other of these species dominates but where both are present. Our aims were (i) to test the HFA hypothesis on wood decomposition rates of these two temperate tree species, and (ii) to investigate if HFA hypothesis can be explained by diversity and community composition of bacteria and in detail N-fixing bacteria (as determined by molecular 16S rRNA and nifH gene amplification) and fungi (as determined by molecular ITS rRNA amplification and sporocarp surveys). Our results showed that wood decomposition rates were accelerated at "home" versus "away" by 38.19% ± 20.04% (mean ± SE). We detected strong changes in fungal richness (increase 36-50%) and community composition (RANOSIM = 0.52-0.60, P < 0.05) according to HFA hypothesis. The changes of fungi were much stronger than for total bacteria and nitrogen fixing for both at richness and community composition levels. In conclusion, our results support the HFA hypothesis in deadwood: decomposition rate is accelerated at home due to specialization of fungal communities produced by the plant community above them. Furthermore, the higher richness of fungal sporocarps and nitrogen-fixing bacteria (nifH) may stimulate or at least stabilize wood decomposition rates at "home" versus "away."

Efficiency dynamics of the Croatian banking industry: DEA investigation

The paper deals with the efficiency dynamics of the Croatian banking industry, covering the period from 2006 to 2015. We have implemented the intermediation approach, using interest and non-interest expenses and revenues as the input and output variables, respectively. The variable return to scale (BCC) Data Envelopment Analysis (DEA) output-oriented model has been implemented, and we have estimated the crisis-driven efficiency trends, as well as the impact of the EU membership. We further estimated the efficiency effects of the relative market power/size, ownership structure, and origin of capital. The global crisis had detrimental effects since the overall efficiency score dropped by about 3%. On the contrary, Croatian banks have largely benefited from the EU membership, and the efficiency score after the EU association increased by about 45%. The market leaders are more efficient than the competitive fringe, which is in line with the efficiency structure hypothesis. In addition, the biggest banks are the most efficient ones, meaning that the scale efficiency hypothesis has also been upheld. Contrary to the agency theory hypothesis, state-owned banks are permanently more efficient than private banks. Finally, the results support the home-field advantage hypothesis exclusively for the pre-crisis period (2006–2009).

Direct and legacy effects of plant-traits control litter decomposition in a deciduous oak forest in Mexico.

BackgroundLitter decomposition is a key process in the functioning of forest ecosystems, because it strongly controls nutrient recycling and soil fertility maintenance. The interaction between the litter chemical composition and the metabolism of the soil microbial community has been described as the main factor of the decomposition process based on three hypotheses: substrate-matrix interaction (SMI), functional breadth (FB) and home-field advantage (HFA). The objective of the present study was to evaluate the effect of leaf litter quality (as a direct plant effect, SMI hypothesis), the metabolic capacity of the microbial community (as a legacy effect, FB hypothesis), and the coupling between the litter quality and microbial activity (HFA hypothesis) on the litter decomposition of two contiguous deciduous oak species at a local scale.MethodsTo accomplish this objective, we performed a litterbag experiment in the field for 270 days to evaluate mass loss, leaf litter quality and microbial activity in a complete factorial design for litter quality and species site.ResultsThe litter of Quercus deserticola had higher rate of decomposition independently of the site, while the site of Quercus castanea promoted a higher rate of decomposition independently of the litter quality, explained by the specialization of the soil microbial community in the use of recalcitrant organic compounds. The Home-Field Advantage Index was reduced with the decomposition date (22% and 4% for 30 and 270 days, respectively).DiscussionWe observed that the importance of the coupling of litter quality and microbial activity depends on decomposition stage. At the early decomposition stage, the home-advantage hypothesis explained the mass loss of litter; however, in the advanced decomposition stage, the litter quality and the metabolic capacity of the microbial community can be the key drivers.

Fungal communities influence decomposition rates of plant litter from two dominant tree species

The home-field advantage hypothesis (HFA) predicts that plant litter decomposes faster than expected underneath the plant from which it originates. We tested this hypothesis in a decomposition experiment where litters were incubated reciprocally in neighbouring European beech and Norway spruce forests. We analysed fungal communities in the litter through DNA metabarcoding and evaluated the effect of mesofauna (mites and springtails) on litter mass loss by using different litter-bag mesh sizes. Accounting for general differences in decomposition between litter and forest types, we found a significant home field advantage of 24%. Litter decomposed faster in the beech forest but spruce litter decomposed faster than beech litter. Fungal communities showed a clear dependency on both forest and litter type. Mesofauna did not affect litter mass loss rates or microbial species composition.

Leaf litter decomposition in urban forests: test of the home-field advantage hypothesis

The home-field advantage (HFA) hypothesis states that leaf litter decomposes faster in the habitat from which it was derived (i.e., home) than beneath a different plant species (i.e., away from home). We conducted reciprocal translocation experiments to explore the HFA effect of urban leaf litter decomposition. HFA of litter decomposition varied with species and season, and interacted with nutrient and environmental dynamics. Although forest litterfall and subsequent decay are acknowledged as a critical factor regulating nutrient cycling, soil fertility, and ecosystem carbon budgets in natural ecosystems, they remain less understood in urban ecosystems and the evidence for HFA has not been universal. We select Beijing Olympic Forest Park (BOFP), the largest urban forest park of Asia, as a case study to explore HFA of leaf litter decomposition in urban forest ecosystems. We investigated the litterfall production, mass loss, and nutrient dynamics of two species (Robinia pseudoacacia and Pinus armandii) commonly planted in Beijing urban forest ecosystems. Variations in litterfall production were measured in R. pseudoacacia stand and P. armandii stands over 12 months. HFA of litter decomposition was explored by reciprocal leaf litter translocation experiments, and leaves were analyzed for C, N, and P during decomposition of 297 days. Two major peaks of total litterfall in R. pseudoacacia were observed, while litterfall in P. armandii followed a unimodal distribution pattern, which were similar to seasonal patterns of broadleaf and coniferous litter production in natural forest ecosystems. The loss of initial ash-free mass of R. pseudoacacia (19 %) was about twofold of P. armandii (11 %). The litter quality (e.g., initial C, N, and P) might have contributed to the differences between broadleaf and coniferous species. Leaf litter decomposition of R. pseudoacacia showed seasonal switch of HFA. In contrast, P. armandii showed a constant HFA during the whole study period. HFA of litter decomposition in urban forests varied by species and season. We found the seasonal switch of the HFA effect for R. pseudoacacia, which has not been observed in nonurban ecosystems. More observations or experiments with multiple species or mixed species across various cities are needed to understand the processes and mechanisms of litter decomposition and nutrient dynamics in the urban ecosystems.

Determinants of efficiency in the malaysian banking sector: Does bank origins matter?

The paper follows Simar and Wilson's (2007) two-stage procedure to analyze the efficiency of the Malaysian banking sector. In the first stage, we employ the bootstrap Data Envelopment Analysis (DEA) method to compute the efficiency of individual banks during the period 1999–2008. We then use bootstrap regression to examine the impact of origins on bank efficiency, while controlling for the potential influence of contextual variables. The DEA results indicate that the Malaysian banking sector has exhibited increase in efficiency over the sample period. We find that banks from the Asian countries to be relatively more efficient compared to foreign banks from other regions and their domestic bank peers. In essence, the empirical evidence rejects the home field advantage hypothesis, but lends support to the “limited form” of the global advantage and the liability of unfamiliarness hypotheses.

Decomposition of Eucalyptus grandis and Acacia mangium leaves and fine roots in tropical conditions did not meet the Home Field Advantage hypothesis

Unlike Eucalyptus monocultures, nitrogen fixing trees are likely to improve the soil nutrient status through the decomposition of N-enriched litter. The Home Field Advantage (HFA) hypothesis states that plants can create conditions that increase the decomposition rates of their own litter. However, there may not be any HFA when most of the decomposers are generalists. A reciprocal transplant decomposition experiment of fine roots and leaves of Acacia mangium and Eucalyptus grandis was undertaken in monocultures of these two species to test the HFA hypothesis using a complete randomized design with three blocks. Three litterbags containing leaf or fine root residues of each species were collected every 3months from each plot over 12months for fine roots and 24months for leaves. The litter mass and C, N and P concentrations were measured at each sampling date. The concentrations of C-compounds were measured 0, 12 and 24months from the start of the experiment. There was no evidence of HFA for either the leaves or the fine roots of either species. The decomposition rates were slower for Acacia litter than for Eucalyptus litter even though initial N concentrations were 1.9–2.9 times higher and P concentrations were 1.5–3.3 times higher in the Acacia residues. N:P ratios were greater than 20–30 for the residues of both species, with the highest values for Acacia. Litter decomposition depended partly on the C quality of the litter, primarily in terms of water soluble compounds and lignin content. As shown recently in tropical rainforests, these results suggest that the activity of decomposers is limited by energy starvation in tropical planted forests. Decomposer activity may also have been limited by P availability which may not have been directly related to the P concentrations or C:P ratios in the residues.

A traits-based test of the home-field advantage in mixed-species tree litter decomposition

Litter often decomposes faster in its environment of origin (at 'home') than in a foreign environment ('away'), which has become known as the home-field advantage (HFA). However, many studies have highlighted the conditional nature of the HFA, suggesting that current understanding of this phenomenon is not yet sufficient to generalize across systems. The HFA hypothesis was tested for mono-specific and mixed-species litter using a tree-based experiment that manipulated the functional identity and diversity of the host tree community. Litter types of varying quality were transplanted between several host tree communities and decomposition rates were measured using litterbags. Since the decomposer community should respond to traits of the litter input and not their taxonomic identity, a traits-based index of litter-tree similarity was developed. Mono-specific litter exhibited HFA, but when the same litter was decomposed in mixture, this trend was not observed. Mixed-species litter decomposed on average no faster or slower than monoculture litter and exhibited both positive and negative species interactions. These non-additive interactions of decomposition rates in mixture were influenced by the degree of similarity between litter and tree traits. Both synergistic and antagonistic interactions decreased in magnitude with increasing litter-tree similarity such that mixture rates were predictable from monocultures. The HFA occurred more strongly for mono-specific litter than for the litter types mixed together because interactions between species may have masked this effect. However, when expressed as a function of trait similarity between litters and tree communities, the HFA was not detected.

Bank reforms, foreign ownership, and financial stability

Numerous studies have focused on foreign ownership of banks, but instead of linkages to financial stability, they typically analyzed other issues and used country-level data. This article fills the gap in the literature by applying the GMM techniques on dynamic panels using bank-level data for Asian countries to investigate the impact of foreign ownership on financial stability, as well as whether the relation between foreign ownership and stability changes under different conditions of bank reforms in the host country. Specifically, we reach five conclusions. First, the existence of the home field advantage hypothesis is supported; nevertheless, when considering the effects of bank reforms, the global advantage hypothesis holds. Second, an inverse U-shaped relation between foreign ownership and stability is supported. Third, a higher degree of credit control liberalization mitigates the negative effect of foreign ownership on stability. Fourth, liberalization of interest rate control and banking supervision do enhance stability. Fifth and finally, we confirm a significantly negative relation between an explicit deposit and stability.

Tree Species Effect on Litter Decomposition and Nutrient Release in Mediterranean Oak Forests Changes Over Time

Tree species can affect the decomposition process through the quality of their leaf fall and through the species-specific conditions that they generate in their environment. We compared the relative importance of these effects in a 2-year experiment. Litterbags containing leaf litter of the winter-deciduous Quercus canariensis, the evergreen Q. suber and mixed litter were incubated beneath distinct plant covers. We measured litter carbon loss, 9 macro- and micronutrients and 18 soil chemical, physical and biological parameters of the incubation environment. Tree species affected decay dynamics through their litter quality and, to a lesser extent, through the induced environmental conditions. The deciduous litter showed a faster initial decomposition but left a larger fraction of slow decomposable biomass compared with the perennial litter; in contrast the deciduous environment impeded early decomposition while promoting further carbon loss in the latter decay stages. The interaction of these effects led to a negative litter–environment interaction contradicting the home-field advantage hypothesis. Leaf litter N, Ca and Mn as well as soil N, P and soil moisture were the best predictors for decomposition rates. Litter N and Ca exerted counteractive effects in early versus late decay stages; Mn was the best predictor for the decomposition limit value, that is, the fraction of slowly decomposable biomass at the later stage of decomposition; P and soil moisture showed a constant and positive relation with carbon loss. The deciduous oak litter had a higher initial nutrient content and released its nutrients faster and in a higher proportion than the perennial oak litter, significantly increasing soil fertility beneath its canopy. Our findings provide further insights into the factors that control the early and late stages of the decomposition process and reveal potential mechanisms underlying tree species influence on litter decay rate, carbon accumulation and nutrient cycling.

Multiple mechanisms for trait effects on litter decomposition: moving beyond home‐field advantage with a new hypothesis

Summary1. Evidence is growing that leaf litter generally decomposes faster than expected in its environment of origin, owing to specialization of litter and topsoil decomposer communities to break down litter encountered most often. Nevertheless, this home‐field advantage (HFA) in decomposition is inconsistently supported by experimental data and fails to account for situations where contrasting qualities of litter coexist within the same litter matrix.2. In contrast to the HFA hypothesis, which expects a positive interaction between every litter species produced locally and the local decomposer communities irrespective of litter species quality, we define here an alternative substrate quality–matrix quality interaction (SMI) hypothesis that expects a continuum from positive to negative interaction between specific litters (substrates) and decomposer communities as specific litters and the ecosystem litter layer (i.e. the matrix, which drives local decomposer community composition) become increasingly dissimilar in quality.3. To test this hypothesis, we conducted a reciprocal transplant decomposition experiment of eight leaf, six fine‐stem and nine fine‐root litter species from three neighbouring ecosystems of the subarctic biome: dry forest, riparian forest and forest‐surrounded pond; and characterized the quality (represented by lignin content and an integrated measure of carbon/nutrient economics) of each litter species and each ecosystem litter layer.4. We found substantial overall effects of SMI on decomposition rates of leaf (20% explained variance), stem (14%) and root (15%) litters, although this effect was lower than the single effects of litter quality and microclimate (remaining explained variance). Despite being partly inconsistent across litter species, likely due to the complexity of litter quality–decomposer community relationships, the SMI hypothesis appeared more broadly applicable than the HFA hypothesis.5.Synthesis. We demonstrate here that plant traits, likely via their control on litter and topsoil decomposer community composition, have indirect effects on litter breakdown rates, not only at the interface between ecosystems but alsowithinecosystems, with likely implications for many other ecosystems world‐wide. These results suggest functional variation in decomposer communities between ecosystems with respect to theirefficiencyto degrade litters with contrasting qualities, such as different lignolytic and detoxification activities but also contrasting efficiencies to degrade non‐recalcitrant tissues.

Long-term presence of tree species but not chemical diversity affect litter mixture effects on decomposition in a neotropical rainforest

Plant litter diversity effects on decomposition rates are frequently reported, but with a strong bias towards temperate ecosystems. Altered decomposition and nutrient recycling with changing litter diversity may be particularly important in tree species-rich tropical rainforests on nutrient-poor soils. Using 28 different mixtures of leaf litter from 16 Amazonian rainforest tree species, we tested the hypothesis that litter mixture effects on decomposition increase with increasing functional litter diversity. Litter mixtures and all single litter species were exposed in the field for 9 months using custom-made microcosms with soil fauna access. In order to test the hypothesis that the long-term presence of tree species contributing to the litter mixtures increases mixture effects on decomposition, microcosms were installed in a plantation at sites including the respective tree species composition and in a nearby natural forest where these tree species are absent. We found that mixture decomposition deviated from predictions based on single species, with predominantly synergistic effects. Functional litter diversity, defined as either richness, evenness, or divergence based on a wide range of chemical traits, did not explain the observed litter mixture effects. However, synergistic effects in litter mixtures increased with the long-term presence of tree species contributing to these mixtures as the home field advantage hypothesis assumes. Our data suggest that complementarity effects on mixed litter decomposition may emerge through long-term interactions between aboveground and belowground biota.