Home-field Advantage Effect Research Articles

Variability in the home-field advantage of litter decomposition mediates alterations in soil CO2 and CH4 fluxes: A transplantation experiment study

The decomposition of litter is susceptible to the influence of climate change and soil conditions, which can subsequently impact the release of carbon dioxide (CO2) from forest soils and the absorption of methane (CH4). Ecological theory proposes the existence of a home-field advantage (HFA) in litter decomposition, suggesting that the decomposition rate of litter (such as fallen leaves, twigs, and roots) may be faster in their native habitat than in foreign environments. Therefore, we selected litter from Pinus tabuliformis (PT) and Quercus acutissima Carruth (QC) in the field and conducted a 439-day litter transplant experiment to test the magnitude and direction of the HFA of these two litter types in three forest stands. During this experiment, we monitored the changes in soil CO2 and CH4 fluxes associated with the decomposition of PT and QC leaf litter in their native and foreign sites. Furthermore, we measured various soil physical, chemical, and biological indicators. The results indicated that the decomposition rate of QC leaf litter was faster in its native habitat, demonstrating a clear HFA effect. Conversely, the decomposition of PT leaf litter was observed to be more rapid in away soil, suggesting a pronounced home-field disadvantage (HFD). The study found that PT leaf litter exhibited greater CO2 release when decomposing in away soil, demonstrating 43 % and 32 % increases compared to bare soil, respectively. Conversely, QC leaf litter was observed to release more CO2 in its home soil. Additionally, the bare soils of the PT and QC home sites were found to absorb more CH4 compared to leaf litter coverage, with increases of 37.8 % and 31.2 %, respectively. The partial least squares model indicated that the litter attributes had a significant direct effect on soil temperature and enzyme activity. Soil temperature and enzyme activity further directly influenced the soil CO2 and CH4 fluxes. The results of our study indicate that the HFA of litter is dependent on litter type, and that litter transplantation can impact soil greenhouse gas exchange. This research provides a theoretical foundation for forest management and conservation strategies, as well as valuable data for global carbon neutrality efforts.

Soil microbial identity explains home-field advantage for litter decomposition.

Unraveling the mechanisms of home-field advantage (HFA) is essential to gain a complete understanding of litter decomposition processes. However, knowledge of the relationships between HFA effects and microbial communities is lacking. To examine HFA effects on litter decomposition, we identified the microbial communities and conducted a reciprocal transplant experiment, including all possible combinations of soil and litter, between sites at two elevations in cool-temperate forests. Soil origin, rather than HFA, was an important factor in controlling litter decomposition processes. Microbiome-wide association analyses identified litter fungi and bacteria specific to the source soil, which completely differed at a low taxonomic level between litter types. The relative abundance of these microbes specific to source soil was positively correlated with litter mass loss. The results indicated that the unique relationships between plant litter and soil microbes through plant-soil linkages drive litter decomposition processes. In the short term, soil disturbances resulting from land-use changes have the potential to disrupt the effect of soil origin and hinder the advancement of litter decomposition. These findings contribute to an understanding of HFA mechanisms and the impacts of land-use change on decomposition processes in forest ecosystems.

How does position affect the decomposition of fine woody debris in subtropical forest?

Fine woody debris (FWD: 1 cm ≤ diameter ≤ 10 cm) may be intercepted by understory vegetation (including the branches of canopy trees). However, the decay dynamics of aerial FWD are often overlooked. In this study, we collected wood from four different tree species (Platycarya strobilacea, Lithocarpus glaber, Pinus massoniana, and Cryptomeria japonica) from four forests in subtropical China, and the mesh bag method was used to measure the remaining mass and microbial respiration by reciprocally transplanting mesh bags filled with different species among the four forests. The main objectives of this study were to reveal the influence of position (the ground and the air) on the decay rates of FWD and the home-field advantage (HFA) effect during a two-year experimental period. Irrespective of the experimental periods and decay fields, the mass loss of FWD was significantly higher on the ground (58.05%) than in the air (45.74%), and the microbial respiration of wood was significantly higher on the ground (18.87 μg CO2 h−1 g−1) than in the air (7.79 μg CO2 h−1 g−1). Microbial respiration was negatively correlated with wood remaining mass on the ground during the entire decay period and in the air only during the late decay period. The HFA effect was observed only on the ground (5.03–23.86%). Our study highlights that soil contact predominantly regulated the decomposition patterns and the HFA effect of fine woody debris and suggests that we should not neglect the decay of fine woody debris in the air due to the interception of understory vegetation in subtropical Chinese forests.

High functional breadth of microbial communities decreases home-field advantage of litter decomposition

Home-field advantage (HFA) predicts that litter decomposes faster under its derived plant species. Growing evidence suggests that HFA depends on litter chemical traits and the microbiome's composition, but whether and how their interactions influence HFA effects has rarely been explored. Here, we conducted a reciprocal field transplantation experiment in a temperate forest to examine the effects of litter quality and microbial community composition on decomposition rates. We collected leaf litter from four dominant tree species (Pinus koraiensis, Tilla amurensis, Fraxinus mandshurica, and Acer mono) and utilized two mesh sizes (i.e., 0.5-μm and 35-μm) to manipulate the composition of decomposer communities (i.e., small-sized bacteria only or bacteria + fungi). We assessed the effects of HFA and the ability of decomposers to decay a wide range of litter, i.e., the functional breadth (FB). We found that HFA was stronger for recalcitrant litter in the fine-mesh litterbags. Low litter phosphorus (P) and nitrogen (N) content, explained the positive HFA effects when only small-sized bacteria were present during litter decomposition, but not when both bacteria and fungi were present. Soil parameters such as potassium content and dissolved organic carbon also significantly affected decomposer communities and contributed to the variability in HFA effects. Finally, the FB negatively correlated with HFA in coarse- and fine-mesh litterbags and accounted for 46 and 54% of the observed variation in HFA effects, respectively. Our results highlight that the interactive relationships between litter quality, soil properties, and the microbiome's composition, are central in understanding the functional abilities of microbes during litter decomposition, and suggest a tradeoff between the microbiome's capacity to degrade all litter efficiently and the specialization of decomposers toward their own litter. This further underscores the independent role of decomposers communities in litter decomposition rates, which should be considered when predicting biogeochemical cycling in forest ecosystems.

Agricultural impacts on lowland tropical streams detected through leaf litter decomposition

Stream ecosystems are highly vulnerable to changes in land use and vegetation in their catchments for two reasons: firstly, they receive inputs of nutrients, contaminants and sediments through runoff; and secondly, terrestrial leaf litter is the major basal resource supporting their food webs. Leaf litter decomposition by microorganisms and detritivores is thus a key stream ecosystem process, and a valuable functional indicator of impacts associated to agriculture and other alterations of human origin. Here, we investigated the joint effects of land use changes associated to agriculture (low, medium and high intervention areas: LI, MI and HI, respectively) in a tropical lowland catchment in Panama, through a decomposition experiment using three leaf litter types differing in nativeness (Ficus insipida, native to the study area; Alnus acuminata, native to Panama but not present in the study area; and Musa balbisiana, exotic to Panama). Lowland tropical areas are often poor in litter-consuming detritivores, and we accordingly observed a high contribution of microorganisms to total decomposition (>60% on average). However, only in the presence of detritivores, decomposition of Alnus discriminated among different degrees of agricultural intervention, being higher at the LI area. Leaf litter of the native Ficus showed higher microbial decomposition than the other types, possibly in relation to a home-field advantage effect. Despite the scarcity of detritivores in tropical lowland streams compared to tropical highland or temperate streams, our study indicates that their activity reflects impacts of land use change on these streams and they should therefore be included in assessments of anthropogenic impacts.

Home-field advantage effects in litter decomposition is largely linked to litter quality

Climate change and associated environmental alterations affect plant communities, potentially decoupling links between plants and their associated soil microbial communities. This may in turn affect processes like litter decomposition, an important function that controls nutrient and carbon cycling as well as many other ecosystem processes. Microbial decomposers have been proposed to specialize, being able to easier decompose litter from its ‘home’ community than litter from other communities, in what is termed the home field advantage (HFA) hypothesis. We report a litter decomposition experiment including four alpine meadow communities spread along a geographical gradient that ranged from the Atlas in Morocco to the Iberian Peninsula to the Swiss Alps. We tested whether litter decomposition rate would differ depending on litter and soil origin, expecting interactions between litter and soil microbial communities to be at the core of responses. We expected to find HFA in all four alpine communities. HFA ranged from very negative to neutral to positive along our geographical gradient, in a variation that could be attributed to the interaction of microbial communities with soil and plant traits, and linked to the relative abundance of microbial groups performing specific functions. Litter decomposition depended on litter quality and on the fungal community, which seemed adapted to deal with poor-quality, recalcitrant litter, leading to HFA. Climate plays a role as well, indirectly through plant community composition. Phyllosphere communities competed with soil communities when in interaction, a fact that may have blurred results of some previous HFA experiments. In summary, there is a clear HFA in systems with low-quality litter that requires a specialised fungal community to maximize decomposition. By contrast, high-quality, easy to decompose litter would be dealt with by any decomposer community, not showing evidence of HFA.

Soil nutrient dissimilarity and litter nutrient limitation as major drivers of home field advantage in riparian tropical forests

AbstractDecomposition is a key process driving carbon and nutrient cycling in ecosystems worldwide. The home field advantage effect (HFA) has been found to accelerate decomposition rates when litter originates from “home” when compared to other (“away”) sites. It is still poorly known how HFA plays out in tropical, riparian forests, particularly in forests under restoration. We carried out three independent reciprocal litter transplant experiments to test how litter quality, soil nutrient concentrations, and successional stage (age) influenced HFA in tropical riparian forests. These experimental areas formed a wide gradient of soil and litter nutrients, which we used to evaluate the more general hypothesis that HFA varies with dissimilarity in soil nutrients and litter quality. We found that HFA increased with soil nutrient dissimilarity, suggesting that litter translocation uncouples relationships between decomposers and litter characteristics; and with litter N:P, indicating P limitation in this system. We also found negative HFA effects at a site under restoration that presented low decomposer ability, suggesting that forest restoration does not necessarily recover decomposer communities and nutrient cycling. Within each of the independent experiments, the occurrence of HFA effects was limited and their magnitude was not related to forest age, nor soil and litter quality. Our results imply that HFA effects in tropical ecosystems are influenced by litter nutrient limitation and soil nutrient dissimilarity between home and away sites, but to further disentangle major HFA drivers in tropical areas, a gradient of dissimilarity between litter and soil properties must be implemented in future experimental designs.Abstract in Portuguese is available with online material.

Habitat Significantly Affect CWD Decomposition but No Home-Field Advantage of the Decomposition Found in a Subtropical Forest, China

The home-field advantage (HFA) effect has been reported to occur in coarse woody debris (CWD) and litter. It is thought that the HFA effect may be due to the specialization of decomposers in their original habitats. However, the relative contribution of microorganisms, particularly fungi and bacteria, to deadwood decomposition is unclear because of differences in their functional at-tributes and carbon requirements, and the microorganisms that drive the HFA effect of deadwood are also unclear. Here, we analysed a dataset of microbial PLFA and substrate properties collected from the soil and CWD of two subtropical trees, Cryptomeria japonica and Platycarya strobilacea, from forests dominated by one or the other of the two species, with both species present in the forests. Our results showed that habitat and tree types all significantly affected CWD respiration rates, the CWD respiration rates were significantly higher in the deciduous broadleaf forests (DBF) than in the coniferous forest (CF) regardless of tree types, but no a large HFA of CWD decomposition found (HFA index was 4.75). Most biomarkers indicated bacteria and fungi were more abundant in the DBF than in the CF, and the concentration of microbial PLFAs was higher in Platycarya strobilacea than in Cryptomeria japonica. In addition, the relative abundance of fungi and soil B/F were remarkably positively correlated with CWD respiration, indicating that fungi may be the primary decomposers of CWD. In conclusion, our work highlights the importance of interactions between the three primary drivers (environment, substrate quality and microbes) on CWD decomposition.

Effect of N deposition on the home-field advantage of wood decomposition in a subtropical forest

Nitrogen (N) can influence the functions of forest ecosystems by altering the abundance and activity of microbial and faunal communities. The impact of N deposition on the home-field advantage (HFA) effect of dead wood decomposition remains unclear. In this study, a 24-month field reciprocal wood translocation experiment was conducted with three levels of N deposition (control (N0), 60 (N1) and 120 (N2) kg N ha−1 yr−1) in both Platycarya strobilacea (PL) forest and Cryptomeria japonica (CR) forest in subtropical China, where anthropogenic N deposition is among the highest in the world. The influence of soil biota groups on the HFA effect was partitioned using different sizes of mesh bags. We found that N1 facilitated wood decomposition by enhancing wood faunal and microbial community abundance and soil extracellular enzyme activity. However, N2 promoted wood decomposition in coarse-mesh bags by attracting more fauna and in fine-mesh bags by increasing fungal growth. In the control (CK) treatments, we found a 4.55-fold greater HFA effect in fine-mesh bags than in coarse-mesh bags. On average, a 6.6- and 4.8-fold greater HFA effect was observed with N1 treatment than with N2 and control treatments, respectively, and these differences were associated with greater differences in microbial and faunal communities between home and away fields. In summary, our results indicated that low levels of anthropogenic N enrichment could increase the HFA effect on wood decomposition through the modification of microbial and faunal communities in the wood decomposition process and thereby influence C sequestration, with peak carbon emissions and carbon neutrality reached in the next few decades in the forests of subtropical regions.

Evaluating the roles of microbial functional breadth and home‐field advantage in leaf litter decomposition

AbstractSoil biota are increasingly recognized as a primary control on litter decomposition at both local and regional scales, but the precise mechanisms by which biota influence litter decomposition have yet to be identified.There are multiple hypothesized mechanisms by which biotic communities may influence litter decomposition—for example, decomposer communities may be specially adapted to local litter inputs and therefore decompose litter from their home ecosystem at elevated rates. This mechanism is known as the home‐field advantage (HFA) hypothesis. Alternatively, litter decomposition rates may simply depend upon the range of metabolic functions present within a decomposer community. This mechanism is known as the functional breadth (FB) hypothesis. However, the relative importance of HFA and FB in litter decomposition is unknown, as are the microbial community drivers of HFA and FB. Potential relationships/trade‐offs between microbial HFA and FB are also unknown.To investigate the roles of HFA and FB in litter decomposition, we collected litter and soil from six different ecosystems across the continental US and conducted a full factorial litter × soil inoculum experiment. We measured litter decomposition (i.e. cumulative CO2‐C respired) over 150 days and used an analytical model to calculate the HFA and FB of each microbial decomposer community.Our results indicated clear functional differences among decomposer communities, that is, litter sources were decomposed differently by different decomposer communities. These differences were primarily due to differences in FB between different communities, while HFA effects were less evident.We observed a positive relationship between HFA and the disturbance‐sensitive bacterial phylum Verruomicrobia, suggesting that HFA may be an important mechanism in undisturbed environments. We also observed a negative relationship between bacterial r versus K strategists and FB, suggesting an important link between microbial life‐history strategies and litter decomposition functions.Microbial FB and HFA exhibited a strong unimodal relationship, where high HFA was observed at intermediate FB values, while low HFA was associated with both low and high FB. This suggests that adaptation of decomposers to local plant inputs (i.e. high HFA) constrains FB, which requires broad rather than specialized functionality. Furthermore, this relationship suggests that HFA effects will not be apparent when communities exhibit high FB and therefore decompose all litters well and also when FB is low and communities decompose all litters poorly. Overall, our study provides new insights into the mechanisms by which microbial communities influence the decomposition of leaf litter.Read the freePlain Language Summaryfor this article on the Journal blog.

Litter Decomposition in Wet Rubber and Fruit Agroforests: Below the Threshold for Tropical Peat Formation

Peatlands are shaped by slow litter decomposition, but threshold decomposition rates that allow peat formation remain unclear. Can agroforestry in the tropics be compatible with paludiculture that allows peat formation? We explored the determinants of litter decomposition in wet agroforests adjacent to tropical peatlands in Central Kalimantan (Indonesia) by litterbag studies (up to 16 weeks) with standing litter sources to estimate rate constants, characterize litter quality (especially lignin (L), polyphenolics (Pp) and nitrogen (N)), and monitor temperature and groundwater levels. In litter transfer experiments we tested for home-field advantage (HFA) effects between land cover types. Mean residence times around 85 weeks at 27 °C were associated with a high (L + Pp)/N ratio. However, in the crossover treatments, mean residence times varied from 30 to 180 weeks and strong HFA effects (up to 80% faster decomposition at “home”) were found when litter from other sources was tested in old fruit-based agroforests. HFA indicates a local decomposer community well-adapted to its normal litter diet. Litter residence times of around two years are below the apparent peat formation threshold. Maintaining wet agroforest conditions adjacent to peat domes supports peatland rewetting and restoration but does not contribute to on-site peat formation processes.

Leaf litter phosphorus regulates the soil meso- and micro-faunal contribution to home-field advantage effects on litter decomposition along elevation gradients

Home‐field advantage (HFA) in litter decomposition implies that litter decomposes faster in its ‘home’ habitat, i.e., where the litter originates, than in any other distant (i.e., ‘away’) environment. Soil fauna plays a key role in litter decomposition, while its contribution to HFA may vary greatly. To elucidate how soil fauna interacts with litter quality to influence the occurrence and variability in HFA, leaf litter reciprocal transplant experiments were conducted in the Wuyi Mountains at five different elevations. Naphthalene was used to inhibit soil faunal communities. We found that the magnitude and direction of HFA, and meso- and micro-faunal contributions to HFA varied inconsistently at different elevations. The non-linear direct effects of climate and the variation of soil faunal diversity seemingly led to variations in meso- and micro-faunal contributions to HFA at different elevations. Although HFA was independent of litter quality, meso- and micro-faunal contributions to HFA were significantly related to litter phosphorus. Larger meso- and micro-faunal contributions to decomposition in low leaf litter phosphorus and phosphorus limited habitats may result mainly from the important role of meso- and microfauna in making nutrient-poor soil substrates more accessible to the soil microbial community.

Low‐quality carbon and lack of nutrients result in a stronger fungal than bacterial home‐field advantage during the decomposition of leaf litter

Abstract Decomposition of litter is a key biochemical process that regulates the rate and magnitude of CO2 fluxes from biosphere to atmosphere and determines soil nutrient availability. Although several studies have shown that plant litter decomposition accelerated in their native compared to a foreign environment, that is, a home‐field advantage (HFA) for litter degradation, to date HFA has only been considered in terms of respiration or litter mass loss. The competitive success of the decomposer micro‐organism will be determined by its ability to transform used OM into population growth. Therefore, we hypothesized that HFA for microbial growth would be more pronounced than that for decomposition. We also expected that HFA effect for decomposition and microbial growth would increase with lower quality litter, which the fungal role in litter decomposition would be more dominant than that of bacteria, and that HFA effects would strengthen with more pronounced differences between ‘home’ and ‘away’ environments. We designed a 2‐month microcosm reciprocal transplant experiment with litter from two sites with contrasting climates (Atlantic and Sub‐Mediterranean climates) and including three tree species (Quercus robur, Pinus sylvestris and Fagus sylvatica). We found a stronger HFA for microbial growth than for decomposition, that the nutrient content and C‐quality of litter influenced the microbial HFA and that interactions between bacterial and fungal communities during litter decomposition modulated the HFA for litter degradation. Low litter nutrient content, strong nutrient limitations and low C‐qualities all favoured fungal over bacterial decomposers, and our results suggest a dominant functional role of the fungal community and gave rise to HFA effect for fungal growth but that this translated to only marginal implications for overall decomposition of litter. A free Plain Language Summary can be found within the Supporting Information of this article.

Soil mesofauna participating in driving home-field advantage differ between litter mass loss and nutrient release

Soil organisms play an important role in litter mass loss and nutrient release. Although soil mesofauna participating in driving home-field advantage (HFA) differ between litter mass loss and nutrient release, this has rarely been investigated. A reciprocal transplant experiment was conducted using litterbags with two sizes of mesh (0.01 mm and 1 mm) in Pinus koraiensis Sieb. & Zucc. and Larix olgensis Henry plantations. We found that P. koraiensis and L. olgensis litter had a significantly higher soil mesofaunal abundance at home habitat after 7 and 9 months, respectively. The P. koraiensis and L. olgensis litter were associated with a significantly higher abundance of Oribatida and Tomoceridae at home habitat after 7 and 9 months, respectively. Soil mesofauna enhanced the positive effect on HFA for litter mass loss and carbon release in P. koraiensis and L. olgensis litter that could be observed at months 7 and 9 of the experiment. Nevertheless, the soil mesofauna significantly contributed to the negative effect on HFA for nitrogen and sulphur release for both litter types after 12 months. Our findings suggest that soil mesofaunal specialization could promote HFA effect for litter mass loss and carbon release, but that their effect was only apparent during specific stages of litter decomposition. Soil mesofaunal specialization dynamics are correlated with microclimate conditions and litter quality. Soil mesofauna significantly contributed to the negative effect on HFA for nitrogen and sulphur release, due to the change in the litter quality and imbalance of soil mesofauna between the home and away from home habitats.

Home field advantage describes the carbon and nitrogen dynamics of Cynodon dactylon and Phoenix dactylifera leaf litters in arid sandy soil

Based on evidence from various ecosystems, it is hypothesized that interaction between leaf-litter and soil decomposer communities results in higher decomposition when leaf litter is decomposed in its home than away soil, a phenomenon called home field advantage (HFA). However, the generality of this hypothesis remains unclear due to the emergence of contrasting results across various biomes. Here, we tested if HFA also occurs in lawn grass (Cynodon dactylon; GL) and date palm (Phoenix dactylifera) leaf litter (DL) decomposition in arid sandy soil using reciprocal litter transplant mesocosms experiment. Litter decomposition was monitored by measuring CO2 emission (alkali trap), dissolved organic C (DOC), and mineral N (Nmin) over 180 days. Regression analysis was used to estimate HFA, litter quality (QI), and soil decomposer communities' ability (FA) indices. The highest HFA (69%) was observed for non-cumulative CO2 emission on day 14 that was decreased to 4% on day 180. Similarly, Nmin from leaf litter was 4 and 6% higher at home than away soil on days 90 and 180, respectively. These HFA effects were mainly attributed to higher CO2 emission and soil Nmin from grass litter at home than away-soil. In addition, microbial biomass C from GL and N immobilization from DL was lower at home than away-soil. However, we did not observe HFA for DOC on day 90 or 180. The QI indicates that CO2 emission or Nmin was lower from DL than GL irrespective of home or away soil. The QI and FA did not change over time for the aforesaid parameters despite HFA effects decreased with time for non-cumulative CO2 emission. This indicates that leaf litter and soil specific interactions did not remain constant for litter C and N cycling, and hence this interaction could be nutrient-specific during leaf litter decomposition in soil.

The consistency of home-field advantage effects with varying climate conditions

The home-field advantage (HFA) hypothesis predicts that plant litters decompose faster in the vicinity of the plant from which they are derived than away from ‘home’. Although we are aware that both litter quality and the efficiency of decomposers within soil communities (hereafter, “soil ability”) are important drivers of HFA effects, we know little on variation in HFA effects and underlying processes of these changes across years with varying climates. In order to address these questions, we repeated four years with varying climates (two mild years, 2016 & 2018 and two stressed years, 2017 & 2019) a reciprocal transplant experiment with four litter types, crossing vegetation structure and soil fertility contrasts of both litter and ecosystems (forest and grassland litters from both fertile and unfertile soils). We used the Decomposer Ability Regression Test for both types of years to search for evidence of HFA effects and conducted ANOVAs on the cross effects of vegetation structure and soil fertility contrasts to further identifying the underlying processes of changes in HFA across climates. HFA effects were only significant for the most recalcitrant litter of Pinus pinaster, and much more significant during the mild years. Litter quality was stable across species and years, whereas differences in soil ability among ecosystems of the four species were strongly affected by climate, with highly significant differences among ecosystems occurring only during the mild years. Changes in soil ability across climates (decreasing HFA effects during stressed years) were explained by an overall increase in litter decomposition in forests as compared to grasslands during the stressed years, due to the facilitation of soil decomposers by forest canopies. Our study showed that HFA effects vary across climates as a result of changes in soil ability and that forest canopies may buffer the negative effects on litter decomposition of increasing stress with climate change.

Effects of Litter Quality Diminish and Effects of Vegetation Type Develop During Litter Decomposition of Two Shrub Species in an Alpine Treeline Ecotone

Because climate change is predicted to have a strong impact on high-altitude ecosystems, a better knowledge of litter decomposition in alpine ecosystems is critical to improve our predictions of the effect of climate change on ecosystem processes and services such as nutrient cycling, carbon sequestration, and below-ground biodiversity. To evaluate the effects of vegetation types [alpine shrubland (AS) and alpine meadow (AM)] and litter quality on litter decomposition and related biochemical processes, the decomposition of leaf litter of two dominant shrub species, Sorbus rufopilosa (SR, high quality) and Rhododendron lapponicum (RL, low quality), was studied using the litterbag method in an alpine treeline ecotone on the eastern Tibetan Plateau. After 1 year of decomposition, cellulolytic enzyme activities and gram-negative bacterial biomass were higher in shrubland than in meadow. However, higher fungal biomass, fungal/bacteria ratio and ligninolytic activity were observed in meadow than in shrubland after 2 years of decomposition. During the first year of decomposition, litter decomposition was faster in shrubland than in meadow probably due to the home-field advantage (HFA) effect and the bacteria-dominated decomposition, whereas in later decomposition stages, litter decomposition was faster in meadow than in shrubland, as the HFA effect diminished and fungal-dominated decomposition of recalcitrant components took over. These results indicated that litter quality effects were generally strongest in the first year and diminished in later stages when the effect of vegetation type in incubation sites developed.

Litter C transformations of invasive Spartina alterniflora affected by litter type and soil source

Litter types and soil properties can affect litter decomposition rate and litter carbon (C) transformation, consequently regulating soil C cycling. Yet, litter C transformations of leaves and roots of invasive plants are poorly understood, which limits our understanding of the role of plant residues in soil C sequestration during plant invasion. In a laboratory incubation experiment lasting for 153 days, we used two types of soil which were collected from invasive S. alterniflora and native Phragmites australis marshlands, and traced the transformation of 13C from leaf and root litter of invasive Spartina alterniflora into CO2, soil-dissolved organic C (DOC), microbial biomass C (MBC), and soil organic C (SOC). The leaf litter of S. alterniflora decomposed faster than root litter, resulting in higher soil respiration and higher transformation of litter-derived 13C into CO2, MBC, and DOC. Although the root litter of S. alterniflora decomposed slowly, SOC comprised up to 24% of litter-derived 13C. Furthermore, the litter C transformations of S. alterniflora showed a positive home-field advantage effect. Soil respiration, MBC, fractions of litter-derived 13C in Gram-negative bacteria, 13C recovered in CO2, DOC, and SOC were higher in the soil colonized by S. alterniflora than in the soil colonized by P. australis, with the home-field advantage effect being more pronounced in root than leaf litter treatments. Therefore, litter type and soil source had differential impacts on litter C transformation patterns of S. alterniflora and the root litter of invasive S. alterniflora played an important role in SOC formation and C sequestration in soils from its invaded ecosystems.

Fungi participate in driving home-field advantage of litter decomposition in a subtropical forest

Home-field advantage (HFA) hypothesis predicts that plant litter decomposes faster beneath the plant species from which it was derived than beneath other plant species. However, it remains unclear, which groups of soil organisms drive HFA effects across a wide range of litter quality and forest types. We set up a reciprocal transplant decomposition experiment to quantify the HFA effects of broadleaf, coniferous and bamboo litters. Litterbags of different mesh sizes and high-throughput pyrosequencing of microbial rRNA gene were used to test the contribution of different decomposer groups to HFA effect. The recalcitrant broadleaf litter and the labile bamboo litter exhibited HFA. Presence of meso-and macrofauna did not substantially change the HFA effects. Bacterial and fungal community composition on litters were significantly influenced by litter type. Bacterial community composition remained unchanged when the same litter was decomposed in different forest types, whereas fungal community composition on broadleaf and bamboo litters were significantly influenced by incubation site. Our data demonstrate specific association between fungal community composition and faster litter decomposition in the home site, suggesting that fungi probably participate in driving the HFA effect of broadleaf and bamboo litters.

A comparison of competitive profiles across the Spanish football leagues

Abstract The purpose of this study was to compare the competitive profiles across the Spanish football leagues at the present time. The final standings (n=32) and results of the matches played (n=11,122) in the 2015/2016 season were analysed. Four categories of analysis were selected: Level of competitive balance of matches, Level of compactability of team standings, Magnitude of home-field advantage effect, and Degree of openness of the matches. Using statistical procedures for the comparison of means by analysis of variance (ANOVA) and the Chi-Squared test, it was concluded that in the panorama of Spanish football, the men's 2nd division stands out as the Championship that corresponds to a competitive profile with greater equality and that the women's 1st division presents the most unbalanced competitive profile (p < .05). A trend was also observed that indicated that the more professionalized Championships present a higher level of competitive balance of the matches, a higher level of compactability of the team standings, and a lower degree of openness of the matches with respect to the less professionalized Championships, due to the presence of statistically significant differences (p < .05) in the set of categories analysed.