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Plasmids are so closely associated with pathogens and antibiotic resistance that their potential for conferring other traits is often overlooked. Few studies consider how the full suite of traits encoded by plasmids is related to a hosts environmental adaptation, particularly for Gram-positive bacteria. To investigate the role that plasmid traits might play in microbial communities from natural ecosystems, we identified plasmids carried by isolates of Curtobacterium (phylum Actinomycetota) from a variety of soil environments. We found that plasmids were common, but not ubiquitous, in the genus and varied greatly in their size and genetic diversity. There was little evidence of phylogenetic conservation among Curtobacterium plasmids even for closely related bacterial strains within the same ecotype, indicating that horizontal transmission of plasmids is common. The plasmids carried a wide diversity of traits that were not a random subset of the host chromosome. Furthermore, the composition of these plasmid traits was associated with the environmental context of the host bacterium. Together, the results indicate that plasmids contribute substantially to the microdiversity of a soil bacterium and that this diversity may play a role in niche differentiation and a bacteriums adaptation to its local environment.

Floral mimics deceive their pollinators by developing visual and olfactory resemblance to various models. We report a flower that exhibits phenotypes like aerial litter and deceives an aerial litter specialist beetle to achieve pollination. We assessed the floral phenology and the effective pollinators of an Australian understorey treelet, Meiogyne heteropetala (Annonaceae). The similarities of morphology, colour and odour between the flowers and co‐occurring aerial litter were investigated. The terpene synthase involved in floral scent emission was identified by expression patterns and product profile. The behavioural responses of the pollinator to various odours were assessed using bioassays. The erotylid beetle Loberus sharpi is the most likely effective pollinator because it was the only pollen‐laden visitor during the pistillate phase. Loberus sharpi was exclusively found in aerial litter and M. heteropetala flowers. The flowers offer an honest shelter reward. The beetle also oviposits there, but most larvae eventually perished as the petals dropped onto the forest floor. The morphology and spectral reflectance of the flowers overlap with aerial litter. The floral scent was dominated by monoterpenes, especially 1,8‐cineole. The cineole synthase MhCINS was the only highly expressed floral terpene synthase and possessed a highly similar product profile to the floral scent composition. The volatile composition of M. heteropetala flowers is distinct from other congeners and highly similar to aerial litter, indicating advergence to aerial litter. Visual and odour resemblance, coupled with low larval survivorship, provides evidence that the beetles were deceived into pollinating the flowers. Behavioural experiments showed that the pollinator was attracted to both aerial litter and M. heteropetala flowers. The beetles were also attracted to 1,8‐cineole and synthetic mixes of floral odour and MhCINS products. The beetles were unable to distinguish floral scent from MhCINS products nor from 1,8‐cineole, suggesting MhCINS alone sufficed to attract the pollinator olfactorily. The beetles, however, preferred aerial litter over flowers. The beetles likely categorised the flower as a general, but not the most preferred, brood substrate. Synthesis. This study reports the first case of floral mimicry of aerial litter and characterises the biochemical process responsible for olfactory mimicry. [ABSTRACT FROM AUTHOR]

Snowfall/cover and snowmelt are essential determinants of winter soil processes/events that may force the biogeochemical dynamics of soils in temperate regions. Increasing variability of the European hydroclimate is expected to lead to more frequent intermittent warm periods, which cause snowmelt during winter and rapidly mobilize large amounts of dissolved organic matter (DOM). This study, conducted at the Hainich Critical Zone Exploratory in Germany, seeks to address a significant gap in understanding the molecular impacts of snowmelt-induced DOM flows and their ability to alter soil ecosystems rapidly. During two snowmelt events between January and March 2021, we observed that DOM concentration and composition varied more in forest soil seepage than in grassland soil seepage. Forest seepage showed a pronounced DOM flux peak and synchronous increases in the relative abundances of aromatic DOM components, indicating surface-derived transport of plant litter carbon. In the grassland, however, peak DOM fluxes were characterized by a marked increase in nitrogen-containing (N-containing) DOM components, indicating a predominance of microbial carbon. Notably, the unique DOM components specific to each ecosystem increased during peak fluxes in the forest but decreased in the grassland. We suggest that an overall higher molecular richness and the broader functional metabolic potentials in grassland may account for its relatively greater DOM stability compared to the forest during peak snowmelt events. [ABSTRACT FROM AUTHOR]

Summary: The first step in carbon (C) turnover, where senesced plant biomass is converted through various pathways into compounds that are released to the atmosphere or incorporated into the soil, is termed litter decomposition. This review is focused on recent advances of how solar radiation can affect this important process in terrestrial ecosystems. We explore the photochemical degradation of plant litter and its consequences for biotic decomposition and C cycling. The ubiquitous presence of lignin in plant tissues poses an important challenge for enzymatic litter decomposition due to its biological recalcitrance, creating a substantial bottleneck for decomposer organisms. The recognition that lignin is also photolabile and can be rapidly altered by natural doses of sunlight to increase access to cell wall carbohydrates and even bolster the activity of cell wall degrading enzymes highlights a novel role for lignin in modulating rates of litter decomposition. Lignin represents a key functional connector between photochemistry and biochemistry with important consequences for our understanding of how sunlight exposure may affect litter decomposition in a wide range of terrestrial ecosystems. A mechanistic understanding of how sunlight controls litter decomposition and C turnover can help inform management and other decisions related to mitigating human impact on the planet. [ABSTRACT FROM AUTHOR]

Exotic plant litter presents different chemical and physical properties relative to native plant litter and alters ecosystem processes and functions that may facilitate exotic plant dispersal. However, these effects are largely unknown, especially within wetland ecosystems. This study examines whether introducing litter from the exotic mangrove Laguncularia racemosa could result in (1) accelerated community litter decomposition rates and increased nutrient cycling rates and (2) microbial community structure changes in the invaded areas. A single decomposition experiment using litterbags was conducted to examine the shortterm effects of L. racemosa litter in the native mangrove forest ecosystem. The soil nutrients and microbial communities of Rhizophora stylosa, L. racemosa, and mixed forests were also compared to explore the long-term cumulative effects of L. racemosa litter in native ecosystems. The results indicated that L. racemosa has lower-quality leaf litter than R. stylosa and a significantly faster decomposition rate. Thismay result from changes in the soil microbial community structure caused by L. racemosa leaf litter input, which favors the decomposition of its own litter. Both the short-term and cumulative effect experiments demonstrated that L. racemosa leaf litter significantly increased the relative abundance of microbes related to litter decomposition, such as Proteobacteria and Bdellovibrionota, and enhanced the alpha diversity of soil fungi, thus creating a microbial environment conducive to L. racemosa leaf litter decomposition. Moreover, the accumulation of soil nutrients was lower under L. racemosa than under R. stylosa over several years. Thismay be related to themore rapid growth of L. racemosa, which causes soil nutrient absorption and storage within the plant tissues, thereby reducing the soil nutrient content. Inputting exotic mangrove L. racemosa leaf litter reduced the soil blue carbon content, potentially adversely affecting global climate change. L. racemosa may employ a unique strategy to lower soil nutrient levels in native mangroves based on its lowquality leaf litter, thereby weakening the competitive ability of native plants that are intolerant to low-nutrient conditions and enhancing its own competitive advantage to further spread into these areas. In summary, the input of exotic L. racemosa leaf litter accelerates nutrient cycling in local mangroves. [ABSTRACT FROM AUTHOR]

Litter decomposition is expected to be positively associated with precipitation despite evidence that decomposers of varying sizes have different moisture dependencies. We hypothesized that higher tolerance of macro-decomposers to aridity may counterbalance the effect of smaller decomposers, leading to similar decomposition rates across climatic gradients. We tested this hypothesis by placing plant litter baskets of different mesh sizes in seven sites along a sharp precipitation gradient, and by characterizing the macro-decomposer assemblages using pitfall trapping. We found that decomposers responded differently to precipitation levels based on their size. Microbial decomposition increased with precipitation in the winter while macro-decomposition peaked in arid sites during the summer. This led to similar overall decomposition rates across the gradient except in hyper-arid sites. Macro-decomposer richness, abundance, and biomass peaked in arid environments. Our findings highlight the importance of macro-decomposition in arid-lands, possibly resolving the dryland decomposition conundrum, and emphasizing the need to contemplate decomposer size when investigating zoogeochemical processes. [ABSTRACT FROM AUTHOR]

From soil to freshwater ecosystems, decomposition can be conceived as the result of interactions between organic matter and a diversity of organisms. This function is driven in part by detritivores, invertebrates that feed on detritus or graze on its associated microbes and that have a significant but extremely variable contribution to decomposition.In order to better understand and predict detritivore–detritus pairwise interactions, we propose a conceptual framework, called Detri2match, to study the consumption of detritus by detritivores, using a trait‐matching approach at the individual detritivore level. Here, we focus on the interaction between saprophagous detritivores that fragment plant detritus.We propose a novel definition of a saprophagous detritivore as an animal that consumes plant detritus when its traits match sufficiently the traits of its resource, passing through five interaction facets of consumption. These include (1) a spatial match rule regarding the encounter, (2) a biomechanical match rule regarding ingestion, (3) a digestive match rule regarding assimilation, (4) an energetic match rule regarding the fulfilment of metabolic needs and (5) a nutritional match rule regarding the fulfilment of chemical element needs in adapted proportions.The main goal of this framework is to guide future research to establish generic rules of misunderstood detritus–detritivore pairwise interactions by identifying relevant interaction facets and their key associated traits for both detritivores and detritus. This investigation should be conducted over the temporal variability of trait‐matching constraints throughout the whole decomposition process. Coupled with adequate accumulation of trait information, the Detri2match framework could also facilitate predictions by inference of non‐tested pairwise detritivore–litter interactions.We also outline conceptual, methodological and analytical challenges of this framework. The main challenge would be to scale up these pairwise rules at the detrital network level and to test their genericity, which would contribute to a better understanding of the functioning of the detrital network and its contribution to decomposition. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Phosphorus (P), a crucial element for all life forms on Earth, is often insufficiently available in terrestrial ecosystems. The interaction and feedback between plants and soil microorganisms are crucial links integrating above‐ and below‐ground ecosystems. However, changes in soil P fractions in response to plant‐microbe interactions during vegetation succession remain poorly understood. This study investigated the trends and relationships between plant resorption, microbial properties, and soil P fractions in the transformation interface soil layer (TIS) and underlying topsoil layer (UTS) during grassland vegetation succession. The results point to a combination of soil properties, alongside microbial and plant factors driving soil P changes. However, the TIS and UTS layers differ, with phosphorus dynamics in the TIS layer primarily influenced by microorganisms. Microorganisms are co‐limited by C and P in both the TIS and UTS layers. Under microbial P‐limitation, microorganisms produce alkaline phosphatases (AP), while C deficiency stimulates the production of C‐acquiring enzymes, subtly regulating soil P dynamics through organic matter decomposition. Plant P resorption efficiency and microbial P‐limitation exhibit synergistic variations, reaching their lowest levels during the mixed Bothriochloa ischaemum and Stipa bungeana Trin (Bo.I + St.B) stage. This study emphasizes that P cycling is influenced by plant‐microbe‐soil interactions and feedback. Plants and soil microorganisms jointly regulate soil nutrient effectiveness and partitioning in the ecosystem. Plain Language Summary: Phosphorus (P) is an indispensable element found in all living organisms, essential for various biological functions like photosynthesis, energy transfer, and the synthesis of DNA and RNA. Focusing on vegetation restoration, we found that soil microorganisms faced limitations from both P and carbon (C). Notably, in the soil layer at the transformation interface, where plant litter was plentiful, microorganisms enjoyed improved access to P. This improvement was attributed to the plants in our study absorbing more nitrogen (N) than P, resulting in a higher concentration of P in their decomposing foliage. Furthermore, the production of alkaline phosphatase (AP) by microbes facilitates their access to additional P from the soil. From the viewpoint of P acquisition, an increase in microbial P‐limitation leads to a reduction in dissolved inorganic P, thereby enhancing the efficiency of plant P resorption. This process ultimately results in a net decrease in the total soil P content. Understanding the dynamics of P cycling in soil amid vegetation restoration is vital for the sustainable management of land. By ensuring that both plants and microorganisms have adequate access to P, we can foster successful and eco‐friendly vegetation restoration initiatives. Key Points: Microbial P limitation is more pronounced in the underlying topsoil layer compared to the transformation interface soil layerMicrobial factors such as extracellular enzymes are the main drivers of P variation within the transformation interface soil layerDuring the course of vegetation succession, microbial P‐limitation is found to enhance plant P resorption efficiency [ABSTRACT FROM AUTHOR]

Hydrothermal pretreatments are commonly employed prior to the biotechnological conversion of lignocellulosic biomass (LCB) into value-added products, such as fuels and chemicals. However, the by-products of this pretreatment, including furaldehydes, lignin-derived phenolics, and carboxylic acids, can inhibit the enzymes and microbes used in the biotechnological process. In this study, LCB degrading enzymes of endophytic and litter fungi were screened for their tolerance to potential pretreatment-derived inhibitors. Several fungi produced endo- and exoglucanases that remained functional in the presence of lignocellulose-derived phenolics. Some were also active in the presence of tannic acid. Additionally, thermostable endoglucanase activity was observed in some fungi. The ability of some of these fungi to utilize furaldehyde inhibitors as a sole carbon source was also noted. The culture supernatants of the fungal strains were tested in hydrolysis experiments using microcrystalline cellulose as a substrate, in the presence of lignocellulose phenolics and tannic acid. With some strains, higher sugar yields were obtained in the hydrolysis of cellulose when phenolics were added. Our results highlight the need for more intensive exploration of endophytic and plant litter fungi for novel inhibitor-resistant cellulases for biofuel production. [ABSTRACT FROM AUTHOR]

With rapid climate warming, some coastal high‐latitude ecosystems are experiencing more frequent tidal floods. Yet little is known about tundra plant‐community responses to flooding, and whether Arctic warming may modulate such responses. In a 2‐year, full‐factorial field experiment in coastal tundra wetlands of the Yukon‐Kuskokwim (Y‐K) Delta (western Alaska), we simulated periodic tidal flood events at two severities under both ambient and warmed summer conditions and measured above‐ground plant‐community responses. Low‐severity flooding represented overbank flooding 1 day per month, which is consistent with projections in the next 5 years. High‐severity flooding represented a more impactful flooding regime (three consecutive days per month) that is projected to occur in the next 10 years. Our warming treatment (+1°C) also represented a change projected in the next 10 years. Regardless of temperature, high‐severity flooding increased graminoid biomass by >45%, in turn increasing live plant‐community biomass by >18%. Low‐severity flooding had similar, though weaker, effects. Flooding had overall negative effects on both forb and shrub biomass, though shrub responses were weaker. Only during the second summer, warming increased graminoid biomass by 20% and tended to increase shrub biomass, regardless of flooding. Concurrently, warming enhanced standing‐dead graminoid biomass by 20%, while high‐severity flooding decreased it by 15%. Therefore, wet tundra that was both flooded and warmed had the greatest proportion of graminoids and total live biomass, but standing‐dead biomass comparable to that of unmanipulated wet tundra. Synthesis. While our manipulations simulated flooding and warming regimes expected in the wetlands of the Y‐K Delta over the same, near‐future (5‐to‐10 years) time frame, flooding had stronger effects than warming. What is striking is the rate at which graminoid increases occurred, becoming apparent after only two monthly flood events in the first experimental year. Flooding‐induced decreases in standing‐dead biomass suggests that the incorporation of dead plant material into the litter layer might be facilitated by tidal floods. These rapid increases in plant biomass and potentially biomass turnover, especially of graminoids, which are characterized by high‐quality litter, may have major implications for carbon and nutrient cycling of more frequently flooded coastal ecosystems in a warmer Arctic. [ABSTRACT FROM AUTHOR]

Summary: 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. See also the Commentary on this article by Keiser, 243: 2048–2049. [ABSTRACT FROM AUTHOR]

Rising temperatures and higher atmospheric CO2 levels can potentially increase plant photosynthesis and boost forest productivity, thereby spurring litter inputs to soils on a global scale. Understanding the feedback loops between increased litter inputs and soil biota activity will allow for better prediction of organic matter and carbon (C) cycling in terrestrial ecosystems.Nematodes represent the full spectrum of trophic groups within the soil biota. Accordingly, we studied the link between nematode metabolic activities and plant litter input. For this, different litter input levels were manipulated in a temperate forest, including control zones without litter, natural litter input zones and zones with double, triple and quadruple amounts of natural litter input. Soil top layers (0–10 cm) were then collected to study the responses of nematode communities.Increased litter input positively influenced the abundance and diversity of nematodes, except for plant‐parasitic species. Higher litter input levels led to an enhancement in the ratio of bacterivores to the total of bacterivores and fungivores. More litter increased the K/r strategist ratio among bacterivores and the corresponding nematode metabolic footprints. More litter also stimulated nematode production and respiration components and improved the carbon use efficiency of bacterivores. Moreover, structural equation modelling revealed the crucial role of bacterivores in influencing soil organic C under increased litter input.In conclusion, our study shows that increased plant above‐ground litter input modifies the taxonomic and functional communities of soil nematodes, ultimately regulating carbon cycling in forest soils. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

This study presents the first genome assembly of the freshwater saprobe fungus Neonectria lugdunensis and a comprehensive phylogenomics analysis of the Nectriaceae family, examining genomic traits according to fungal lifestyles. The Nectriaceae family, one of the largest in Hypocreales, includes fungi with significant ecological roles and economic importance as plant pathogens, endophytes, and saprobes. The phylogenomics analysis identified 2684 single-copy orthologs, providing a robust evolutionary framework for the Nectriaceae family. We analyzed the genomic characteristics of 17 Nectriaceae genomes, focusing on their carbohydrate-active enzymes (CAZymes), biosynthetic gene clusters (BGCs), and adaptations to environmental temperatures. Our results highlight the adaptation mechanisms of N. lugdunensis, emphasizing its capabilities for plant litter degradation and enzyme activity in varying temperatures. The comparative genomics of different Nectriaceae lifestyles revealed significant differences in genome size, gene content, repetitive elements, and secondary metabolite production. Endophytes exhibited larger genomes, more effector proteins, and BGCs, while plant pathogens had higher thermo-adapted protein counts, suggesting greater resilience to global warming. In contrast, the freshwater saprobe shows less adaptation to warmer temperatures and is important for conservation goals. This study underscores the importance of understanding fungal genomic adaptations to predict ecosystem impacts and conservation targets in the face of climate change. [ABSTRACT FROM AUTHOR]

Plant litter imported from forest headwater streams is an important supply of material and energy to the downstream aquatic ecosystems, affecting the storages and fluxes of carbon and nutrients of the whole forest ecosystems. However, our knowledge on the dynamics of plant litter potassium (K) storage is still limited. Here, we monitored the spatial and temporal characteristics of plant litter K concentration and storage in a subtropical forest headwater stream for an entire year. Results showed that: (1) the annual average concentration and storage of K in plant litter were 1.4 mg/kg and 19.6 mg/m2, respectively, with an overall decreasing trend throughout the year and from the source of the stream to the mouth; (2) riparian forest type (broadleaved vs. mixed forests) and the presence of a tributary showed significant effects on twig K concentration and storage, but did not affect those of other types of plant litter (total, fine woody debris, leaf, reproductive part, and twig); (3) water depth and active channel width positively correlated with litter K storage, while stream gradient, water dissolved oxygen, and alkalinity negatively corrected to litter K storage. Our results clearly demonstrated the spatiotemporal dynamics of plant litter K storage in the subtropical forest headwater stream, which provides basic data and scientific basis for an in-depth understanding of nutrient fluxes and cycling along with ecohydrological processes in subtropical forest ecosystems. [ABSTRACT FROM AUTHOR]

(1) Background: Moso bamboo (Phyllostachys edulis (Carrière) J. Houz.) expansion has seriously altered the species composition and structure of adjacent forest ecosystems in subtropical regions. However, the shift in phosphorus (P) biogeochemical cycling has yet to be assessed, which is a critical gap considering the great variation in ecophysiological properties between invasive bamboo and the displaced native tree species. (2) Methods: We investigated and compared expansion-induced changes in P pools (plant, litter, and soil) and P fluxes (plant uptake and litterfall return) using paired sampling of the bamboo-dominated forest (BDF) and secondary evergreen broadleaved forest (EBF) at Jiangxi province's Dagang Mountain National Forest Ecological Station. (3) Results: Both the P storage of the plants and litter were significantly greater by 31.8% and 68.2% in the BDF than in the EBF, respectively. The soil total P and available P storage were 28.9% and 40.4% lower, respectively, in the BDF than in the EBF. Plant P uptake was 15.6% higher in the BDF than in the EBF, and the annual litter P return was 26.1% lower in the BDF than in the EBF due to higher P resorption efficiency for moso bamboo compared with evergreen broadleaved tree species. The ecosystem P cycling rate was reduced by 36.1% in the BDF compared with the EBF. (4) Conclusions: Moso bamboo expansion slowed the broadleaved forest ecosystem's P cycle rate, likely because moso bamboo has higher P-use efficiency, reserving more P in its tissues rather than returning it to the soil. The results from this study elucidate an understudied element cycle in the context of forest succession, demonstrating the ecosystem consequences related to bamboo invasion. [ABSTRACT FROM AUTHOR]

The litter decomposition of plant leaves is a vital process in carbon (C) and nitrogen (N) cycling in global terrestrial ecosystems. However, previous assessments of the key determinants of the N deposition effects of litter decomposition have been more controversial. In this meta-analysis, we compared the overall effects of N addition on the litter decomposition rates, litter nutrient content (C and N), and litter constituent (lignin and cellulose) residual rates using a log response ratio approach. Our results showed that exogenous N addition increased the N content and inhibited lignin degradation in litter. N deposition decreased the leaf litter decomposition rate by increasing the lignin and N residues and decreasing the litter C content and soil pH. The analysis also concluded that the initial litter C/N ratio, lignin content, and soil pH were main factors in mediating the effect of N deposition on litter decomposition rate. Overall, the results of this study indicate that N deposition can slow decomposition rates by inhibiting N release and lignin degradation of litter. Notably, these results emphasize that the effect of N deposition on litter decomposition mainly depends on the endogenous quality of the litter and soil pH in the decomposition environment. [ABSTRACT FROM AUTHOR]

Especially steppe-forest ecotones, formed naturally or human-induced, are under threat due to overuse, inappropriate land use, and wrong interventions. These transition zones have long been a focus of interest for ecologists, and more research is needed, especially on the relationship between plant diversity and edaphic factors. The research area is located in the northern part of Çankırı province in Türkiye. The study used the line transect approach to evaluate the link between plant species diversity, litter, and soil parameters in the steppe-to-forest transition zone. The transects are about 12 kilometers long and create a line from the steppe to the forest. According to RDA findings, plant species diversity in the transition zone was significantly correlated with litter concentrations of Ca, K, P, and Mg. Plant biodiversity in the steppe zone correlated with soil Ca, CaCO3, Na, and pH levels. Our findings shed light on the relationship between plant diversity and edaphic (soil) properties in the steppe, forest, and transition zones. Elevated calcium levels in the steppe and transition zones indicate a higher appropriateness for calcicole plants (those that grow in calcium-rich habitats). This insight provides useful information for using native plant species in restoration and rehabilitation activities aimed at steppe and transition zone ecosystems. [ABSTRACT FROM AUTHOR]

Interactions between plant roots and rhizosphere bacteria modulate nitrogen (N)-cycling processes and create habitats rich in low molecular weight compounds (exudates) and complex organic molecules (decaying root litter) compared to those of bulk soil. Microbial N-cycling is regulated by edaphic conditions and genes from many interconnected metabolic pathways, but most studies of soil N-cycling gene expression have focused on single pathways. Currently, we lack a comprehensive understanding of the interplay between soil N-cycling gene regulation, spatial habitat, and time. We present results from a replicated time series of soil metatranscriptomes; we followed gene expression of multiple N transformations in four soil habitats (rhizosphere, detritusphere, rhizo-detritusphere, and bulk soil) during active root growth for the annual grass, Avena fatua. The presence of root litter and living roots significantly altered the trajectories of N-cycling gene expression. Upregulation of assimilatory nitrate reduction in the rhizosphere suggests that rhizosphere bacteria were actively competing with roots for nitrate. Simultaneously, ammonium assimilatory pathways were upregulated in both rhizosphere and detritusphere soil, which could have limited N availability to plants. The detritusphere supported dissimilatory processes DNRA and denitrification. Expression of nitrification genes was dominated by three phylotypes of Thaumarchaeota and was upregulated in bulk soil. Unidirectional ammonium assimilation and its regulatory genes (GS/GOGAT) were upregulated near relatively young roots and highly decayed root litter, suggesting N may have been limiting in these habitats (GS/GOGAT is typically activated under N limitation). Our comprehensive analysis indicates that differences in carbon and inorganic N availability control contemporaneous transcription of N-cycling pathways in soil habitats. IMPORTANCE Plant roots modulate microbial nitrogen (N) cycling by regulating the supply of root-derived carbon and nitrogen uptake. These differences in resource availability cause distinct micro-habitats to develop: soil near living roots, decaying roots, near both, or outside the direct influence of roots. While many environmental factors and genes control the microbial processes involved in the nitrogen cycle, most research has focused on single genes and pathways, neglecting the interactive effects these pathways have on each other. The processes controlled by these pathways determine consumption and production of N by soil microorganisms. We followed the expression of N-cycling genes in four soil microhabitats over a period of active root growth for an annual grass. We found that the presence of root litter and living roots significantly altered gene expression involved in multiple nitrogen pathways, as well as tradeoffs between pathways, which ultimately regulate N availability to plants.

Forest soils store substantial amounts of carbon in various soil organic matter (SOM) components due to high plant litter inputs and active microbial turnover. However, the variations in plant- and microbial-derived SOM components in surface and subsurface forest soils across a wide geographic scale remain poorly understood. This study investigated the SOM components from aboveground and belowground plant inputs and fungal and bacterial necromass in surface (soil0–5 cm) and subsurface (soil5–10 cm) soils across 32 forest sites in China and analyzed their relationships with climate and edaphic factors. Compared to soil0–5 cm, soil5–10 cm exhibited lower soil organic carbon content and cutin biomarker concentration but higher concentrations of fungal necromass carbon and lignin phenols. Higher mean annual precipitation led to higher concentrations of cutin and suberin biomarkers in soil0–5 cm and soil5–10 cm, respectively. Higher soil organic carbon content was associated with lower plant-derived lignin biomarkers, higher lignin oxidation degrees, and increased microbial necromass-derived amino sugars across sites, highlighting the pivotal role of microbial necromass in SOM stabilization. Additionally, both fungal and bacterial necromass decreased with increasing mineral weathering across sites. These insights improve the understanding of environmental drivers of source-specific carbon storage in forest soils. Highlights: • There were more cutin and less lignin or fungal derivatives in 0–5 cm than in 5–10 cm soils. • MAP increased cutin derivatives (0–5 cm soils) and suberin derivatives (5–10 cm soils). • Amino sugars and cutin derivatives increased and lignin derivatives decreased with SOC. • Both fungal and bacterial necromass decreased with increasing mineral weathering. [ABSTRACT FROM AUTHOR]

The spatial and intraprofile variations of soil δ13C values are assessed along with the corresponding environmental and edaphic factors in the Baikal region, a vast territory in the south of Eastern Siberia, which is highly heterogeneous in terms of physiographic conditions. The studied sites are located in the altitudinal range of 403–2315 m a.s.l., which defines a strong landscape and climatic gradient comprising mountainous tundra, subalpine grasslands, mountainous taiga, subtaiga, and steppe landscapes. The soil organic matter there considerably varies in the 13C/12C isotopic ratio corresponding to δ13C values characteristic of the plants with C3 photosynthesis. The δ13C values in topsoil organic matter vary from –29.50 to –22.98‰. The changes in δ13C values in the altitudinal profile correlate well with the changes in landscapes. The highest δ13C values are characteristic of the soils in mountainous tundra and steppe landscapes. Organic matter of taiga soils is depleted in 13C. A lower carbon turnover rate is observed in the steppe and mountainous tundra soils, which is explained by limited moisture and heat supply, respectively. The soils formed in taiga landscapes with their more favorable balance of temperatures and precipitation display a more intensive carbon turnover (β). The β values in forest soils correlate with the changes in pH, C and N contents, and the variations in C/N ratio in soil organic matter, thereby suggesting a considerable effect of the plant litter quality and microbiological activity on the carbon turnover in the regional soils formed under more favorable climatic conditions. [ABSTRACT FROM AUTHOR]

Summary: A large fraction of plant litter comprises recalcitrant aromatic compounds (lignin and other phenolics). Quantifying the fate of aromatic compounds is difficult, because oxidative degradation of aromatic carbon (C) is a costly but necessary endeavor for microorganisms, and we do not know when gains from the decomposition of aromatic C outweigh energetic costs.To evaluate these tradeoffs, we developed a litter decomposition model in which the aromatic C decomposition rate is optimized dynamically to maximize microbial growth for the given costs of maintaining ligninolytic activity. We tested model performance against > 200 litter decomposition datasets collected from published literature and assessed the effects of climate and litter chemistry on litter decomposition.The model predicted a time‐varying ligninolytic oxidation rate, which was used to calculate the lag time before the decomposition of aromatic C is initiated. Warmer conditions increased decomposition rates, shortened the lag time of aromatic C oxidation, and improved microbial C‐use efficiency by decreasing the costs of oxidation. Moreover, a higher initial content of aromatic C promoted an earlier start of aromatic C decomposition under any climate.With this contribution, we highlight the application of eco‐evolutionary approaches based on optimized microbial life strategies as an alternative parametrization scheme for litter decomposition models. See also the Commentary on this article by Shao & Sulman, 243: 825–827. [ABSTRACT FROM AUTHOR]

A characteristic feature of Earth's drylands is the patchy nature of the vegetation, often referred to as a two‐phase mosaic landscape, comprised of a homogenous matrix containing distinctive vegetated patches. The latter are considered vital for ecosystem functioning as they provide refuge to biota from unsuitable conditions. Ground‐living (epigeic) and foliage arthropods contribute to dryland biodiversity patterns and processes, but little is known of how their richness, abundance, and composition varies between patches and the matrix in these systems. Throughout the Succulent Karoo, South Africa, such patches (earthen mounds referred to as heuweltjies) are hotspots for both floral and faunal diversity. We investigate how epigeic and foliage‐dwelling arthropod species richness, abundance, and community composition respond to heuweltjie patch characteristics, particularly isolation (distance to nearest neighbor, average distance to nearest neighbor, patch density), size (area), and quality (average plant height, dead plant cover, leaf litter cover, termite frass) during a severe drought. Patch isolation and quality were significantly correlated with arthropod richness, abundance, and community composition. More specifically, average proximity of sampled heuweltjies to other neighboring heuweltjies, termite frass, and vegetation structure (height, leaf litter and dead plant cover) were key determinants for epigeic and foliage‐dwelling arthropods' species richness, abundance, and community composition. The uniqueness of these mounds as landscape features increases niche and microhabitat availability for arthropods. This emphasizes their importance as promoters of landscape heterogeneity and highlight heuweltjies as key to the spatial distribution of arthropod assemblages in the Succulent Karoo. [ABSTRACT FROM AUTHOR]

Plant species affect key ecosystem processes like nutrient cycling and overall ecosystem productivity through their litter. The outcome of litter effects is largely determined by its decomposability, which directly effects soil properties. If litter remains standing or unshed (i.e. marcescent), its final decomposability can be increased by photodegradation of recalcitrant structures (like lignin). If the litter is immediately shed, its decomposability largely depends on its original nutrient content. Moreover, plant species may affect soil also through other, more direct effects. It is however unknown whether marcescent and immediately shed litters affect soil, and by that plants, differently, whether direct effects of plants on soil interact with those of marcescent and shed litters, and whether these interactions are consistent under different soil conditions.We set up a pot experiment, where we tested the effects of originally marcescent and shed litters (both added on the soil surface of the pots) on three grassland species (Bromus erectus, Filipendula vulgaris and Plantago media) in contrasting soils from long‐term stable ancient grassland and grassland restored on arable land 20 years before. We also tested how litter types and plant species affect soil chemical properties and microbial community (characterised by PLFA markers).Marcescent litter contained a lower amount of nutrients, but still increased plant biomass more than shed litter, although only for F. vulgaris (likely due to mobilisation of soil nutrients).The effect of litter on soil chemical properties and microbial community was low. These were largely affected by the plant species growing in the pot. The effect of these species on the microbial community was stronger in the undisturbed soil of ancient grasslands, while plant species affected mainly chemical properties in disturbed soil of restored grasslands. B. erectus slowed down the decomposition of both litter types in restored grassland soil.The effect of marcescent litter on living plants was significant but species‐specific and depended on soil conditions. Marcescence seems to have a stronger effect on plants in disturbed soil, which indicates its importance for recovery of the ecosystem after disturbance. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: As cities grow, it is essential to understand how landscape management decisions in urban spaces alter ecosystem function. This study demonstrates that the ubiquitous practice of long‐term leaf litter removal in suburbs, even in relatively small patches of a yard, reduces the soil's ability to cycle nutrients in plant litter and results in lower amounts of carbon stored in the soil. Even two years of retaining leaves where they previously were removed is insufficient to restore decomposition rates or carbon pools. This research is an important step in creating best practices for litter management to maintain essential ecosystem functions, like carbon sequestration, water holding capacity, and soil fertility. Summary: Seasonal senesced leaf litter removal eliminates considerable organic material from suburban soils annually. We test if this disturbance alters decomposition and carbon cycles and depletes soils of organic matter over time, creating persistent legacy effects.We used a factorial experimental design to implement 1–2 years of current leaf litter manipulations (remove or retain fallen leaves) within historically raked and unraked areas in suburban Maryland yards. We then compared total organic soil carbon and decomposition using a standardized substrate decomposition methodology (Tea Bag Index) across treatment plots.Long‐term litter removal in suburban yards reduced decomposition rates by 17% and total soil organic carbon concentration by up to 24% compared to areas where leaf litter was retained in situ. In contrast, short‐term management changes (1–2 years) did not significantly impact decomposition rates or total organic soil carbon concentrations.Our findings suggest that long‐term suburban litter raking creates legacy effects that alter decomposition and carbon storage process trajectories that are not easily reversed. This is important in understanding urban ecosystem function and sustainable management. [ABSTRACT FROM AUTHOR]

The forest headwater streams are important hubs for connecting terrestrial and aquatic ecosystems, with plant litter and sediments as the major carriers for material migrations; however, until now we knew little about the dynamics of trace elements such as iron (Fe) and aluminum (Al) in forest headwater streams. Here, we quantitatively identified the spatiotemporal dynamics of Fe and Al storages in plant litter and sediments and their influencing factors in a subtropical forest headwater stream, and assessed the potential pollution risk. The results showed that: (1) the mean concentrations of Fe and Al in plant litter (sediments) were 5.48 and 8.46 (7.39 and 47.47) g·kg−1, and the mean storages of Fe and Al in plant litter (sediments) were 0.26 and 0.43 (749.04 and 5030.90) g·m−2, respectively; (2) the storages of Fe and Al in plant litter and sediments significantly fluctuated from January to December, and showed a decreasing pattern from the source to mouth; and (3) storages of Fe and Al had no significant correlation with riparian forest type and the present of tributary and the Fe and Al storages in plant litter were mainly affected by water temperature and water alkalinity, and their storages in sediments were mainly affected by water temperature and frequency of rainfall; and (4) there were no anthropogenic pollution in Fe and Al in the forest headwater stream. Our study revealed the primary factors of concentrations and storages of Fe and Al in plant litter and sediments in a forest headwater stream, which will improve our understanding of the role of headwater streams in forest nutrient storage and cycling along with hydrological processes. [ABSTRACT FROM AUTHOR]

Global environmental change has redistributed earth's biomass and the inputs and dynamics of basal detrital resources in ecosystems, contributing to the decline of biodiversity. Yet efforts to manage detrital necromass for biodiversity conservation are often overlooked or consider only singular resource types for focal species groups. We argue there is a significant opportunity to broaden our perspective of the spatiotemporal complexity among multiple necromass types for innovative biodiversity conservation. Here, we introduce an ecosystem-scale perspective to disentangling the spatial and temporal characteristics of multiple and distinct forms of necromass and their associated biota. We show that terrestrial and aquatic ecosystems contain a diversity of necromass types, each with contrasting temporal frequencies and magnitudes, and spatial density and configurations. By conceptualising an ecosystem in this way, we demonstrate that specific necromass dynamics can be identified and targeted for management that benefits the unique spatiotemporal requirements of dependent decomposer organisms and their critical role in ecosystem biomass conversion and nutrient recycling. We encourage conservation practitioners to think about necromass quantity, timing of inputs, spatial dynamics, and to engage with researchers to deepen our knowledge of how necromass might be manipulated to exploit the distinct attributes of different necromass types to help meet biodiversity conservation goals. [ABSTRACT FROM AUTHOR]

The study evaluated the decomposition and mineralization of pineapple and sorghum litter applied to the surface and subsurface of a Cambisol. The experiment was conducted in pot using pre-treatment (dry oven and fragmented), in a completely randomized design with four replications, following a 2 × 2 × 9 factorial consisting of two plant litters (pineapple and sorghum), two managements (surface and subsurface), and nine incubation times (0, 14, 28, 42, 56, 70, 84, 98, and 112 days after application-DAA). The remaining dry mass, the t1/2 (half-life), and macronutrient mineralization were evaluated (N, P, K, Ca, and Mg). The pineapple litter showed the highest loss compared to sorghum litter. Ca and Mg showed the longest half-life and the lowest mineralization rate regardless of the management. The allocation of pineapple and sorghum litter to the soil subsurface favors nutrient mineralization, contributing to the potential release of 82 to 99 kg ha−1 of N, 9 to 17 kg ha−1 of P, and 286 to 401 kg ha−1 of K, respectively, after 112 days. At least 50% of these nutrients were mineralized between four and 35 days, highlighting the litter potential as a nutrient source for tropical crops. [ABSTRACT FROM AUTHOR]

Boreal freshwaters go through four seasons, however, studies about the decomposition of terrestrial and plastic compounds often focus only on summer. We compared microbial decomposition of 13C‐polyethylene, 13C‐polystyrene, and 13C‐plant litter (Typha latifolia) by determining the biochemical fate of the substrate carbon and identified the microbial decomposer taxa in humic lake waters in four seasons. For the first time, the annual decomposition rate including separated seasonal variation was calculated for microplastics and plant litter in the freshwater system. Polyethylene decomposition was not detected, whereas polystyrene and plant litter were degraded in all seasons. In winter, decomposition rates of polystyrene and plant litter were fivefold and fourfold slower than in summer, respectively. Carbon from each substrate was mainly respired in all seasons. Plant litter was utilized efficiently by various microbial groups, whereas polystyrene decomposition was limited to Alpha‐ and Gammaproteobacteria. The decomposition was not restricted only to the growth season, highlighting that the decomposition of both labile organic matter and extremely recalcitrant microplastics continues throughout the seasons. [ABSTRACT FROM AUTHOR]

Research Highlight: Piccoli, G. C. d. O., Antiqueira, P. A. P., Srivastava, D. S., & Romero, G. Q. (2024). Trophic cascades within and across ecosystems: The role of anti‐predatory defences, predator type and detritus quality. Journal of Animal Ecology, 00, 1–14. https://doi.org/10.1111/1365‐2656.14063. Ecosystem functioning is controlled by the interplay between bottom‐up supply of limiting nutrients and top‐down animal feedback effects. However, the degree of animal versus nutrient control is context‐dependent. A key challenge lies in characterizing this context dependency which is hypothesized to depend on differences in animal functional traits. Reporting on an important experiment, Piccoli et al. (2014) evaluate how interactions among functionally different predators and decomposer prey create context dependency in top‐down control of a model system–tropical bromeliad tank ecosystems. Bromeliad plants hold water in their tanks supporting microcosm ecosystems containing terrestrial and aquatic insect larvae and arachnids. The ecosystems are supported by nutrients in plant litter that rains down from forest canopies into the tanks. Nutrients are released after litter is decomposed by a functionally diverse community of larval insect decomposers that differ in feeding mode and antipredator defence strategy. This decomposer community is preyed upon by an exclusively narrowly ranging aquatic insect larval predator and widely ranging spider predator that crosses between the aquatic and surrounding terrestrial ecosystems. Experimental manipulation of the animal community to test for the degree of control by predators mediated by the functionally diverse prey community included four treatments: (i) a control with the detritivores composing different function groups but without predators, (ii) the cross‐ecosystem spider predator added, (iii) the purely aquatic damselfly larvae predator added and (iv) both predator types added to capture their interacting effect on ecosystem function (decomposition, nutrient release, and plant growth). Notably, the study resolved the causal pathways and strengths of direct and indirect control using structural equation modelling. These findings reveal how context dependency arises due to different capacities of the predators alone and together to overcome prey defences and control their abundances, with attendant cascading effects that diminished as well as enhanced decomposition and nutrient release to support bromeliad plant production. The study reveals that predators have a decided, albeit qualitatively and quantitatively different, hand in shaping the degree of bottom‐up control through feedback effect on the release of limiting nutrients. This ground‐breaking study provides a way forward in understanding the mechanisms determining context dependency in the control over ecosystem functioning. [ABSTRACT FROM AUTHOR]

Background: Floodplains play an important role in the global carbon (C) cycle, particularly due to their large soil organic carbon (SOC) storage potential. However, a heterogeneous microrelief and anthropogenic landscape modifications complicate the understanding of stabilization processes of SOC in floodplains. Aim: Determining the predominant drivers for SOC stabilization in Elbe River floodplain soils. Methods: We measured SOC density fractions, microbial biomass, and mineralization characteristics in top‐ and subsoils of eight floodplain sites of the lower middle Elbe River. Results: The heavy fraction (HF) was the most important SOC pool, with a contribution of >64% at both depth intervals. With soil depth, HF pool size increased and the occluded light fraction (oLF) decreased, whereas the free LF (fLF) stayed the same. The contribution of the HF to SOC was positively related to fine texture (R2 = 0.64). Mineralizable C was negatively related to fine texture at both depth intervals. Both results suggest a positive effect of fine texture on SOC stabilization. The metabolic quotient was related to the amount of available SOC in the topsoil, but no relation was found in the subsoil. However, in top‐ and subsoil, the mineralization rate constant was positively related to the C/N ratios of the fLF and the oLF, indicating that the quality of fresh plant litter is an important energy source for microbial mineralization. Conclusion: Sedimentation of fine‐textured material is the most important driver for SOC stabilization rather than fresh plant litter input. Thus, SOC stabilization strongly depends on relief, flooding, and sedimentation. [ABSTRACT FROM AUTHOR]

The initial concentration of litter nutrient not only affects the following decomposition process but also determines the quantities of nutrients returned to the soil. The aim of this study is to assess the global patterns and driving factors of three macronutrients, namely potassium (K), calcium (Ca) and magnesium (Mg), in freshly fallen litter.By synthesizing 5861 data points extracted from 584 publications, we quantitatively evaluated the concentrations of litter K, Ca and Mg in different litter types, life forms, taxonomic divisions and mycorrhizal associations. Also, using the machine learning method, we predicted their global patterns in forests, grasslands and shrublands.We found that (1) mean K, Ca and Mg concentrations ranged from 2.63 to 6.23, 1.05 to 11.50 and 0.20 to 2.74 g/kg, respectively, across different litter types; (2) the initial nutrients of the litter were significantly affected by plant functional types (e.g. life form, taxonomic division and mycorrhizal association), climate (e.g. isothermality, mean diurnal range, annual evapotranspiration and precipitation seasonality) and soil properties (e.g. pH, exchangeable Ca concentration and water content), with a higher litter K concentration of herbaceous plants, higher K, Ca and Mg concentrations from angiosperms and higher K and Mg concentrations from plants associated with arbuscular mycorrhiza (AM) fungi; and (3) the predicted leaf litter K, Ca and Mg concentrations were lower in high‐latitude regions compared with those in low‐ and/or mid‐latitude regions.Our study provides a globally comprehensive analysis on the patterns and driving factors of three important macronutrients in freshly fallen litter, contributing to a better understanding of their role in the decomposition process of litter, as well as the associated biogeochemical cycles under the future climate change scenario. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Melanommataceous species exhibit high diversity with a cosmopolitan distribution worldwide and show a prominent saprobic lifestyle. In this study, we explored five saprobic species collected from plant litter substrates from terrestrial habitats in China and Thailand. A combination of morphological characteristics and multi-locus phylogenetic analyses was used to determine their taxonomic classifications. Maximum Likelihood and Bayesian Inference analyses of combined LSU , SSU , ITS and tef1-α sequence data were used to clarify the phylogenetic affinities of the species. Byssosphaeria poaceicola and Herpotrichia zingiberacearum are introduced as new species, while three new host records, Bertiella fici, By. siamensis and Melanomma populicola are also reported from litter of Cinnamomum verum, Citrus trifoliata and Fagus sylvatica, respectively. Yet, despite the rising interest in the melanommataceous species, there is a considerable gap in knowledge on their host associations and geographical distributions. Consequently, we compiled the host-species associations and geographical distributions of all the so far known melanommataceous species. [ABSTRACT FROM AUTHOR]

Anthropogenic disturbances associated with land use and land cover changes negatively influence soil organic C, reducing ecosystem functionality. These adverse effects may be even more pronounced in Brazilian subtropical riparian zones due to recent changes in environmental legislation that reduced the size of these protected areas in small scale farms. This study evaluated how different land uses in riparian zones influence ecosystem services related to soil, litter, and roots C and N stocks. The field experiment was carried out in a drainage area with four land uses and cover: forest fragment (FF), plantation forest (PF), pasture (PA), and agriculture (AG). Soil, root, and litter C and N stocks were analyzed. Monocultures (PF, PA, and AG) had lower soil C and N stocks than FF. The FF and PF did not differ in litter and root C content, but FF had higher N values. Differences in the quality of plant residues were associated with a lower soil C: N ratio in FF. The lowest soil C and N stocks were observed in AG sites, and the conversion from AG to PF and PA seems to increase soil C and N stocks. Our findings indicate that, even in small forest patches, the higher quality of organic residues drives soil C and N storage, highlighting the negative effects of vegetation replacement to monocultures in riparian zones. Hence, the maintenance of riparian forests is essential for providing ecosystem services related to soil C and N cycling. [ABSTRACT FROM AUTHOR]

In streams, short‐term element‐specific solute fluxes are often not balanced with long‐term chemical weathering fluxes determined in the residual solids from fractional element loss and denudation rate. The ratio of both estimates—the "Dissolved Export Efficiency" (DEE)—is frequently <1, indicating deficits in the stream dissolved load. To explore the cause of the stream deficits, we performed a daily water sampling campaign for one year in a forested headwater watershed in Southern Germany. We sampled surface runoff, above‐canopy and below‐canopy precipitation, subsurface flow from the organic soil layer, upper, and deep mineral soil, and groundwater. Regolith samples were obtained from a drill core and revealed the weathering front to lie between 7 and 15 m depth. We found a DEE < 1 for K, Si, Al, Fe. These elements are characterized by shallow slopes in C‐Q relationships, and the imbalances were found to originate in the deep saprolite. Their export pathway potentially includes "hidden" Critical Zone compartments or fluxes, presumably unsampled colloids that are exported preferentially during rare flushing events with stochastic temporal distribution. The DEE of nutritive elements like Ca, Mg, and P is also <1. These elements are characterized by steeper C‐Q slopes, and their imbalance can be explained by deep nutrient uptake followed by nutrient retainment in re‐growing forest biomass or export in plant debris. The collective evidence for these imbalances, including previous evidence from metal stable isotopes, suggests that the deep Critical Zone represents the location for chemical or biogenic retention and release of solutes. Plain Language Summary: Mineral dissolution by chemical weathering produces solutes in the weathering zone that are eventually exported by streams. Yet, often an imbalance between element‐specific solute export fluxes in stream water and element‐specific chemical weathering fluxes determined from residual solids in the weathering zone is apparent. This imbalance is expressed as a deficit in the stream dissolved load. To explore the origin of this deficit, we performed a daily water sampling campaign for one year in a forested watershed in Southern Germany. We studied concentration‐discharge relationships and quantified solute fluxes in stream‐ and groundwater. A comparison of solute fluxes in stream water with chemical weathering fluxes integrating mineral dissolution over the whole weathering zone revealed indeed deficits in the stream dissolved load. These deficits originate in deep isovolumetrically weathered bedrock (saprolite). The elements K, Si, Al, and Fe, which show invariant concentration changes with increasing discharge, may follow a "hidden" export pathway involving colloids that are only mobilized and exported during rare flushing events that were missed during this study's sampling period. Deficits of nutrients (Ca, Mg, P), which show dilution behavior with increasing discharge, can be explained by deep nutrient uptake and retention in growing forest biomass or plant litter erosion. Key Points: Imbalances between short‐term and long‐term estimates of element‐specific chemical weathering fluxes (DEE < 1) emerge in deep saproliteElements with shallow C‐Q slopes showing chemostatic or enrichment behavior are likely exported in colloidal form during flushing eventsElements with steeper C‐Q slopes showing weak dilution behavior remain in re‐growing biomass or are exported in particulate biogenic form [ABSTRACT FROM AUTHOR]

Invasive alien plant species are among the major drivers of change in natural ecosystems; therefore, their eradication or control is a common and effective conservation tool to reverse biodiversity loss. The LIFE LETSGO GIGLIO project was implemented with the objective of controlling the invasion of Carpobrotus spp., among the most threatening invasive alien species in Mediterranean ecosystems, on the Island of Giglio (Tuscan Archipelago, Italy). The management of Carpobrotus spp. was conducted across an area of approximately 33,000 m2 of coastal habitats. The main intervention was conducted during the winter of 2021–2022, primarily through manual removal, with a limited use of mulching sheets. Subsequent years saw the continued removal of seedlings. We monitored the habitats of vegetated sea cliffs and coastal garrigues (both protected under Directive 92/43/EEC), as these were the two habitats most affected by the control actions. A total of 24 permanent plots were sampled annually from 2020 to 2023 in a Before-After-Control-Impact (BACI) design. We analysed the variation pre- and post-removal of Carpobrotus spp. cover and litter and of native plant cover and diversity, as well as the changes in the composition of native plant communities. Our results show that already two years after the main intervention of removal, thus in the short term, the community's composition shifted considerably towards the pre-invasion set of species. This recovery was also evident in terms of diversity indices, although the impact of Carpobrotus spp. on ecological parameters (mainly soil) favoured nitrophilous species. Furthermore, we highlight the need for yearly removal of Carpobrotus spp. seedlings for the next 5–10 years, in order to continue promoting the recovery of native communities. [ABSTRACT FROM AUTHOR]

Variation in leaf traits is critical for carbon gains and losses during leaf life and drives litter carbon and nutrient losses via decomposition. Accurately quantifying litter decomposition parameters is essential for assessing ecosystem carbon and nutrient dynamics. Leaf litterbags have commonly been employed to measure effects of environmental drivers, decomposers, and plant traits on decomposition rates. There has been much debate regarding the suitability of substituting senesced dead leaves with fresh (green) leaves in litterbags, which has been common practice for mimicking green leaf fall or for practical reasons. Therefore, we tested the null hypothesis that replacement of dead leaves with fresh leaves in litterbag experiments is justified, based on similarities in structural and chemical traits between fresh and dead leaves across plant species and growth forms.We conducted a paired litterbag decomposition experiment with both fresh and dead leaves of 26 common species in subtropical China, in each of five contrasting ecosystems.While fresh leaves generally decomposed faster than dead leaves, this deviation varied among species and growth forms, based on their traits. Overall, there was significant but rather weak correlation between dead leaf decomposition rate k and fresh leaf k, across species and ecosystem types; the deviation between fresh and dead leaf k was larger for fast‐decomposing, mostly herbaceous species. The different decomposition patterns for fresh versus dead leaves were underpinned by key underlying traits integrated in leaf resource economics spectra (LES) for fresh and dead leaves. The dead leaf LES exhibited a greater predictive capability for dead leaf k while the fresh leaf LES had higher explanatory value for the fresh leaf k values.Our findings partly reject the null hypothesis and ask for caution in inferring leaf litter decomposition rates based on green leaf litterbags or traits data. We suggest follow‐up research on substituting senesced roots and stems with fresh ones in decomposition experiments.Synthesis. Human activities and extreme weather events are leading to increasing pulse inputs of fresh plant parts and our study contributes to knowledge on how they contribute to overall decomposition rates besides senesced litter inputs. [ABSTRACT FROM AUTHOR]

Litter decomposition is a key ecosystem process, relevant for the release and storage of nutrients and carbon in soil. Soil fungi are one of the dominant drivers of organic matter decomposition, but fungal taxa differ substantially in their functional ability to decompose plant litter. Knowledge is mostly based on observational data and subsequent molecular analyses and in vitro studies have been limited to forest ecosystems. In order to better understand functional traits of saprotrophic soil fungi in grassland ecosystems, we isolated 31 fungi from a natural grassland and performed several in vitro studies testing for i) leaf and wood litter decomposition, ii) the ability to use carbon sources of differing complexity, iii) the enzyme repertoire. Decomposition strongly varied among phyla and isolates, with Ascomycota decomposing the most and Mucoromycota decomposing the least. The phylogeny of the fungi and their ability to use complex carbon were the most important predictors for decomposition. Our findings show that it is crucial to understand the role of individual members and functional groups within the microbial community. This is an important way forward to understand the role of microbial community composition for the prediction of litter decomposition and subsequent potential carbon storage in grassland soils. [ABSTRACT FROM AUTHOR]

Nutrient cycling through leaf litter consumption is an essential ecological function performed by macrodetritivorous invertebrates such as isopods and millipedes. Leaf litter consumption rates can vary greatly depending on the environment, consumer identity and litter traits, but generalizations about the effects of plant traits on macrodetritivore leaf litter consumption, assimilation and growth are not well established and are mostly indirectly inferred.We conducted a systematic search of the global literature and obtained 456 standardized measures from laboratory experiments of relative consumption (RCR), assimilation (RAR) and growth (RGR) rates of terrestrial isopods and millipedes, extracted from 56 different articles. We investigated if commonly measured leaf traits, plant functional groups, prior microbial conditioning of leaves and climatic conditions affected these rates. We obtained data on commonly measured leaf traits from the TRY global plant trait database, inferred plant functional groups from taxonomic groupings and obtained climatic data from information reported within articles.RCR, RAR and RGR varied greatly among macrodetritivore and plant species, but overall, there were no differences between isopods and millipedes. Microbial conditioning of litter greatly increased RCR. Plant functional group was an important predictor of RCR, with eudicot trees and forbs being consumed in greater quantities than magnoliid trees and grasses. Fresh leaf N:P ratio had a positive effect on RAR, and leaf N and C:N ratio had positive and negative effects on RGR, respectively, while climatic variables had weak effects on the three rates.Our work shows that plant traits (both those associated with plant functional groups and commonly measured leaf traits) exert strong effects on resource processing rates by terrestrial macrodetritivores. Further, prior microbial conditioning of leaf litter has a large and globally consistent positive effect on macrodetritivore litter consumption, suggesting that they may consume little, if any, freshly senesced leaf material when microbially conditioned litter is available. Our results suggest that, where extremes of temperature or precipitation do not occur, variables reflective of food quality (leaf traits and microbe conditioning) are more important drivers of macrodetritivore leaf litter consumption than are extrinsic climatic variables. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Managing ecosystems to sequester soil carbon requires a thorough understanding of complex soil processes. Here, we integrate these soil processes through the metaphor of a game—one that moves through multiple dimensions (from macro‐aggregates to micropores and clay particles) and scales (from centimeters to nanometers) of the soil. The rules of the game are based on current understanding of soil carbon persistence, which differs from the classic humus concept of molecular complexity. The game's objective is to win points, by keeping "tokens" (plant‐derived organic compounds) within the soil organic matter for as long as possible. The game begins when tokens enter different "pool‐levels" (plant litter, particulate organic matter, dissolved organic matter, and mineral‐associated organic matter) of the soil, either directly or after metabolic transformation by soil biota. Points are lost through either respiration by soil biota or leaching. We invite readers to play this game and explore different natural ecosystems and land‐use scenarios to better comprehend complex soil processes. [ABSTRACT FROM AUTHOR]

Background: Moonmilk represents complex secondary structures and model systems to investigate the interaction between microorganisms and carbonatic rocks. Grotta Nera is characterized by numerous moonmilk speleothems of exceptional size hanging from the ceiling, reaching over two meters in length. In this work we combined microbiological analyses with analytical pyrolysis and carbon stable isotope data to determine the molecular composition of these complex moonmilk structures as well as the composition of the associated microbiota. Results: Three moonmilk structures were dissected into the apical, lateral, and core parts, which shared similar values of microbial abundance, richness, and carbon isotopes but different water content, microbiota composition, and organic matter. Moonmilk parts/niches showed higher values of microbial biomass and biodiversity compared to the bedrock (not showing moonmilk development signs) and the waters (collected below dripping moonmilk), indicating the presence of more complex microbial communities linked to carbonate rock interactions and biomineralization processes. Although each moonmilk niche was characterized by a specific microbiota as well as a distinct organic carbon profile, statistical analyses clustered the samples in two main groups, one including the moonmilk lateral part and the bedrock and the other including the core and apical parts of the speleothem. The organic matter profile of both these groups showed two well-differentiated organic carbon groups, one from cave microbial activity and the other from the leaching of vascular plant litter above the cave. Correlation between organic matter composition and microbial taxa in the different moonmilk niches were found, linking the presence of condensed organic compounds in the apical part with the orders Nitrospirales and Nitrosopumilales, while different taxa were correlated with aromatic, lignin, and polysaccharides in the moonmilk core. These findings are in line with the metabolic potential of these microbial taxa suggesting how the molecular composition of the preserved organic matter drives the microbiota colonizing the different moonmilk niches. Furthermore, distinct bacterial and archaeal taxa known to be involved in the metabolism of inorganic nitrogen and C1 gases (CO2 and CH4) (Nitrospira, Nitrosopumilaceae, Nitrosomonadaceae, Nitrosococcaceae, and novel taxa of Methylomirabilota and Methanomassiliicoccales) were enriched in the core and apical parts of the moonmilk, probably in association with their contribution to biogeochemical cycles in Grotta Nera ecosystem and moonmilk development. Conclusions: The moonmilk deposits can be divided into diverse niches following oxygen and water gradients, which are characterized by specific microbial taxa and organic matter composition originating from microbial activities or deriving from soil and vegetation above the cave. The metabolic capacities allowing the biodegradation of complex polymers from the vegetation above the cave and the use of inorganic nitrogen and atmospheric gases might have fueled the development of complex microbial communities that, by interacting with the carbonatic rock, led to the formation of these massive moonmilk speleothems in Grotta Nera. [ABSTRACT FROM AUTHOR]

Roadside vegetation in Central Europe is mostly species‐poor and dominated by a few grass species. Hemiparasitic plant species, including Rhinanthus spp., might effectively restrict grass growth, thereby making space for light‐dependent herb species. Despite the significance of abiotic site conditions for plant establishment in general, their effects on Rhinanthus establishment are less well known. We investigated combined effects of water availability, litter amount and seed position within litter on Rhinanthus seedling emergence and growth.Two parallel greenhouse experiments were conducted with R. angustifolius and R. minor. In these, we tested the impact of 200 or 400 g litter·m−2 with seeds sown beneath or on top of a litter layer under constantly humid or intermittently dry conditions on seedling emergence and biomass production of Rhinanthus.Presence of litter positively affected Rhinanthus seedling emergence when sown beneath the litter layer and reduced negative effects of water deficiency. Sowing beneath a litter layer increased seedling emergence by 157%, with similar effects at 200 and 400 g litter·m−2. Water level did not affect biomass production. Compared to R. minor, R. angustifolius had higher mean biomass, and its seedlings emerged earlier and in higher numbers.Our results indicate that Rhinanthus spp. react similarly to litter as non‐hemiparasitic plant species from temperate grasslands. Litter presence positively influenced Rhinanthus seedling emergence and growth under intermittently dry conditions. Its hemiparasitic characteristics might reduce drought impacts on biomass production. To ensure seed contact with the soil surface, seeds should be sown when no litter is present, or mulching should occur post‐sowing. [ABSTRACT FROM AUTHOR]

Litter decomposition is a key ecological process that determines carbon (C) and nutrient cycling in terrestrial ecosystems. The initial concentrations of C and nutrients in litter play a critical role in this process, yet the global patterns of litter initial concentrations of C, nitrogen (N) and phosphorus (P) are poorly understood.We employed machine learning with a global database to quantitatively assess the global patterns and drivers of leaf litter initial C, N and P concentrations, as well as their returning amounts (i.e. amounts returned to soils).The medians of litter C, N and P concentrations were 46.7, 1.1, and 0.1%, respectively, and the medians of litter C, N and P returning amounts were 1.436, 0.038 and 0.004 Mg ha−1 year−1, respectively. Soil and climate emerged as the key predictors of leaf litter C, N and P concentrations. Predicted global maps showed that leaf litter N and P concentrations decreased with latitude, while C concentration exhibited an opposite pattern. Additionally, the returning amounts of leaf litter C, N and P all declined from the equator to the poles in both hemispheres.Synthesis: Our results provide a quantitative assessment of the global concentrations and returning amounts of leaf litter C, N and P, which showed new light on the role of leaf litter in global C and nutrients cycling. [ABSTRACT FROM AUTHOR]

Animals assimilate macronutrients and mineral nutrients in specific quantities and ratios to maximise fitness. To achieve this, animals must ingest different foods that contain the needed nutrients or facilitate the digestion of those nutrients. We explored how these multidimensional considerations affect the desert isopods (Hemilepistus reaumuri) curious food selection, using field and laboratory experiments. Wild isopods consumed three‐fold more macronutrient‐poor biological soil crust (BSC) than plant litter. Isopods tightly regulated macronutrient and calcium intake, but not phosphorus when eating the two natural foods and when artificial calcium and phosphorus sources substituted the BSC. Despite the equivalent calcium ingestion, isopods performed better when eating BSC compared to artificial foods. Isopods that consumed BSC sterilised by gamma‐radiation ate more but grew slower than isopods that ate live BSC, implying that ingested microorganisms facilitate litter digestion. Our work highlights the need to reveal the multifaceted considerations that affect food‐selection when exploring trophic‐interactions. [ABSTRACT FROM AUTHOR]

Sediments and plant litter in forest headwater streams serve as vital repositories and carriers of elements, including heavy metals, that influence material cycling and energy flow of the forest ecosystem, but until now we know little about the dynamics of heavy metals in headwater streams. Here, we continuously monitored the storage and assessed the drivers of copper (Cu), cadmium (Cd), chromium (Cr), and lead (Pb) in sediments and plant litter from a subtropical forest headwater stream between March 2021 and February 2022. Results showed that (1) the total storage of Cu, Cd, Cr, and Pb in the sediments were 285.7, 10.4, 1084.7, and 4347.5 mg m−2, respectively, while those in plant litter were 0.23, 0.02, 3.5, and 0.68 mg m−2; (2) the storage of Cu, Cd, Cr, and Pb varied between different sampling reaches, showing an overall decrease pattern from the source of the stream to the mouth; and (3) heavy metal storage was significantly higher in the reaches with than without tributaries and with mixed riparian forests than broad-leaved riparian forests, and was positively affected by rainfall intensity, stream water dissolved oxygen and alkalinity and water depth, but negatively by stream water pH and temperature. Our results suggest that forest headwater streams play an important role in heavy metal storage and flux, which will help to better understand the dynamics of heavy metals along with the hydrological process in forest ecosystems. [ABSTRACT FROM AUTHOR]

Litter decomposition facilitates the recycling of often limiting resources, which may promote plant productivity responses to diversity, that is, overyielding. However, the direct relationship between decomposition, k, and overyielding remains underexplored in grassland diversity manipulations.We test whether local adaptation of microbes, that is, home‐field advantage (HFA), N‐priming from plant inputs or precipitation drive decomposition and whether decomposition generates overyielding. Within a grassland diversity‐manipulation, altering plant richness (1, 2, 3 and 6 species), composition (communities composed of plants from a single‐family or multiple‐families) and precipitation (50% and 150% ambient growing season precipitation), we conducted a litter decomposition experiment. In spring 2020, we deployed four replicate switchgrass, Panicum virgatum, litter bags (1.59 mm mesh opening), collecting them over 7 months to estimate litter k.Precipitation was a strong, independent driver of decomposition. Switchgrass decomposition accelerated with grass richness and decelerated as phylogenetic dissimilarity from switchgrass increased, suggesting decomposition is fastest at 'home'. However, decomposition slowed with switchgrass density. In plots that contained switchgrass, we observed no relationship between decomposition and fungal saprotroph dissimilarity from switchgrass. However, in plots without switchgrass, decomposition slowed with increasing saprotroph dissimilarity from switchgrass. Combined these findings suggest that HFA is strongest when closely related neighbours, that is, heterospecific neighbours, are present in the community, rather than other individuals of the same species, that is, conspecifics. Legumes accelerated decomposition with more litter N remaining in those plots, suggesting that N‐inputs from planted legumes are priming decomposition of litter C. However, decomposition and overyielding were unrelated in legume communities. While in grass communities, overyielding and decomposition were positively related and the relationship was strongest in plots with low densities of switchgrass, that is, with heterospecific neighbours.Combined these findings suggest that plant species richness and community composition stimulate litter decomposition through multiple mechanisms, including N‐priming, but only HFA from local adaptation of microbes on closely related species correlates with overyielding, likely through resource recycling. Our results link diversity with ecosystem processes facilitating above‐ground productivity. Whether diversity loss will affect litter decomposition, productivity or both is contingent on resident plant traits and whether a locally adapted soil microbiome is maintained. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Purpose: The decomposition of litter and nutrient cycling in terrestrial ecosystems are significantly influenced by ultraviolet-B (UV-B) radiation. The direction and magnitude of this effect are largely regulated by the dry and wet conditions of the environment. The impact of UV-B radiation on the decomposition process of different litter types in arid desert regions under future precipitation changes remains poorly understood. Methods: A field experiment was conducted to investigate the impact of precipitation changes (natural precipitation, a 30% increase in precipitation, and a 30% reduction in precipitation) on the litter decomposition of Reaumuria soongarica and Salsola passerina under both natural and reduced UV-B radiation conditions. Results: The reduction in UV-B radiation significantly decreased mass loss and nutrient release. However, these adverse effects were counteracted by increased precipitation, with an average value of 4.17% for mass loss and 34.35% for nutrient release. Conversely, decreased precipitation intensified these negative effects. The ameliorating effects of increased precipitation were associated with improved soil properties, including higher soil moisture and lower soil temperature, as well as elevated soil enzyme activities such as higher CBH and POD. Moreover, these mitigating effects on mass loss and nutrient release were more pronounced in S. passerina litter than in R. soongarica. A structural equation model revealed that precipitation and UV-B radiation indirectly influenced mass loss by altering soil properties (ST and SM) and soil enzyme activities (CBH and POD). Conclusion: Our results suggest that changes in precipitation will modify the effects of reduced UV-B radiation on litter decomposition and nutrient cycling of various plant litters, particularly in plants with lower initial nitrogen content, under climate change. [ABSTRACT FROM AUTHOR]

Anthropogenic forest fires are occurring with increasing frequency in tropical forests, with negative consequences for a variety of ecological processes, including litterfall. Litterfall provides several ecosystem services, such as nutrient cycling and carbon storage, thus playing an important role in ecosystem functioning. We assessed the impacts of fire and fire-created edges on litterfall in Atlantic Forest remnants in Bahia, Brazil. Litterfall was assessed at monthly intervals over one year along seven 300 m-long transects placed perpendicular to the edge between the unburnt forest and the burnt forest. We installed litterfall traps at the edge (0 m) and 20, 40, 60, 80, 100 and 150 m into both the burnt and unburnt forest. The total litterfall was smaller in the burnt forest (mean of 2.5 ± 2.2 SD t.ha−1.y−1) than in the unburnt forest (mean of 5.9 ± 3.4 SD t.ha−1.y−1). In addition, leaf litter gradually increased from the edge toward the unburnt forest interior. Our results highlight that there is less litterfall in the burnt forest, and that the relative contribution of different litter types (leaves, twigs, and miscellaneous litter) differ between burnt forest and unburnt forest. The lower amount of litterfall in the burnt forest and forest edge may have negative consequences for the natural regeneration of these areas, as the ecosystem services provided by plant litter that are important for forest regeneration are likely to be impaired. [ABSTRACT FROM AUTHOR]

The EFSA Panel on Plant Health performed a pest categorisation of Dendrolimus punctatus (Lepidoptera: Lasiocampidae), following a commodity risk assessment of bonsai Pinus parviflora grafted onto P. thunbergii from China, in which D. punctatus was identified as a pest of possible concern to the European Union (EU). D. punctatus, also known as the Masson pine caterpillar, is present in China, Taiwan, Vietnam, India and has recently spread to Japanese islands close to Taiwan. Larval feeding on the needles of Pinus elliottii, P. luchuensis, P. massoniana, P. merkusii and P. tabulaeformis causes important damage. D. punctatus larvae can also feed on P. armandii, P. echinata, P. latteri, P. parviflora, P. sylvestris var. mongolica, P. taeda, P. taiwanensis and P. thunbergii, but full development on these hosts is uncertain. The pest has three to five generations per year; winter is spent as larvae on branch tips, on tree trunks and in the soil. The females lay egg clusters on pine needles. Pupation occurs in cocoons attached to branches or needles. D. punctatus could enter the EU either as eggs, larvae or pupae in the foliage of plants for planting or cut branches, as larvae on wood with bark or as overwintering larvae in branches, crevices in the bark or in the litter of potted plants. However, Annex VI of 2019/2072 prohibits the introduction of D. punctatus hosts (Pinus spp.) from countries and areas where the pest occurs. There are climate zones where the pest occurs in Asia that also occur in the EU, though they are limited, which constitutes an uncertainty regarding establishment. The pest's main hosts are not grown in the EU. However, the fact that it attacks the North American Pinus echinata, P. elliottii and P. taeda in its Asian native area suggests a potential capacity to shift to pine species occurring in the EU territory. D. punctatus satisfies all the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest. Whether the Pinus commonly found in Europe could act as hosts is unknown but is fundamental, affecting the criteria of establishment and magnitude of impact. [ABSTRACT FROM AUTHOR]

Litter decomposition determines soil organic matter (SOM) formation and plant‐available nutrient cycles. Therefore, accurate model representation of litter decomposition is critical to improving soil carbon (C) projections of bioenergy feedstocks. Soil C models that simulate microbial physiology (i.e., microbial models) are new to bioenergy agriculture, and their parameterization is often based on small datasets or manual calibration to reach benchmarks. Here, we reparameterized litter decomposition in a microbial soil C model (CORPSE ‐ Carbon, Organisms, Rhizosphere, and Protection in the Soil Environment) using the continental‐scale Long‐term Inter‐site Decomposition Experiment Team (LIDET) dataset which documents decomposition across a range of litter qualities over a decade. We conducted a simplified Monte Carlo simulation that constrained parameter values to reduce computational costs. The LIDET‐derived parameters improved modeled C and nitrogen (N) remaining, decomposition rates, and litter mean residence times as compared to Baseline parameters. We applied the LIDET litter decomposition parameters to a microbial bioenergy model (Fixation and Uptake of Nitrogen – Bioenergy Carbon, Rhizosphere, Organisms, and Protection) to examine soil C estimates generated by Baseline and LIDET parameters. LIDET parameters increased estimated soil C in bioenergy feedstocks, with even greater increases under elevated plant inputs (i.e., by increasing residue, N fertilization). This was due to the integrated effects of plant litter quantity, quality, and agricultural practices (tillage, fertilization). Collectively, we developed a simple framework for using large‐scale datasets to inform the parameterization of microbial models that impacts projections of soil C for bioenergy feedstocks. Plain Language Summary: Decomposition breaks down organic matter like leaves and roots, creating soil organic material and releasing essential nutrients for plant and microbial growth. Soil creation and nutrient release are processes that affect how much carbon is stored in soil. Soil carbon storage in bioenergy agriculture may help create a favorable carbon balance for biofuels, ultimately reducing the rate of climate change. However, environmental decision makers need reliable information about how different bioenergy plants change soil carbon stocks to predict long‐term outcomes of present‐day decisions. These predictions are generated by computer models that mathematically represent ecological processes using observations from field studies. However, some models that include microbial decomposition lack a robust observational and mathematical basis for their representation of decomposition. We used a large‐scale litter decomposition dataset and simplified a statistical simulation that is typically complex and time‐consuming to improve the mathematical basis for litter decomposition in a soil carbon model. We used the improved decomposition representation in a different model that calculates soil carbon in bioenergy agriculture, and found the new representation increased predicted soil carbon in bioenergy feedstocks. Our statistical, data‐based framework can be adopted to help make model predictions more accurate, and environmental management decisions more effective. Key Points: Simplified Monte Carlo method uses constrained parameter sets and extensive dataset to parameterize decomposition in a microbial modelThe new litter decomposition parameters improved carbon and nitrogen decomposition metrics in a process‐based microbial modelApplying the new parameters to bioenergy systems altered modeled soil carbon with variation by plant traits, management, and litter inputs [ABSTRACT FROM AUTHOR]

Soluble components leach rapidly during the early stage of litter decomposition and represent the earliest nutrient input to the soils after leaf fall, which have significant importance for the material cycle in ecosystems. However, the concentration characteristics and primary drivers of litter soluble components at the global scale remain unclear. Therefore, 303 observations of water soluble compounds (WSCs), dissolved organic carbon (DOC), and dissolved organic nitrogen (DON) and auxiliary plant functional traits (mycorrhizal association, taxon division, plant life form, and leaf type) were collected worldwide. Linear mixed-effect models were used to examine the relative effects of climate, soil, topography, and plant functional traits on the concentration of different soluble components of litter. The average concentrations of leaf litter WSCs, DOC, and DON were 22.50, 4.15, and 0.01%, respectively. The concentration of WSCs in leaf litter was regulated by plant functional traits and soil properties, with mycorrhizal association and soil microbial biomass carbon to nitrogen ratio as the primary drivers. The concentration of DOC in leaf litter was influenced by climate and topography, with elevation being the most important factor. Our study reveals the global patterns and drivers of different soluble components in leaf litter, which is crucial for predicting litter decomposition under future climate change. [ABSTRACT FROM AUTHOR]