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Conceptual depiction of the main research questions. The temperature dependency across the temperature range (figure b) is arbitrary.
Source publication
Through litter decomposition enormous amount of carbon is emitted to the atmosphere. Numerous large-scale
decomposition experiments have been conducted focusing on this fundamental soil process in order to understand
the controls on the terrestrial carbon transfer to the atmosphere. However, previous studies were mostly
based on site-specific litte...
Context in source publication
Context 1
... et al., 2013), (2) are abiotic drivers controlling the initial stage of mass loss (Bradford et al., 2016) with temperature being the main regulating factor in the cold biomes and precipitation in the warmer biomes (Adair et al., 2008), and (3) does early stage litter mass losses vary between land-use types due to changes in the microclimates (Fig. ...
Similar publications
The Tea Bag Index (TBI), a novel approach to assessing organic matter decomposition using commercial tea bags, has been increasingly utilized as a standard method in academic studies worldwide. This approach was designed to obtain an early-stage decomposition constant (k) indicative of early-stage decomposition rates and a litter stabilization fact...
Patchy global data on belowground litter decomposition dynamics limit our capacity to discern the drivers of carbon preservation and storage across inland and coastal wetlands. We performed a global, multiyear study in over 180 wetlands across 28 countries and 8 macroclimates using standardized litter as measures of “recalcitrant” (rooibos tea) and...
The Bag Index (TBI) is a novel approach using standardized materials (i.e., commercial tea bags) to evaluate organic matter decomposition by determining two indexes: the early stage decomposition constant k (k_TBI) and litter stabilization factor S (S_TBI). k_TBI is defined as the decomposition constant of an asymptote model describing the decompos...
Decomposition of plant litter is an important process in the terrestrial carbon cycle and makes up approximately 70% of the global carbon flux from soils to the atmosphere. Climate change is expected to have significant direct and indirect effects on the litter decomposition processes at various timescales. Using the TeaBag Index, we investigated t...
Litter decomposition is a key process for carbon and nutrient cycling in terrestrial ecosystems and is mainly controlled by environmental conditions, substrate quantity and quality as well as microbial community abundance and composition. In particular, the effects of climate and atmospheric nitrogen (N) deposition on litter decomposition and its t...
Citations
... Temperature has been determined as a major driver of OM decomposition on a global scale (Allison et al. 2010; Davidson and Janssens 2006;Nissan et al. 2023), and it is therefore unsurprising that high seasonal variability in decomposition rates has been observed, particularly in temperate environments (Arndt et al. 2013). Leaf litter quality and bio-available nitrogen are also important factors, with low C:N ratios and high initial tissue nitrogen concentration accelerating decomposition (Djukic et al. 2018;Nordhaus et al. 2017;Parton et al. 2007). Organic matter quality can be variable in mangrove forests, ranging from highly labile compounds associated with microphytobenthic (MPB) production and root exudates to refractory leaf litter and woody fragments (Arndt et al. 2013;Friesen et al. 2018;Kristensen et al. 2008). ...
... However, these studies generally focused on single variables that affect decomposition rates, thereby neglecting the complexity of interacting factors that may regulate this process (Schmidt et al. 2011;Stoica et al. 2023). On the other hand, studies that focus on global drivers of change in decomposition rates can be biased by large-scale patterns that understate the importance of local conditions (Djukic et al. 2018;Mueller et al. 2018;Sarneel et al. 2024). Moreover, very few studies attempt to identify a direct link between anthropogenic stressors, such as eutrophication, and OM decomposition in mangrove forests (Santos-Andrade et al. 2021;Spivak et al. 2019). ...
The sediments in mangrove forests play an important role in the global carbon cycle due to high inputs of organic matter (OM) and low decomposition rates, making them highly efficient at sequestering carbon. The balance between OM sequestration and decomposition in these systems is influenced by a complex interplay of environmental factors. However, there is a large amount of uncertainty surrounding decomposition rates from mangrove forests, particularly at regional scales. We used standardized decomposition assays of a labile and recalcitrant substrate in 30 estuaries, spanning a gradient in human land use intensity, to identify dominant drivers of OM decomposition in temperate mangrove forests. Our results reveal that, while labile OM decomposition is strongly driven by eutrophication, recalcitrant OM decomposition is primarily influenced by increases in the minimum sediment temperature. Furthermore, we demonstrate that nutrient enrichment from human land use, in combination with increased sediment temperature, synergistically accelerates the decomposition of labile OM, thereby threatening the carbon sequestration potential of these ecosystems. This suggests that coastal eutrophication can exacerbate the effects of warming on decomposition, leading to heightened vulnerability of carbon storage and potential feedbacks between local and global stressors.
... Después de una década de su proposición, este se ha convertido en un estándar global para los estudios comparativos de descomposición a escalas espaciales que van desde algunos cientos de metros dentro de un ecosistema hasta diferentes ecosistemas y biomas a lo largo de gradientes latitudinales (e.g. Djukic et al., 2018;Kwon et al., 2021;Trevathan-Tackett et al., 2021). Este método estima las tasas de descomposición (k) en ambos tipos de té y el factor de estabilización (S). ...
... A decade since their proposal, this has become a global standard for comparative decomposition studies on spatial scales ranging from a couple hundred meters within an ecosystem to different ecosystems and biomes along latitudinal gradients (e.g. Djukic et al., 2018;Kwon et al., 2021;Trevathan-Tackett et al., 2021). This method estimates the decomposition rates (k) for both types of tea as well as the stabilization factor (S). ...
... A pesar de la popularización del método TBI en todo el mundo, aun son pocos los estudios en manglares (e.g. Djukic et al., 2018), con la excepción de Trevathan-Tackett et al. (2021), quienes realizaron el primer estudio a escala continental en el que compararon la dinámica a lo largo de un año entre humedales mareales (marismas y manglares), humedales de agua dulce y pastos marinos de Australia. ...
La descomposición de la materia foliar transfiere carbono a los sedimentos de los manglares. El “método de las bolsas de té”, que propone estudiar la descomposición utilizando un substrato estandarizado, aun no se ha implementado en Colombia. Aquí se presenta una adaptación que utiliza bolsas de té verde de una marca local, para estimar la masas remanente a 90 y 180 días en un manglar (Rincón del Mar, Sucre). Se enterraron 192 bolsas en un parche de 165 ha, arregladas en un diseño espacialmente anidado (10 ha, 16 m2, 1 m2, 300 cm2 y 150 cm2) y que fueron retiradas a los 90 días. En un experimento pareado para medir la masa remanente a los 90 y 180 días, se enterraron 48 bolsas en el centro de cada bloque de 1 m2. La masa remanente promedio a los 90 días fue 63,6 % (desviación estándar: 11,8%). No existieron diferencias significativas en el nivel espacial más grueso, sin embargo existío variación significativa dentro de los niveles inferiores. La masa remanente a los 180 días fue significativamente menor (49%). Este estudio demuestra la utilidad del método como una aproximación al proceso de incorporación de carbono orgánico en los sedimentos de manglar.
... In addition to temperature, the different k D values (Table 2) are due to the ability of microorganisms to utilize the molecular and elementary compositions of each leachate, with the carbon mineralization of the dissolved fraction spending the most DO available on the bioassays (Peret and Bianchini 2004;Bianchini, Cunha-Santino, and Peret 2008). Moreover, a study that evaluated the initial stages of the decomposition in different biomes concluded that the quality of the detritus has a great influence on the loss of biomass at this stage, being of great importance for carbon cycling (Djukic et al. 2018;Ma et al. 2024). The mineralization of leachate from Chara sp. ...
Aquatic macrophyte leachate is one of the autochthonous sources of carbon and nitrogen in aquatic systems, and microbial communities easily mineralize these elements. Understanding the effects of climate change on the consumption of dissolved oxygen (DO) due to the mineralization of leachate from aquatic macrophytes is fundamental for accurately establishing the oxygen balance in aquatic systems and forecasting element cycling rates. Bioassays were developed to determine the consumption of DO owing to the mineralization of carbon and nitrogen of the aquatic macrophytes leachates ( Myriophyllum aquaticum , Hedychium coronarium , Salvinia auriculata , and Chara sp.) when exposed to a temperature increase of 4°C (from 21°C to 25°C). The results concerning accumulated DO were fitted to a first‐order kinetic model. At 25°C, oxygen consumption due to mineralization increased by 9.6%, whereas the chemical composition of the leachate changed oxygen consumption between 7.2 (21°C) and 9.2% (25°C). The O/C stoichiometry (oxygen consumed by oxidized carbon) indicated the compositions of the leachate, and temperatures determined the pattern of oxygen consumption. Due to the chemical composition of the leachate, the values varied by approximately 17% and were higher at 25°C (about 30%). Regardless, the increase in temperature improved the oxygen consumption of leachate mineralization. After 90 days at 25°C, the highest concentrations of remaining dissolved organic carbon occurred, suggesting the selection of microorganisms and the catabolic routes that favored the production of refractory organic compounds to the detriment of mineralization. The results indicate that knowledge of the effects of climate variations on aquatic systems is crucial for an accurate understanding of the biogeochemical cycles in these environments.
... Generally, decomposition rates increase with temperature and precipitation in temperature-limited systems (Aerts, 2006). Yet, some studies have found negative correlations between precipitation and decomposition rates -for example, in very wet regions (Althuizen et al., 2018;Djukic et al., 2018;Sierra et al., 2017;Schuur, 2001). These contrasting findings from observational studies illustrate the dual role of soil moisture, where decomposition is limited in both wet (anaerobic) and dry (or freezing) conditions, with an optimum somewhere in between. ...
Litter decomposition is a vital part of the carbon cycle and is thoroughly studied both in the field and with models. Although temporally and spatially limited, litterbag decomposition experiments are often used to calibrate and evaluate soil models, coupled to land models, that are intended for use on large scales. We used the microbially explicit soil decomposition model MIMICS+ to replicate two high-latitude litterbag decomposition experiments of different spatial and temporal scales. We investigated how well the model represented observed mass loss in terms of the controlling factors of climate and litter quality and their relative importance with time. In addition to default model forcing, we used measured and site-specific model-derived microclimatic variables (soil moisture and temperature), hypothesizing that this would improve model results. We found that MIMICS+ represented mass loss after 1, 3, and 6 years well across a climatic gradient of Canadian sites but had more variable results for 1-year mass loss across a climate grid in southern Norway. In terms of litter quality, the litter metabolic fraction had more influence on modeled mass loss than the carbon-to-nitrogen ratio of the litter. Using alternative microclimate sources led to up to 23 % more mass remaining and down to 22 % less mass remaining compared to the simulations using default model inputs. None of the input alternatives significantly improved results compared to using the default model setup. We discuss possible causes for our findings and suggest measures to better utilize short-term field experiments to inform microbially explicit decomposition models.
... Alternatively, there are a number of experimental approaches that do not involve large-scale perturbation of natural site conditions, and can clearly benefit from applying the experiment across a range of sites that have existing long-term environmental observations. For example, the Global Teabag Experiment, which investigated the influence of climate on litter decomposition using the same substrate, which included the TERENO sites (Djukic et al., 2018). Another way to address this issue is to outsource experiments to another location, and link them mechanistically to the in situ observations (e.g., by controlling the experimental boundary conditions). ...
The need to develop and provide integrated observation systems to better understand and manage global and regional environmental change is one of the major challenges facing Earth system science today. In 2008, the German Helmholtz Association took up this challenge and launched the German research infrastructure TERrestrial ENvironmental Observatories (TERENO). The aim of TERENO is the establishment and maintenance of a network of observatories as a basis for an interdisciplinary and long‐term research program to investigate the effects of global environmental change on terrestrial ecosystems and their socio‐economic consequences. State‐of‐the‐art methods from the field of environmental monitoring, geophysics, remote sensing, and modeling are used to record and analyze states and fluxes in different environmental disciplines from groundwater through the vadose zone, surface water, and biosphere, up to the lower atmosphere. Over the past 15 years we have collectively gained experience in operating a long‐term observing network, thereby overcoming unexpected operational and institutional challenges, exceeding expectations, and facilitating new research. Today, the TERENO network is a key pillar for environmental modeling and forecasting in Germany, an information hub for practitioners and policy stakeholders in agriculture, forestry, and water management at regional to national levels, a nucleus for international collaboration, academic training and scientific outreach, an important anchor for large‐scale experiments, and a trigger for methodological innovation and technological progress. This article describes TERENO's key services and functions, presents the main lessons learned from this 15‐year effort, and emphasizes the need to continue long‐term integrated environmental monitoring programmes in the future.
... N additions had been reported accelerating decomposition in low-lignin litters, while this effect was inhibiting in high-ligning litters (Hobbie et al. 2012;Knorr et al. 2005). Another aspect to consider is the stage of the litter decomposition, with earlier stages characterised by the decomposition of non-lignified cellulose and hemicellulose; and the leaching of soluble compounds; while later stages encompasses the degradation of the lignified tissues, requiring a more complex metabolism (Djukic et al. 2018). ...
... Earlier stages of decomposition are less specific, as they consist on the mineralisation of labile C. However, later stages of decomposition require complex metabolites to degrade the recalcitrant tissues (Djukic et al. 2018). Impacts on the microbiota due to nutrient enrichments (Maaroufi and De Long 2020) may be more critical during a less generalistc later stage of decompositon. ...
Aims
The cycling of nutrients from plant litter has key implications for the functioning of terrestrial ecosystems by controlling nutrient availability and net primary production. Despite extensive research on the effects of global change on ecosystem functioning, the direct implications of global change on stoichiometry and nutrient dynamics during litter decomposition remain poorly understood. To address this gap, we conducted a meta-analysis.
Methods
We analysed 178 experiments that simulated (i) warming, (ii) drought, (iii) increased water availability, (iv) N enrichment, (v) P enrichment, and (vi) combined N and P (N + P) enrichment. We compared earlier (approximately six months) and later (approximately one year) stages of decomposition and analysed the specific effects taking into account climate and plant type.
Results
The C:N and C:P ratios decreased in most warming and nutrient enrichment scenarios, leading to losses of litter C content, while the N:P ratio remained more resilient and affected by water availability. Furthermore, the abundance of resources (water and N + P) fosters the decomposition of litter. The nutrient mobilisation increases for both P and N under non-limited nutrient enrichment and it is faster for N than for P when water increases its availability. Nutrient enrichment was relevant in later stages of decomposition.
Conclusions
Our study provides insights into the fate of litter decomposition and its stoichiometric dynamics in response to drivers of global change. Concerning scenarios of C release and N and P immobilisation were identified. However, further experimentation and analysis are necessary to consider all interacting drivers.
... Leaf functional traits also play an essential role in litter decomposition [9], such as stoichiometric traits (e.g., carbon, nitrogen, and phosphorus concentrations), physical traits (e.g., leaf thickness, leaf density, force to tear and punch), and size traits (e.g., leaf length, width, and area). Djukic et al. [10] related to the SSS, including leaf length, leaf width, and leaf area, which moderate the litter layer's temperature, humidity, and oxygen content, thereby affecting the foraging behavior and nutrient cycling activities of soil fauna [1,27,34]. (iii) traits related to chemical defense spectrum, such as cellulose, total phenol, and the concentrations of condensed tannins, these chemicals may cause leaves to decompose more slowly, thus reducing the available food for soil fauna [38,39]. ...
Leaf litter quality has been acknowledged as a crucial determinant affecting litter decomposition on broad spatial scales. However, the extent of the contribution of soil fauna to litter decomposability remains largely uncertain. Nor are the effects of leaf size and defensive traits on soil fauna regulating litter decomposability clear when compared to economics traits. Here, we performed a meta-analysis of 81 published articles on litterbag experiments to quantitatively evaluate the response ratio of soil fauna to litter decomposition at the global level. Our results revealed that soil fauna significantly affected litter mass loss across diverse climates, ecosystems, soil types, litter species, and decomposition stages. We observed significantly positive correlations between the response ratio of soil fauna and leaf length, width, and area, whereas the concentrations of cellulose, hemicellulose, total phenols, and condensed tannins were negatively correlated. Regarding economic traits, the response ratio of soil fauna showed no relationship with carbon and nitrogen concentrations but exhibited positive associations with phosphorus concentration and specific leaf area. The mean annual temperature and precipitation, and their interactions were identified as significant moderators of the effects of soil fauna on litter decomposition. We evidenced that the contribution of soil fauna to litter decomposability is expected to be crucial under climate change, and that trait trade-off strategies should be considered in modulating litter decomposition by soil fauna.
... and the TeaComposition Initiative (https://www.teacomposition.org/teacomposition-initiative/), which applied a common protocol and standard litter samples (tea bags of Lipton rooibos and green tea) (Keuskamp et al., 2013;Djukic et al., 2018). Although the TeaComposition Initiative has achieved impressive spatial coverage across Europe, providing valuable insights into soil decomposition dynamics in this region, its representation across the rest of the globe is less comprehensive. ...
... Countries with vast territories and diverse climate belts, such as Russia and Canada, and regions like Africa, remain underrepresented in the existing TeaComposition database. For example, Russian sites constitute only 8 out of the 336, with the majority located in south Siberia and only 1 in the European part of the country (Khibiny Station Russia, Murmansk region) (Djukic et al., 2018). This highlights how European Russia is a notable white spot on the tea bag map. ...
... This highlights how European Russia is a notable white spot on the tea bag map. Djukic et al. (2018), in a global study, alongside climate effects, examined the role of land-use type in distribution patterns of tea litter loss. However, urban soils-important hotspots of anthropogenic activities-were not considered. ...
... We found that historical management decomposition differences were driven by greater decomposition of the more recalcitrant rooibos tea leaves in yard areas than historically retained leaves. Leaching, an early decomposition process drives the mass loss of the more labile green tea leaves (Djukic et al., 2018). Perhaps litter management has a greater impact on biotic processes, such as microbial decomposition, more observable in rooibos tea than abiotic processes that drive green tea (Djukic, personal communication). ...
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.
... To address these limitations, it is recommended to calculate k using time- series data (Mori 2022c;Mori et al. 2022). An alternative approach employs only the unprocessed raw mass loss data from tea bags (Djukic et al. 2018;). In the present study, we chose the latter approach, following previous studies (Djukic et al. 2018;Mori 2022c), analyzing the raw mass loss data of both rooibos and green teas. ...
... An alternative approach employs only the unprocessed raw mass loss data from tea bags (Djukic et al. 2018;). In the present study, we chose the latter approach, following previous studies (Djukic et al. 2018;Mori 2022c), analyzing the raw mass loss data of both rooibos and green teas. ...
... In our field study, we followed the protocol described in Djukic et al. (2018) (the data in control-plots were provided for their report). We used commercially available tetrahedron-shaped synthetic tea-bags containing 2 g of rooibos tea (EAN: 87 22,700 18,843 8; Lipton) or green tea (EAN: 87 22,700 05552 5; Lipton). ...
