scholarly journals Using the Tea Bag Index to determine how two human pharmaceuticals affect litter decomposition by aquatic microorganisms

Ecotoxicology ◽  
2021 ◽  
Author(s):  
William Ross Hunter ◽  
Ashley Williamson ◽  
Judith Maria Sarneel
Keyword(s):  
Litter Decomposition ◽  
Tea Bag Index ◽  
Aquatic Microorganisms

scholarly journals TeaTime4Schools: Using Data Mining Techniques to Model Litter Decomposition in Austrian Urban School Soils

2021 ◽  
Vol 9 ◽  
Author(s):  
Taru Sandén ◽  
Anna Wawra ◽  
Helene Berthold ◽  
Julia Miloczki ◽  
Agnes Schweinzer ◽  
...  
Keyword(s):  
Data Mining ◽  
Litter Decomposition ◽  
Decomposition Rate ◽  
Classification Trees ◽  
Urban School ◽  
Attribute Selection ◽  
Decomposition Rates ◽  
Soil Attributes ◽  
Tea Bag Index ◽  
Stabilization Factor

Litter decomposition plays a pivotal role in the global carbon cycle, but is difficult to measure on a global scale, especially by citizen scientists. Here, citizen scientists, i.e., school students with their teachers, used the globally applied and standardized Tea Bag Index (TBI) method to collect data on litter decomposition in urban areas in Austria. They also sampled soils to investigate the linkages between litter decomposition and soil attributes. For this study, 54 sites were selected from the school experiments and assembled into a TBI dataset comprising litter decomposition rates (k), stabilization factors (S), as well as soil and environmental attributes. An extensive pre-processing procedure was applied to the dataset, including attribute selection and discretization of the decomposition rates and stabilization factors into three categories each. Data mining analyses of the TBI data helped reveal trends in litter decomposition. We generated predictive models (classification trees) that identified the soil attributes governing litter decomposition. Classification trees were developed for both of the litter decomposition parameters: decomposition rate (k) and stabilization factor (S). The main governing factor for both decomposition rate (k) and stabilization factor (S) was the sand content of the soils. The data mining models achieved an accuracy of 54.0 and 66.7% for decomposition rates and stabilization factors, respectively. The data mining results enhance our knowledge about the driving forces of litter decomposition in urban soils, which are underrepresented in soil monitoring schemes. The models are very informative for understanding and describing litter decomposition in urban settings in general. This approach may also further encourage participatory researcher-teacher-student interactions and thus help create an enabling environment for cooperation for further citizen science research in urban school settings.

scholarly journals Testing the Tea Bag Index as a potential indicator for assessing litter decomposition in aquatic ecosystems

2021 ◽  
Author(s):  
Taiki Mori ◽  
Kenji Ono ◽  
Yoshimi Sakai
Keyword(s):  
Litter Decomposition ◽  
Green Tea ◽  
Aquatic Ecosystems ◽  
Terrestrial Ecosystems ◽  
Terrestrial Environment ◽  
Validation Data ◽  
Standard Material ◽  
Tea Bag Index ◽  
Potential Indicator

AbstractThe Tea Bag Index (TBI) approach is a standardized method for assessing litter decomposition in terrestrial ecosystems. This method allows determination of the stabilized portion of the hydrolysable fraction during the decomposition process, and derivation of a decomposition constant (k) using single measurements of the mass-loss ratios of green and rooibos teas. Although this method is being applied to aquatic systems, it has not been validated in these environments, where initial leaching tends to be higher than in terrestrial ecosystems. Here, we first validated a critical assumption of the TBI method that green tea decomposition plateaus during the standard incubation period of 90 days, and then tested the accuracy of a TBI-based asymptote model using a second model obtained from fitting actual decomposition data. Validation data were obtained by incubating tea bags in water samples taken from a stream, a pond, and the ocean in Kumamoto, Japan. We found that green tea decomposition did not plateau during the 90-day period, contradicting a key assumption of the TBI method. Moreover, the TBI-based asymptote models disagreed with actual decomposition data. Subtracting the leachable fraction from the initial tea mass improved the TBI-based model, but discrepancies with the actual decomposition data remained. Thus, we conclude that the TBI approach, which was developed for a terrestrial environment, is not appropriate for aquatic ecosystems. However, the use of tea bags as a standard material in assessments of aquatic litter decomposition remains beneficial.

Effects of long-term field experiments on early stage litter decomposition in Austria and Sweden

2020 ◽  
Author(s):  
Maria Regina Gmach ◽  
Martin A. Bolinder ◽  
Lorenzo Menichetti ◽  
Thomas Kätterer ◽  
Taru Sandén
Keyword(s):  
Litter Decomposition ◽  
Decomposition Rate ◽  
Field Experiments ◽  
Early Stage ◽  
Tillage Systems ◽  
K Value ◽  
Tea Bag Index ◽  
The Impact ◽  
Term Field

<p>Soil organic matter decomposition affects the local and global C cycles. Decomposition is mainly affected by soil type and climatic conditions, for a given quality of organic material. This study tested the effect of land use and management, litter type, and climate on the early stage decomposition rate in long-term field experiments (LTEs) in Austria and Sweden. Standardized litter (Rooibos and Green tea) were used according to the Tea Bag Index (TBI) protocol (Keuskamp et al. 2013) for comparison of litter decomposition rate (k) and stabilization factor (S) in 11 sites in Austria (2015 and 2016) and 9 sites in Sweden (2016). The tea bags were buried at 8 cm depth and collected after ~90 days. Austrian LTEs focused on mineral nitrogen fertilization, mineral potassium fertilization, organic fertilization, tillage systems, and crop residues management. The LTEs evaluated in Sweden focused mainly on annual and perennial crops, mineral fertilization, and tillage systems. The impact of environmental parameters (air temperature and precipitation) was modeled to normalize the variance due to climatic effects at each site. The preliminary results show that in Austria TBI decomposition differed more between sites than between treatments at the same LTE. Minimum tillage treatment had significantly higher decomposition rates compared to reduced and conventional tillage. In Sweden, decomposition rate differed more between treatments than between sites. Fertilized plots showed higher stabilization than unfertilized, and maximum N fertilization had the highest k, while unfertilized had the lowest k. The effect of different tillage systems on k and S were variable across sites and treatments, although ploughing tended to result in the lowest k. The northernmost site resulted in the highest k value. Results indicated higher stabilization in perennial forage crops compared to annual crops. We also considered time-series decomposition for some sites with measurements at different time points by the TBI approach (retrieving tea bags after 15, 30, 60, and 90 days), and the use of Random Forest regressions to evaluate the importance of pedo-climatic variables on early stage decomposition.</p>

scholarly journals Tea Bags—Standard Materials for Testing Impacts of Nitrogen Addition on Litter Decomposition in Aquatic Ecosystems?

Nitrogen ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 259-267
Author(s):  
Taiki Mori
Keyword(s):  
Time Series ◽  
Litter Decomposition ◽  
Green Tea ◽  
Aquatic Ecosystems ◽  
Time Series Data ◽  
Nitrogen Addition ◽  
Series Data ◽  
N Addition ◽  
Rooibos Tea ◽  
Tea Bag Index

How the anthropogenic addition of nutrients, especially nitrogen (N), impacts litter decomposition has attracted extensive attention, but how environmental factors other than nutrients affect the impacts of N addition on litter decomposition is less understood. Since different local litters could respond differently to N addition, standard materials are necessary for comparing the impacts among various environments. The present study tested if tea bags used for the Tea Bag Index (TBI) approach, i.e., constructing an asymptote model by using a green tea decomposition datum and a rooibos tea decomposition datum (single measurement in time), can be standard materials for testing the impacts of N addition on litter decomposition in aquatic ecosystems. A laboratory incubation experiment was performed using a water sample taken from a stream in Kumamoto, Japan. Since a recent study suggested that the TBI approach may be inapplicable to aquatic ecosystems, a time-series data approach, i.e., fitting models to time-series mass loss data of tea bags, was also used for testing if tea bag decomposition can pick up the impacts of N addition on aquatic litter decomposition. The time-series data approach demonstrated that N addition significantly suppressed rooibos tea decomposition, whereas green tea decomposition was not affected by N addition. The TBI approach was unsuitable for testing the sensitivity of the response of tea bag decomposition to N addition because the TBI-based asymptote model failed to predict the observed data, confirming the suggestion by a previous study. Overall, the present study suggested that the tea bags can be used as standard materials for testing the impacts of N addition on litter decomposition in aquatic ecosystems, but only when using a time-series measurement and not the TBI.

scholarly journals Pairing litter decomposition with microbial community structures using the Tea Bag Index (TBI)

2021 ◽  
Author(s):  
Anne Daebeler ◽  
Eva Petrová ◽  
Elena Kinz ◽  
Susanne Grausenburger ◽  
Helene Berthold ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Litter Decomposition ◽  
Green Tea ◽  
Plant Litter ◽  
Soil Types ◽  
Community Structures ◽  
Decomposition Rates ◽  
Tea Bag Index ◽  
Decomposition Dynamics

Abstract. Including information about soil microbial communities into global decomposition models is critical for predicting and understanding how ecosystem functions may shift in response to global change. Here we combined a standardised litter bag method for estimating decomposition rates, Tea Bag Index (TBI), with high-throughput sequencing of the microbial communities colonising the plant litter in the bags. Together with students of the Federal College for Viticulture and Fruit Growing, Klosterneuburg, Austria, acting as citizen scientists, we used this approach to investigate the diversity of prokaryotes and fungi colonising recalcitrant (rooibos) and labile (green tea) plant litter buried in three different soil types and during four seasons with the aim of (i) comparing litter decomposition [decomposition rates (k) and stabilisation factors (S)] between soil types and seasons, (ii) comparing the microbial communities colonising labile and recalcitrant plant litter between soil types and seasons (iii) correlating microbial diversity and taxa relative abundance patterns of colonisers with litter decomposition rates (k)and stabilisation factors (S). Stabilisation factor (S), but not decomposition rate (k), correlated with the season and was significantly lower in the summer. This finding highlights the necessity to include colder seasons in the efforts of determining decomposition dynamics in order to quantify nutrient cycling in soils accurately. With our approach, we further showed selective colonisation of plant litter by fungal and prokaryotic taxa sourced from the soil. The community structures of these microbial colonisers differed most profoundly between summer and winter, and rooibos litter was generally a stronger selector than green tea litter. Moreover, this study indicates an equal, if not higher, importance of fungal versus prokaryotic degraders for recalcitrant and labile plant litter decomposition. Our results collectively demonstrate the importance of analysing decomposition dynamics over multiple seasons and isolating the effect of the active component of the microbial community.

scholarly journals Impact of land-use change in mountain semi-dry meadows on plants, litter decomposition and earthworms

Web Ecology ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 53-63 ◽  
Author(s):  
Ines Jernej ◽  
Andreas Bohner ◽  
Ronnie Walcher ◽  
Raja Imran Hussain ◽  
Arne Arnberger ◽  
...  
Keyword(s):  
Species Richness ◽  
Litter Decomposition ◽  
Plant Species ◽  
Plant Traits ◽  
Plant Biomass ◽  
Plant Cover ◽  
Higher Plant ◽  
Study Region ◽  
Earthworm Species ◽  
Tea Bag Index

Abstract. Traditionally managed mountain grasslands are biodiversity hotspots in central Europe. However, socio-economic trends in agriculture during the last decades have changed farming practices, leaving steep and remote sites abandoned. Especially the abandonment of meadows is well known to directly affect plant and insect diversity. However, not much is known about the effects on soil processes and soil biota. To assess this, we studied four extensively managed (mown once a year, no fertilization) and four abandoned (no mowing, no fertilization) semi-dry meadows in a mountain region in Austria. Plant species richness, plant cover, plant traits, plant biomass, litter decomposition (tea bag index), and earthworm species richness and density were assessed. Additionally, soil temperature, moisture and electrical conductivity were measured. Results showed that managed meadows contained more plant species than abandoned meadows (118 vs. 93 species, respectively). We also observed different plant species assemblages between the two management types. In managed meadows, hemirosette and ruderal plant species were more abundant, while more plant species without rosettes and a higher plant necromass were found in abandoned meadows. Additionally, decomposition rate was higher in abandoned meadows. There was a trend towards higher earthworm densities in managed meadows, but there was no difference in earthworm species richness. We conclude that meadow management has effects on both aboveground vegetation and belowground biota and processes. Both abandoned and extensively managed meadows were important to sustain overall biodiversity and ecosystem functioning in the study region.

scholarly journals Learning Science during Teatime: Using a Citizen Science Approach to Collect Data on Litter Decomposition in Sweden and Austria

2020 ◽  
Vol 12 (18) ◽  
pp. 7745
Author(s):  
Taru Sandén ◽  
Heide Spiegel ◽  
Hannah Wenng ◽  
Michael Schwarz ◽  
Judith M. Sarneel
Keyword(s):  
Litter Decomposition ◽  
Soil Depth ◽  
Global Carbon Cycle ◽  
Lessons Learned ◽  
Basic Process ◽  
Decomposition Rates ◽  
Tea Bag Index ◽  
Life On Earth ◽  
Critical Process ◽  
Global Carbon

The decay of organic material—litter decomposition—is a critical process for life on Earth and an essential part of the global carbon cycle. Yet, this basic process remains unknown to many citizens. The Tea Bag Index (TBI) measures decomposition in a standardized, measurable, achievable, climate-relevant, and time-relevant way by burying commercial tea bags in soil for three months and calculating proxies to characterize the decomposition process (expressed as decomposition rate (k) and stabilization factor (S)). We measured TBI at 8 cm soil depth with the help of school and farm citizen scientists in 2015 in Sweden and in 2016 in Austria. Questionnaires to the participating schools and farms enabled us to capture lessons learned from this participatory data collection. In total >5500 citizen scientists participated in the mass experiments, and approximately 50% of the tea bags sent out yielded successful results that fell well within previously reported ranges. The average decomposition rates (k) ranged from 0.008 to 0.012 g d−1 in Sweden and from 0.012 to 0.015 g d−1 in Austria. Stabilization factors (S) were up to four times higher in Sweden than Austria. Taking part in a global experiment was a great incentive for participants, and in future experiments the citizen scientists and TBI would benefit from having enhanced communication between the researchers and participants about the results gained.

scholarly journals Tea Bag Index to Assess Carbon Decomposition Rate in Cranberry Agroecosystems

Soil Systems ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 44
Author(s):  
Wilfried Dossou-Yovo ◽  
Serge-Étienne Parent ◽  
Noura Ziadi ◽  
Élizabeth Parent ◽  
Léon-Étienne Parent
Keyword(s):  
Litter Decomposition ◽  
Green Tea ◽  
Decomposition Rate ◽  
Terrestrial Ecosystems ◽  
Carbon Accumulation ◽  
N Leaching ◽  
Decomposition Rates ◽  
Rooibos Tea ◽  
Tea Bag Index ◽  
Stabilization Factor

In cranberry production systems, stands are covered by 1–5 cm of sand every 2–5 years to stimulate plant growth, resulting in alternate layers of sand and litter in soil upper layers. However, almost intact twigs and leaves remain in subsurface layers, indicating a slow decomposition rate. The Tea Bag Index (TBI) provides an internationally standardized methodology to compare litter decomposition rates (k) and stabilization (S) among terrestrial ecosystems. However, TBI parameters may be altered by time-dependent changes in the contact between litter and their immediate environment. The aims of this study were to determine the TBI of cranberry agroecosystems and compare it to the TBI of other terrestrial ecosystems. Litters were standardized green tea, standardized rooibos tea, and cranberry residues collected on the plantation floor. Litter decomposition was monitored during two consecutive years. Added N did not affect TBI parameters (k and S) due to possible N leaching and strong acidic soil condition. Decomposition rates (k) averaged (mean ± SD) 9.7 × 10−3 day−1 ± 1.6 × 10−3 for green tea, 3.3 × 10−3 day−1 ± 0.8 × 10−5 for rooibos tea, and 0.4 × 10−3 day−1 ± 0.86 × 10−3 for cranberry residues due to large differences in biochemical composition and tissue structure. The TBI decomposition rate (k) was 0.006 day−1 ± 0.002 in the low range among terrestrial ecosystems, and the stabilization factor (S) was 0.28 ± 0.08, indicating high potential for carbon accumulation in cranberry agroecosystems. Decomposition rates of tea litters were reduced by fractal coefficients of 0.6 for green tea and 0.4 for rooibos tea, indicating protection mechanisms building up with time in the tea bags. While the computation of the TBI stabilization factor may be biased because the green tea was not fully decomposed, fractal kinetics could be used as additional index to compare agroecosystems.

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