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

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.

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Tea Bag Index to Assess Carbon Decomposition Rate in Cranberry Agroecosystems

Soil Systems ◽

10.3390/soilsystems5030044 ◽

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

10.5194/egusphere-egu2020-10280 ◽

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>

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Evaluating the tea bag method as a potential tool for detecting the effects of added nutrients and their interactions with climate on litter decomposition

10.1101/2021.01.28.428520 ◽

2021 ◽

Author(s):

Taiki Mori ◽

Toru Hashimoto ◽

Yoshimi Sakai

Keyword(s):

Environmental Factors ◽

Litter Decomposition ◽

Rate Constant ◽

Decomposition Rate ◽

Late Stage ◽

Early Stage ◽

Nutrient Addition ◽

Interactive Effects ◽

Decomposition Rate Constant ◽

Stabilization Factor

AbstractIt is acknowledged that exogenous nutrient addition often stimulates early-stage litter decomposition in forests and late-stage decomposition is generally suppressed by nitrogen addition, whereas the interactive effects of nutrient addition and abiotic environmental factors, such as climate, on decomposition remain unclear. The tea bag method, which was developed to provide the decomposition rate constant k of early-stage decomposition and stabilization factor S of labile materials in the late stage, is a potentially useful tool for examining the impacts of nutrient addition on both early- and late-stage litter decomposition and their interactions with climate. At a long-term (38-year) continuous fertilization experimental site (an Abies sachalinensis Fr. Schmidt stand) in Hokkaido, Japan, we examined whether a standard tea bag method protocol was sufficiently sensitive to reveal any impacts of nutrient addition on early- and late-stage decomposition. In addition, we tested the interactive effects of nutrient addition and climate on litter decomposition. The short incubation period of the tea bag method (ca. 90 days) enabled us to obtain decomposition data from the same location at three different times in a year, i.e., early summer, midsummer, and winter, providing an opportunity to test interactive effects. We demonstrated that the decomposition rate of rooibos tea and the decomposition rate constant k of early-stage decomposition were clearly stimulated by fertilization in midsummer, but no impacts were detected in other seasons, probably because the relative importance of nutrient availability was elevated in midsummer, during which decomposition rates were less constrained by temperature and moisture. The green tea decomposition rate and stabilization factor S, an index related to late-stage decomposition, were unaffected by fertilization. This was probably because the tea bag method does not take into account lignin degradation, which is considered a key factor controlling late-stage litter decomposition. Overall, the present study (i) successfully determined the interactive effects of nutrient addition and climate factors on litter decomposition by making full use of the tea bag method, and (ii) the results suggest that the tea bag method can be a suitable tool for examining the direct effects of nutrient addition and their interactions with environmental factors on early-stage litter decomposition, but not those on late-stage decomposition.

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

10.5194/soil-2021-110 ◽

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.

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Combined effects of water temperature, grazing snails and terrestrial herbivores on leaf decomposition in urban streams

PeerJ ◽

10.7717/peerj.7580 ◽

2019 ◽

Vol 7 ◽

pp. e7580 ◽

Cited By ~ 1

Author(s):

Hongyong Xiang ◽

Yixin Zhang ◽

David Atkinson ◽

Raju Sekar

Keyword(s):

Organic Matter ◽

Water Temperature ◽

Leaf Litter ◽

Litter Decomposition ◽

Decomposition Rate ◽

Litter Quality ◽

Urban Streams ◽

Combined Effects ◽

Decomposition Rates ◽

Terrestrial Insects

The decomposition of organic matter in freshwaters, such as leaf litter, can affect global nutrient (e.g., carbon) cycling. This process can be influenced by fast urbanization through increased water temperature, reduced aquatic diversity and changed leaf litter quality traits. In this study, we performed a mesocosm experiment to explore the individual and combined effects of warming (8°C higher and ambient), the presence versus absence of grazing snails (Parafossarulus striatulus), and intraspecific difference of leaf litter quality (intact versus > 40% area of Liriodendron chinense leaves grazed by terrestrial insects) on litter decomposition in urban streams. Litter decomposition rates ranged from 0.019 d−1 to 0.058 d−1 with an average decomposition rate of 0.032 ± 0.002 d−1. All the three factors had significant effects on litter decomposition rate. Warming and the presence of snails accelerated litter decomposition rates by 60% and 35% respectively. Litter decomposition rates of leaves damaged by terrestrial insects were 5% slower than that of intact leaves, because litter quality of terrestrial insect-damaged leaves was lower (i.e., higher specific leaf weight) than intact leaves. For treatments with snails, warming stimulated microbial and snail mediated litter decomposition rates by 35% and 167%, respectively. All combinations of treatments showed additive effects on litter decomposition except for the interaction between warming and snails which showed positive synergistic effects. In addition, neither temperature nor litter quality affected snail growth rate. These results imply that higher water temperature and the presence of abundant snails in urban streams greatly enhanced litter decomposition. Moreover, the effect of pest outbreaks, which resulted in lower litter quality, can cascade to aquatic ecosystems by retarding microbe-mediated litter decomposition. When these factors co-occurred, warming could synergistically interact with snails to speed up the depletion of organic matter, while the effect of leaf quality on litter decomposition may be diminished at high water temperature. These effects could further influence stream food webs and nutrient cycling.

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STABILIZATION AND DECOMPOSITION RATE OF STANDARD MATERIAL IN HERBACEOUS COMMUNITIES OF THE FOREST ZONE

Ekosistemy ◽

10.37279/2414-4738-2021-25-12-21 ◽

2021 ◽

pp. 12-21

Author(s):

T. G. Elumeeva ◽

O. V. Cherednichenko ◽

T. M. Gavrilova

Keyword(s):

Decomposition Rate ◽

Plant Litter ◽

Ecological Indicator ◽

Herbaceous Plant ◽

Indicator Values ◽

Standard Material ◽

Tea Bag Index ◽

Stabilization Factor ◽

Decomposition Constant ◽

Moscow River

The rate of plant litter decomposition depends on two simultaneous processes: the decomposition and stabilization of organic matter. To compare the rates of these processes in various ecosystems now a Tea Bag Index (TBI) is widely used. The samples of standard material (green tea and rooibos) were buried into soil at the depth of 8 cm in four herbaceous plant communities of Central Forest State Nature Biosphere Reserve (CFSNBR) and seven communities of the Moscow river floodplain near the MSU Zvenigorod biological station (ZBS). Considering the mass losses of samples during the incubation time we calculated the values of decomposition constant and stabilization factor according to the protocol by J. A. Keuskamp et al. (2013) and estimated the links of these parameters with Ellenberg’s ecological indicator values. The stabilization factor values ranged from 0.122 g/g in Filipendula community of CFSNBR to 0.379 g/g at the natural levee of the Moscow river, and the decomposition constant values ranged from 0.0089 g/g/day in Filipendula community of CFSNBR to 0.0308 g/g/day at the slope of the high floodplain. The mean values of these parameters were significantly positively correlated. The decomposition rate was lower in the communities of CFSNBR and was positively correlated with the soil pH Ellenberg’s indicator values. The stabilization factor values did not depend on the region and decreased with the increase in soil moisture and nitrogen. The mainland meadows of CFSNBR and the meadows of the high floodplain of the Moscow river, belonging to Cynosurion cristati alliance, had the most similar parameters of decomposition.

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

Sustainability ◽

10.3390/su12187745 ◽

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.

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Urbanisation differently affects decomposition rates of recalcitrant woody material and labile leaf litter

Urban Ecosystems ◽

10.1007/s11252-021-01125-3 ◽

2021 ◽

Author(s):

DJ Kotze ◽

H Setälä

Keyword(s):

Mass Loss ◽

Litter Decomposition ◽

Decomposition Rate ◽

Vegetation Type ◽

Climatic Conditions ◽

Urban Habitat ◽

Urban Habitats ◽

Decomposition Rates ◽

Spruce Forests ◽

The City

AbstractLitter decomposition is a fundamental ecosystem process and service that supplies nutrients to the soil. Although decomposition rate is influenced by litter quality, climatic conditions, the decomposer community and vegetation type in non-urban ecosystems, little is known about the degradation of different organic matter types in urban settings. We investigated the decomposition rates of recalcitrant (wood sticks for 4 years) and labile litter (green tea leaves in pyramid-shaped teabags for 3 years) in urban habitats that differed in level of management and disturbance. We found that recalcitrant woody material decomposed slower in urban habitat types (ca. 60–75% mass loss after 4 years in remnant spruce forests, park lawns, ruderal habitats) than in natural to semi-natural spruce forest soils (84% mass loss) outside the city. Labile tea litter, however, decomposed faster in typical open urban habitats (70% mass loss after 3 years in park lawns, ruderal habitats) than in forested habitats (60% mass loss in semi-natural and remnant spruce forests), with a remarkable dichotomy in decomposition rate between open and forested habitats. We suggest that the slower rate of wood decomposition in the city relates to its depauperate saprotrophic fungal community. The faster rate of labile litter decomposition in open habitats is difficult to explain, but is potentially a consequence of environmental factors that support the activity of bacteria over fungi in open habitats. We propose that the reintroduction of decaying woody material into the urban greenspace milieu could increase biodiversity and also improve the ability of urban soils to decompose an array of organic material entering the system. This reintroduction of decaying woody material could either occur by leaving cut logs – due to management – in urban remnant forests, which has been shown to be accepted as natural features by residents in Fennoscandian cities, and by placing logs in urban parks in ways that communicate their intentional use as part of urban landscape design and management.

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Effects of soil fauna on litter decomposition in Chinese forests: a meta-analysis

PeerJ ◽

10.7717/peerj.12747 ◽

2022 ◽

Vol 10 ◽

pp. e12747

Author(s):

Peng Zan ◽

Zijun Mao ◽

Tao Sun

Keyword(s):

Litter Decomposition ◽

Effect Size ◽

Decomposition Rate ◽

Temperate Forest ◽

Litter Quality ◽

Soil Fauna ◽

Spatial Scales ◽

Meta Analysis ◽

Decomposition Rates ◽

The Impact

Litter quality and climate have been presumed to be the dominant factors regulating litter decomposition rates on broad spatial scales. However, the role of soil fauna on litter decomposition is poorly understood, despite the fact that it could strongly influence decomposition by fragmentation and subsequent modification of the activities of microorganisms.In this study, we carried out a meta-analysis on the effects of soil fauna on litter decomposition rates in Chinese forests, ranging from boreal to tropical forests, based on data from 20 studies. The effects of climatic factors on decomposition rate were assessed by comparing the contribution of soil fauna to litter decomposition from studies carried out at different latitudes.The degree of influence of the soil fauna was in the order tropical (200%) > subtropical (47%) > temperate forest (28%). Comparing the effect size of soil fauna, it was found that when soil fauna was excluded, the decomposition rate, calculated using Olson’s equation, was most affected in tropical forest (−0.77), while the litter decomposition rate both subtropical (−0.36) and temperate forest (−0.19) were also suppressed to varying degrees (P < 0.001). These results highlight that soil fauna could promote litter decomposition to different extents. Using stepwise multiple linear regression, the effect size of the soil fauna was negatively correlated with the cellulose and nitrogen concentrations of the initial litter material. In Chinese forests, litter decomposition rates were reduced, on average, by 65% when soil fauna was excluded. The impact of soil fauna on decomposition was shown to be closely related to climate and litter quality.

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Recognizing Job Apathy Patterns of Iraqi Higher Education Employees Using Data Mining Techniques

Journal of Southwest Jiaotong University ◽

10.35741/issn.0258-2724.54.4.30 ◽

2019 ◽

Vol 54 (4) ◽

Author(s):

Mustafa S. Abd ◽

Suhad Faisal Behadili

Keyword(s):

Higher Education ◽

Data Mining ◽

Psychiatric Patients ◽

Human Life ◽

A Priori ◽

Psychological Research ◽

Attribute Selection ◽

Specific Class ◽

Data Mining Techniques ◽

Using Data

Psychological research centers help indirectly contact professionals from the fields of human life, job environment, family life, and psychological infrastructure for psychiatric patients. This research aims to detect job apathy patterns from the behavior of employee groups in the University of Baghdad and the Iraqi Ministry of Higher Education and Scientific Research. This investigation presents an approach using data mining techniques to acquire new knowledge and differs from statistical studies in terms of supporting the researchers’ evolving needs. These techniques manipulate redundant or irrelevant attributes to discover interesting patterns. The principal issue identifies several important and affective questions taken from a questionnaire, and the psychiatric researchers recommend these questions. Useless questions are pruned using the attribute selection method. Moreover, pieces of information gained through these questions are measured according to a specific class and ranked accordingly. Association and a priori algorithms are used to detect the most influential and interrelated questions in the questionnaire. Consequently, the decisive parameters that may lead to job apathy are determined.

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