FAQ – University of Copenhagen


How to join?

  • Sign your site under: https://docs.google.com/spreadsheets/d/15NjWkpjsvR7VkghpAkHa_ClSl7OtOh1VMSzcLdmGRGY/edit?usp=sharing

  • Register under emailing list by:
    • Send a message to sympa@list.ilternet.edu
    • type in the subject line “subscribe litter_bag_initiative [GivenName] [Name]”
    • leave the message body blank
  • Once you have registered you will receive "instruction package" including protocol for installation as well as templates for data reporting

  • Site commitment involves that each site need to agree to the protocol and ensure that this is followed.

Tea received but not installed

Received tea should be installed and obtained data reported. In case the tea is not used at the given start of initiative, we are encouraging you to bury them in the coming season. If this is also not feasible, then the tea should be send back.

Start of the incubation

We aim to start the incubation at the same time of year. In northern hemisphere this would be June and in southern Hemisphere the December. This is of importance to be able to compare the sites globally. Any deviations from the protocol have to be announced and discussed a priori.

Why Tea bags – why not use normal litterbags?

Common litter bags are most often conducted based on site-specific litters and methodologies so that comparison of similar data across different experiments and sites still poses a major challenge due to the lack of common protocols and standard matrices. Tea bags are commercially available and they constitute a pre made “litterbag” reducing any variation related to user differences in preparation. This method provides a common metric for studying decomposition and C dynamics and storage. The common metric will provide a strong tool and results for inter-site comparison within the network as well as with other global networks. By obtaining harmonized data on one of the basic soil processes we will be able to draw general conclusions on the impact of climate and other drivers on litter decomposition and thereby on the greenhouse gas emissions and terrestrial feedback as well as soil carbon storage in different ecosystems worldwide.

However, TeaCompositon method does not give the actual magnitude for C-losses and decomposition rates, since the tea is not equivalent to the real local litter, but can be related to local rates (e.g. by simultaneous incubation of native litter) and modeling. Therefore, it would be of advantage installing the tea bags together with the local litterbags or using the sites for the installation with already existing data on native litter decomposition.

What is the difference between TBI and TeaComposition?

See Table (TBI_TeaComposition _flagsheet _END(4).pdf)

What is the TeaComposition H2O?

Wetlands are among the world’s most effective ecosystems for carbon sequestration. Maintenance or loss of wetland ecosystems will therefore have profound impact on the Earth’s climate. What is missing, however, is standardized information on how carbon retention varies among wetland types – i.e. which wetlands are optimal for preserving carbon and thereby helping offset the atmospheric CO2 pool? This project, ‘TeaComposition H2O’, is a global-scale analysis of litter decomposition within wetland ecosystems. It will systematically measure the balance between wetland carbon storage and release, thereby providing critical information to inform nature-based climate change mitigation initiatives involving wetlands. This research is timely given that wetland ecosystems are declining globally. The focus will be on four important aquatic ecosystems: seagrass meadows, mangrove forests, tidal marshes and freshwater wetlands. The current TeaComposition H2O network consists of more than 350 sites in 34 countries tracking biomass and carbon decomposition as well as the microbial communities driving this process.

Sign-up is still open for the Southern Hemisphere until 31 August 2017.


Some photos for the H2O initiative could be seen here: https://www.dropbox.com/sh/3004e6r4ikegiu7/AADTh-EIh8Pf2HlFI8ePUjjka?dl=0

How much time do I have to invest?

The amount of work for each site is restricted to installation and collection of the bags.

The site has to provide manpower and resources for:

  • Installation of the teabags and retrieval (collection) after incubation
  • Cleaning and weighing of the tea bags after incubation providing standard information about the site (standard and generally available for most sites)
  • Optional: parallel running of a litterbag study with local litter
  • Optional: Chemical analyses of tea material and soil (no resources can be provided but a common project may be applied for to cover this)

To do

Time [day]

Sample preparation &   installation, if needed soil sampling (3x 100g per site)


Sample collection


Sample preparation



10 (in 3 years)

Costs for tea

is sponsored by UNILEVER

How much space does the method require

If you would like to install the tea at your site without any experimental treatments then the desirable set up should be as follow: 2 replicate areas (~1m2) with a minimum distance between the bags of 10 cm and a distance between the rows ~ 30 cm. Replicate areas should be selected randomly and should have homogenous vegetation and topography. Distance between the replicate areas should be at least 1-2 m2.

If the study should be implemented within an existing experimental set up, then the design should be adapted accordingly. However, beside the changes in space the protocol should be followed.

Tea type and its availability

UNILEVER, the company that produces the Lipton tea, is sponsoring the "TeaComposition" initiative. The initiative uses two very specific badges of Green Tea and Rooibos Tea (see Tea Types)

Do note that since 2017 the fabric of the tea bags has changed from woven, nylon to non-woven, polypropylene and the obtained mass loss cannot be compared.

Hosted by University of Copenhagen