Processing of invasive alien plant species into new, useful products

Instead of composting or incinerating invasive alien plant species, we are developing new ways how to process them into new, useful products (paper and wood products, dyes and hybrid coatings, extracts for controlling of plant harmful organisms, food source, input materials for the industries of the future and 3D composites). Invasive alien species are a locally accessible and abundant resource and opportunity for a new business model, promoting zero‑waste approach and circular economy.

Innovation Summary

Innovation Overview

Invasive alien plant species (IAPS) are one of the biggest challenges in European ecosystems. They displace local vegetation, destroy agricultural land and cause damage to European economy in billions of euros every year. Many of them are daily removed and mainly burned. Ljubljana, like many European cities, is faced with overgrowth of Japanese knotweed, one of the top 100 most invasive alien species in the world. Its rapid growth and strong, deep roots result in dense stands that quickly displace local vegetation and cause economic disadvantages.

In the past four years, the City of Ljubljana has offered its residents free deposition of removed Japanese knotweed in waste collection centers, before transferring it to an incinerator. Seeking to find innovative solutions to deal with this invasive plant and its further reuses, we have shifted the perspective, recognizing this undesirable plant as a locally accessible and abundant material for producing cellulose.

Currently in Slovenia, the pulp and paper industry is using somewhere between 350,000 and 400,000 tons of cellulose, all of which is imported from abroad. As part of promoting the title of European Green Capital 2016, the evolving initiative gathered five partners from different disciplines and sectors to test the first small scale industrial process of paper production from the widespread invasive plant. Approximately 100 volunteers and partners of the project were invited to take part in a series of urban harvesting actions organized by the City of Ljubljana, which included collecting 1,520 kg of Japanese knotweed stems. Taking the advice from the University Botanic gardens in Ljubljana, the volunteers collected dry winter stems. In this way, the new shoots of Japanese knotweed are weakened and the production process is shortened as the material doesn’t need additional drying. With the help of Snaga Public Waste Management Company, the gathered materials were cut into smaller pieces and taken to the Pulp and Paper Institute where they were carefully processed into a final amount of 415 kg of paper.

Two very useful products have emerged, namely notebooks and paper bags, designed by the Re-generacija collective. In autumn 2016, a campaign among vendors at the central open market in Ljubljana was carried out, promoting the replacement of plastic with paper bags, in which 1,600 bags made from Japanese knotweed were distributed among the vendors and buyers. The industrial-produced paper is also used for environment protection publishing.

In 2017 we have upgraded the pilot project with a hand crafted paper production from Japanese knotweed. The paper was used for the promotional purposes of the landscape park Tivoli, Rožnik and Šišenski hrib which lies right in the city centre. With more than 1.7 million visitors each year it is also the most frequently visited area in Slovenia. The area is covered with natural forest and is home to numerous species that are important in terms of nature conservation and appear on the Red List of endangered species. 12 motifs of landscape park’s natural features and activities were designed and printed onto a memory game, calendar, graphics and postcards. The promotional products are addressing not only the foreign visitors of the park, but also the residents of Ljubljana.

From November 2017, the City of Ljubljana is implementing the APPLAUSE project in which IAPS are considered a RESOURCE and starting point of a NEW BUSINESS MODEL: through large-scale educational and awareness raising campaigns citizens are encouraged to participate in IAPS harvesting and use. Collected IAPS feed three main ways of their further transformation that is performed at home (e.g. food, dyes), at tutored workshops (e.g. to produce wood or paper products) and in craftsman laboratories (e.g. to manufacture innovative products with market potential in social enterprises, employing vulnerable groups).

New green technologies are introduced (e.g. pilot enzymatic processing of IAPS fibers instead of chemical, reuse of wastes generated during primary wood processing and paper production, transformation of residues into liquefied wood, development of biotech-based biorafinery device for the conversion of liquor, production of 3D novel bio-composites, production of dyes, production of IAPS coloured coatings, development of a model of IAPS’s dye based solar cell and development of home-made formulations against plant harmful organisms).

ICT technology is used to address target groups and to produce open data, new knowledge and develop new services like IAPS monitoring with data from aerial orthophotos and Sentinel-2 satellites.

The results of the project are presented at public events and discussed at different expert meetings. The residents are strongly supporting the activities, linking the results with the higher quality of the living environment. New products are strong ambassadors, drawing people's attention to the IAPS issues and solutions.

Innovation Description

Innovation Development

Innovation Reflections

Leave a Reply

Your email address will not be published. Required fields are marked *

Year: 2016
Level of government: Local government


  • Implementation - making the innovation happen

Innovation provided by:

Join our community:

It only takes a few minutes to complete the form and share your project.