Bioversity International: research for development in agricultural and tree biodiversity

A tool to guide species and seed selection for the restoration of seasonally dry tropical forest in Colombia

12 Dec 2016

Making sure that native species and seed sources are site-adapted requires a certain degree of scientifically-based decision making capacity, which most restoration practitioners currently do not have.  As part of our CBD COP13 Forest and Landscape Restoration blog series, Evert Thomas writes about how Bioversity International scientists are working to overcome this.

Making sure that native species and seed sources are site-adapted requires a certain degree of scientifically-based decision making capacity, which most restoration practitioners currently do not have. To overcome this, Bioversity International scientists are developing an online decision-support tool which is intended to assist anyone interested in planting trees for whichever purpose with the identification of appropriate tree species and sources of planting material.

One of the guiding principles for integrating biodiversity considerations into ecosystem restoration that will be presented for adoption by the parties to the CBD at COP13 states that: “If ecosystem restoration is being aided by planting and reintroduction, make use of native site-adapted species, giving attention to genetic variation within and among native species, their life histories and the consequences of their interactions with each other and with their environment”.

This is a very pertinent guideline, which is very much in line with the recommendations featured in key publications on the topic led by Bioversity International scientists.

Making sure that native species and seed sources are site-adapted requires a certain degree of scientifically-based decision making capacity, which most restoration practitioners currently do not have. To overcome this, Bioversity International scientists are developing an online decision-support tool which is intended to assist anyone interested in planting trees for whichever purpose with the identification of appropriate tree species and sources of planting material.

To test the feasibility of this tool, we chose seasonally dry tropical forest (SDTF) in Colombia as a model case. Of all Colombian ecosystems, SDTF is the most threatened. Approximately 90% of its original cover has disappeared and less than 4% of old growth forest remains, while another 5% show some degree of degradation. With most forest fragments being located on private lands and less than 5% being represented in the national system of protected areas, the risks of further forest loss remain high. In response to this unsettling reality, the conservation and restoration of SDTF has become a national priority in Colombia.restool.org

Our tool is user friendly and it bases its decision-making on the integration of information on the expected effects of climate change at a restoration site; the functional trait diversity of tree species; and indications of the genetic quality of seed sources. Users of the tool are invited to provide a number of specifications of the planting site and the objectives of the planned restoration activities.

In the first step the user is invited to locate the restoration site on a Google Earth map interface. This allows for the tool to identify which tree species could possibly be used at the site for their expected ability to persist there under current and future climatic conditions. Identification of potential species is based on the results of habitat suitability modeling we carried out for more than 430 tree species known to occur in Colombian SDTF.

Next, the user is invited to specify how many species they aim to plant and their life history strategies (sunlight-demanding versus shade-tolerant species), as this will influence the optimal species choice. In the following step, prevailing environmental and stress conditions at the restoration site need to be specified, such as the presence of water bodies, compacted soil, steep slopes or the risks of fire.

Lastly, the user is solicited to identify the restoration objectives, which can be one or manifold, and combine productive goals with biodiversity conservation. Based on this user-defined information the tool will look for the tree species that are expected to be able to persist at the restoration site under climate change and whose functional trait profiles are best matched to the restoration objectives and enhance resistance against local stress factors. For example, if the restoration objective is to sequester carbon, and there is a risk of fire at the restoration site, then long-lived tree species with high wood density (associated with capacity to sequester carbon) and thick barks (resistance against fire) might be preferred.

The tool will then generate maps of recommended areas for seed sourcing to meet the restoration objectives. These seed sources are identified based on the principle that if climate change is predicted to considerably alter habitat conditions at the restoration site, seeds sourced from healthy local populations should be mixed with seeds from areas where habitat conditions are currently similar to those expected in the future at the restoration site. The maps are generated using genetic characterization data and the results of ecogeographical analyses. Users can specify to which time horizon climate change effects should be anticipated.

The resulting report will include options of species combinations that promote site adaptedness, resistance against locally prevailing stress factors and best contribute to the specified restoration objectives. Users can also choose for details on recommended propagation methods and management of the species to be included.

A beta version of the tool can already be consulted at www.restool.org, but will require further testing before it can be confidently used by practitioners. Feedback may be sent to Evert Thomas (e.thomas(at)cgiar.org). It is our hope that this tool will first and foremost make the life of restoration practitioners easier.

However, it also has potential of being used by governments, donors or implementers of restoration projects to ensure that due diligence is applied in the selection of appropriate species end seed sources. At Bioversity International we are committed to promoting the development and use of this type of user-friendly knowledge-based tools more widely by applying it to other ecosystems and countries around the world. We are now starting similar work in Peru, and hope to expand to other countries soon.

By Evert Thomas, Scientist, Conservation and Use of Forest Genetic Resources in Latin America, Bioversity International

This blog is part of a series that Bioversity International is rolling out around COP13 - Mainstreaming Biodiversity for Well-Being. The blogs explain why mainstreaming agricultural and tree biodiversity is critical in sustainable food and production systems if we are to achieve the Convention on Biological Diversity's Strategic Action Plan for Biodiversity 2011-2020 that "By 2050, biodiversity is valued, conserved, restored and widely used, maintaining ecosystem services, sustaining a healthy planet and delivering benefits essential for all people".

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Photo: Different stages of restoration of seasonally dry tropical forest in Colombia. Credit: Luis Gonzalo Moscoso Higuita

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