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Citation:
Boshier D. 2012. Trees outside of forests. Introductory notes for teachers. In: Forest Genetic Resources Training Guide. Edited by Boshier D, Bozzano M, Loo J, Rudebjer P. Bioversity International, Rome, Italy.
www.bioversityinternational.org

ISBN 978-92-9043-902-8
ISSN 2223-0165

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© Bioversity International, 2011
Bioversity International is the operating name of the International Plant Genetic Resources Institute (IPGRI).

Acknowledgements

The editors of this Forest Genetic Resources Training Guide wish to thank Jarkko Koskela and Barbara Vinceti for their contribution in identifying the need for the guide and for their continuous support during its preparation. We acknowledge the important advice from a reference group of scientists at Bioversity International - Elizabeth Goldberg, Jozef Turok and Laura Snook - who at various stages supported this project.

This training guide was tested during several training events around the world. We would like to acknowledge the valuable feedback received from many students and their teachers, in particular Ricardo Alía and Santiago González-Martínez from the National Institute of Agriculture and Food Research (INIA), Spain.

We would like to give special thanks to Ian Dawson, World Agroforestry Centre for his review of the Case studies presented in this module. His valuable feedback led to important improvements of the module.

Finally, the production of the Forest Genetic Resources Training Guide would never have been possible without the financial support of the Austrian Development Cooperation through the project, ‘Developing training capacity and human resources for the management of forest biodiversity’, implemented by Bioversity International during 2004-2010. We would also like to thank the European Commission-funded “SEEDSOURCE” project for additional financial support.

All cover illustrations were drawn by Rosemary Wise and the layout was created by Patrizia Tazza. We are grateful for their beautiful work.

Module 2

Trees outside of forests

Introductory notes for teachers

David Boshier, Department of Plant Sciences, University of Oxford

Background

Human disturbance of forests is omnipresent. The human uses of forests are wide-ranging (e.g. timber, fuel, food, clearance for habitation, agriculture, grazing) and vary in their impacts, depending on the type and intensity of use. Deforestation and forest degradation in recent decades have led to dramatic reductions in the area of forest and to its fragmentation into smaller patches of varying size and spatial isolation. For some forest ecosystems, the remaining forests often are highly fragmented and below the size considered viable, such that the ideal of maintaining large, continuous in situ reserves is impractical.

The limitations of in situ and ex situ conservation approaches, and recognition that farmers maintain large arrays of plant diversity in some traditional farming systems, for a range of reasons have led to a re-examination of the potential role of “conservation through use” on farms. The term circa situm has been used to distinguish the very different circumstances of utilitarian conservation of a species outside its natural habitat but still within its native geographical range, such as within agricultural landscapes (e.g. agroforestry systems, home gardens).

The agricultural matrix in which many forest remnants now exist is in itself a complex mosaic of varying land use practices. They vary in their degree of tree cover from almost none (e.g. crop monocultures such as sugarcane) to highly complex agroforests (e.g. shade coffee) in which there is maintenance not only of a high degree of tree cover but also a variety of tree species. Therefore, in some cases, conservation initiatives must consider approaches that depart from the traditional in situ conservation paradigm (i.e. protected wilderness areas), to ways in which managers can conserve the species of an already highly altered forest type by managing networks of small forest patches in such mosaics of land-use types. Where species occur wholly on farms, such landscapes will constitute the only remaining conservation option, while still potentially under threat from human pressure and changing agricultural practices.

Deforestation and fragmentation may have obvious effects such as the elimination of some species. However, there may also be less immediate effects on the longer-term viability of species through impacts on ecological and genetic processes (e.g. increased inbreeding, reduced fruit/seed production). Functional use may also relate to conservation in farmland, e.g. fruit tree species that are obligate outcrossers will depend on connectivity for fruit production and hence humans continuing to value and maintain them. Some medicinal trees, if only used locally, may be maintained at very low densities, such that connectivity becomes very important. In contrast, while fodder/soil fertility species may have very high densities, short rotation management may limit seeding opportunities. Managers must therefore consider the reproductive and regenerative capacities of priority species as well as the perpetuation of management practices that allow natural or artificial regeneration to ensure that tree populations have a long-term future and continue to be valued.

The effects of fragmentation on remnant stands and trees, their gene pools, and consequent conservation value are subject to debate. At the pessimistic extreme are views characterizing remnant trees in agroecosystems as “living dead” because, being isolated from potential mating partners, they may not produce offspring, or offspring may fail to establish new generations and are thus considered of little conservation value. More optimistically, the possibility of extensive gene flow between isolated trees of many taxa, through pollen transport over long distances by animal or wind vectors, suggests that remnant trees can be effective and important in conserving genetic diversity.

Introduction to Module 2 Case studies

This Module allows students to explore the role that trees outside of forests may play in conserving tree species diversity and genetic resources. The two case studies in this Module cover a number of issues that fall under the overall question of ‘Can valuable tree genetic resources persist outside of forests?’ The Module explores forest genetic resources aspects such as:

Fragmentation - gene flow patterns and maintenance of viable populations

Conservation of species and genotypes

Conservation paradigms - in situ, ex situ, through use (circa situm)

Reproductive materials - source and collection

Case study 2.1: Conservation of tree species diversity in cocoa agroforests in Nigeria. This allows students to explore the role that cocoa agroforests may play in conserving tree species diversity. The exercise considers the overall question of ‘Can cocoa agroforests be important for conserving native tree species and if so what measures need to be taken to ensure they persist?’ The case study presents information from research in cocoa farms and forest reserves in Nigeria. It focuses on comparing levels of tree species diversity found in native forests and cocoa agroforests. In particular, it raises issues of different measures of diversity and considerations of whether important species are conserved. The exercise suits 1-3 groups of 4-5 students per group. Some groups present a case for the conservation benefits in terms of tree species diversity in the cocoa agroforests of Nigeria, while others derive an action plan to ensure optimum conservation benefits in terms of tree species diversity in the cocoa agroforests of Nigeria.

Case study 2.2: Devising options for conservation of two tree species outside of forests. This allows students to explore the role that trees outside of forests may play in conserving tree genetic resources. The exercise considers the overall question of ‘Can valuable tree genetic resources persist outside of forests and if so what measures need to be taken to ensure they persist?’ The case study presents information from multidisciplinary research (ecological, genetic, socio-economic) in dry forests of Costa Rica and Honduras. It focuses on two timber species, Bombacopsis quinata, Bombacaceae, and Swietenia humilis, Meliaceae, both of local socio-economic importance, with superficially similar ecology and of conservation concern. The exercise suits 1-3 groups of 4-5 students per group.

How to use the case studies

The case studies are designed for use as class exercises on devising options for conservation of tree species outside of forests, where a lot of information is available. Teachers can use one or both of the two case studies, depending on the particular conservation issue, class size and availability of time. Although the case studies are tropical, extensive testing shows they are suitable for students from tropical and non-tropical countries alike. If class sizes are larger than the numbers indicated, it is better to use both case studies from the same unit, rather than increasing the size of each group. If groups are larger than six, some students tend to not contribute to the discussion and work of their group.

Each case study consists of:

The Case study - introduces the exercise to be assigned to the students and presents information from research on the particular forest genetic resources issues.

Teacher’s notes - give extensive tips on how to prepare and run the exercise and discuss the main learning points that students should be able to derive from the case study.

Additional background information - can be used to introduce the case study to the students. It includes video and PowerPoint presentations.

Reference materials - these include PDF files of key publications relevant to the case study.

The exercises can be run in a number of ways depending on the time available and size of the class. The exercises work best if students work in groups of 4-5 (no more than 6 per group). It is best if the students have already read the case study before they start the exercise. This way valuable class time is not lost with students reading the paper during the class. So give the case study out in a previous class with instructions to read it before the next class. It perhaps goes without saying that it is vital that the teacher and any assistants are fully familiar with the whole text. Each exercise lasts approximately 3 hours, broken down as follows:

Introduction: use the video followed by the PowerPoint - approx 20 minutes.

Group work: students discuss the case study amongst themselves, responding to the specific points and developing their strategy. The teacher should be around to answer any queries the groups have. However it is not essential that all of the time is spent with the whole class together with the teacher. Once the teacher and groups are happy they understand the assignment and issues, they could meet, discuss and prepare the strategy outside of class time - 1.5 hours.

Presentations: each group presents its strategy verbally to the class (supported by main points written on large paper or in a PowerPoint presentation) - 10 minutes per presentation, plus 5 minutes for questions/comments by the rest of the class and teacher.

Final discussion: led by the teacher allowing them to make general comments about what was good, what was missed, etc. - 10 minutes.

Key background publications

The following documents can be found on the accompanying DVD, or at the Forest Genetic Resources Training Guide webpage at:

www.bioversityinternational.org

They give more background to the issues raised in this module and can be used by the teacher to strengthen their knowledge and help give ideas about the topics.

Conservation of tree genetic resources themes:

Participatory approach: FAO et al. (2004), pp. 54-57, 70-71.

Assumptions/misconceptions about local communities: FAO et al. (2004), pp. 58-60.

Harmonise human needs and in situ conservation: FAO et al. (2001), p. 57; Geburek and Turok (2005), pp. 507-508, 523.

Glossary of genetics terms: FAO et al. (2004), pp. 103-106; FAO et al. (2001), pp. 87-90.

Boffa J. 2000. West African agroforestry parklands: keys to conservation and sustainable management. Unasylva 51:11-17.

Boshier DH, Gordon JE, Barrance AJ. 2004. Prospects for circa situm tree conservation in Mesoamerican dry forest agro-ecosystems. In: Frankie GW, Mata A, Vinson SB, editors. Biodiversity Conservation in Costa Rica, Learning the Lessons in the Seasonal Dry Forest. University of California Press, Berkeley, USA. pp. 210–226.

Boshier DH. 2004. Agroforestry systems: important components in conserving the genetic viability of native tropical tree species? In: Schroth G, Fonseca G, Harvey CA, Gascon C, Vasconcelos HL, Izac AMN, editors. Agroforestry and Biodiversity Conservation in Tropical Landscapes. Island Press, USA. pp. 290-314.

Dawson IK, Lengkeek A, Weber JC, Jamnadass R. 2009. Managing genetic variation in tropical trees: linking knowledge with action in agroforestry ecosystems for improved conservation and enhanced livelihoods. Biodiversity and Conservation 18:969-986.

FAO, DFSC, IPGRI. 2001. Forest genetic resources conservation and management, vol. 2: In managed natural forests and protected areas (in situ). International Plant Genetic Resources Institute, Rome, Italy.

FAO, FLD, IPGRI. 2004. Forest genetic resources conservation and management, vol. 1: Overview, concepts and some systematic approaches. International Plant Genetic Resources Institute, Rome, Italy.

Geburek T, Turok J, editors. 2005. Conservation and Management of Forest Genetic Resources in Europe. Arbora Publishers, Zvolen, Slovakia.

Gordon J, Barrance A, Schreckenberg K. 2001. Tree Diversity Conservation in Mesoamerican Dry Forest: a briefing paper for international conservation agencies. Available from: www.etfrn.org. Date accessed: 1 April 2011

IUCN Standards and Petitions Working Group. 2008. Guidelines for Using the IUCN Red List Categories and Criteria. Version 7.0. Prepared by the Standards and Petitions Working Group of the IUCN SSC Biodiversity Assessments Sub-Committee in August 2008. Available from: intranet.iucn.org. Date accessed: 1 April 2011

Janzen DH. 1986. Blurry catastrophes. Oikos 47:1–2.

Jarvis DI, Myer L, Klemick H, Guarino L, Smale M, Brown AHD, Sadiki M, Sthapit B, Hodgkin T. 2000. A Training Guide for In Situ Conservation On-farm. Version 1. International Plant Genetic Resources Institute, Rome, Italy.

McNeely JA, Schroth G. 2006. Agroforestry and biodiversity conservation - traditional practices, present dynamics, and lessons for the future. Biodiversity and Conservation 15:549–554.