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  • Rich Morris
    ... Subject: The Overstory #210--Underutilised plant species and biodiversity Date: Mon, 15 Sep 2008 10:31:59 -1000 From: The Overstory
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      Subject: The Overstory #210--Underutilised plant species and biodiversity
      Date: Mon, 15 Sep 2008 10:31:59 -1000
      From: The Overstory <overstory@...>
      To: Richard Morris <rich@...>

      Publication date: September 15, 2008

      The Overstory #210--Underutilised plant species and biodiversity
      by Ian K Dawson, Luigi Guarino and Hannah Jaenicke


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      The Overstory #210--Underutilised plant species and biodiversity
      by Ian K Dawson, Luigi Guarino and Hannah Jaenicke


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      The term 'biodiversity' encompasses all variation found in living
      organisms, both between and within ecosystems, and includes species
      diversity and intra-specific genetic variation. Biodiversity is at the
      foundation of human society, because we survive on the range of products
      and services that it provides. Biodiversity is vital for the food
      security, proper nutrition, income and self-reliance of human
      communities, and also sustains the environment. In addition, through
      sometimes complex linkages with food habits, languages, traditional
      medicine, and religious and other practices, biodiversity sustains
      cultural richness and community identity, encourages organisation and
      communication, maintains social cohesion, and fulfils the aesthetic
      needs that allow societies to flourish (Brush, 2004).

      Biodiversity is also essential for providing an adaptive capability in a
      world that is continually undergoing change - change that may be
      positive, such as general improvements in human health and increases in
      purchasing power - or pose challenges, such as global warming. In
      agricultural systems, adaptive pressures include the changing
      requirements of farmers and the markets they serve, which require
      adjustments over time in the types of crops cultivated and products

      Diversity among and within species is linked to the productivity and
      stability of ecosystems, including agricultural systems, in several
      ways. In a smallholder farm or micro-enterprise context, more diverse
      cropping systems often appear to be both more productive (improved mean
      incomes) and more stable (decreased variance in incomes, across seasons
      and years). This is because efficiency increases are possible when
      different crop species or varieties occupy different production niches
      (physically and temporally) in the heterogeneous environment typical of
      small farms. Also, resistance and resilience are generally higher when
      more diversity is present, because the risks presented by possible
      environmental and market fluctuations can be spread among different
      crops and products. Plant species diversity in agricultural ecosystems
      is also often crucial for the maintenance of the birds, bats and insects
      that are the principal pollinators of many crops, any decline in which
      has significant implications for food production, measured in billions
      of USD annually - witness for example recent concerns about bee
      population losses in the USA (McNeely and Scherr, 2001).

      >>> Complexities in linkages between diversity, productivity and
      stability in ecosystems

      Whilst the interconnections between biodiversity and nutritive, economic
      and other values can sometimes be visualised in relatively
      straightforward ways, linkages with ecosystem productivity and stability
      are often rather complex. In farming systems, the utility of diversity
      depends on the different production environments of different crops
      complementing each other. Existing synergies may have evolved over
      centuries, and new interventions require careful choice of species if
      complementarities are to be maintained. Issues to consider include the

      * Available evidence suggests that, while there is often a positive
      relationship between species diversity and ecosystem function, this is
      conditional on the traits (e.g., growth characteristics) of the species
      in question and the level of environmental heterogeneity present.

      * In order to maximise the efficiency of ecosystem processes,
      interventions are better to focus on the different functions of taxa,
      rather than the absolute number of species; that is, it may be best to
      give more detailed attention to fewer species that have optimally
      complementary traits. In addition, interventions must operate at a
      geographic scale that matches environmental heterogeneity.

      * Although on-farm diversity can generally be seen as positive, its
      utility depends on how different production activities complement each
      other: there are instances when higher diversity can result in lower
      productivity and lower value, even in smallholder farming systems that
      are typically characterised by high variation. Thus, attention needs to
      be given to crop complementary when choosing species for cultivation.

      * Dealing with many species simultaneously can sometimes lead to a 'lack
      of focus' for farmers, as accessing current knowledge for the proper
      management of a large number of crops can be difficult. Dealing with
      many crops can also lead to larger transaction costs in accessing
      markets, with volume and processing issues arising for small amounts of
      a wide range of products. Co-operative action can help overcome these


      Increased contacts and exchanges of germplasm and knowledge between
      human populations over the last centuries have resulted in a few dozen
      crops dominating world agricultural trade (see the classic text of
      Harlan, 1975). During the Green Revolution of the 1960s and 1970s, a
      focus on the productivity of major crops led to large increases in yield
      through plant breeding and associated agronomic practices, and improved
      food availability for rapidly increasing human populations in the
      tropics and subtropics. At the same time, however, intensive promotion
      of a few widely available high-yielding cultivars of these crops has led
      to significant biodiversity losses in farm ecosystems, with displacement
      of traditional varieties and other species, and the simplification of
      human diets. This has been exacerbated by other worldwide trends, such
      as habitat destruction and extinctions caused by deforestation,
      increased international commodity trading, substitution of natural with
      manufactured products, and the consolidation of plant breeding
      enterprises. Global food security and agricultural incomes currently
      rely heavily on a few varieties of a very few crops - especially maize,
      wheat and rice - making humankind vulnerable to social and environmental


      The example of important commodity crops is illustrative of the
      tradeoffs often faced in agriculture. Greater use of a species often
      leads to a process of selection for a generally narrow set of
      characters, coupled with an intensification of production systems that
      is associated with a tendency toward monoculture and the displacement of
      other varieties and species.

      >>> Effects of selection

      Selection by definition results in a narrowing of the genetic base and
      functional use of a crop, with production therefore becoming
      increasingly vulnerable to adaptive pressures, such as changes in market
      requirements or possible disease attack. For those species subjected to
      intensive selection, sustaining production in the medium- to long-term
      requires the periodic infusion of new variation from the wider gene
      pool, including wild relatives, through continual breeding and promotion
      of new cultivars. Sustaining high performance, therefore, carries the
      cost of maintaining diversity that is not 'immediately useful' in the
      production process. Such diversity can be classed as a 'public' or
      'social' good, rather than a 'private' or 'personal' one, because the
      consequences of loss for farmers and wider society may not be
      experienced immediately. As a result, new ways, often outside
      'mainstream' cultivation, may need to be found to maintain this
      variation; in the case of major crops, this is done partly through
      significant ex situ 'genebank' collections, which store and regenerate
      seed and vegetative materials at central locations.

      The promotion of high-yielding varieties is often also accompanied by
      more variable production. This is because of the heightened sensitivity
      of modern cultivars to the availability of appropriate external inputs
      such as irrigation, fertilisers and pesticides, and the lack of
      'micro-adaptation' to particular local conditions. Modern cultivars may
      therefore on average perform better than older varieties, but in
      particular situations, such as extreme events of drought or flood, they
      may do worse, showing higher variance in yield between 'good' and 'bad'
      seasons. Additional tradeoffs are therefore sometimes required between
      average returns and risks of production. For poor farmers who are unable
      to afford the inputs required to sustain the yields of modern crop
      varieties, reducing risks by growing older types may be more important
      than increasing returns, since the results of crop failure are often


      Intensification of production systems with selected cultivars often
      leads to the displacement of other varieties of the promoted species,
      and loss of alternative crops and associated (plant and animal)
      biodiversity. Donald (2004) describes the process of intensification for
      a number of tropical and subtropical commodities (cocoa, coffee, oil
      palm, rice and soybean; see below). He indicates that low intensity
      cropping systems under alternative management regimes can, however,
      offer some advantages for both biodiversity and livelihoods. Such
      systems are more feasible for some species (e.g., coffee) than others,
      for which economically viable diversity-friendly management options may
      be rather limited (e.g., oil palm).

      Donald (2004) makes the obvious, though often un-stated, point that the
      extent to which intensification has an impact on biodiversity depends on
      how degraded the current environment already is. If existing
      agricultural ecosystems are already low in variation, e.g., if they only
      contain modern cultivars, further intensification may make little
      difference to the biodiversity found in the immediate farm environment.
      In this situation, intensification appears a more appropriate option for
      farm management than in circumstances where biodiversity in farmland is
      still high.

      >>> Cocoa

      Full-sun production of cocoa on large intensive farms in, e.g., Malaysia
      is generally unsympathetic to landscape biodiversity and has resulted in
      increased pressures from various pests and diseases, contributing to
      business collapse. In, e.g., Indonesia, however, traditional small-scale
      shade-production practices that protect diversity persist, in which part
      of the forest canopy is maintained during land clearance, or shade trees
      are planted over cocoa. These practices help prevent disease problems,
      and the cocoa business has faired better.

      >>> Coffee

      Like cocoa, coffee is grown in shade as well as non-shade systems, from
      almost wild conditions to monoculture. Shade systems that better support
      landscape biodiversity can help control pest problems and can (because
      of slower ripening) produce better tasting coffee that can be sold at a
      premium. In addition, although coffee is partly self-pollinating, yield
      depends to a degree on the presence of pollinating insects. These are
      more likely to be found in more biologically diverse landscapes.

      >>> Oil palm

      Due to the biological characteristics of the crop and the way in which
      it is generally managed for efficient production and harvest, oil palm
      cultivation appears to have particularly negative consequences for
      biodiversity, with limited options available for improvement.

      >>> Rice

      Many traditional varieties of rice were replaced by a few modern
      selected cultivars in India and elsewhere during the Green Revolution.
      How rice cultivation is managed has important consequences for
      biodiversity: flooding paddy fields during the fallow season can provide
      a habitat for birds, and can help control weeds and diseases. Planting
      of a more diverse range of rice varieties can be used as a strategy to
      control rice blast disease, thereby increasing yields, reducing chemical
      use and providing a friendlier environment for biodiversity. Using a
      more diverse range of varieties can also contribute to human nutrition,
      since traditional varieties often have better nutritive profiles than
      higher-yielding modern types (see also Frei and Becker, 2004).

      >>> Soybean

      Large-scale soybean production in locations such as Brazil has displaced
      smallholder farmers, who have cleared new, previously forested, land.
      Soybean cultivation has slowed down the development of other more
      sustainable crop production systems.


      As a means of supporting farmers' livelihoods and maintaining and
      enhancing biodiversity, Jaenicke and Höschle-Zeledon (2006) advocate
      renewed emphasis on the cultivation of underutilised plants species as
      agricultural crops, and indicate five 'maximum impact' areas for their

      >>> Generating new knowledge

      For example, by studying specific cultural practices for underutilised
      plants, and through improved determination of important species that
      producers, processors and consumers are interested in. Also included is
      further scientific research on: characterising available genetic
      resources and their value, the genetic enhancement of priority species,
      how to better maintain genetic and species diversity, how to supply
      farmers with germplasm, more appropriate crop management procedures; and
      improved methods for post-harvest handling and processing.

      >>> Better communication of knowledge

      For example, through more farm demonstration sites, by collecting and
      disseminating successful promotion stories, by reducing information
      asymmetries during promotion, through lobbying of policy makers and
      other influential interest groups, by more targeted media campaigns, and
      through the continued development of school curricula that promote
      underutilised crops.

      >>> Better policies to remove barriers to production and marketing

      For example, by initiating national dialogues on underutilised crops, by
      promoting policies that enhance access to existing and new markets
      (e.g., through less costly certification schemes and by the reduction of
      other non-tariff barriers), and through better protecting farmers'
      intellectual property rights to local knowledge on taxa.

      >>> Improved market development

      For example, through increased entrepreneurial training to support value
      chain development, by fostering more public-private partnerships,
      through organising buyer-supplier fora, through demonstrations and trade
      fairs, by promoting credit and grant schemes for marginalized
      stakeholders, and by carrying out more market surveys on preferences,
      risks, compatibilities, etc.

      >>> Better partnerships amongst all stakeholders

      For example, through further encouraging strategic alliances on
      underutilised crops, by promoting multidisciplinary research teams and
      regional networks, and by strengthening relationships among all
      participants in value chains.


      Important in understanding how current agricultural practices impact on
      biodiversity is the relationship with markets. Nill and Böhnert (2006)
      reviewed the work processes and actors involved in the production,
      processing, trade and end consumption of three species grown in low
      income countries - potato, coffee and argan oil - and assessed
      development opportunities and biodiversity implications of different
      value chains for each. The results for each crop are summarised below:

      >>> Potato in Peru

      Around 2,000 varieties of potato are grown in the Peruvian Andes, a
      centre of diversity for the crop. Potatoes cultivated in Peru enter
      different value chains: for immediate fresh consumption, in the form of
      traditionally processed preserved potato (e.g., chuño and tunta, for
      'bitter' varieties); and for industrial processing (e.g., into chips and
      crisps). All three chains can support farmer livelihoods, but only the
      first two make any noteworthy contribution towards the conservation of
      biodiversity. Local markets for immediate fresh consumption contain many
      different varieties, while traditional products are made from several
      dozen types, which are generally grown by smaller farmers. Only a few
      varieties of potato are, however, considered suitable for industrial
      processing nationally. This market is generally supplied by bigger
      farms, which can meet large volume requirements. Market measures to
      support potato diversity include the sale of mixed varieties as branded
      products in Peru's biggest supermarket chain, and the organisation of
      farmers into groups to supply such products.

      >>> Coffee in Ethiopia

      Several hundred 'arabica' types of coffee grow in their centre of origin
      in Ethiopia, where most production centres on smallholder plantations,
      though some coffee is collected directly from the wild and from mixed
      wild-cultivated systems. Support measures for coffee production from the
      1970s initially involved activities such as the breeding of
      disease-resistant varieties and the development of centralised washing
      stations. These measures have not, however, been able to maintain farmer
      incomes during periods of coffee oversupply on the world market. More
      recently, emphasis has been placed on increasing quality and promoting
      access to specialised global markets, including through various
      certification initiatives (e.g., through Fair Trade and the Rainforest
      Alliance). These activities support community organisations and use the
      uniqueness of Ethiopian arabica types, and certified adherence to social
      and ecological standards, as selling points to achieve higher prices.
      These measures target poverty reduction measures to smallholder
      producers, and help conserve the diversity of the arabica types that
      these farmers' manage.

      >>> Argan oil in Morocco

      Argan oil is pressed from the nut of the argan tree that grows in the
      Arganeraie region of Morocco. The oil is a premium product for food use
      and skincare, and is traded locally, nationally and internationally.
      However, argan populations are being reduced through inadequate
      regeneration and deforestation. Argan oil can be produced both by
      hand-extraction and mechanical pressing: in the first case, harvesting
      and oil extraction are undertaken in rural areas, whereas in the latter
      case rural communities only collect the nuts for processing elsewhere.
      Measures implemented to help rural communities in production include
      training local women in processing, helping them to organise into
      groups, and the establishment of new argan stands. Through certification
      and partnership with international buyers, higher prices will be
      achieved, while new plantings based on improved markets, and the
      recognition of the Arganeraie as a UNESCO biosphere reserve, will
      facilitate conservation of the species.


      Incorporating more biodiversity into farming systems should not be seen
      as an end in itself - that is, simply for conservation purposes - but as
      an important intervention that brings benefits to rural communities in
      improved livelihoods and in a better living environment. Supporting
      biodiversity, such as through the promotion of underutilised crops,
      requires both proactive and reactive measures, i.e. promoting the
      introduction of new biodiversity into farms, and ameliorating ongoing
      biodiversity losses.

      The relationships between biodiversity and outcomes that are important
      for farmers can be complex. Certain tradeoffs are often necessary, and
      the promotion of any one species or variety can have implications for
      wider landscape diversity that may be negative, and that are sometimes
      difficult to predict and prevent. To minimise any negative consequences
      of promotion, activities should generally focus on those species for
      which diversity-friendly management systems are at least conceivable.
      Intervention should also normally take a 'spear and shield' approach, in
      which, while certain (or even just one) crop may be the focus of
      concerted action, the use of a much wide range of other species is also
      promoted at the same time in 'piggy-back' fashion.

      The practices, innovations and experimentation of the poor depend upon
      the particular range of limitations and opportunities that they face,
      but activities centre on improving the livelihoods of their families and
      communities. Practical experience shows that germplasm availability and
      market access are crucial factors in determining what is planted on
      farms. Key interventions to support diversity therefore include
      improving access to planting material and associated knowledge for a
      variety of species and cultivars, and the development of 'intelligent
      markets' for a wide range of products.


      Brush S (2004) Farmer's Bounty: Locating Crop Diversity in the
      Contemporary World. Yale University Press, New Haven, USA. 327pp.

      Donald PF (2004) Biodiversity impacts of some agricultural commodity
      production systems. Conservation Biology, 18, 17-37.

      Frei M, Becker K (2004) Agro-biodiversity in subsistence-oriented
      farming systems in a Philippine upland region: nutritional
      considerations. Biodiversity and Conservation, 13, 1591-1610.

      Harlan JR (1975) Crops and Man. The American Society of Agronomy and the
      Crop Science Society of America, Madison, Wisconsin, USA. 295pp. (1985

      Jaenicke H, Hschle-Zeledon I (eds.) (2006) Strategic Framework for
      Underutilised Plant Species Research and Development with Special
      Reference to Asia and the Pacific, and to Sub-Saharan Africa.
      International Centre for Underutilised Crops, Colombo, Sri Lanka and the
      Global Facilitation Unit for Underutilized Species, Rome, Italy. 33pp.

      McNeely JA, Scherr SJ (2001) Common Ground, Common Future: How
      Ecoagriculture can Help Feed the World and save Wild Biodiversity. The
      World Conservation Union, Gland, Switzerland and Future Harvest,
      Washington, USA. 24pp.

      Nill D, Bhnert E (2006) Value Chains for the Conservation of Biological
      Diversity for Food and Agriculture. Potatoes in the Andes, Ethiopian
      Coffee, Argan Oil from Morocco and Grasscutters in West Africa. Deutsche
      Gesellschaft fu_r Technische Zusammenarbeit, Eschborn, Germany and the
      Global Facilitation Unit for Underutilized Species, Rome, Italy. 78pp.


      This article was excerpted with the kind permission of the authors from:

      Dawson, I.K., Guarino, L. and Jaenicke, H. 2007. Underutilised Plant
      Species: Impacts of Promotion on Biodiversity. Position Paper No. 2.
      International Centre for Underutilised Crops, Colombo, Sri Lanka.


      Ian K. Dawson is interested in optimising the use of underutilised plant
      species in farm systems through better management of genetic and species
      diversity. He has a particular interest in tropical tree crops. He works
      as a consultant from his base in the UK.

      Luigi Guarino has been involved in the conservation and use of plant
      genetic resources, including of underutilised species, for a number of
      years. He is currently doing so at the Global Crop Diversity Trust.

      Hannah Jaenicke has been interested in the effect of promotion on
      biodiversity since working on the vegetative propagation and
      domestication of indigenous trees in the 1990s. She is the Director of
      ICUC. Contact Hannah at Tel: +94-11-2880193; e-mail:
      h.jaenicke@...; Web: <http://www.icuc-iwmi.org>


      Global Facilitation Unit for Underutilized Species' list of web sources:

      Plants for a Future: <http://www.pfaf.org>, links page:

      Bioversity International's Neglected and Underutilized
      Species Overview:

      Purdue University New Crop Resource Online Program


      The Overstory #201--Indigenous Fruit Tree Domestication
      The Overstory #162--Agroforestry Tree Products (AFTPs): Markets
      The Overstory #145--Wild Foods and Food Security
      The Overstory #139--"Hungry season" food from the forests
      The Overstory #136--Underutilised Indigenous Fruit Trees
      The Overstory #135--Medicinal and Aromatic Plants in Agroforestry
      The Overstory #128--Wild Foods
      The Overstory #127--Food Security
      The Overstory #117--Between Wildcrafting and Monocultures
      The Overstory #106--The Hidden Bounty of the Urban Forest
      The Overstory #113--Forest Biodiversity
      The Overstory #109--Cultural Landscapes
      The Overstory #105--Complex Agroforests
      The Overstory #93--Trees, Forests and Sacred Groves
      The Overstory #77--Tropical Forest Conservation
      The Overstory #76--Ethnoforestry
      The Overstory #64--Homegardens
      The Overstory #51--Expanding Traditional Agroforests
      The Overstory #49--Traditional Pacific Island Agroforestry Systems


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