Role for enhancing connectivity with home gardens and other reserves of forest genetic resources
Schools can offer an important space in urban or peri-urban landscapes to enhance tree cover. This can increase tree population sizes and connectivity, and consequently help conserve local genetic diversity. There is a growing network of arboreta (Arbnet.org) across the globe. Arboreta have long been part of university campuses, botanic gardens, and city parks, but only recently are schools recognizing the value of establishing arboreta and initiatives to integrate restoration activities into their curricula (Hall and Bauer-Armstrong, 2010). Moreover, trees around schools have even been linked to higher student cognitive function (Tallis et al., 2018; Bratman et al., 2019). Typically arboreta have been established by wealthy landowners, but Yongneng et al. (2006) found a positive correlation between household income and species richness in southernmost Yunnan Province, China; the lower the income level, the higher the number of species in the garden had to be to counterbalance risks and increase the level of food security or income generating products. In peri-urban environments of the Yucatan Peninsula Mexico, school gardens have been valuable in raising awareness of conservation and food security related to native trees (Poot-Pool et al., 2018). The presence of different trees can also depend on their products and their use for construction, foods, medicines, fuels, or fodder.
School gardens are highly heterogeneous in terms of size, scope, and structure. They exist under different environmental, geographic, and socio-economic conditions as well as different history and ethno-cultural traditions, all of which influence their socio-ecological role. School garden networks’ abilities to cover wide geographic and environmental variation means that they can be useful locations for planting a broad diversity of trees. This can both help to conserve genetic diversity and also enable research on provenances across regions to better understand the importance of genetic differences. Therefore, school gardens offer not only a very valuable platform for demonstrating the great diversity of native trees but also a way to institutionalize the transfer of traditional knowledge on the uses of different species and varieties in order to conserve important knowledge.
School gardens can be a place not only to ensure urban greening and for education or food production but also for the restoration and ex situ conservation of rare and underutilized trees (Poot-Pool et al., 2018). These gardens can play an important role in mobilizing action for the conservation of plant genetic resources; especially for native tree species that have highly fragmented and degraded habitats, they can help in increasing population sizes, increasing connectivity, reducing extinction risk, and reducing pressure on other tree populations by demonstrating sustainable use.
Kuzevanov and Sizykh (2006) have demonstrated that botanic gardens enhance the establishment of gene banks for indigenous plants and seed banks as well as the development of scientific studies and the involvement of local communities in plant protection and decision-making processes with regards to environment conservation. As mentioned by Moreno-Black (1996), ‘the home garden plot is also important as an informal experimental station where indigenous species can be transferred, encouraged and tended as the women try to adapt them for use’. School gardens can become experimental stations and ex situ conservation places for such research purposes.
Active contributions to conservation using school gardens could include students being encouraged to propagate and plant native trees in their school gardens: this can be viewed as a strategy to increase biodiversity and explore different aspects of conservation biology, such as the minimum size of conservation unit needed to sustain a viable population (Galluzzi et al., 2010); it can also help with, as in Kehlenbeck et al. (2013), considering local preferences, the nutrition values of planted species, seasonality, resilience to climate change, and the available market or value chain process. In the context of school gardens, it is more likely that trees are planted for their renewable products, such as food and medicine, shade, and soil fertility, than for a one-off function, such as timber (Boshier et al., 2017), so this helps to maintain population sizes.
Geldenhuys (2007) shows that many edible and medicinal plants usually harvested from the wild can be grown as small-scale agricultural crops. Both seeds and vegetative propagation techniques have been tested, and especially trees, in the framework of the ‘Commercial Products from the Wild Innovation Fund
Project’ in South Africa, could be included in school gardens, considering their low risk and relatively large harvesting window.
In research conducted by Shackleton et al. (2007), the authors investigate incentives to promote the diversity of trees in rural areas of South Africa; these findings can shed light on what drives decisions on how to optimize the level of tree diversity in school gardens. The study examines correlations between household characteristics and the density of both indigenous and exotic trees, and number of tree species. Important variables affecting the density and number of varieties of trees included access to space, gender of the household head, and level of wealth. Female-headed households had significantly less trees than their male equivalents. This highlights how school gardens can be a great equalizer in terms of exposure to tree diversity if the activities are organized equally between boys and girls.
Together with diversity of species and varieties, there should be a level of diversity in terms of nutritional composition in fruit trees, vegetables, and medicinal trees planted in school gardens. To ensure this, schools can adopt garden diversity kits, which include seeds and samples of different species, depending on documented nutritional gap analysis, market demand, agroecology, and school capacity (Sthapit et al., 2008). Seeds, plants, and products can be exchanged to maintain diversity; an example of this is seen in the UK Garden Organisation and its Heritage Seed Library, where a network of volunteers contribute to the reproduction, conservation, and exchange of seeds. The same can be achieved by creating a network of schools participating in similar school garden programmes. The Plant for the Planet campaign, for example, now has 100,000 students from more than 26 countries leading a campaign to plant a trillion trees to tackle climate change (Plant-for-the-planet.org). Linking such school garden nurseries to local restoration projects could be a powerful tool for scaling the production of diverse and high-quality native trees. Different schools could exchange their germplasm or seed material, making conservation of neglected species more effective while also increasing the pool of people with the horticultural knowledge needed to grow them and scaling the production of native tree seeds, which is a major bottleneck in many restoration projects.
Finally, school gardens can be a good place to promote agrobiodiversity because they are a link within the community where tree breeders and farmers can access seeds and seedlings suitable for their environment and their needs. When biodiversity and ecosystems services are taken into consideration, school gardens can have a complex vegetation structure, hosting organisms that would not exist in the urban context.
In schools, tree identification can become an additional teaching tool to engage students with taxonomy and botany. Trees can be identified through registers, horticultural experts, interviews, and field observation, both by local and scientific names. Assessing the level of genetic diversity of trees within the garden, the identities of local cultivars, and the variation of the morphological characteristics of fruits and leaves can be the starting point (Galluzzi et al., 2010); a food web pathway can be used for a more comprehensive analysis, with indicators such as soil fertility, diversity and cover of plants at the plot level, and diversity of land use types (Remans and Smukler, 2013).
Finally, an interesting result from a study conducted in the Chivi district of Zimbabwe highlighted how the elderly interviewed about the planting and management of indigenous trees were more sceptical than middle aged people; this suggests that targeting young students with explanations of the properties and the benefits of conservation and diversity of indigenous trees can be more effective (Gerhardt and Nemarundwe, 2006).
BOX 7.2: SCHOOL CARDENS AND CONSERVATION OF IMPORTANT FRUIT TREE GENETIC RESOURCES IN CENTRAL ASIA
As part of a Bioversity International project entitled 'Improving seed systems for smallholder farmers' food security' in 2018, five orchards with 12 local varieties of apple, 9 of apricot, 9 of grape, and 7 of pomegranate were established in the field area of 3 rural schools and 2 colleges in Khorezm, Surhandarya, and Fergana Province, Uzbekistan. The objective of this project was to establish these school orchards in order to increase knowledge among school students about traditional varieties of fruit trees from Central Asia developed by their ancestors (Figure 7.1). These varieties, which are well adapted to local environmental stress factors, are superior in terms of taste and nutritional value, and have been passed from generation to generation of local farmers. Unfortunately, globalization in agriculture and food production has resulted in the erosion of the valuable diversity of important fruit tree species and the malnutrition of children due to reduced consumption of fruits.
In May 2018 the project team met with the staff and managers of rural schools and colleges located in the project sites where the establishment of Schools of Young Breeders and Seed Growers were discussed to spark young people's interest in working in agriculture and agricultural research. The staff and authorities of rural schools and colleges met these suggestions with enthusiasm. Subsequently, 'Young Breeders and Seed Growers' has been established in five rural schools and one college, including 92 school and 18 college students. Curators of 'Young Breeders and Seed Growers' schools were selected and appointed with the permission of school authorities. The project team collaborated with the appointed curators to develop a curriculum for the schools, which included topics on the basics of fruit tree breeding using local varieties and technologies to produce high-quality seeds and saplings.
FIGURE 7.1 Dr Dorohova is explaining to schoolchildren technology of artificial cross-breeding of fruit trees used to create a new plant in a school orchard. Source: Nodir Jalilov.
Conclusion and way forward
Unlike other underutilized species, trees require significant space, time, and resources to ensure their adequate conservation. Protected areas are often inadequate to capture the diversity of species as well as adequate numbers of individuals to conserve genetic diversity within those species. We have highlighted a number of ways in which school gardens could be employed not only to conserve knowledge and raise awareness but also to actually have an effective role in in situ and ex situ conservation of important tree genetic resources. The scale of the problem is great and requires large networks of stakeholders, who will need to consider a time frame that includes more than one generation of students. This is why schools with a long-term vision are so important.
School gardens can serve as tools to conserve not only genetic diversity but also traditional knowledge and skills in determining what trees are edible, how to cultivate them, and their socio-economic value in society. Using schools as a platform to broadly engage community members, including elders, through fairs or festivals can also enhance a sense of togetherness within the community, especially in a context of increasing urbanization.
These projects dismantle the traditional perception that farming and gardening are last choice activities, something seen as a punishment; school gardening can break barriers not only to a healthy diet but also to peer pressure and social stigmas. The stakeholders involved are not only students and teachers but farmers from the community; vegetable and fruit traders and processors; agricultural extension officers; and experts in agricultural economics, agronomy, ethnobot- any, health, and nutrition.
School gardens have great potential to become places for the conservation and restoration of underutilized and threatened trees. Local edible species can be used to complement school feeding programmes. They can be easy to cultivate; can produce nutritious fruit, leaves, and vegetables; and are adaptable to different environmental conditions.
There is a growing movement towards using school gardens to inspire the next generation of tree breeders and conservation scientists (Hall and Bauer-Armstrong, 2010) but, more importantly, to demonstrate the vital role that trees play in agroecological systems and the necessity that they be maintained at adequate scales for resilient delivery of the broad ecosystem services that we all depend on.
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