By Iván Jiménez (Center for Conservation and Sustainable Development, Missouri Botanical Garden), Carlos A. Vargas (Herbario, Jardín Botánico de Bogotá José Celestino Mutis), Carlos I. Suárez (Colecciones Vivas, Jardín Botánico de Bogotá José Celestino Mutis), and Erika Benavides (Finca Milmesetas, Pasca, Sumapaz, Cundinamarca, Colombia)
As anthropogenic pressures on biodiversity mount, plant species conservation increasingly requires the integration of a variety approaches, including ex situ conservation: the maintenance of populations in intensively managed living collections. Conventional seed banking is commonly regarded as a particularly effective and efficient method of ex situ conservation, because a large number of seeds representing many species can be stored for long periods in relatively small spaces at seemingly low cost. It entails drying seeds to 15% relative humidity and storing them at −20 °C. For some “exceptional” species that cannot be easily represented in conventional seed banks, cryopreservation and associated methods are seen as good choices. In contrast, living collections of whole growing plants are often seen as relatively inefficient, requiring more space and care.
A particular problem with seed banks and cryopreservation projects, however, is that they may suffer from a “bunkered” conception of biodiversity conservation. By example, the Millenium Seed Bank is a “flood, bomb and radiation proof” underground facility designed as a “global insurance policy” to conserve seed diversity. Although focused on crops rather than wild plants, the Svalbard Global Seed Vault has a similar bunker ethos, aiming to guard against the loss of plant diversity due “not only to natural catastrophes and war, but also to avoidable disasters, such as lack of funding or poor management”. These bunker-like seed banks invite obvious questions: what protects them from lack of funding, miscalculation, poor management or extreme political ideology?
Both bunker-like seed banks are remarkable spatial concentrations of resources for ex situ conservation, seemingly at odds with the key biological insight according to which a large spatial spread decreases the probability of extinction. At the same time, these seed banks correspond to what Bruno Latour called “centers of calculation”, institutions where observations and specimens from faraway locations are amassed, organized and combined to produce scientific knowledge. Centers of calculation were foundational to the expansion of European colonialism. The Millenium Seed Bank and the Svalbard Global Seed Vault may be seen as contemporary extensions of the same colonial mindset, repurposed in the context of biodiversity conservation.
While other seed banks might not seem as obviously colonial, many do dislocate plant propagules from their original wild plant populations and human milieu. Most plant diversity in ex situ collections is held in the Global North, largely away from sources at the main centers of plant diversity. Even seed banks focused on nearby regional floras remove propagules from their immediate human and non-human environments.
And while not all seed banks boast about their bunker-like properties, many do sit well within the “ark paradigm”, whereby representative samples of species must be secured away (perhaps even in the back side of the moon, as suggested by a foundational paper) in preparation for a likely apocalyptic future of widespread extinction. The ark paradigm is clearly articulated in a chapter about the role of botanical gardens in ex situ plant conservation: “The primary goal of ex situ collections is to maintain a representation of the species as a source of material for restoration, should the species be lost in the wild, and this should be done as effectively and efficiently as possible”. This salvific post-extinction role for seed banks (let alone cryopreservation projects) seems to have little support in practice.
An alternative to the ark paradigm suggests that ex situ conservation can play a primary role before the extinction of wild populations. Ex situ collections may be used for research, training, education, awareness-raising and incentive programs that directly target the causes of primary threats to wild populations. In terms of this pre-extinction role, the conservation value of ex situ collections may be determined by their geographic location. The primary threats to many plant species are local. To address the causes of such threats, the most valuable living collections may be those able to engage the human communities coexisting with threatened plants. Bunkered living collections, removed from the human and non-human environment of the source plant populations, would likely be ineffective and inefficient at this task.
The alternative to the ark paradigm also suggests that ex situ conservation can play a central role in offsetting the effects of threats to wild populations, through the restoration of wild populations via reinforcement. Ex situ collections may provide plant stock for population management aimed at mitigating the effects of threats. Here, again, the geographic location of ex situ collections may determine their effectiveness and efficiency. Ex situ collections in the vicinity of threatened species would seem best for reinforcement programs. Moreover, issues related to propagation of whole growing plants would seem far more germane in this context than the worries about long-term storage prioritized by the ark paradigm and pursued in seed banks and cryopreservation projects.
An initiative adopting this alternative view of ex situ conservation is taking place in the páramo de Sumapaz, perched on the Eastern Colombian Andes. Páramos are high elevation ecosystems that are central for provisioning water to human populations in the tropical Andes. They are perilously affected by global change. The páramo de Sumapaz occupies about 315,000 hectares and, based on analysis of a recently compiled and edited database, hosts more than 3,000 plant species. Although the conservation status of 76% of these species has yet to be evaluated, currently 64 species are known to be threatened.
In this context, a group of researchers including local campesinos as well as staff and students from the Jardín Botánico de Bogotá, Parque Nacional Natural Sumapaz, Universidad Nacional de Colombia, Washington University in St. Louis, and the Missouri Botanical Garden, are engaged in participatory action research, with partial support from the Living Earth Collaborative. The aim is to develop the concept of “páramo biodiversity farms”, provisionally defined as properties in or near the páramo that derive economic benefits from at least one of four activities: i) biodiversity research, ii) education about biodiversity, iii) ex situ conservation of threatened plant species in living collections, and iv) plant stock production for population or ecosystem restoration.
A pilot páramo biodiversity farm began in 2019 at “El Carmen”, a 40-hectare property in the Sumapaz region. This pilot is focused on an ex situ collection of plants in the genus Espeletia (Asteraceae). Although páramo biodiversity farms would include work on many other plants, the focus on Espeletia at El Carmen is strategic. First, Espeletia are dominant “nurse-plants” in páramos and largely determine the physical structure of these ecosystems. Second, despite being locally dominant, several taxonomic species of Espeletia are threatened. Third, obtaining meaningful monitoring data for conservation is often difficult because the species boundaries in Espeletia are poorly understood and field identification is problematic.
The living collection at El Carmen serves multiple purposes. First, it is a “common garden” experiment, designed to understand species boundaries and phenotypic characteristics of Espeletia species from Sumapaz. The experiment entails propagating plants from seeds sourced from +500 mother plants occurring across the páramo de Sumapaz, initially in a nursery and subsequently in an outdoor landscape. Second, the living collection serves as a facility to train local students in plant biology and conservation. Third, the collection conserves ex situ threatened Espeletia species that are endemic to the Sumapaz region. Finally, the living collection may serve as a seed-increase field providing Espeletia plant stock for future population or ecological restoration projects.
A central theme of the project is the participation of local campesinos as co-investigators and managers, alongside researchers and officials from academic and environmental institutions. Achieving true participatory research and exchange of knowledge across these actors is far from trivial. Nonetheless, a concrete result of the project is that co-investigators, including campesinos, developed a sophisticated understanding of the phenotypic groups of Espeletia and their geographic distributions across Sumapaz, facilitating conservation monitoring programs. This increase in plant awareness among people coexisting with Espeletia plants is a key step towards addressing the causes of threats to páramo plant diversity. Campesino management of the ex situ collection at El Carmen (and the associated information) provides modest but direct economic benefits to a local family. We hope it also builds local capacity for the governance of biodiversity and collaborative relationships between campesinos and institutions focused on studying and managing biodiversity.
The pilot biodiversity farm at El Carmen hints at how ex situ collections of whole growing plants may help prevent extinction of wild populations. This kind of collection is often thought to be inefficient because requirements of space and resources may be higher than for seed banks and cryopreservation. Collections of whole growing plants for ex situ conservation can indeed be costly when bunkered inside botanical gardens. But they can be more efficient when spread across lands owned by human communities coexisting with threatened plants. We suspect that páramo biodiversity farms may not be more costly than comparable seed banks in the Global North. And the benefits from páramo biodiversity farms would include ex situ collections that act not only as safeguards (the ark paradigm) but also as tools to prevent extinction in the wild and promote local (rather than colonial) biodiversity governance. Studies comparing costs and benefits, beyond back-of-the-envelope calculations, are needed to determine which approaches to ex situ conservation are more effective and efficient in different regions of the world.