One of the things I enjoy about teaching this Applied Plant Conservation Workshop is that the participants share the wealth of their experience with rare plant species and freely discuss their questions and issues with the class. Today I discussed in situ conservation – rare plant reintroductions. Twenty years ago this was a controversial practice and many attempted reintroductions were unsuccessful. But as the science and practice of reintroduction has grown, the success rate has improved. As Fairchild has done 55 reintroductions of 13 species, we have a bit of experience about this topic. But admittedly our experience is biased. Because many of our species in South Florida are critically endangered with fewer than 5 populations and far less than 1000 individuals, I certainly have a different perspective than some other practitioners working with populations of plants with thousands of individuals spread across many populations. Unlike other regions of the country that have diverse topography and soil types, we are working within areas with comparatively less variation in soils and very slight changes in elevation. Our mild climate and usually abundant rainfall importantly improves the success of our reintroductions.
The most controversial thing we discussed today was the fate of very small populations. One of the participants from Hawaii has shared that she is working with 53 species that have fewer than 50 individuals surviving in the wild. Her priorities for these species are to fence the populations to exclude feral herbivores and to remove invasive species. She feels like she is in a race to prevent these species from going extinct. Our problems in Florida are not as severe as those in Hawaii. Through guidelines and examples the class can learn about how we approach our conservation of very small populations.
An important link is ex situ (nursery) collections with in situ (wild habitat) restoration. Fairchild researchers collect seeds and cuttings of rare species for long-term preservation, research, and reintroduction to the wild. One example is the federally endangered Key Tree Cactus, which has suffered serious decline in the lower Keys within the past decade. We have been making collections and maintaining healthy beautiful plants ready to go back to the wild. See our video about this process.
Key Tree Cactus in the ex situ collection
Before reintroducing any species, it is important to learn about its biology, its habitat requirements, and community and then try to find new locations that have similar qualities. Sam Wright developed a great matrix that we have used for both beach jacquemontia and the Key Tree Cactus to assess the quality of potential reintroduction sites. We are currently working to identify potential reintroduction sites for the Key Tree Cactus.
Each part of the world has its issues, but many of the threats to biodiversity are similar. I think what is particularly helpful about this course is that the participants can connect with others working on rare plants and can know they are not alone. The participants share contact information and the instructors encouraged the group to contact us if they have questions after the course, so that we keep the network alive.