SAVE PLANTS

Carnivorous plants have devised several types of traps to capture prey: pitfall, snap traps, fly paper, lobster pots and bladder (vacuum). Passive traps rely on sticky or slippery surfaces to cause prey to stick or slide into the digestive fluid. Pitfalls, such as those found in Nepenthes, Heliamphora, and Brocchinia rely on slippery surfaces; while Drosera, Pinguicula, and Drosophyllum are examples of genera that depend on flytraps – sticky glandular hairs that coat prey with mucilage. Lobster traps are leaves that use hairs to prevent prey from exiting once they are lured into the trap. This type of trap is found in Genlisea. Bladder traps are only found in Utricularia, an aquatic genus of carnivorous plants, where a bladder uses a vacuum to suck protozoans into the trap. Active or “snap” traps are found in Dionaea and Aldrovanda. Trigger hairs signal when it’s time to snap shut on unwary prey.  In each case, specialized cells in the leaf excrete digestive fluids that break down the prey and are then reabsorbed into the leaf.

Despite the occurrence of carnivorous plants in many areas of the world, many are under threat due to habitat loss, climate change and illegal collection from the wild. At the San Diego Zoo Wildlife Alliance (SDZWA), the horticulture department has developed a robust collection of carnivorous plants, with over 90 species from several families, and new additions being acquired annually.

The majority of our collection is comprised of Nepenthes species, with many of them ranked from vulnerable to critically endangered. Twelve of the Nepenthes species under our care are listed as critically endangered by IUCN. Three of the most endangered Nepenthes in our collection are:

• N. khasiana is the only species native to India where it occurs in isolated populations. An endangered species, Nepenthes khasiana produces a sweet nectar that also contains a disorienting neurotoxin that increases the likelihood of prey falling into the trap. This species also fluoresces on its peristome and underside of the lid as a method of attracting prey.

• N. aristolochioides is a species endemic to the highlands of Sumatra and is critically endangered due to overcollection. The mouth of the pitcher is held at an almost vertical angle, and the digestive fluid inside is thick and syrupy.

• N. clipeata: an extremely rare species found only on Mt. Kelam, Borneo. Populations of this beautiful species have been drastically reduced by fires and overcollection. With few mature specimens left in the wild, it is feared this species is functionally extinct in its native habitat.

Our efforts in the SDZWA horticulture department are aimed at cultivating a diverse and healthy ex situ population of these rare species against the threat of extinction. As our specimens mature, we hope to participate in breeding programs with partner institutions to ensure the genetic diversity of each species is preserved.

As part of our public outreach, we have collection specialists set up displays and discuss our work at monthly Plant Days and Wild Weekends, as well as give presentations in our summer camp program and to other groups. Our collection has been featured on TV and podcasts. Those in San Diego wishing to learn more about these unique plants can visit the Zoo on the third Friday of every month to see them up close and ask the horticulture team any questions about all things botanical.

For 30 years, Atlanta Botanical Garden (ABG) has provided ex situ conservation and in situ guidance to support the implementation of successful efforts in Georgia’s rarest habitat—mountain bogs. Safeguarding these wild treasures in the 1990’s led to the formation of the Georgia Plant Conservation Alliance (GPCA) and with other founding members, we have worked together to restore these and other high-priority habitats identified in Georgia’s State Wildlife Action Plan.

Georgia’s mountain bogs are early successional communities that support a variety of imperiled organisms. These include the federally endangered swamp pink (Helonias bullata), as well as the state-listed purple pitcher plant (Sarracenia purpurea var. montana). Relatively few high-quality sites remain in Georgia, but a high proportion of those are found on public land. An essential part of our conservation work has included propagation of rare plants from wild populations and reintroduction of this material into suitable habitat, as well as routine habitat maintenance and monitoring. ABG also leads the coordination of annual meetings to review accomplishments, set goals, coordinate work, and share data. Our current focus includes monitoring and remediation efforts following disturbance from feral hogs (Sus scropha) and exclusion to prevent additional damage; maternal line seed collection and banking; conducting and planning genetic research; and habitat management assessments and planning.

The first attempts at rare plant reintroduction in Georgia’s mountain bogs involved safeguarding swamp pink and mountain purple pitcher plants. These taxa are wild at only two locations, including a remote site on the Chattahoochee National Forest containing only the pitcher plant and a privately-owned bog that once supported both species but has lost ecological integrity following severe hydrologic alteration. Reintroduction into suitable habitat on protected lands has been conducted with the goal of creating experimental populations and spreading the risk of extirpation among multiple sites.

More than 500 individual mountain purple pitcher plants have been used to establish 7 experimental sites since 1997. Recruitment has been documented at 5 of those sites. The original wild population has been augmented with more than 200 additional individuals since 1995. Fruit set, the first known from Georgia in decades, was documented there in 1999. In 2000, the first seedlings were noted. A 2013 census indicated multiple generations of plants, flowering recruits, and over 400 total individuals. A 10-year site assessment and population inventory in the fall of 2023 will inform the first maternal line seed collection for this species in Georgia. This material will be banked and could be used for future augmentation and reintroduction work, guided by the results of a population genetics study currently underway at ABG for this species.

Similar safeguarding efforts have established new populations of swamp pink at 4 protected bogs. Since 1997 over 400 individuals have been returned to the wild—most in the experimental sites. The first flowering of this species in a created population (2010) and the resultant seedlings (2011) represented the first documented seedling recruitment of this species in Georgia. There are now multiple generations of this species in multiple sites on protected and appropriately managed land, which was the ultimate goal. More recent outplantings have been individually tagged. ABG began maternal line seed and leaf sample collections for swamp pink in 2020, and this material has also been added to ABG’s Conservation Seed Bank and DNA Biorepository, respectively.

Cooperative management has been the key to successful establishment and independent reproduction in both wild and experimental sites. Management activities have included manual and mechanical removal of woody vegetation in ecotones (transition zones) between the wetland and upland habitats, invasive exotic plant treatment, prescribed fire, and exclusion of invasive hogs. These activities have been critical in preventing damage to sensitive sites, reducing competition, and decreasing shading and evapotranspiration to maintain integrity, sunlight, and moisture. Vegetative growth, flowering, seed production, and seedling recruitment have increased for both swamp pink and purple mountain pitcher plant following management events. These collaborative efforts likewise support the state listed Southern bog turtle (Glyptemys muhlenbergii), which also relies on captive rearing to supplement and reinforce the limited number of fragmented populations remaining. These examples illustrate how reintroducing rare plants can have complementary benefits to other species and that reintroduction itself is not sufficient—ongoing site management is required to successfully reestablish and maintain thriving in situ populations.

ABG maintains a database on behalf of GPCA that houses information on rare plant conservation activities. This provides a central repository to track ex situ collections, in situ augmentations/reintroductions, monitoring data and survivorship analysis, and collaborative management actions for priority species. This system was developed using the suite of mountain bog species and sites and has been essential in coordination and evaluation of key actions for collaborative projects. The success of these efforts are serving as models of success for the Bog Learning Network(BLN) and the Southeastern Plant Conservation Alliance (SE PCA). Applying and updating the Center for Plant Conservation’s Best Practices Guidelines helps to ensure the survival of these species and their habitats in the wild, while documenting successes and steps to improve outcomes helps to refine best practices and promotes their importance and use in other networks.

When did you first fall in love with plants?

Plants were part of my life pretty early. I gardened with my mom and we spent a lot of time camping and hiking in the Colorado Rockies, often stopping to admire wildflowers and examine the trees. But it was a general botany course at the University of Colorado, Boulder where I really realized how much I loved plant ecology. Every part of that class really connected with me and I found something I was very passionate about.

What was your career path to your career at North Carolina Botanical Garden?

After my botany course I started looking for any job I could find that was plant related.  I sorted tundra plants for researchers, volunteered for invasive species pulls, worked for county extensions, conducted research in desert grasslands of Arizona – the list goes on and on. After a short stint as a high school teacher, I moved to North Carolina and started at NCBG as an ecologist. My path there also drifted from land stewardship to rare plant conservation. I was lucky enough to have a supportive environment to allow me to grow and do more rare plant work, eventually leading to my PhD program (Environment, Ecology and Energy Program, University of North Carolina at Chapel Hill) and becoming the Director of Conservation at NCBG.

Based on your experience, what are some of the pressing conservation needs impacting imperiled plants, including carnivorous plant species, in North Carolina and the Southeastern U.S.? How has your (or your institution’s) work addressed them?  

Land use changes, including direct loss of habitat, and fire suppression are two of the biggest threats to many species in the Southeast, including carnivorous plants. On top of this, I am a firm believer in that we need to know how these changes, and those associated with climate change and management decisions, are actually impacting populations and species. For many rare species, we don’t actually know how species are responding to this rapid global change and until we do, finding ways to balance societal and ecological needs is really difficult. This is all very true for carnivorous plants in the Southeast where land continues to be converted into development and agriculture, hydrology is changing, and people and climate change are altering the fire regime.

What conservation projects are you currently working on? What successes or challenges have you encountered in your work?

A new project we are a part of is looking at how Venus flytrap populations are likely to respond to changing climate and fire factors and translating the results to partners so they are better equipped to manage flytraps and other rare species in the future. This is a collaboration with Kansas State University and Duke University with funding from the National Science Foundation and the Paul G. Allen Family Foundation’s Partnership to Advance Conservation Science and Practice. This is a great collaboration that allows all the partners to continue advancing our knowledge and conservation action to help plant conservation.

What has surprised you about working with and learning more about rare plants?

For me, one of the biggest challenges is how little we know about so many rare plants and how little material we have to work with to follow best practices. But this is also one of the things that keeps me engaged and working to fight extinction. Even in the smallest number of plants we can deepen our understanding of these intricate connections.

What advice would you give to those who wish to learn more about how they can help save imperiled plant species?

Visit and support botanical gardens and reach out to local conservation organizations – there is a wealth of expertise in these networks. I also think one of the best ways to do more to save plants is to help a diversity of people find their own unique way to connect to a plant, any plant.  The more we build a society that values plants at all levels, the more likely we are to advocate for their conservation. So, teach a friend anything cool about a plant and be willing to listen when they tell you their plant stories.

David Doyle is a retired attorney with a passion for plants and nature conservation residing in San Diego, California. He graduated with a Bachelor of Arts, Magna cum Laude, from the University of California -San Diego (UCSD), and subsequently took a Master of Laws (LLM) degree from the University of California – Los Angeles Law School.

After working in government as a Law Clerk and Assistant U.S. Attorney in the Southern District of California, Mr. Doyle entered private practice specializing in patent litigation.  He served as managing partner of the San Diego office of Baker & McKenzie and as Chair of the Patent Group at Morrison & Foerster, where he was named in multiple years by U.S. News & World Report as one of the top ten national patent trial lawyers.

Mr. Doyle has engaged in many community activities, including serving on the Boards of Trustees of the UCSD Alumni Foundation, UCSD CONNECT (a University/ Technology Industry interface organization), the Kyoto Symposium Organization (Board Chair 2015-2022), as well as volunteering with Big Brother San Diego (2008 – 2015). In 2017, he co-chaired the annual Gala of Voices for Children – San Diego with his wife, former Center for Plant Conservation Trustee Nancy Doyle.

“There is an impressive roster of botanic garden and plant conservation groups. Among those, I see the CPC as the one most ‘having its hands in the dirt’: digging into the nitty-gritty to save plants, so I am thrilled to be a part of this dynamic organization and network.” – David Doyle

As Seen on the Rare Plant Academy: Range-wide Ex Situ Seed Conservation and Population Genetic Architecture Analysis in Venus Flytrap

CPC’s Best Practices guidelines are brought to life in our Rare Plant Academy (RPA) Video Library, serving to keep the conservation community up-to-date with rapidly evolving technology and advanced methodologies. The RPA Video Library is home to many informational videos on plant conservation topics, from educational videos to case studies and recorded conference presentations.

“Range-wide Ex Situ Seed Conservation and Population Genetic Architecture Analysis in Venus Flytrap (Dionaea muscipula)” was presented by Dr. Johnny Randall of North Carolina Botanical Garden (NCBG) during the 2020 Southeastern Partners in Plant Conservation Conference (SePPCon), providing an in-depth overview on NCBG’s double-pronged conservation approach of collecting and banking seeds by maternal line, and doing genetic analysis across the populations using RADSeq. For even more information on NCBG’s work to preserve the Venus’ Flytrap, watch this video, too!

CPC National Office staff recently attended the 2024 SePPCon in Atlanta, Georgia, and were pleased to connect with so many conservation scientists and practitioners in the Southeast region. Look for 2024 SePPCon presentations on the RPA Video Library coming soon!