federally endangered

Heather Schneider, Santa Barbara Botanic Gardens

There are times when drying and storing seeds is not an option for the conservation of a plant species. This might be because the seeds cannot survive the freezing process, or maybe because the species no longer produces seeds in the wild. Researchers at the Santa Barbara Botanic Garden have been working with one such species, the Federally endangered Island Barberry, which no longer reproduces well naturally. While once found on several different channel islands, this species now occurs in a single location. 

Santa Barbara BG has established an ex-situ population of this rare species, allowing them to both conserve the genetic diveristy in a controlled environment, and use these plants to perform experiments without adversely effecting the small wild population. In 2019 these researchers began a propagation study using this ex-situ collection of island barberry to determine the best propagation methods for the species. Their experimental design had 4 variables. They planted cuttings in both the winter and the spring, they took cuttings from source material of different ages, they tested the use of a heating pad in propagation, and they tested different rooting hormone concentrations. Their results clearly defined the best practices for propagating the species. Cuttings should be made from old growth source material, and should be planted in the winter rather than the spring without the use of a heating pad. Rooting hormone is effective at both a 1:10 and 1:15 dilution. With this information, researchers have been very successful in propagating cuttings from the wild population for reintroductions.

This project is a great example of the value of living collections and horticultural expertise in rare plant conservation. An ex situ population was used to curate best practice recommendations for use by everyone involved in saving this species. From the boots on the ground on Santa Cruz Island to the dedicated staff and volunteers at SBBG, these efforts have ensured the Island Barberry a fighting chance at survival.

Contributing Author(s): 
Date Recorded: 
Wednesday, September 16, 2020

Tara Littlefield, Senior Botanist/Plant Conservation Section Manager, Office of Kentucky Nature Preserves

It all started with a monitoring study of a declining White fringeless orchid (Platanthera integrilabia) population in 2007 at a State Nature Preserve in the Cumberland Plateau of Kentucky. This talk will outline this long term monitoring study of the white fringeless orchids and the associated seep communities and how they responded to management of the associated habitat. In addition, status survey trends of all WFO populations in Kentucky, partnerships with the forest service on recovery of populations on forest service lands, in situ and ex situ conservation strategies, as well as the importance of restoration and connection of the adjacent upland pine oak barrens will be discussed. Topics of partnerships, life history studies, seep and habitat management, seed and mycorrhizal banking, propagation, surveys and trends will be highlighted in this white fringeless orchid recovery and seep restoration talk.

Contributing Author(s): 
Date Recorded: 
Wednesday, March 4, 2020

Shawn C. McCourt, Sally M. Chambers, and Bruce K. Holst, Marie Selby Botanical Gardens

The genus Harrisia (Cactaceae) comprises 20 narrowly endemic species of night-blooming cacti with two widely separated geographic ranges, including South America south of Amazonia, as well as the West Indies and southern Florida. Commonly known as aboriginal prickly-apple, H. aboriginum is a sprawling, multi–stemmed, columnar cactus endemic to ancient native American shell mounds, as well as coastal berms, coastal grasslands, and maritime hammocks in four counties along the southwest coast of Florida. This federally-listed species is in steep decline, primarily due to the development of beachfront property, invasive species dominance, and the erosion of coastal barrier islands. Some populations have disappeared entirely. Researchers at MSBG have been conducting an inventory of extant populations, assessing the health of each population, and determining what genetic variation (if any) occurs across the species’ geographic range. When possible, a small portion of seed has been collected for seed banking and to grow plants for the augmentation of shrinking populations and introduction to ecologically suitable sites situated above projected rises in sea level. To date, we have visited nine sites and collected detailed demographic data for 89 plants. Spines were collected from all 89 plants for DNA extraction and the testing and developing of microsatellite loci. Seeds from seven fruits were collected from three sites. Data presented represent the preliminary findings of our work, which has a focus on the importance of maintaining genetic diversity in ex situ collections for the purpose of rare plant conservation.

Contributing Author(s): 
Date Recorded: 
Wednesday, March 4, 2020

Noah Dell, Missouri Botanical Garden, Geoff Call, United States Fish and Wildlife Service, Matthew A. Albrecht, Missouri Botanical Garden

Short’s bladderpod (Physaria globosa) was recently listed as federally endangered due to population decline across its range in Tennessee and Kentucky. However, little is known about the biology of the species and the potential mechanisms underlying range-wide declines. In short-lived mustards, seed dormancy and seed bank persistence can play an important role in regulating population dynamics and response to disturbance. To address the recovery plan objective of enhancing knowledge of Short’s Bladderpod to facilitate the development of scientifically sound management plans, we conducted laboratory experiments and a seed burial study to examine what environmental cues promote dormancy break and whether or not seeds form a persistent seed bank. A majority of seeds are in primary dormancy when dispersed in summer. Germination percentages are generally low, and long cold stratification times are needed to break dormancy. Seeds that were cold stratified at 2°C for 12 weeks and then incubated in a 20/10°C alternating temperature regime achieved the highest average germination percentage (24%). Warm stratification with or without alternating wet/dry cycles did not improve germination percentages over cold stratification treatments. However, constant imbibition in warm temperatures may have promoted viability loss, as germination percentages were lower than seeds kept at warm temperatures with alternating wet/dry cycles. Results from the seed burial study were consistent with those in laboratory experiments and indicate a cold stratification requirement for dormancy-break. Germination of buried seeds was greater in light than darkness and varied seasonally: 0% and 1% in dark and light conditions, respectively, in October following dispersal, 7% and 21% in January, 23% and 36% in March, 9% and 10% in June, and 4% and 8% in October in the year following dispersal. Seeds that afterripened in ambient indoor conditions for up to one year germinated to low (< 2%) percentages, indicating dry storage does not substitute for cold stratification in breaking seed dormancy. The germination niche of P. globosa can be defined by physiological dormancy, a long cold stratification period at low temperatures for dormancy break, formation of a persistent soil seed bank, and annual dormancy/non-dormancy cycling in buried seeds. Results from this study shed light on Short’s bladderpod regeneration biology and have implications for population management.

Contributing Author(s): 
Date Recorded: 
Wednesday, March 4, 2020