seed collection

David Remucal, University of Minnesota Landscape Arboretum

While many seedbanks avoid working with orchids, more groups are taking them on, or collecting them for groups that are. Collecting rules and protocols are not different for orchids but there are enough complexities in their biology to intimidate collectors new to orchids. Orchid seeds are the smallest in the world, and individual capsules can have from hundreds to thousands to over a million seeds in them. Banking orchid seed is complicated by this small size, the difficulty in determining seed viability as well as the difficulty in germinating and growing seedlings of nearly all species. On top of this orchid seeds are likely not orthodox, or if they are they may not store very long in a bank. Given all of these issues, research on orchid seed banking and ex situ conservation techniques is vital. In this short video we will introduce collectors to the basics of orchid seed work, covering issues of collection timing, mechanics of collecting, and storage that may trip up those that haven’t worked with orchids before.

Contributing Author(s): 
Date Recorded: 
Friday, October 9, 2020

Nina Rønsted, National Tropical Botanical Garden

Climate can play a critical role in plant physiological processes at all life stages, but investigations into climate effects often focus on only adult life stages. However, climate can influence seed development and germination, which can in turn strongly affect community dynamics. Native Hawaiian Metrosideros spp. (Myrtaceae; ʻōhi‘a,; 13 taxa) are the most dominant and ecologically important trees in mesic and wet rainforest ecosystems of Hawaiʻi. Aditionally, ʻōhi‘a are the most bioculturally important native plant in Hawai‘i. Recently, new fungal pathogens are causing rapid ʻōhi‘a death (ROD). As ʻōhi‘a are foundational species, ROD threatens the native forests that compose the majority of intact Hawaiian ecosystems. Making the most of Covid19 disruptions of our daily work, we used initial seed viability data from germination experiments routinely conducted by National Tropical Botanical Garden’s Seed Laboratory to explore if seed viability is correlated with collection locality and environmental variables. We included seed viability data of the most widespread and common taxon, M. polymorpha var. glaberrima, from 86 collection sites across Kauaʻi Island. Correlation of seed viability with environmental data from the Online Climate Atlas of Hawaiʻi was explored using linear models in R and suggest initial seed viability is correlated with mean temperature of coldest quarter and to a lesser extent with precipitation of warmest quarter reflecting the complex topology of Kauaʻi. As ROD threatens ʻōhi‘a across the islands, knowledge of these climatic effects on seed germination can be used as a proxy for understanding the health of populations across the distribution range and at its extremes. Linking seed viability information with environmental variables and locality can further help inform conservation priority planning as well as guide seed collection for safeguarding in seed banks.

Date Recorded: 
Friday, October 9, 2020

Michelle DePrenger-Levin, Denver Botanic Gardens; Michael Kunz, North Carolina Botanical Garden; Emily Coffey, Atlanta Botanic Garden; Tom Kaye, Institute for Applied Ecology; Anna Lampei Bucharová, Institute of Landscape Ecology (ILÖK), University of Münster

Seed collection is a vital conservation method used to ensure global food security by maintaining a source of genetic diversity in food crops and prevent the loss of biodiversity from natural or anthropogenic events that cause the extirpation of small populations. The Global Strategy for Plant Conservation facilitates global and national level plant conservation strategies including a target of collecting at least 75% of the threatened plant species in ex-situ collections with at least 20% being available for recovery and restoration. Local participation to reach this goal is facilitated by the Center for Plant Conservation (CPC). However, removing seed from small populations can increase extinction risk for species of conservation concern. Current restrictions on seed harvest meant to limit risk to rare species is based on stochastic simulations of a few perennial species with limited demographic data. Our work examines the universality of this threshold across lifespans (annuals to long-lived perennials). We account for variation in vital rate responses by using many transition matrices and adding predictions of worsening conditions due to climate change and human impacts by simulating different harvesting practices in years with high vs. low seed production.

Date Recorded: 
Thursday, October 8, 2020

Katherine D. Heineman, Christa Horn, Naomi Fraga, Cheryl Sevilla, Heather Schneider, Vanessa Handley, Holly Forbes, Brett Hall, Evan Meyer, Tony Gunroe, Shannon Still, David Magney, Stacy Anderson, Bart O’Brien, Joyce Maschinski

Center for Plant Conservation, San Diego Zoo Institute for Conservation Research, Rancho Santa Ana Botanic Garden, Santa Barbara Botanic Garden, University of California Botanic Garden, University of California-Santa Cruz Botanic Garden & Arboretum, University of California-Los Angeles, Mildred E. Mathias Botanic Garden, San Diego Botanic Garden, University of California-Davis, Botanic Garden & Arboretum, California Native Plant Society, Regional Parks Botanic Garden

California is home to one third of the globally rare plant species in the United States. To secure this incredible flora, ten botanical institutions in California have joined together to form the seed banking collaborative, California Plant Rescue. By sharing our accession data and integration of combined dataset with our natural heritage database, we created a suite of tools in support of seed collections. These tools include a web-based accessions database, a mapping application for collections targeting, and a web-app that prioritizes species for collection based on location, conservation status, and phylogenetic diversity. From our dataset, we also conducted a gap analysis of current collections in order to direct our seed strategy moving forward. Our analysis evaluated the spatial, phylogenetic, landownership, and ecological patterns of seed collections in California. Some patterns were intuitive: Our seed collections were heavily biased toward Southern California where the majority of our permanent seed banks, including our most prolific collector, is located. Ecological patterns were somewhat less intuitive: despite high interannual variation in population size, annuals are more likely to be represented in seed collection than perennials perhaps owing toward larger seed set and lower incidence of recalcitrance. Finally, our landownership analysis demonstrated that the greatest potential for seed collection in California is on US Forest Service land, which has the highest density of extant rare plant occurrences. We identified five specific National Forests which are home to 20 or more uncollected rare species, an insight that will be crucial for prioritizing permitting and relationship building with agency collaborators. In 2019, California Plant Rescue was awarded $3.6 million by the State of California to seed bank the remaining 650 rarest plant species in California. We will leverage these tools and insights to take full advantage of this exciting opportunity.

Date Recorded: 
Wednesday, March 4, 2020
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Photo Credit: 
Christa Horn
Tobin Weatherson from the San Diego Zoo Native Plant Seed Bank Collecting Field Data
Photo Categories: 
Photo Credit: 
Joe Davitt

Tom Kaye, Institute for Applied Ecology

Golden paintbrush (Castilleja levisecta) is listed as threatened and has become regionally extinct in the southern portion of its range due to habitat conversion.  A few wild populations remain in Washington and British Columbia.  Efforts to conserve the species in Oregon have emphasized wild seed collection across multiple remnant WA populations, agricultural seed increase, plug planting and seeding into restoration sites and prairies, and follow up management (including mowing, burning, and seed addition to increase plant diversity).  Concurrent research has demonstrated that the species is a generalist hemiparasite that benefits from having multiple hosts, underscoring the need to maintain or enhance plant diversity at reintroduction sites.  In addition, field tests have helped narrow the habitat type in which the species will thrive.  Since 2010, the species has established and increased in Oregon dramatically through reintroduction on conserved public and private lands, to over 350,000 plants across 23 populations in 2018.  The US Fish and Wildlife Service is currently considering delisting the species due to these recent successes with population establishment.

Contributing Author(s): 
Date Recorded: 
Friday, May 3, 2019

Michael Kunz, North Carolina Botanical Garden

Recently updated Best Plant Conservation Practices to Support Species Survival in the Wild detail guidelines for seed collection of rare plants. These include multiple aspects to consider in making seed collections regarding target species characteristics, collection timing, seed collection amount, population genetics and maintaining site quality. Here we outline seed collections for two species for which exceptional situations required special considerations for project success. We explore the use of the Best Practices for seed collections of 1) Phemeranthus piedmontanus (Piedmont fameflower), a species with a small population, identification challenges, and the need for multiple visits to sensitive habitat and 2) Macbridea caroliniana (Carolina birds-in-a-nest)¸ where sequential seed set, distance to the field site and a hurricane presented collection challenges.

Contributing Author(s): 
Date Recorded: 
Thursday, May 2, 2019

How many seeds can I take from a single individual if only a few plants have available seed?

Only a few plants in a population have seed available for collection. Can I take all of the seed from a single plant or should I only collect 10% of the seed from that plant?

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