• Current restoration successes hard to monitor and quantify due to remote locations, limited information on rare endemic plants, and limited funding.
• Ethos shift moving away from restoring only in pristine, native dominant habitat to planting in semi-novel ecosystems that are increasingly more common.
• Inter situ sites provide an easily accessible location to study the preferred growth conditions of rare and little studied plants in semi-wild ecosystems that are representative of natural habitats prior to outplanting.
• Botanical gardens can play a critical role in the conservation of endangered species through the establishment of intermediate or inter situ restoration sites.  
• This type of restoration can provide empirical information to researchers and managers to test best practices prior to implementation and create adaptive managment techniques.

        The Harold L. Lyon Arboretum is nestled in 193.5 acres of tropical rain forest at the top of the Manoa Valley watershed. Lyon Arboretum serves as a cultural and scientific resource to urban O’ahu’s diverse communities.  A vital resource for the University of Hawai’i system-wide,  Lyon Arboretum provides the scientific community with many research opportunities.  Lyon Arboretum coordinates, facilitates, and executes research, instruction, and service activities that utilize its collections and resources. Its major emphases are tropical plants, native Hawaiian plants, conservation biology, and Hawaiian ethnobotany.

          The role of arboreta and botanical gardens in the world has assumed an increasingly more critical and visible role in terms of species conservation and protection.  Lyon Arboretum is leading the way in terms of it's living collections and Hawaiian Rare Plant Program!

Ex-Situ Conservation:  The Living Collections

            Over 5,000 taxa of tropical and sub-tropical plants are found throughout our grounds.  This includes one of the largest palm collections at any botanic garden with over 700 species in a150 genera.  We also have an important Zingiberales collections with 350 Ginger species in 37 genera, 120 Heliconia species with 170 varieties and over 120 species of Bromleiads with 200 varieties and 20 genera!  Additionally, we have over 1,000 plant taxa designated red-listed by the IUCN

Hawaiian Rare Plant Program

          The mission of the HRPP is to aid in the prevention of further extinction of Hawaiian plant species by initiating and maintaining an in vitro plant and seed bank collection, and propagating plants for use in approved restoration and reintroduction projects. Since 1992, the Hawaiian Rare Plant Program (HRPP) has focused on the rescue and recovery of Hawai’i’s most critically endangered native plants, such as the native taxa that have 50 or fewer representatives left in the wild.  The Hawaiian Rare Plant Program serves as an ex situ plant and seed germplasm repository, propagation, and distribution site for plant propagators, land managers, and other end users who do not possess the resources to store and propagate their Hawaiian endemic plants.

 Cyrtandra kaulantha (Gesneriaceae)

 Image 1. Cyrtandra kaulantha (Gesneriaceae) winged petioles.

           Cyrtandra kaulantha (also known as ha‘iwale) is an endemic species found only on the windward side of O‘ahu’s Ko‘olau Mountains.This plant is a  As of last year, the IUCN declared the species “critically endangered” with a single population consisting of less than 20 mature individuals. With such small population numbers, it is unlikely that the species will ever regenerate on its own.

Inter situ Site Selection: Riparian Restoration on 'Aihualama Stream

         Image 3. GIS overview image of Lyon Arboretum and Inter situ site as located in Mānoa

Preliminary setup of intermediate restoration site established with Plant Extinction Prevention Program at Lyon Arboretum in Mānoa Valley. The site was chosen because:

1. -Reflects the observed habitat of the species collection site in Waikāne Valley (steep, tallus soils, low elevation, mesic, riparian)
2. -Easily accessible to management staff who can monitor and intervene
3. -Limited ungulate interference

Image 4. Inter situ restoration site

         We planted 40 Cyrtandra kaulantha (Cyr Kau) individuals at random across the site. Prior to planting, we removed all small non-native plants, but left a non-native tree canopy of Ficus sp. Survivorship was recorded every month and plants were kept free from weeds 2ft from the base of the plant. None of the habitat conditions were quantitatively measured and there was no plan for maintenance or experimentation. 

Figure 1. Schematic of 'Aihualama Inter situ outplanting site and general placement of Cyrtandra kaulantha individuals 

Figure 2. Kaplan-Meier survivorship curve of Cyrtandra kaulantha individuals at Lyon Inter situ site over 12 months (n=40).

1.  Less than 40% survivorship of all Cyrtandra kaulantha individuals after 12months.
2. After 18 months, only 5 individuals remain. They are significantly smaller than they were at time of outplanting and show signs of twig borer damage and other pathogen distress.
3. There was no evidence of pig damage around the site at any point and herbivory was limited.

Table 1. Comparison of Soil Sample Analysis between Waikāne and Mānoa Valley

1. Phosphorous (P) levels were very low,  below acceptable levels for volcanic soils. P is an important nutrient for plant growth and is often accessed via beneficial soil microbial relationships when limited.

 Conclusions:

1. Cytandra kaulantha did not successfully recruit at Lyon Arboretum's ʻAihualama inter situ site, however, certain critical dangers were mitigated, (i.e. absence of ungulate damage).
2. Staff at Lyon Arboretum were able to visit the site regularly to record data about mortality, creating first regular survivorship information for the species.
3. Significant differences in phosphorous levels between Waikāne and ʻAihualama sites might impact the success of Cyrtandra kaulantha restoration at this site.

Next Steps: Investigation of Soil Microbial Interactions

Cyrtandra kaulantha, as a model to explore the larger questions:

1. How can we better inform adaptive restoration practices to successfully restore plants that we know little about? How can we measure the factors that impact a novel species before we put it into wild?

Future Research:

1.  Impacts of soil inocula treatments in the greenhouse on the success of translocation of the native species Cyrtandra kaulantha to an intermediate restoration site located in Mānoa Valley.
2. Greenhouse and Field Experiment--> Our data collection will focus largely on mycorrhizal and soil microbial relationships and limitations of phosphorous.