Conservation Assessment and Management Plan for St Helena: a Collaborative Workshop
Volume 2 Number 4 - December 1994
Mike Maunder, Alastair Culham, Ulysses S. Seal, & Paul Pearce-Kelly
Conservationists face a very real challenge when developing priorities for species conservation, just how many species should be adopted for ex situ management and for what purpose? This is particularly relevant for botanic gardens, where managers have to select a limited number of species for ex situ propagation from an expanding number of candidate species. In May 1993, an exploratory exercise was held at Kew to assess the value of the conservation planning protocols of the Captive Breeding Specialist Group of the IUCN Species Survival Commission. Using the remote Atlantic island of St Helena as an example, the native biota (vascular plants, invertebrates, selected endemic marine fish, and the one native vertebrate) was reviewed with the aim of identifying conservation priorities and those taxa requiring management intervention to assure long term survival.
The Conservation Unit (Living Collections Division) of the Royal Botanic Gardens, Kew, is currently managing the Sustainable Environment and Development Strategy for St Helena. This project is funded by the British Government (ODA) on behalf of the Government of St Helena. This work is being undertaken in collaboration with the International Institute for Environment and Development (IIED) and the St Helena Working Group. The strategy recognises the need to balance economic, social and ecological systems to support the goal of sustainable development. International experience has consistently shown that conservation strategies focusing on any one or two of these systems alone will not succeed.
One part of the project involved a review of the island's conservation priorities. This involved a review of the island's biota and the identification of actions required to prevent further reduction and degradation of surviving habitat fragments and extinction of endemic species. It was decided to use this opportunity for a exploratory workshop utilising the wide spectrum of expertise on St Helena resident in the UK, most notably the St Helenan Working Group. The workshop was chaired by Dr Ulie Seal of the Conservation Breeding Specialist Group (CBSG) of the IUCN Species Survival Commission, a group whose primary goal is to contribute to the development of broadly based and viable conservation strategies and action plans for threatened species. The objective of the workshop was to review the applicability of CBSG protocols to botanical conservation and to general conservation planning for islands.
The conservation challenges facing managers are so enormous that it is imperative that the available limited resources are employed as efficiently and effectively as possible. The CBSG has developed protocols in response to this need; the Conservation Assessment and Management Plan (CAMP) and the Population Habitat Viability Analyses (PHVA).
Conservation Assessment and Management Plans (CAMPs)
CAMPs are developed to provide strategic guidance for information collection and intensive management of threatened taxa. They provide a rational and comprehensive means of assessing priorities for intensive management, including ex situ management, within the context of the broader conservation needs of the threatened taxa and associated habitats.
A CAMP workshop brings together 10-40 experts from a variety of backgrounds to evaluate the threat status of all taxa within a taxonomic group or defined geographical area, to set priorities for conservation action and information gathering actions. Within the Kew meeting the following disciplines were represented: conservation planning, ex situ management (zoological and botanical), population geneticists (zoological and botanical), data scientist (botanical) and postgraduate students. As many of the workshop participants should have direct experience of the taxon or area under review, and importantly the management authorities for the taxon or area under review should take the lead in the activity. It is an attempt to develop a process that will: 1) make broad based recommendations concerning species management: and 2) recommend specific conservation biology research needed to support the management and recovery of the species concerned.
The CAMP process is heavily dependent upon the interaction of specialists from a variety of backgrounds. Participants develop the assessment of risks and formulate recommendations for actions using a spreadsheet recording the status of species and habitats. The spreadsheets are supplemented with Taxon Data Sheets for each taxon under review. This sheet records information on distribution, range, area of occupation, wild popuations, number of populations, trends and threats.
During the workshop the size and value of both wild and captive populations are reviewed, with an attempt made to estimate size of populations. The CAMP process attempts to be as quantitative as possible for two major reasons: Action Plans should establish numerical objectives, numbers providing more objectivity and better focus.
CAMPs assess the degree of threat for each taxon in the wild and recommend appropriate action that may reduce the risk of extinction. During the workshop accurate and recent survey results were available, resulting from field work undertaken by Tim Upson (then RBG Kew) and George Benjamin (St Helena) in May 1993. Based on assessments carried out during the workshop a set of recommendations are produced, these include:
- The need for species specific Population and Habitat Viability Assessment (PHVA) Workshops
- Broad based recommendations for intensive protection and management in the wild
- In situ and ex situ based research that can direct management and recovery programmes
- Captive propagation programmes
- Genetic resource banking
Population and Habitat Viability Analyses (PHVAs)
The PHVA workshop provides population viability assessments for each population of a specific taxa under review. The assessment for each taxon will vary in depth according to the information available on life history, population dynamics, ecology, known and potential threats and population history of the individual populations. All available pertinent information is collated before the workshop to allow for full briefing.
Using a computer simulation model (VORTEX programme) and group discussion the workshop exercises are able to assist the formulation of management scenarios for the species reviewed and evaluate the impacts of differing management regimes, disasters, disease, genetic problems etc.
Results of the CAMP and PHVA Workshops
Flora: The review was restricted to the native and endemic species of St Helena. Species were assigned the existing IUCN Categories of Threat and the proposed categories (Mace et al. 1992). The list of 60 species includes: 32 Dicotyledons, all evaluated, of which 6 are Extinct, 2 are Extinct in the Wild, 19 are Threatened including 7 Critical; 5 Monocotyledons, all evaluated, 1 Extinct, 4 are Threatened; and 24 Pteridophytes of which 5 were evaluated. Recommendations were made for detailed assessments and management planning (PHVAs) for 20 species, some 54 research and management projects were suggested, and 16 captive propagation programmes were recommended. (SEE TABLE) Preliminary PHVAs were conducted on 2 species, Commidendrum rotundifolium (Asteraceae) and Trochetiopsis melanoxylon (Sterculiaceae). These provisional studies suggested that existing re-introduction programmes are subject to a high risk of failure.
The following areas of relictual habitat were identified as priority areas for conservation:
- Diana's Peak - Tree fern thicket and cabbage tree woodland
- High Peak - Tree fern thicket and cabbage tree woodland
- Peak Dale - Dry gumwood forest
- Distant Cottage to Asses Ears - Scrubwood scrub
- Man and Horse Cliffs - Scrubwood scrub
- The Barn - Scrubwood scrub
- Dandy Beach to Lots Wife - Saline semi-desert
The following taxa are recommended as candidates for immediate ex situ propagation programmes. All are recognised as having a very high probability of extinction in the wild. Any propagation programme should be based upon utilising all available founder individuals on the island:
Nesiota elliptica St Helena Olive
One surviving and moribund individual in the wild, suffering from a pathogenic fungal infection. The ex situ population on the island consists of 1 vegetative individual from the wild plant and 3 seedlings from the same parent. The wild plant has subsequently died (December 1994). (Extinct in the Wild)
Commidendrum spurium False Gumwood
Maximum of 17 mature plants surviving, population appears to be declining and threatened by invasives, possible infra-generic hybridisation and effects of introduced scale-insect, Orthezia. (Critical)
Commidendrum rotundifolium Bastard Gumwood
All plants (35-40 have been re-introduced and 6 are in the Agriculture and Forestry Nursery on St Helena) are descended from one plant. (Extinct in the Wild)
Wahlenbergia linifolia Large Bellflower
Wild population of between 40 and 60 plants, none in cultivation. Wild populations setting good seed and regenerating well. (Critical)
Trochetiopsis erythroxylon Redwood
Extinct in the wild and suspected of possessing a narrow genetic base. More difficult to grow than the ebony, a total of 50 plants grow after re-introductions, with a further 70 in cultivation on the island. (Extinct in the Wild)
Trochetiopsis melanoxylon Ebony
Two surviving wild plants, majority of cultivated stock descended from one of the two surviving wild plants only. Grown widely in botanic garden collections, subject of a research project by Rebecca Rowe, University of Oxford. Widely planted on St Helena, long term viability of these plantings still uncertain. (Critical)
Phylica polifolia St Helena Rosemary
Only 30 plants survive in 4 or 5 sub populations. Historically recorded as a large shrub or small tree, all extant individuals appear to form a sprawling shrub. Not represented in cultivation. (Critical)
Sium burchellii Dwarf Jellico
A maximum of 50 plants survive at 2 sites. Relatively easy to cultivate. (Critical)
A number of species are recognised as requiring trial cultivation to develop propagation/cultivation protocols in anticipation of any possible decline in population, e.g. Sium helenianum. Others are recovering well in the wild and do not justify cultivation ex situ for conservation purposes, e.g. Commidendrum rugosum or Perlagonium cotyledonis.
Invertebrates: The results underlined the vulnerable position of most of the island's endemic invertebrates, now largely dependent upon a mosaic of remnant habitats. Many species were recognised as facing competition or direct predation from exotic species. PHVAs were recommended for 25 species and 25 research and management projects were suggested. Six captive breeding programmes were recommended. In total 55 taxa were evaluated. Preliminary PHVAs were conducted on 2 species.
Vertebrates: The same review and assessment mechanisms highlighted the fragile status of the endemic Wire bird and the 10 endemic species of marine fish. A preliminary PHVA undertaken for the Wire bird indicated a high level of vulnerability due to mortality at the juvenile stage.
- The applicability and value of the CAMP and PHVA procedures for botanical and island biota conservation were demonstrated, conservation priorities and recovery plans for St Helena have been revised following the results of the workshop. Importantly it demonstrated the value of multi-disciplinary groups in developing regional and island conservation strategies. With particular reference to botanical conservation, the CAMP protocol could be profitably utilised in reviewing taxonomic groups at generic or family level for regional or global planning; or for reviewing geographical responsibilities for botanic gardens or protected areas. Islands with relatively small floras and a discrete area will be particularly suited to this activity. In addition, the level and type of ex situ management can be assigned.
The proposed IUCN Categories of Threat (Mace, et al., 1992. The Development of New Criteria for Listing Species on the IUCN Red List. Species 19:16-22) can only be assigned at the global level, the CAMP Workshops are an ideal forum for reviewing defined taxonomic groups and geographical areas.
- Exploratory Population and Habitat Viability Assessments were undertaken for selected species. The VORTEX programme was reviewed for its applicability and limitations for botanical work. A number of recommendations for modification have been drafted and submitted to the CBSG.
- For the first time a complete island system has been reviewed as part of a CBSG workshop. The workshop succeeded because practical answers were being sought by a group dedicated to promoting conservation on the island; additionally the wide variety of expertise and organisational representation encouraged a broad and open debate, and discouraged dogmatism.
- The results of this workshop will be incorporated into the protected areas plan for St Helena. Ideally such a workshop should only be undertaken in-country, it is hoped to repeat this exercise on St Helena.
- The workshop is an ideal vehicle for introducing ex situ managers and horticulturists to the dynamics of population biology and the role of modelling in conservation biology. It can also be modified as a very potent teaching tool. "Vortex" is already being used as a teaching tool for students at the University of Reading (BSc Botany) and the Royal Botanic Gardens, Kew (Plant Conservation Techniques Course).
As a result of this first exploratory workshop it is evident that the procedures developed by the CBSG have great value to planners assessing regional and taxonomic priorities. The Royal Botanic Gardens, Kew, will continue to refine these procedures to develop planning tools for botanic gardens.