Ex Situ Plant Conservation and Beyond - Oxford Academic

Professional Biologist

Ex Situ Plant Conservation and Beyond KAYRI HAVENS, PATI VITT, MIKE MAUNDER, EDWARD O. GUERRANT JR., AND KINGSLEY DIXON

In recent years, the mission of many botanic gardens and arboreta has expanded from a traditional focus on developing a horticultural collection to one that includes taking a proactive role in plant conservation. To use their limited resources more effectively, many gardens are seeking ways to quantify their contributions to conservation efforts, both as a self-assessment tool to improve their effectiveness and as a way to give an explicit accounting of activities to donors and funding agencies. We suggest many ways gardens can measure the success of their conservation programs, and present results from a survey conducted to assess current conservation activities at botanic gardens. Keywords: botanic garden, performance indicators, conservation strategies

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f ex situ conservation is to play an effective role in conserving wild plant diversity and supporting habitat conservation, appropriate levels of infrastructure and capacity need to be established (Maunder et al. 2004a), quantifiable goals need to be set, and progress toward those goals needs to be measured. The Global Strategy for Plant Conservation (CBD 2002) and other international policy documents provide conservation organizations with a globally relevant framework and measurable targets for conserving plant diversity. While individual ex situ plant conservation organizations (botanic gardens, arboreta, seed banks, etc., hereafter referred to as “gardens”) can, and do, contribute to the effort of meeting international targets, the targets are less useful for individual gardens seeking to assess the performance of their own conservation programs. Gardens are increasingly faced with the challenge of measuring and articulating the success of their applied conservation programs, in part because most funding agencies require an accounting of what their funding has accomplished, and in part as an effort to improve and expand conservation programs. Success can be measured in numerous ways, including resources conserved; improved management implemented; better laws and policies; changes in knowledge, attitudes, and behaviors of stakeholders; and reduction of threats to biodiversity. As Christensen (2003) points out, however,“It is far easier to measure what you do and call it a success than it is to take a hard look at whether you actually made a difference” (p. 14). In the end, the most appropriate yardstick for assessing the success of a program or project is the degree to which it contributes to conserving the resource (e.g., plant diversity), either directly or indirectly. www.biosciencemag.org

Performance indicators and botanic garden survey We have developed a set of performance indicators (box 1) for botanic gardens and other ex situ plant conservation organizations, following the conceptual framework outlined by Salafsky and colleagues (2002) and Salafsky and Margoluis (1999), and incorporating the conservation mission evaluation questions suggested by Miller and colleagues (2004) and Bartos and Kelly (1998), as well as several of our own. Salafsky and colleagues’ framework outlines a “taxonomy” of conservation approaches and strategies, including biodiversity protection and management, law and policy, education and awareness, and changing incentives (Salafsky et al. 2002). We have developed those themes with a particular focus on the current and future roles ex situ organizations can perform.

Kayri Havens (e-mail: [email protected]) is director, and Pati Vitt is a conservation scientist, at the Institute for Plant Conservation, Chicago Botanic Garden, Glencoe, IL 60022. They both have research interests in rare plant conservation using demographic and quantitative genetic techniques. Mike Maunder is the director of Fairchild Tropical Botanic Garden, Coral Gables, FL 33156, and chair of the IUCN Species Survival Commission Plant Conservation Committee. He has interests in ex situ plant conservation research, international policy development, and capacity building. Edward O. Guerrant Jr. is conservation director of the Berry Botanic Garden, Portland, OR 97219, and has research interests in seed germination and storage and rare plant reintroduction. Kingsley Dixon is the director of science at Kings Park and Botanic Garden in West Perth, Western Australia, where he has developed programs in conservation biology and restoration ecology focused on the biodiversity hotspot in southwestern Australia. © 2006 American Institute of Biological Sciences.

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Professional Biologist We conducted a Web-based survey of botanic gardens to establish a baseline assessment of current botanic garden conservation contributions. The survey was sent to approximately 400 ex situ plant conservation institutions represented at the Botanic Gardens Conservation International Congress in 2004 and to the 33 US-based botanic gardens in the Center for Plant Conservation network. Over 200 gardens responded in some form, and 45 (11 percent) from 19 countries completed the survey. Of those gardens completing the survey, 19 were from the United States and 10 were from other English-speaking countries, potentially biasing our results and indicating that language difficulties may have contributed to the low completion rate. We restrict our analysis to the 43 gardens that completed the survey and indicated conservation was part of their institutional mission (two responding gardens did not undertake any conservation activities and were omitted).

Survey results The survey revealed that botanic gardens currently contribute to plant conservation in a many ways (box 1), but there are also areas for improvement. Many gardens contribute directly to in situ conservation, either through direct ownership or through habitat management activities. Even gardens that do not manage natural areas contribute to in situ conservation efforts, both directly and indirectly. Over 70 percent of the responding gardens own, secure through conservation agreements, or manage natural areas on their grounds, in their region, or at remote sites. The average numbers of hectares owned, managed, restored, and legally protected by each garden are, respectively, 157, 399, 138, and 301. Many gardens manage (e.g., through weed removal or prescribed fire) or restore (e.g., by adding native plants or seeds to reestablish a community) properties they do not own. If the averages are calculated after removing those respondents that own or manage no natural areas, the average numbers of hectares owned, managed, restored, and legally protected are, respectively, 184, 461, 166, and 340. At the species level, gardens that responded are contributing to the conservation of endangered plant species in a variety of ways. Many are collecting and banking seed (58 percent), providing propagules for reintroduction (56 percent), and assisting with conservation assessments and recovery plans (44 percent). Surprisingly, only 3 of the 43 respondents indicated that they had an active conservation research program. In the areas of law and policy, 86 percent of our respondents are involved in formal conservation agreements. The mean number was 1.9 international, 2.6 national, and 3.5 local agreements. Fifty-eight percent of the respondents are already involved in lobbying or advocacy activities regionally, 40 percent nationally, and 18 percent internationally. Interestingly, over half of the respondents (56 percent) indicated that they were involved in advocacy within their institution, suggesting that conservation “buy-in” is not institution-wide for many organizations. 526 BioScience • June 2006 / Vol. 56 No. 6

Education is an area where many gardens excel. The vast majority of our respondents (80 percent) indicated that their garden has active on-site conservation interpretation programs; informal outreach through Internet and media venues was also well represented (69 percent of respondents). Many gardens also are involved in formal education programs, including those for primary and secondary students (69 percent), undergraduates (62 percent), and graduate students (53 percent), as well as professional education programs (36 percent) and symposia (51 percent).

Improving conservation practices For the foreseeable future, increasing demands for natural resources will continue to degrade habitats and push an increasing number of plants toward extinction. A critical and fundamental role of ex situ institutions is to combat extinctions (Maunder and Byers 2005). The “ark paradigm,” the idea that ex situ facilities would hold cultivated stocks of threatened species during a period of habitat degradation, was established as a working objective by botanic gardens in the 1970s. However, the traditional ark model for gardens is no longer sufficient. While ex situ seed storage or cultivation will continue to be an important conservation function, we believe that in order for gardens to operate in a biologically and financially viable manner, the species banking approach must be integrated with a habitat and ecosystem approach. Protection and management. Some of the most tangible conservation actions undertaken by gardens are for the protection and management of threatened plant species and communities. Support for in situ habitat management. Gardens can support habitat protection directly by owning or managing natural areas, or they can contribute to in situ conservation efforts indirectly through research, advocacy, and outreach programs. Stewardship professionals face many practical challenges that can be approached using ex situ techniques. When habitats are degraded and lose diversity, ex situ facilities can provide landscape species for habitat restoration, threatened taxa for reintroductions, and often the skills and resources needed for effective reestablishment of species. Conservation efforts for individual species should, wherever possible, be integrated with regional conservation plans for ecosystems as well as suites of species. As habitat declines in quality and quantity, the species load for ex situ management increases. As a result, gardens and other ex situ facilities will increasingly need to coordinate ex situ responsibilities with habitat restoration. Species-level conservation. Many gardens are actively engaged in seed banking and growing threatened plants, but the need for additional investment in this area is still great. Many biodiverse countries face an overwhelming ex situ load; that is, there are many more threatened plants than the country’s conservation infrastructure can seed bank and recover (Maunder et al. 2004a). As a result, the selection and prioritization of threatened species for ex situ management continues to be www.biosciencemag.org

Professional Biologist Box 1. Performance indicators for ex situ plant conservation facilities. For most of the performance indicators listed below, we give a baseline assessment of conservation involvement by ex situ plant conservation organizations (e.g., botanic gardens, seed banks, or arboreta), based on a survey of 430 institutions with 45 respondents. Some performance indicators were not included in the survey. Only respondents that included conservation as part of their stated mission (n = 43) were included; means include zero values. Most of the conservation actions listed here can be undertaken on several levels: institutional, regional, national, and international. For example, policy development can be institutional (general conservation plan, invasive plant policy, or adherence to conservation conventions and treaties), regional or national (participation in state or federal endangered and threatened listings), or international (IUCN, Global Strategy for Plant Conservation). Not all indicators are appropriate for any single institution, and gardens are encouraged to select and weight performance indicators according to their mission and goals.

Protection/managementa Hectares owned in native habitats: mean, 157; median, 25 Hectares secured in native habitats (e.g., through conservation agreements): mean, 301; median, 40 Hectares managed in native habitats (e.g., weeds removed): mean, 986; median, 130b Hectares restored in native habitats (e.g., native plants added): mean, 340; median, 10b Species in ex situ conservation collections: 73 percent of respondents Number of accessions per taxon (genetic diversity measure): not included in survey Species in formal reintroduction programs: 61 percent of respondents Formal recovery plan contributions: 49 percent of respondents Recovery team membership: 34 percent of respondents Reserve plan contributions: 22 percent of respondents Species recovered: not included in survey Species conservation assessments (e.g., red-listing): 39 percent of respondents Formal agreements established with other conservation agencies (local, national, or international): mean, 6.8 ± 8.4; median, 3 Steps taken to reduce ex situ liabilities: not included in survey Steps taken to avoid invasive introductions: not included in survey Applied research projects focused on high-priority species or habitats, or both: 63 percent of respondents

Law and policy Institutional mission and role directly linked to established priorities for conservation, capacity building, and/or sustainable development (institutional decisionmaking driven by conservation ethic; steps taken to conserve resources institutionally through reduced resource use, recycling, responsible use of chemicals, protection of water quality, etc.): not included in survey Policy development (policies openly available on Web): not included in survey Certification/licensing of facilities by federal authorities (e.g., US Fish and Wildlife Service) for endangered and threatened species work: 46 percent of respondents Advocacy or lobbying for conservation issues: 63 percent within state or province; 44 percent nationally

Education/awareness Informal—interpretation (in garden): 80 percent of respondents Informal—outreach (beyond garden): 69 percent of respondents Formal—primary and secondary (K–12): 69 percent of respondents Formal—university undergraduate: 62 percent of respondents Formal—university graduate: 53 percent of respondents Formal—certificate program/continuing education/symposia: 51 percent of respondents Communications—peer-reviewed general science publications: 61 percent of respondents Communications—peer-reviewed biodiversity/conservation publications: 56 percent of respondents Communications—lay publications: 90 percent of respondents Communications—alternative (e.g., Web pages): 80 percent of respondents Demonstrating environmentally sound and sustainable practices: not included in survey Displaying species and landscapes that promote the conservation work of the institution and collaborators and do not harm native species or habitats: not included in survey

Changing incentives Contributing to sustainable use (e.g., garden retailing that supports sustainable development of economically disadvantaged communities; promotion of ecotourism): 49 percent of respondents Using market pressure (e.g., certification programs for nursery-propagated stock; boycotting overharvested taxa): not included in survey

Institutional investment Percentage of operated budget spent on conservation internally (i.e., on the actions listed above, not on science generally; suggested benchmark is 25 percent [Miller et al. 2004]): 12 percent Percentage of operating budget spent on extra-institutional conservation projects, including capacity building in high-priority areas (e.g., shared positions with other conservation organizations; functional links between garden exhibits/interpretation and landscape-level conservation): not included in survey Professional development/training in conservation (for all staff, not just conservation staff): not included in survey Number and training of conservation staff (full-time, part-time, and students/interns): mean, 9.0; median, 2.5 (average of 9 percent of employees are conservation employees); training not included in survey Number of conservation volunteers: mean, 40.5; median, 4.4 Grant funding secured annually: not included in survey a. Seventy percent of respondents reported that their institutions were involved with the protection or management of natural areas. b. Some gardens manage or restore lands they do not own.

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Professional Biologist a serious challenge. These decisions are guided by a variety of criteria, including level of threat; legislative and institutional responsibilities; probability of successful storage and reintroduction; cost-effectiveness; relevant social, political, and economic issues; and curatorial preferences. Whenever possible, target species for ex situ management should be identified before they experience catastrophic declines, because the chances of successful recovery and reintroduction can be severely reduced when sampling genetically depauperate populations (Maunder et al. 1999), and because sampling numerically small populations has a proportionally greater impact on population viability (Menges et al. 2004). Ex situ facilities have an increasingly important legal and ethical responsibility for managing the inherent risks associated with living plant collections. Ex situ living collections face many of the same problems as small populations in the wild, as well as some hazards unique to the ex situ environment. There are three major ways in which the genetic makeup of ex situ populations can shift relative to wild populations: random genetic drift, artificial selection, and mutation accumulation. For programs with a primary goal of producing plants or seeds for reintroduction, managers can help minimize genetic threats by maintaining large population sizes, minimizing generations in captivity, providing periodic immigration from wild populations, and ensuring naturalistic grow-out conditions (Havens et al. 2004). Ex situ populations may also face risks of hybridization, which can occur between species within collections or between collections and wild populations. Hybridization can, in a sense, also occur within a species if differentially adapted populations are grown in artificial sympatry. Any of these scenarios can devalue the cultivated stock, making it inappropriate for use in restorations (Maunder et al. 2004b). Phytosanitary problems also can limit collection use. Ex situ collections have unintentionally served as vectors for pests, facilitating the distribution of the fungus Armillaria to South Africa (Coetzee et al. 2001) and the spread of a New Zealand flatworm (Boag et al. 1994). Applied research. Although many botanic gardens have been, and continue to be, leaders in plant taxonomic and floristic research, far fewer have applied conservation research programs. To cope with the increased range of threatened taxa requiring ex situ management, there will need to be an increased emphasis on conservation research. The development of horticultural protocols for wild taxa and of effective storage technologies for seed, tissue, and pollen continue to be research foci for ex situ organizations. Understanding threats to wild populations, reasons for rarity, and ways to abate those threats are important areas of research for effective adaptive management of in situ populations. There is also a need for research on species reintroduction and habitat restoration techniques, particularly in biodiverse regions of the tropics and subtropics. Avoiding invasive introductions. Invasive species have been recognized as a serious threat to biodiversity, second only to habitat loss (Wilcove et al. 1998). When exotic plants are 528 BioScience • June 2006 / Vol. 56 No. 6

introduced to a new location, they have the potential to spread rapidly, outcompete native species for resources, and ultimately dominate the landscape (Smith et al. 2000, Dukes 2001, Collier et al. 2002). Up to 85 percent of the invasive plant species in the United States were originally introduced for horticultural purposes (Marinelli 1996, Reichard and Campbell 1996). Although only a small percentage of exotic species become invasive, those that do can have devastating effects on biodiversity (Pimentel et al. 2000). Invasive species are estimated to cost the United States $138 billion per year, while invasive plants alone are conservatively estimated to cost $35 billion per year (Pimentel et al. 2000). Collection managers should assess their collections to identify high-risk taxa and take basic measures to remove them or, at the very least, reduce the risk of escape and provide visitor interpretation (Wittenberg and Cock 2001, Baskin 2002). Plants that are new to the country or region should be assessed for invasion risk before their introduction to the garden or release to the horticultural industry (Groves et al. 2001, NRC 2002). Law and policy. Safalsky and colleagues’ (2002) framework emphasizes the importance of supporting the development of conservation policy in external agencies. We expand this concept to include an institution’s own policies and procedures. Conservation ethics and institutional policy. Botanic gardens espousing a conservation mission should consider the conservation ramifications of all decisions and policies, not just those within conservation departments. For instance, the North Carolina Botanical Garden has embraced a role as a “conservation garden.” Throughout its campus, conservation ethics drive collection and display policies, site development plans, building materials, educational offerings, interpretation, resource consumption, and other activities (White 1996, 1999). We suggest that as such conservation policies are developed, they should be available on the Web to assist other gardens in similar efforts. Policies also should be distributed and explained to all staff and trustees. Even in organizations with a long history of commitment to conservation, there is an ongoing need to educate incoming staff and trustees about the role and value of such work. Ex situ policy. Botanic gardens can strengthen their conservation programs by adhering to international conservation treaties. The Convention on Biological Diversity (CBD) and national laws on access to and ownership of plant genetic resources have introduced legal and ethical obligations for ex situ conservation facilities (Glowka et al. 1994). The CBD recognizes the value of ex situ conservation (article 9) “preferably in the country of origin” and as a support to the “recovery and rehabilitation of threatened species and for their reintroduction into their natural habitats” (Glowka et al. 1994). The IUCN Species Survival Commission policy on ex situ conservation (IUCN 2002, Maunder and Byers 2005) recognizes that “the primary objective of maintaining ex situ populations is to help support the conservation of a threatened taxon, its genetic diversity, and its habitat.” www.biosciencemag.org

Professional Biologist The integral role of ex situ conservation has been emphasized in the Global Strategy for Plant Conservation (CBD 2002). However, a shortage of funds and an insufficient understanding of the potential contribution of ex situ conservation hamper the implementation of truly integrated plant conservation strategies. Advocacy and lobbying (within legal limits for tax-exempt organizations) will help raise awareness about threatened species and the role of ex situ methods while potentially increasing funds for biodiversity conservation. Education and awareness. Gardens provide an important venue for introducing the public to the value of plants, biodiversity, and native habitats, as well as offer formal educational programs. Informal education. Informal education is one of the fundamental reasons that botanic gardens and museums exist. Public gardens collectively host over 150 million visitors each year (Wyse Jackson and Sutherland 2000). Consequently, gardens can make a unique and significant impact by becoming centers for public outreach on plant conservation and sustainable use. Messages about conservation can be incorporated into signs, Web sites, and brochures or other printed materials, and can even become part of a garden’s “brand”— that is, the image presented and marketed by the organization. Equally important is the demonstration and interpretation of sustainable practices, such as choosing plants that require minimal water and fertilizer, using integrated pest management strategies to minimize pesticide use, not growing invasive plants, providing recycling opportunities, composting, choosing low-emission vehicles, and incorporating “green” architecture in buildings. Ultimately, botanic gardens need to engage their visitors, to challenge them intellectually and emotionally, in order to change attitudes, behavior, and values related to biodiversity conservation. Admittedly, the concepts of conservation and biodiversity can be complicated to interpret, but public understanding is necessary to engage public and political support for conservation. Through this support, conservation policy can be developed at regional, national, and international levels, which in turn will help to create the culture of sustainability that will be necessary to achieve long-term conservation goals. Formal education. Many undergraduate and graduate programs offered by botanic gardens and their partnering universities focus on plant systematics, such as those at the Missouri Botanical Garden, the New York Botanical Garden, and Rancho Santa Ana Botanic Garden. More recently, a number of gardens are developing educational programs in applied conservation biology. Some of the largest conservation education programs are offered in Australia (Kings Park and Botanic Garden), South Africa (National Botanic Gardens), the United Kingdom (Royal Botanic Gardens, Kew), and the United States (Center for Plant Conservation, Chicago Botanic Garden, Denver Botanic Gardens, Fairchild Tropical Botanic Garden, and New England Wildflower Society). These offerwww.biosciencemag.org

ings include professional workshops, certificate programs, accredited undergraduate courses, and graduate programs. Changing incentives. A relatively recent conservation strategy involves providing economic and other incentives to encourage stakeholders to conserve plants and biodiversity. Contributing to sustainable use. Ex situ facilities can help support sustainable livelihoods and alleviate poverty with their purchasing choices (box 1). An excellent example of promoting sustainability is provided by the Eden Project in the United Kingdom, whose mission is “to promote the understanding and responsible management of the vital relationship between plants, people and resources leading to a sustainable future for all.” Its retail and catering services purchase socially and environmentally responsible products, locally whenever possible. As part of its sustainability strategy, the Eden Project is also tackling resource and waste management. The project aims to become “waste neutral” by purchasing an equal or greater weight of products made from recycled materials than the weight of materials sent off for recycling or disposal. Supporting ecotourism or the marketing of sustainably harvested products through garden retailing may assist conservation efforts and raise the standard of living in developing countries by providing new and highly specialized markets for plant-based products and by promoting “fair trade” ethics. For example, purchasing fair trade products ensures that producers receive a fair price, sustainable production techniques are used, and working conditions are safe. Fair trade organizations work with producers to assist them in following environmentally responsible practices. Developing products based on sustainable use of natural resources in biodiverse regions can also provide incentives for communities to preserve natural habitats. Using market pressure. Overcollection of many plant species, and particularly of groups that are hard to propagate or slow growing, such as orchids and cacti, continues to threaten wild populations. Therefore, gardens should purchase or sell only plants that were nursery propagated from stock that was legally and ethically obtained. Similarly, when purchasing lumber or other natural resource products, gardens should ensure that the product was sustainably harvested, which is becoming easier through certification programs such as the one developed by the Forest Stewardship Council. Garden shops and other retail venues represent a great opportunity for promoting sustainably harvested and fair trade products. They offer a unique opportunity for educating consumers about sustainability issues and empowering them with the choice of buying products that are sustainably produced. The networks of botanic gardens in Europe and North America represent an untapped opportunity to support incountry conservation projects through imaginative retailing to an audience sympathetic to environmental issues. Investment. Perhaps the truest measure of an institution’s commitment to conservation is the investment of human, operJune 2006 / Vol. 56 No. 6 • BioScience 529

Professional Biologist ational, and capital resources in conservation programs both within and beyond the garden walls. Institutional commitment and investment. The commitment to ex situ conservation requires long-term investment in both facilities and staff. Institutional investment could be measured in decades and possibly centuries. As the importance of ex situ collections increases relative to surviving wild populations, there is a corresponding need to ensure the long-term institutional commitment to conservation projects. Such a commitment may last beyond traditional employment periods and in some cases represents an intergenerational responsibility that must persist through institutional changes in strategy. The use of long-term storage techniques, such as seed banks, will greatly facilitate collection longevity, but they must be supported with adequate long-term institutional resources. Extra-institutional capacity building and support. We propose that ex situ plant conservation facilities can and must play an increasingly important role in generating support for in situ conservation. Gardens in developed countries can provide scientific, financial, and managerial support to facilities in developing regions where indigenous species can be maintained more cost-effectively (Stanley Price et al. 2004). Gardens can use their displays to generate revenue and public concern for in situ conservation programs. For instance, the Utrecht Botanical Gardens, in the Netherlands, has purchased rainforest reserves in French Guiana using funds raised from its rainforest exhibit. The Arizona–Sonora Desert Museum and Native Seeds/SEARCH in the southwestern United States conduct cooperative conservation projects with Mexico. In a politically complex world, botanic gardens can serve as politically neutral and noncontroversial agents for conservation, thereby playing a highly effective role in support of conservation activities. Improving professional capacity. Activities that partner economically and technologically developed regions with developing countries provide one mechanism that is already delivering a wide variety of benefits. Given their inherent supporting role, ex situ facilities will be most effective in conserving plant diversity when working in active partnership with land managers and regulatory agencies (Guerrant et al. 2004). The global network Botanic Gardens Conservation International, through the development of the Global Strategy for Plant Conservation, endorses opportunities for shared activities between botanic gardens. Excellent examples of the benefits of local empowerment include the development of the Limbe Botanic Garden in Cameroon (Sunderland et al. 2002) and the broad international activities involved in capacity building for the Millennium Seed Bank project of the Royal Botanic Gardens, Kew (Williams 2001). Some gardens now offer conservation training for interested staff as part of their professional development programs. This helps build an institution-wide understanding of conservation issues and support of the organization’s own conservation policies. It is particularly beneficial to have senior administrative, development, and communications staff 530 BioScience • June 2006 / Vol. 56 No. 6

who are well versed in conservation issues for fundraising purposes. Volunteers can greatly expand a garden’s capacity to conduct conservation activities. Volunteers have been employed by many gardens to monitor rare plant populations (e.g., the New England Plant Conservation Program of the New England Wildflower Society and the Plants of Concern program of the Chicago Botanic Garden), provide early detection of invasive species, collect and process seed for long-term storage (Millennium Seed Bank), and assist with research projects. Some scientists have questioned the validity and reliability of volunteer-collected data, but several studies have shown that these data compare favorably with those collected by professionals (Obrecht et al. 1998, Canfield et al. 2002). In addition, the Chicago Botanic Garden’s Plants of Concern program conducted a study comparing rare plant population censuses and found no significant differences between counts conducted by volunteers and those conducted by staff (p = 0.74; unpublished data from P. V.).

Conclusions It is unlikely that existing networks of protected areas in regions of high plant diversity will be sufficient to ensure the long-term survival of all plant diversity (Tilman and Lehman 2001). Accordingly, there will be a continued need for ex situ activities to directly support in situ conservation through habitat management, recovery management of wild populations, and the management of wild diversity in increasingly human-dominated landscapes. We argue that conservation facilities and institutions can provide quantifiable evidence of the value of their work and resources in terms of species and populations recovered, areas and resources restored, education (including outreach to the public and stakeholders resulting in beneficial change), and services to local communities (e.g., employment and capacity building; box 1). Precise, quantitative evaluation of the impact of such activities is a more difficult challenge and needs to be done at the project level. Integrated plant conservation (sensu Falk 1990) combines the protection of plants in their native habitats with an ex situ conservation program to provide a safety net against extinction in the wild. It provides the tools, resources, and research to better manage wild populations. We encourage an even wider view on conservation and outreach that seeks to integrate applied community- and species-level research and management, professional and volunteer efforts, and a conservation perspective into all garden activities. Many botanic gardens are embracing this approach as their mission evolves and expands from a display of taxonomically diverse, typological collections to the operation of a true conservation organization. Gardens are undergoing great changes, as the historical priorities of horticulture and taxonomic research are being supplemented and modified by the imperatives of biodiversity conservation and public education and outreach. We argue that modern gardens should not be measured simply in terms of their collection and display but, more www.biosciencemag.org

Professional Biologist important, in terms of their contributions to species and habitat recovery in the wild.

Acknowledgments The authors thank all who participated in the Web-based survey as well as our respective institutions for support during manuscript preparation. We thank Stuart Wagenius, Bob Kirschner, and three anonymous reviewers for comments on earlier versions of this manuscript.

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