INTRODUCTION TO ORCHID CONSERVATION

From the Greek god Dionysus to Darwin, orchids have fascinated countless generations with their inescapable beauty and beguiling forms. Whether it is their scent, sexual allure (for both insects and humans), or astonishing ability to grow in some of the most remarkable habitats on earth, it is no doubt that the orchid family — more than any other family of plants — has captured the human imagination. Their sheer diversity, with more species than any plant family, means they might not be that common; but there is an orchid likely to grow in just about any environment or habitat — from sub-Antarctic islands to searing granite rocks in the outback of Western Australia.

With so much diversity and exuberant evolutionary success, why are orchids also the single most endangered family of plants on earth? The answers to this are to be found in the pages of this book, as well as practical approaches currently available in orchid conservation techniques and technology. The concept for this book came from the inaugural International Orchid Conservation Congress (IOCC) held in Perth in 2001. Over time, and four IOCC conferences later, the book has grown to cover all aspects of orchid conservation with a focus on making orchid conservation technology accessible to all.

So why do we need a book on orchid conservation techniques? With 12% of the world's plants facing imminent extinction, and another 40% predicted to be extinct by 2050, never before has global biodiversity been under such threat. As we face the prospect of the sixth great extinction event, the challenge remains for conservation biologists, land managers, orchid enthusiasts, and growers to coordinate and link science and practice for more effective and targeted conservation outcomes. The task is large, and the time is limited. Orchid growers, admirers, and scientists have a special role to build the conservation technology toolkit and use these skills to conserve and reestablish wild orchid populations. Importantly, when engaging with stakeholders — whether they be landholders with orchids on their land, decision makers, or simply community members — dialogue is needed to forge links to deliver a level of conservation that will stem the impending tide of global extinctions threatening to engulf this remarkable family.

1.1 WHY ARE ORCHIDS RARE?

Orchids have significant below- and above-ground interactions with the living and abiotic environments. Few other families have such a diversity of synergies with other organisms: below ground, fungi and bacteria inhabit roots, rhizomes, and stems to assist with nutrient acquisition, immunity, and germination; above ground (and below ground in Australian underground orchids), pollinators from birds to bees, wasps, moths, and butterflies are sometimes rewarded; more often than not, they are duped into shifting orchid pollen around the landscape. With over 25,000 species globally, these critical biotic associations may have played major roles in driving the astonishing diversification of the family, but at the same time, the dependence of orchids on these interactions for sexual reproduction and seed germination through to maturity often results in populations that are highly dispersed, limited in abundance, or vulnerable to even the slightest change in habitat conditions. As a result, such species face heightened extinction risk, particularly from natural climatic shifts and human-induced change.

1.2 WHAT THIS BOOK MEANS TO ORCHID CONSERVATION

This book is structured to provide the reader with the capacity to develop a conservation program primarily for terrestrial orchids; nevertheless, many of the techniques apply equally to epiphytes. It would take an encyclopedia of books to review orchid science and conservation practice; however, this book is a navigation aid to getting started. Though each of these chapters provides stand-alone guidance, collectively they enable practitioners to undertake what were previously considered complex scientific procedures. These chapters are enriched with invited Case Studies that are relevant to illustrating key principles, along with success stories in orchid conservation that were written by world leaders in orchid conservation practice and science.

1.2.1 Chapter Outlines

Monitoring is covered extensively in Chapter 2. The how, when, and what to monitor has been integrated into demographic studies — understanding the recruitment cycle from seed germination to adulthood to senescence of the orchid plant. These life-stage transitions provide a firm foundation for understanding recruitment bottlenecks and where to prioritize conservation actions. Incorporated in Chapter 2 are four salient case studies that were provided by experts in the field. They show the conservation benefits of monitoring and demography studies including analytical approaches as applied by Raymond Tremblay and his colleagues. Chapter 2 concludes by demonstrating another important use of monitoring and demographic data in developing protective policies through processes such as Red Listing under the International Union for Conservation of Nature (IUCN).

Chapter 3 covers core aspects of orchid mycorrhizal ecology relative to conservation actions and planning. Though mycorrhizal ecology of orchids is one of the most wide-ranging and highly published aspects of orchid biology (outside of the orchid taxonomic literature), practitioner benefits of these research studies is often limited. In this chapter, we synthesize approaches used for mycorrhizal isolation and culture using appropriate media. A special case study on the newly emerging, but highly specialized field of isotopic discrimination is presented by Gerhard Gebauer and Julienne Schiebold. This tool enables understanding of orchid nutrition, with the case study providing a readable and up-to-date account of how to use this potent tool to understand the degree of mycorrhizal dependency in orchids — with some surprising outcomes.

Ex situ conservation methods are explored in detail in Chapter 4, where orchid seed sowing techniques are outlined — ranging from sterile to semi-sterile germination techniques and nursery sowing. Though techniques in orchid seed sowing harken back to the pioneering work of Lewis Knudson in the 1940s, techniques and media to solve issues with seed germination continue to develop and improve. This is illustrated by the outstanding case study of the industrial scale propagation of Cypripedium, in both China and Europe, which was once considered to have seed that is deeply dormant and difficult to germinate. Even though the mycorrhizal fungus remains elusive to...