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The Fascinating Ecology of Two Megadiverse Southern Hemisphere EcosystemsPlant Life on the Sandplains in Southwest Australia. LambersH., editor. 2014. University of Western Australia Press, Perth, Australia. 350 pp. $69.99 (hardcover). ISBN 13‐9871742585642.Fynbos. Ecology, Evolution, and Conservation of a Megadiverse Region. AllsoppN., J. F.Colville, G. A.Verboom, editors. CowlingR. A., consulting editor. 2014. Oxford University Press, Oxford, UK. 382 pp. $104.50 (hardcover). ISBN 13‐…

2015; Wiley; Volume: 29; Issue: 6 Linguagem: Inglês

10.1111/cobi.12624

1523-1739

Peggy L. Fiedler,

Ecology and Vegetation Dynamics Studies

Most people have never heard the word kwongan or the word fynbos. Mention of a sandplain, the English language equivalency of the former, likely conjures the image of a shimmering tropical beach; mention a heathland similarly conjures the moors of the British Isles. But kwongan, specifically, the sandplains of Western Australia, is among the most species-rich ecosystems in the world, exceeded in the temperate region only by the richness of South Africa's fynbos. Kwongan (correctly spelled kwongkan, a spelling not widely used [Hopper 2014]) is the Aboriginal (Noongar) name for this landscape. Fynbos is Afrikaans for fine bush, referring to the small and sometimes delicate, sclerophyllous foliage of the dominant species, mainly Restionaceae, Ericaceae, and Proteaceae. Fynbos represents the most species-rich extratropical vegetation anywhere on the globe. Thus, it is extreme good fortune for all scientists interested in plant species patterns in megadiverse landscapes that 2 new publications have recently been published. Plant Life on the Sandplains in Southwest Australia and Fynbos. Ecology, Evolution, and Conservation of a Megadiverse Region are both edited volumes with chapters contributed by the most respected and knowledgeable in-country plant scientists from (mostly) the Southern Hemisphere. Both volumes are billed as “updates” of original landmark publications, respectively, Kwongan—Plant Life of the Sand Plain by John Pate and John Beard (1984) and Richard Cowling's 1992 The Ecology of Fynbos: Nutrients, Fire and Diversity. Both of them are far more than simple updates. University of Western Australia Professor Hans Lambers edited a comprehensive compendium of the latest research on this remarkable suite of Western Australian sandplain ecosystems, sprinkled with the newest insights into and compelling arguments for the preservation of this world-renowned biodiversity. This volume is beautifully produced, replete with full color plates scattered throughout the text, and an intricate collage of kwongan plants delicately rendered by the accomplished Western Australian botanical artist Philippa Nikulinsky graces its cover. Nicky Allsopp, manager of the Fynbos Node of the South African Environmental Observation Network (SAEON), based at the Kirstenbosch National Botanical Gardens, along with 3 South African colleagues has similarly enticed an ensemble of accomplished scientists to provide wide-ranging and up-to-date chapters on fynbos and associated vegetation types (e.g., renosterveld, succulent karoo) of the Greater Cape Floristic Region (GCFR). It is an impeccably edited volume, with black and white images scattered through each chapter, and an inset of 19 color plates in the middle. Both books are from distinguished university presses, and, as such, they are substantial in quality, execution, and content. Plant Life on the Sandplains in Southwest Australia is unusually organized. It begins with an appropriate (and well written) preface and introduction that is followed by chapters 1–7 (including chapters 1A and 1B) on topics ranging from biogeography to wildfire. Chapters 7A through 7D embody a separate section entitled “Pollination,” which is then followed by chapters 7E through 7G in “Herbivory.” “Animals Providing Ecosystem Services,” chapter 7H, covers the ecosystem services of digging vertebrates. Chapters on conservation (chapter 8) and human relationships (chapter 9) and an epilogue conclude the volume. Perhaps in part because of this unorthodox numbering of the chapters and the topical subdivision of the book, there is some overlap in material and an unevenness to the length, style, quality of writing, and editorial oversight. The great majority of contributions, however, are excellent, in no small part simply because Western Australian kwongan ecosystems are utterly fascinating. In the first third of the book, several chapters stand out. Wyrwoll (chapter 1A) and his colleagues provide a fascinating discussion on the origins, geomorphology, and soils of the kwongan. The information is thoroughly illustrated as well as described and includes such facts as “a 1 mm quartz crystal at 25ºC and associated with a weathering environment of pH 5 has a lifespan of 34 × 106 years …,” leading any thoughtful evolutionary ecologist to revisit the notion of time and accumulated evolutionary change (p. 5). Hopper's orthographic, geographic, and historical discussion of the word kwongkan (chapter 1A) is revelatory and thorough. Less satisfactory, however, is Mucina et al.’s chapter 2 on kwongan biogeography, which reads like a mid-20th century European phytosociology textbook. This is a disappointment in that sandplain ecosystems and their ecological relationships are intricate and hard to see in both time and space—a more current mode of analysis would have provided greater insights. The following chapter (3) by Byrne et al. overlaps somewhat with the previous one, but its emphasis on phylogeny and phylogeography is an important contribution to the book. Lambers et al. present a comprehensive review of the nutritive minerals (chapter 4) and carbon and water relations (chapter 5) of the sandplains. Lambers’ first chapter provides a journey through the several plant macronutrients, mycorrhizae and nonmycorrhizal nutrient acquisition strategies, nitrogen fixation, and a thorough discussion of the tremendous diversity of Western Australia's carnivorous and protocarnivorous flora. The carbon and water relations chapter challenges standard academic dogma about such topics as the water-saving positioning of stomatal crypts and the timing and location of hydraulic redistribution in dry environments. They also provide an elegant answer to the curious paucity of succulent plant species in a seriously water-limited environment. Miller and Dixon's chapter on the role of fire in kwongan vegetation is a highlight of the book, presenting a refreshing perspective on plant life history traits in relation to fire and longevity. They dodge, however, the current controversy on whether such traits are adaptations, exaptations, or simply current features that convey some adaptive benefits in a fire-prone environment (see Bradshaw et al. 2011; Keeley et al. 2011). The next one-third of the book (chapters 7 and 7A–7H) explores a variety of specific aspects under the general rubric of plant–animal interactions, from pollination vectors to ecosystem services. These contributions are uniformly strong, current, and illustrative of why “kwongan matters.” Stand-out chapters include Phillips et al.’s summary of kwongan orchid pollination (chapter 7B), Twigg's thorough discussion of highly toxic native fluoroacetate-bearing vegetation (chapter 7F), and Bradshaw's text on the honey possum (Tarsipes rostratus) (chapter 7E). This tiny and elusive marsupial consumes 7 mL of nectar and 1 g pollen each day—roughly its body mass—and represents one of the most fascinating natural histories of the Western Australian marsupial fauna. The 3 final chapters are by David Coates et al., on the challenges of conserving an entire ecosystem few have ever heard of, much less care about; by Hopper and Lambers, on humans and their relationship with kwongan plants and landscapes (chapter 8); and by Lambers (chapter 9), on the future of kwongan in a changing world. Chapter 8 is an extraordinary piece that illustrates the rich botanical knowledge of the Noongar through a few examples, including Nuytsia floribunda (Christmas tree), Xanthorrhoea species (grass tree), and Haemodorum (miern), among others. In reality, the exceptional ethnobotanical heritage of the Noongar and, more broadly, the economic botany legacy and potential of the flora make Western Australia in general, and the kwongan in particular, a well-spring of opportunity for budding anthropologists, ethnobotanists, and horticulturalists. Chapter 9 provides a glimpse into the Gondwana sisterhood of South Africa's Greater Cape Region in part as context to explain the exceptional biodiversity of the kwongan and in part to summarize the highlights of the book. In some contrast to Lambers (2014), Fynbos. Ecology, Evolution, and Conservation of a Megadiverse Region is organized as a sequence of 16 chapters that wanders through the ecological, geological, ecophysiological, conservation, and human history academic landscape. Virtually all the topics one would hope for are covered, from traditional ones, such as vegetation types (chapter 1), climate (chapter 2), fauna (chapter 4 in part), and various aspects of the role of fire in vegetation processes (chapter 3), to more recent topics such as climate change (chapter 13), conservation (chapter 14), people and sustainability (chapter 15), and the future of Mediterranean-type ecosystems (chapter 16). The intellectual fingerprints of South Africa's leading plant scientist, Richard Cowling, are evident throughout, and Professor David Ackerly from the University of California, Berkeley, provides a depth and North American insight to several chapters, particularly the concluding piece. Fynbos begins with a sophisticated analysis of the different types of vegetation in the GCFR, acknowledging that although scientists have long been fascinated with South African vegetation and flora, there are still big gaps in the understanding of its vegetation assemblages. The Cenozoic is a touchstone for the ensuing discussions. Rainfall seasonality and reliability as well as fog and frost (among other phenomena) are presented as both existing and potential drivers of South African climate. This chapter is followed seamlessly by a discussion (chapter 2) of the physical geography and climate of the GCFR. Bradshaw and Cowling point out that this kind of analysis is not new for the Greater Cape, but a broad treatment of floristic pattern and vegetation process within and between fynbos, renosterveld, succulent karoo, and thickets has not been published previously. The inevitable conclusion is that the relatively benign and stable climate of the GCFR, particularly in the west, in an ancient, heterogenous landscape with minor tectonic activity may explain the renowned plant (and animal) diversity of South Africa. These themes are elaborated upon in Verboom et al.’s sophisticated discussion on floristic clades in the GCFR vegetation types (chapter 5) and Ellis et al.’s methodical exposition on evolutionary processes operating across multiple time scales at the population level (chapter 6). Fire is the subject of Kraaij and van Wilgen's chapter 3. These authors argue that to understand the evolution and diversification of Cape flora, one must accept that fire is “inevitable and necessary.” A thorough discussion of fire science is presented, including fire frequency, vegetation flammability, causes of fire, and management of fires. Kraaij and van Wilgen conclude that global climate change will certainly change the incidence and behavior of fires across the region. Colville et al. (chapter 4) provide a rhetorical examination of the Cape biochorion, which is a discreet, coherent biogeographic unit. In 2 words, it's complicated. Tolley et al. (chapter 7) bring molecular analyses to the fore, specifically phylogeography, to infer the location of regional refugia for the Cape's distinctive fauna, and thus phylogeographic patterns across the GCFR. Humans and their impact on the biota feature directly in Marean et al.’s (chapter 8) and Allsopp et al.’s (chapter 15) contributions on ancient and recent hominids and indirectly in Slingsby et al. (chapter 9), Wilson et al. (chapter 12), and Rouget et al. (chapter 14). The inevitable conclusion from all this is that the story of our human footprint in the ancient landscapes of the southern tip of Africa is as enduring as it is influential. Anderson et al.’s chapter is a comprehensive review of biotic interactions across the region. Although it reads a bit like an evolutionary ecology textbook, the natural history discussed is fascinating, from the stories of pollinator shifts across the orchid genus Disa to the extraordinarily rich guild of long-proboscid flies (Nemestrinidae and Tabanidae), upon which at least 200 species of South African plant species depend for pollination services, to the rodent-pollination guild that is a paradigmatic example of pollinator-driven convergent evolution. Ecophysiological diversity is the topic of Cramer et al.’s chapter, which is a nice counterpoint to Lambers’ work in Plant Life on the Sandplains of Southwest Australia. For example, the GCFR is rich with leaf succulents, whereas Western Australia is not, but ecophysiological similarities between these 2 floras exist in phosphorus and nitrogen acquisition strategies (e.g., photosynthetic phosphorus use efficiency, cluster roots, remobilization), the commonness of carnivorous and proto-carnivorous plants, and the diverse mycorrhizal symbioses. Encouragingly, at the time of this writing, several prominent authors of the Western Australian sandplains book, including the editor, are awaiting the results of a petition to list approximately 20% of Western Australia's kwongan, which exists in natural parks and reserves roughly the size of England in total, as a UNESCO World Heritage Site. Of the 10 criteria for listing (e.g., “to contain the most important and significant natural habitats for in-situ conservation of biological diversity, including those containing threatened species of outstanding universal value from the point of view of science or conservation” [http://whc.unesco.org/en/criteria/]), kwongan clearly meets or exceeds at least 6 when only 1 is needed for UNESCO approval. In February 2015, Western Australia's Labor Party publicly supported this proposal. With so much of the kwongan already lost, so much more seriously degraded, and so many kwongan plant and animals species critically threatened with extinction, such a designation would be an important advance in protecting the remaining biodiversity. This new book will surely provide incontrovertible scientific support for World Heritage designation and more simply will provide the science and inspiration to convince everyone that the nutrient-impoverished soils and wonderfully unique plants of the Western Australian sandplains are unquestionably worth protecting. Conservation is a recurrent theme throughout both volumes. The Cape Floral Region Protected Areas received UNESCO World Heritage designation in 2009. Consisting of 8 protected areas, this World Heritage site supports nearly 20% of all of Africa's flora. Thus, the rich science and compelling natural history offered in Fynbos. Ecology, Evolution, and Conservation of a Megadiverse Region command the global conservation community to pay equal attention to this extratropical, megadiverse landscape. With continuing degradation and accelerated species extinctions, coupled with a growing ennui among life-long conservation scientists, the vegetation of the Great Cape Region should be among the highest of priorities for everyone who cares about biodiversity.