Peggy L. Fiedler

Flower defenses against nectar-pilferage by ants

ro determine palatability, floral nectars from 25, and floral tissue extracts from 17, plant species of wet and dry forests of Costa Rica were offered to foraging ants in pairwise tests with sugar solutions. Nectars from all 25, and floral tissues from 10, species were analyzed chemically to ascertain the presence of potentially attractive and deterrent substances. In general, floral nectars are palatable to ants, whereas floral tissues showed highly variable palatability. We observed ants foraging in flowers of only 10 species of plants. Defense from nectar thievery by chewing insects seems most often to involve varying degrees of chemical and morphological modification of floral parts, rather than by the production of deterrent compounds in the nectar itself. FLOWERS THAT OFFER NECTAR as a primary reward to pollinators are common in the tropics. Nectar is generally nutritious and energy-rich, and pollination and seed set regularly occur as a result of the nectargathering activities by a wide array of animals, including many hymenoptera. Ants, however, are only rarely considered reliable pollinators (Kerner von Marilaun 1878, Proctor and Yeo 1972, Hickman 1974, Faegri and van der Pijl 1979), even though they are extremely abundant in a wide variety of habitats and are notorious for their skill in locating even small amounts of sugar. It is surprising that observations in the tropics reveal ants foraging for nectar in flowers only occasionally (van der Pijl

The Paradigm Shift in Ecology and Its Implications for Conservation

A brief precis of ecology is discussed, emphasizing the central theme of succession in the classical paradigm. This is followed by mention of the nonequilibrium paradigm and its central theme of patch dynamics. Conservation implications of this paradigm shift in ecology include (1) the replacement of a model in which some species are better adapted than others with a model in which all species are simply differently adapted; (2) the population as the fundamental unit, or currency, in conservation, (3) the recognition of the complexity of patch dynamics overlain by habitat fragmentation and the confounding implications of these; and (4) a greater appreciation of multiscalar phenomena. Social implications include some mistrust and skepticism of the “new” conservation, and most importantly, the birth of ecologist as polymath.

The Role of Botanic Gardens in the Science and Practice of Ecological Restoration

Many of the skills and resources associated with botanic gardens and arboreta, including plant taxonomy, horticulture, and seed bank management, are fundamental to ecological restoration efforts, yet few of the worlds botanic gardens are involved in the science or practice of restoration. Thus, we examined the potential role of botanic gardens in these emerging fields. We believe a reorientation of certain existing institutional strengths, such as plant-based research and knowledge transfer, would enable many more botanic gardens worldwide to provide effective science-based support to restoration efforts. We recommend botanic gardens widen research to include ecosystems as well as species, increase involvement in practical restoration projects and training practitioners, and serve as information hubs for data archiving and exchange.

Worldwide destruction of inselbergs and related rock outcrops threatens a unique ecosystem

In many parts of the world rock outcrops form important landscape elements that play a role in generatingandmaintainingbiodiversity inaddition toprovidingkeyecosystemservices.These rock outcrops rise abruptly from the surrounding landscape, have a patchy distribution, and represent centersofdiversityandendemismforbothanimalandplant life (HopperandWithers 1997).Known as ‘inselbergs’ and often composed of Precambrian granitoids, these outcrops occur across all continents. Inselbergs are particularly noteworthy inancient biodiversityhotspots, e.g., the Brazilian Atlantic Forest, Guinean Forests of West Africa, Madagascar, the Greater Cape and Southwest Australian Floristic regions (Hopper et al. 2016). The ecological and evolutionary processes that operate in these ancient environments differ significantly from comparatively more recent environments (Hopper 2009). Their conservation is of global importance, in great part because they support unique, endemic biota of recent and deep phylogenetic history.

Is wetter better

This article describes the need to base environmental policy concerning wetlands on current understanding of natural systems. The authors highlight patterns of wildlife use within wetland habitats in the San Francisco Estuary. As a clear mandate of the Clean Water Act, federal protection should be given wetlands with highly variable seasonal hydrology as well as those that are permanently inundated or saturated. Drier wetlands play a crucial role as links between upland and aquatic habitats.

New lessons from ancient history

In 1984, an Ecological Society of Australia (ESA) symposium was convened to explore the effects of evolutionary history on species assemblages within similar present-day environments. Australian ecosystems were deemed to be the perfect natural laboratories because significant portions of that island continent have been more or less undisturbed by sea-level rise, glaciation, volcanism, etc. since the early Cretaceous. As such, many can be contrasted with younger temperate landscapes in the Northern Hemisphere with similar climatic conditions to elucidate evolutionary patterns. Professor Mark Westoby, of Macquarie University, summarized key findings of the symposium (Westoby 1988), beginning with an introductory quotation from the writings of Francois Peron, zoologist on the 1801–1803 Baudin expedition, commissioned to chart the Australian coast. Peron’s comment bears repeating:

The Role of Botanic Gardens in the Science and Practice of Ecological Restoration: Role of Botanic Gardens in Restoration

Many of the skills and resources associated with botanic gardens and arboreta, including plant taxonomy, horticulture, and seed bank management, are fundamental to ecological restoration efforts, yet few of the worlds botanic gardens are involved in the science or practice of restoration. Thus, we examined the potential role of botanic gardens in these emerging fields. We believe a reorientation of certain existing institutional strengths, such as plant-based research and knowledge transfer, would enable many more botanic gardens worldwide to provide effective science-based support to restoration efforts. We recommend botanic gardens widen research to include ecosystems as well as species, increase involvement in practical restoration projects and training practitioners, and serve as information hubs for data archiving and exchange.

Medawar?s medicine: the local-global prescription for conservation actions

Duffy and Kraus (2008) provide a broadly relevant and generally insightful overview of what plagues implementation of effective conservation science. That their overview is true is largely because many, if not all, of their insights and proffered solutions to remedy the ineffectiveness of conservation science apply globally. That is, one could replace ?Hawai?i? with any number of other Pacific islands and continental venues, a depressing and rapidly growing list of threatened ecosystems. In essence, the conservation issues raised by Duffy and Kraus are not local, regional, or by any means, unique to Hawai?i, although Hawai?i does represent one of the more challenging places to implement conservation practice successfully. Distinctions between regional (viz., island) and continental environmental crises are becoming blurred as ecosystems become increasingly fragmented and isolated, and their supporting processes altered. For example, California at approximately 40.5 million hectares, 38 million residents, and 150 years of habitat fragmentation now consists of many much smaller natural habitat fragments surrounded by a matrix of human-altered landscapes than only 50 years ago. These island fragments vary in size, number and spatial orientation not unlike island archipelagos. Furthermore, current knowledge gaps are universal, invasive species are invading every island and continent, more species are endangered or extinct than we can possibly know, document or protect, millions of ecosystems worldwide would benefit from some type of protection, active restoration, and management, and all types of conservation activities are grossly under funded around the globe.