Taxonomic Exaggeration and Its Effects on Orchid Conservation

Abstract:  Orchids are the largest family of flowering plants, encompassing several times as many species as birds or mammals. Because of their diversity, charisma, and threats from overcollection and habitat loss, they are a key group in conservation. Nevertheless, preservation of this group is plagued by taxonomic problems, particularly in Europe, where new taxa are actively being described. We used a checklist of orchids to compare the taxonomic treatment of this family between Europe and neighboring areas to search for geographical patterns. Numbers of invalid, infraspecific, and hybrid names are significantly higher in Europe than in surrounding areas. Recognition of numerous and poorly circumscribed orchid taxa is a serious obstacle to their conservation because rare, poorly defined species may be prioritized for conservation over taxonomically "good" species. This phenomenon may be the result of the popularity of orchids in Europe. We believe that more taxonomic effort should be made in other areas of the world (e.g., the tropics) and on less charismatic groups.     

The Interplay between Climate Variability and Density Dependence in the Population Viability of Chinook Salmon

Abstract:  The viability of populations is influenced by driving forces such as density dependence and climate variability, but most population viability analyses (PVAs) ignore these factors because of data limitations. Additionally, simplified PVAs produce limited measures of population viability such as annual population growth rate (λ) or extinction risk. Here we developed a "mechanistic" PVA of threatened Chinook salmon ( Oncorhynchus tshawytscha ) in which, based on 40 years of detailed data, we related freshwater recruitment of juveniles to density of spawners, and third-year survival in the ocean to monthly indices of broad-scale ocean and climate conditions. Including climate variability in the model produced important effects: estimated population viability was very sensitive to assumptions of future climate conditions and the autocorrelation contained in the climate signal increased mean population abundance while increasing probability of quasi extinction. Because of the presence of density dependence in the model, however, we could not distinguish among alternative climate scenarios through mean λ values, emphasizing the importance of considering multiple measures to elucidate population viability. Our sensitivity analyses demonstrated that the importance of particular parameters varied across models and depended on which viability measure was the response variable. The density-dependent parameter associated with freshwater recruitment was consistently the most important, regardless of viability measure, suggesting that increasing juvenile carrying capacity is important for recovery.     

The Horticultural Trade and Ornamental Plant Invasions in Britain

Abstract:  Ornamental horticulture has been recognized as the main pathway for plant invasions worldwide. We examined the link between propagule pressure created by the presence of ornamental plants in the market and their ability to escape from cultivation and establish in the wild. A random sample of 534 non-native ornamental species on sale in nineteenth century Britain showed that 27% of these species were recorded growing outside cultivation and 30% of those were established. Species that had escaped from cultivation were more frequently on sale both in the nineteenth century and today than nonescaping species. We used logit regression models to identify biological and socioeconomic variables that affect species' abilities to escape cultivation and become established. Frequencies in the market in the nineteenth century and today were good explanatory variables that distinguished escaping from nonescaping species, whereas for the transition from casual to established status these two socioeconomic variables were either absent or only of weak significance. Biological characteristics that increased the probability that a species would escape from cultivation were species height, a European native range, and being an annual. Climbing plants and species intolerant of low temperatures were less likely to escape. In contrast, the establishment probability was greater if the species belonged to a genus native to Britain and increased as the number of continents in a plant's native range increased. Annual plants had a reduced probability of establishment. Market presence, prices, and the date of introduction are among the socioeconomic factors that have had important effects on the observed course of invasions.     

Cultural Erosion and Biodiversity: Canoe-Making Knowledge in Pohnpei, Micronesia

Abstract:  Erosion of traditional knowledge and practice is a serious and accelerating problem, but quantitative work on traditional knowledge loss and its importance to biodiversity conservation is lacking. We investigated traditional knowledge of canoe making, a skill heavily dependent on plant biodiversity, on Pohnpei, Federated States of Micronesia, through a survey of 180 island residents. Our results showed that there has been an intergenerational erosion of canoe-making skills. Given current trends, the present generation of Pohnpeians may be the last to retain any knowledge of this traditional craft. We also identified several correlates of knowledge loss—including Western educational level and occupation—that highlight potential avenues for skill conservation via governments, traditional leadership, and schools. These institutions could intervene to emphasize traditional knowledge, which would reinforce institutional contexts in which traditional knowledge and practice is valued. The heightened awareness of the value of biodiversity that is linked to traditional knowledge is key to biological conservation on Pohnpei and can help support local conservation programs.     

Body Size Variation of Mammals in a Fragmented, Temperate Rainforest

Abstract:  Body size is perhaps the most important trait of an organism, affecting all of its physiological and ecological processes and, therefore, fundamentally influencing its ability to survive and reproduce in different environments, including those that have been modified by human activities. We tested the hypothesis that anthropogenic transformation of old-growth forest landscapes can result in significant intraspecific changes in body size of resident biotas. We collected data on five species of nonvolant mammals (common deer mouse [Peromyscus maniculatus ], northwestern deer mouse [P. keeni] , southern red-backed vole [Clethrionomys gapperi ], montane shrew [Sorex monticolus] , and Trowbridge's shrew [S. trowbridgii] ) to test whether body size (mass and length) of these species varied across types of land cover (macrohabitats) and along elevational gradients of the fragmented, temperate rainforest of Olympic National Forest (Washington, U.S.A.). We measured 2168 and 1134 individuals for body mass and body length, respectively. Three species ( P. keeni , S. monticolus , and S. trowbridgii ) exhibited significantly different body size among macrohabitats: individuals from fragments were smaller than those in old-growth corridors and those in more extensive stands of old-growth forest. Body size of P. keeni was significantly correlated with elevation along corridors, peaking near the medial reaches of the corridors. The effects of anthropogenic transformations of this landscape of old-growth, temperate rainforest, although not universal among the five species, were significant and rapid—developing in just a few decades following tree harvests. Thus, anthropogenic fragmentation may influence not only the diversity, species composition, and densities of local biotas, but also one of the most fundamental and defining characteristics of native species—their body size.     

Building on IUCN Regional Red Lists to Produce Lists of Species of Conservation Priority: a Model with Irish Bees

Abstract:  A World Conservation Union (IUCN) regional red list is an objective assessment of regional extinction risk and is not the same as a list of conservation priority species. Recent research reveals the widespread, but incorrect, assumption that IUCN Red List categories represent a hierarchical list of priorities for conservation action. We developed a simple eight-step priority-setting process and applied it to the conservation of bees in Ireland. Our model is based on the national red list but also considers the global significance of the national population; the conservation status at global, continental, and regional levels; key biological, economic, and societal factors; and is compatible with existing conservation agreements and legislation. Throughout Ireland, almost one-third of the bee fauna is threatened (30 of 100 species), but our methodology resulted in a reduced list of only 17 priority species. We did not use the priority species list to broadly categorize species to the conservation action required; instead, we indicated the individual action required for all threatened, near-threatened, and data-deficient species on the national red list based on the IUCN's conservation-actions template file. Priority species lists will strongly influence prioritization of conservation actions at national levels, but action should not be exclusive to listed species. In addition, all species on this list will not necessarily require immediate action. Our method is transparent, reproducible, and readily applicable to other taxa and regions.     

Influence of Agricultural Antibiotics and 17β-Estradiol on the Microbial Community of Soil

Agricultural pharmaceuticals are a major environmental concern because of their hazardous effects on human and wildlife. This study analyzed phospholipid ester-linked fatty acids (PLFAs) and quinones to investigate the effects of a steroid (17β-estradiol) and agricultural antibiotics (chlortetracycline and tylosin) on soil microbes in the laboratory. Two different types of soil were used: Sequatchie loam (0.8% organic matter) and LaDelle silt loam (9.2% organic matter). The soils were spiked with 17β-estradiol and antibiotics, alone or in combination. In Sequatchie loam, 17β-estradiol significantly increased the microbial biomass, especially the biomarkers for beta proteobacteria (16:1ω7c, 18:1ω7c, Cy17:0, and UQ-8). The coexistence of antibiotics decreased the stimulatory effect of 17β-estradiol on the microbial community. In LaDelle silt loam, there were no significant differences in total microbial biomass and their microbial community structure among the treatments. Overall, 17β-estradiol changed the microbial community of soil and the presence of antibiotics nullified the effect of 17β-estradiol. However, the effects of 17β-estradiol and antibiotics on soil microbes were sensitive to the soil properties, as seen in the LaDelle silt loam.