Coyotes,deer, and wildflowers: diverse evidence points to a trophic cascade

Spatial gradients in human activity, coyote activity, deer activity, and deer herbivory provide an unusual type of evidence for a trophic cascade. Activity of coyotes, which eat young mule deer (fawns), decreased with proximity to a remote biological field station, indicating that these predators avoided an area of high human activity. In contrast, activity of adult female deer (does) and intensity of herbivory on palatable plant species both increased with proximity to the station and were positively correlated with each other. The gradient in deer activity was not explained by availabilities of preferred habitats or plant species because these did not vary with distance from the station. Does spent less time feeding when they encountered coyote urine next to a feed block, indicating that increased vigilance may contribute, along with avoidance of areas with coyotes, to lower herbivory away from the station. Judging from two palatable wildflower species whose seed crop and seedling recruitment were greatly reduced near the field station, the coyote–deer–wildflower trophic cascade has the potential to influence plant community composition. Our study illustrates the value of a case-history approach, in which different forms of ecological data about a single system are used to develop conceptual models of complex ecological phenomena. Such an iterative model-building process is a common, but underappreciated, way of understanding how ecological systems work.     

Book reviews

Making Cities Work: the role of local government in the urban environment. Richard Gilbert, Don Stevenson, Herbert Girardet &; Richard Stren, 1996, London, Earthscan, 203pp. ISBN 1 85383 354 1, £13.95 pbk

Environmental Policy in an International Context, Vols 1–3: Perspectives, Conflicts and Prospects. P. Glasbergen &; A. Blowers (Series Eds) London, Arnold

Rhetoric and Reality in Environmental Policy. M. Wintle &; R. Reeve (Eds), 1994, Aldershot, Avebury Studies in Green Research, 154 pp. ISBN 1 85628 927 3

FutureNatural: Nature, Science, Culture. G. Roberston et al. (Eds) 1996, London, Routledge, ISBN 0415 070139, £40.00 hbk

Environmental Policy with Political Integration: the European Union and the United States. New horizons in environmental economics. John B. Braden, Henk Folmer &; Thomas S. Ulen (Eds), 1996, Cheltenham, Elgar Publishing, 477 pp. ISBN 1 85898 217 0     

Amsterdam: planning and policy for the ideal city?

Is Amsterdam the “ideal city?” Many of the social, economic, and environmental problems facing Amsterdam are considerably less than those in cities in the USA, and in most cases, Western Europe. Amsterdam, at this moment in history, might be the world's greatest city because of its ability to ensure basic necessities, freedom, and creativity. Tolerance of drugs, sexual freedom, along with the integration of different races helps reduce many of the “social problems” faced by most cities. We have compared, on a per capita basis, differences between Amsterdam/Holland and the USA. The Netherlands is a tiny country, and comparisons are made on a city and per capita numbers at the national level. Our data show that Amsterdam has lower crime, murder, rape, drug usage (cocaine, marijuana), teenage pregnancy, diabetes, obesity, suicide, abortion rates, infant mortality, dependence on fossil fuels, and homelessness, and racial segregation is considerably less. People live longer because of Amsterdam's walkability and bike usage and access to parks. Indeed, the Netherlands leads both Western European and the USA in the proportion of trips made walking and bicycling, with significantly reduced car dependency. Ghettos are nearly non-existent compared with the segregation in the 1940s/1950s. Quality housing is supplied to everyone that gives pride of place compared with the stark, cold, and institutional “projects” provided by the US federal government. Amsterdam leads Western Europe by 35% in social housing, compared with runner-up UK, which has significantly less. The modernism of the 1960s where the poor were warehoused is nearly all gone. People living in Amsterdam seem more tolerant, secure, happier, and healthier compared with citizens in the USA. Great cities provide opportunities for all citizens to enhance their lives and ensure an unrivalled level of freedom. We demonstrate that social and environmental justice are tied together. Amsterdam is by no means perfect, but in comparison with many other democratic industrial cities, it is a far better place for citizens of all races, religions, and incomes.     

How to facilitate (or discourage) community-based research: recommendations based on a Canadian survey

The impact of the extreme heat wave that affected Melbourne, Australia, in two distinct phases in January and February 2009 was severe, with 374 (heat) and 173 (bushfire) excess deaths. Whilst the human health issues have been covered in detail in policy and academic arenas, much less attention has been paid to the adverse impacts on urban infrastructure. Analysis of this event, underpinned by participatory actor-based research, has shown that the impacts were experienced disproportionately across different infrastructure types. For water, telecommunications and airports, the impacts were relatively minor and the impact on rail transport and roads (and to a lesser extent, seaports) was of moderate significance, whereas research findings indicate that the electricity sector was found to be the most vulnerable. This paper focuses on the sectors that were worst impacted: electricity, rail and road transport. Commentary identifies the direct and indirect impacts of the heat event, including associated cascading effects, as well as considering actual and potential adaptation responses both before and after the event. Concluding, the authors reflect on the implications of the heat wave for urban resilience, emphasising the crucial importance of understanding the urban environment as a complex and interconnected system.     

Accumulation of radiocesium by mushrooms in the environment: a literature review

During the last 50 years, a large amount of information on radionuclide accumulators or "sentinel-type" organisms in the environment has been published. Much of this work focused on the risks of food-chain transfer of radionuclides to higher organisms such as reindeer and man. Until the 1980s and 1990s, there were few published data on the radiocesium ((134)Cs and (137)Cs) accumulation by mushrooms. The present review of published data for (134,137)Cs accumulation by mushrooms in nature discusses the aspects that promote (134,137)Cs uptake by mushrooms and focuses on mushrooms that demonstrate a propensity for use in the environmental biomonitoring of radiocesium contamination. Transfer factors (TF, as dry weight concentration in fruiting body divided by concentration in substrate) ranged up to 24 (unitless), and aggregate transfer factors (T(ag), as Bq(137)Cs/kg dw in fruiting body divided by the aerial deposition as Bq/m(2)) ranged up to 8m(2)/kg dw.     

Emerging infectious disease as a proximate cause of amphibian mass mortality

A newly discovered infectious disease of amphibians, chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis, is implicated in population declines and possible extinctions throughout the world. The purpose of our study was to examine the effects of B. dendrobatidis on the mountain yellow-legged frog (Rana muscosa) in the Sierra Nevada of California (USA). We (1) quantified the prevalence and incidence of B. dendrobatidis through repeat surveys of several hundred R. muscosa populations in the southern Sierra Nevada; (2) described the population-level effects of B. dendrobatidis on R. muscosa population abundance; and (3) compared the mortality rates of infected and uninfected R. muscosa individuals from pre- through post-metamorphosis using both laboratory and field experiments. Mouthpart inspections conducted in 144 and 132 R. muscosa populations in 2003 and 2004, respectively, indicated that 19% of R. muscosa populations in both years showed indications of chytridiomycosis. Sixteen percent of populations that were uninfected in 2003 became infected by 2004. Rana muscosa population sizes were reduced by an average of 88% following B. dendrobatidis outbreaks at six sites, but at seven B. dendrobatidis-negative sites, R. muscosa population sizes increased by an average of 45% over the same time period. In the laboratory, all infected R. muscosa developed fatal chytridiomycosis after metamorphosis, while all uninfected individuals remained healthy. In the field experiment in which R. muscosa tadpoles were caged at infected and uninfected sites, 96% of the individuals that metamorphosed at infected sites died vs. 5% at the uninfected sites. These studies indicate that chytridiomycosis causes high mortality in post-metamorphic R. muscosa, that this emerging disease is the proximate cause of numerous observed R. muscosa population declines, and that the disease threatens this species with extirpation at numerous sites in California's Sierra Nevada.     

Reactions of the amine-containing drugs fluoxetine and metoprolol during chlorination and dechlorination processes used in wastewater treatment

The reactivities of the amine-containing pharmaceuticals fluoxetine and metoprolol with hypochlorite were studied using conditions that simulate wastewater disinfection including neutral pH (7.0), a range of reaction times (2–60 min), and a molar excess of hypochlorite relative to the pharmaceutical concentration (5.7 times). The reactions were monitored using liquid chromatography (LC) with several detection modes including ultraviolet absorbance (UV), mass spectrometry (MS), and post-column reaction/reductive electrochemistry (EC) for determining active chlorine products. At levels of 10 μM, both compounds reacted rapidly (<2 min) to form principally N-chloramine products that were stable in aqueous solution for at least 1 h. The reaction was also studied in wastewater, and similar reactivity was noted. These results demonstrate that the cations fluoxetine and metoprolol are likely to be rapidly transformed into neutral N-chloramines during wastewater disinfection. The reactivity of the N-chloramines was also studied with sulfite to simulate dechlorination, which is often employed in wastewater treatment. Both N-chloramines reacted slowly with sulfite. In the pure water dechlorination experiments, it was estimated that 70% and 10% of the peak areas remained after 2 min reaction time for fluoxetine and metoprolol, respectively. At longer reaction times both N-chloramines had been completely reduced by sulfite, and the product of the sulfite reduction reaction was the parent pharmaceutical amine. Since typical dechlorination times in wastewater treatment are on the order of seconds, this suggests the chloramines formed from these two basic drugs might evade dechlorination and be released into the environment. The implications of chloramine release are discussed.