The value of species rarity in biodiversity recreation: A birdwatching example

Wildlife viewing recreation offers conservationists opportunities for education and generating revenue but can also have detrimental ecological impacts. To manage these opportunities and impacts effectively, a better understanding is needed of what people value in wildlife viewing events. We examine the relationship between species rarity and value for wildlife viewing recreation. We undertook visitor counts of birdwatchers attending rare (vagrant) bird sightings and collected home postcodes to assess the distances these individuals travelled to achieve these sightings. We also undertook visitor counts at common bird viewing locations for comparison. We regressed birdwatcher numbers against rarity, site protection status, time the bird had been on site and day of the week when the count took place. We undertook these analyses for rare bird sightings only, using a continuous measure of rarity, and for both rare and common species combined, using a categorical rarity index. Species rarity was the clearest predictor of visitor numbers in both the analyses. When studying rare birds only, we found the functional form of the relationship between rarity and visitor numbers to be inverse and asymptotic. Individuals also travelled further to see rarer species. However, while exceptional numbers of visitors attended exceptionally rare bird sightings, the marginal value of rarity appeared to be relatively low. Despite the opportunity for revenue raising and education provided by rare bird sightings, a comparison of visitor numbers at sightings inside and outside protected areas showed no evidence that managers of protected areas capitalise on these opportunities.     

A gamma‐ray spectrometry approach to field separation of illuviation‐type WRB reference soil groups in northern Thailand

According to the World Reference Base for Soil Resources (IUSS Working Group WRB, 2006), the differentiation of Acrisols and Alisols is based on the cation‐exchange capacity of clay, which cannot be directly determined in the field, but needs expensive and time‐consuming soil‐chemical analyses. This is an unsatisfactory situation for pedologists, who urgently require a rapid field method to distinguish illuviation‐type reference soil groups (Alisols, Acrisols, Luvisols, Lixisols). In this study, we tested the ability of gamma‐ray spectrometry to separate major WRB reference soil groups in the field. The underlying hypothesis is that Alisols and Acrisols are distinguished by their clay mineral composition, which should be reflected by geochemistry and consequently gamma‐ray radiation (i.e., K‐containing illite vs. K‐free kaolinite). Highly significant differences in their gamma‐ray spectrum for K, Th, and U were found for limestone and its soils. Especially the K and Th signatures allowed a clear separation of Acrisols and Alisols. In general, the surface radiation was sufficient to separate these soils. Best results were revealed considering parent rock and the whole soil profile. This means by using a portable radiometer and a pH meter, all illuviation‐type reference soil groups could be distinguished in this case. If applicable at other sites, this approach could enormously reduce expenditures for soil‐chemical analysis needed to assist soil classification.     

Genetic diversity assessment of Ethiopian tetraploid wheat landraces and improved durum wheat varieties using microsatellites and markers linked with stem rust resistance

A set of 77 markers was used to describe the genetic diversity in a group of 58 tetraploid wheat accessions. Analysis was performed using 31 neutral SSR markers, 31 SSR/STS markers linked with reported major stem rust resistance genes and 15 SSR markers linked with QTL identified for resistance to Ethiopian stem rust races of Puccinia graminis Pers. f. sp. tritici Eriks. et E. Henn. (Pgt),including Ug99. The material consisted of 32 (Triticum durum s.l. incl. T. aethiopicum Jakubz., Triticum turgidum and Triticum polonicum) landraces and 22 registered T. durum varieties from Ethiopia that were released 1966–2009 and four T. durum varieties from ICARDA. A total of 720 alleles were detected. Considering the three marker sets, the mean number of alleles was higher for major stem rust resistance gene linked markers (9.9) followed by neutral SSR markers (9.2) and markers linked with QTL for stem rust resistance (8.5). Dendrograms derived from UPGMA analysis grouped the accessions into two major clusters. The principal component analysis based on the combination of the three marker sets formed three groups. The 1st group was composed of all the improved varieties, whereas the 2nd and the 3rd group contained the landraces. All the landraces that formed the 3rd group were susceptible to Ethiopian stem rust races of Pgt including Ug99. The information on the extent of the genetic diversity of the improved varieties obtained in this investigation will be helpful for developing appropriate breeding strategies to broadening the genetic base of durum wheat varieties in further breeding programmes.     

Impact of fumigation with metam sodium upon soil microbial community structure in two Japanese soils

The effects of fumigation with sodium methyl dithiocarbamate (metam sodium) on the microbial community structure and function in 2 soils were investigated using a variety of techniques. In both soils ca. 50% and 90% of the populations of total and culturable bacteria, respectively, were killed by fumigation, with recovery to levels prevailing in control soils 26 d after cessation of fumigation. The size of the ammonium and nitrite oxidiser populations was reduced by up to 4 orders of magnitude by fumigation, with the latter showing a slight recovery 105 d later. There were substantial changes in the C-utilisation (Biolog GN) profiles in the fumigated soils even 105 d later. The number and pattern of amplified 16S ribosomal DNA restriction analysis (ARDRA) fragments was changed by fumigation, and there was a shift in the %G+C profile toward a greater proportion of lower %G+C classes in treated soils. It appeared that DNA released from killed cells remained for some time after fumigation, and masked the apparent community DNA profiles. This study demonstrates that the effects of fumigation on the soil microbial community structure and function were pronounced and for some parameters very persistent. However, the effects on broad-scale properties such as total or culturable bacterial numbers were less enduring.     

What makes man human: thirty-ninth James Arthur lecture on the evolution of the human brain, 1970

What makes man human is his brain. This brain is obviously different from those of nonhuman primates. It is larger, shows hemispheric dominance and specialization, and is cytoarchitecturally somewhat more generalized. But are these the essential characteristics that determine the humanness of man? This paper cannot give an answer to this question for the answer is not known. But the problem can be stated more specifically, alternatives spelled out on the basis of available research results, and directions given for further inquiry. My theme will be that the human brain is so constructed that man, and only man, feels the thrust to make meaningful all his experiences and encounters. Development of this theme demands an analysis of the brain mechanisms that make meaning–and an attempt to define biologically the process of meaning. In this pursuit of meaning a fascinating variety of topics comes into focus: the coding and recoding operations of the brain; how it engenders and processes information and redundancy; and, how it makes possible signs and symbols and prepositional utterances. Of these, current research results indicate that only in the making of propositions is man unique–so here perhaps are to be found the keynotes that compose the theme.