The response of heterotrophic CO2 flux to soil warming

In a forest ecosystem at steady state, net carbon (C) assimilation by plants and C loss through soil and litter decomposition by heterotrophic organisms are balanced. However, a perturbation to the system, such as increased mean soil temperature, will lead to faster decay, enhancing CO₂ release from decomposers, and thus upsetting the balance. Recent in situ experiments have indicated that the stimulation of soil respiration following a step increase in annual average soil temperature declines over time. One possible explanation for this decline may be changes in substrate availability. This hypothesis is examined by using the ecosystem model G'DAY, which simulates C and nitrogen (N) dynamics in plants and soil. We applied the model to observations from a soil‐warming experiment in a Norway spruce (Picea abies (L.) Karst.) stand by simulating a step increase of soil temperature. The model provided a good qualitative reproduction of the observed reduction of heterotrophic respiration (R_h) under sustained warming. The simulations showed how the combined effects of faster turnover and reduced substrate availability lead to a transient increase of R_h. The simulated annual increase in R_h from soil was 60% in the first year after perturbation but decreased to 30% after a decade. One conclusion from the analysis of the simulations is that R_h can decrease even though the temperature response function for decomposition remains unchanged. G'DAY suggests that acclimation of R_h to soil warming is partly an effect of substrate depletion of labile C pools during the first decade of warming as a result of accelerated rates of mineralization. The response is attributed mainly to changing levels of C in pools with short time constants, reflecting the importance of high‐quality soil C fractions. Changes of the structure or physiology of the decomposer community were not invoked. Therefore, it becomes a question of definition whether the simulated dynamics of the declining response of CO₂ release to the warming should be named acclimation or seen as a natural part of the system dynamics.     

Pollination biology of two chiropterophilous agaves in Arizona

I studied the pollination biology of two closely related species of agave, Agave palmeri and A. chrysantha (Agavaceae), which exhibit several chiropterophilous (bat-pollinated) traits. Floral studies, floral visitor observations, and pollination studies were conducted over four summers at six different sites to examine floral traits and determine the relative importance of diurnal vs. nocturnal pollinators. Agave chrysantha appears to have developed minor shifts in several floral characters that enhance diurnal pollination. Although floral shifts towards diurnal pollination were fewer in A. palmeri, stigmas were diurnally receptive and copious floral rewards were available in the morning, indicating that some adaptations exist to allow for multiple pollinators. Differences in fruit and seed set between naturally day- and night-pollinated umbels for both species were either not significant or significantly higher in day-pollinated plants. Bats were not important pollinators of A. chrysantha, and the mutualistic relationship between A. palmeri and the lesser long-nosed bat was found to be asymmetric. "Bat-adapted" floral traits appear to be flexible enough to respond to the climatic and pollinator unpredictability experienced by agaves at the northern edge of their distribution. This variability may be a more important factor affecting evolution of floral characters than a particular pollinator.     

Comparison of maternal lineage and biogeographic analyses of ancient and modern Hungarian populations

The Hungarian language belongs to the Finno-Ugric branch of the Uralic family, but Hungarian speakers have been living in Central Europe for more than 1000 years, surrounded by speakers of unrelated Indo-European languages. In order to study the continuity in maternal lineage between ancient and modern Hungarian populations, polymorphisms in the HVSI and protein coding regions of mitochondrial DNA sequences of 27 ancient samples (10th-11th centuries), 101 modern Hungarian, and 76 modern Hungarian-speaking Sekler samples from Transylvania were analyzed. The data were compared with sequences derived from 57 European and Asian populations, including Finno-Ugric populations, and statistical analyses were performed to investigate their genetic relationships. Only 2 of 27 ancient Hungarian samples are unambiguously Asian: the rest belong to one of the western Eurasian haplogroups, but some Asian affinities, and the genetic effect of populations who came into contact with ancient Hungarians during their migrations are seen. Strong differences appear when the ancient Hungarian samples are analyzed according to apparent social status, as judged by grave goods. Commoners show a predominance of mtDNA haplotypes and haplogroups (H, R, T), common in west Eurasia, while high-status individuals, presumably conquering Hungarians, show a more heterogeneous haplogroup distribution, with haplogroups (N1a, X) which are present at very low frequencies in modern worldwide populations and are absent in recent Hungarian and Sekler populations. Modern Hungarian-speaking populations seem to be specifically European. Our findings demonstrate that significant genetic differences exist between the ancient and recent Hungarian-speaking populations, and no genetic continuity is seen.     

Dental caries in nineteenth century Upper Canada

This study examines the presence of dental caries in a large sample of adult skeletons from the 19th century cemetery of St. Thomas' Anglican Church in Belleville, Ontario. The cemetery was used from 1821 to 1874. Caries prevalence and frequencies of diseased and missing teeth were calculated both by observing summary statistics of individual rates and by the total sample of teeth. Postmortem tooth loss is low in this sample and antemortem tooth loss is highest in first mandibular molars, all other molars and then premolars. Age at death, but not sex, was found to be significantly related to the overall Caries Rate while both age and sex were significantly associated with the Diseased-Missing Index. The increase in diseased and missing teeth in older individuals is expected while the sex difference is not explained by simple dietary factors. When compared to reports on British and American samples, caries and antemortem tooth loss in the St. Thomas' sample is most similar to a pre-1850 British group and higher than American samples. Although there is undoubtedly a complex of factors contributing to caries prevalence in this sample, more data are required from large historic samples, particularly from the American northeast and late 19th century Britain, to have a clearer understanding of the influence of diet, cultural, and environmental factors affecting caries rates in historic populations. Am J Phys Anthropol 104:71–87, 1997. © 1997 Wiley-Liss, Inc.     

The ‘Bundi dodo’: a drawing copying European animals – a curious byway in nineteenth century Indian art

A nineteenth-century Indian sheet of sketches showing a dodo Raphus cucullatus and other animals is shown to consist of copies of wood engravings from British popular animal books from the early to mid-1800s, and has no connection with Mansur’s classic dodo from 1624.     

Towards an anthropometric history of latin America in the second half of the twentieth century

We examine the evolution of adult female heights in twelve Latin American countries during the second half of the twentieth century based on demographic health surveys and related surveys compiled from national and international organizations. Only countries with more than one survey were included, allowing us to cross-examine surveys and correct for biases. We first show that average height varies significantly according to location, from 148.3 cm in Guatemala to 158.8 cm in Haiti. The evolution of heights over these decades behaves like indicators of human development, showing a steady increase of 2.6 cm from the 1950s to the 1990s. Such gains compare favorably to other developing regions of the world, but not so much with recently developed countries. Height gains were not evenly distributed in the region, however. Countries that achieved higher levels of income, such as Brazil, Chile, Colombia and Mexico, gained on average 0.9 cm per decade, while countries with shrinking economies, such as Haiti and Guatemala, only gained 0.25 cm per decade.     

Race, health, and disease in 19th-century-born males

This study analyzed skeletal health disparities among African American and Euro-American males of low socioeconomic status born between 1825 and 1877. A total of 651 skeletons from the Cobb, Hamann-Todd, and Terry anatomical collections were macroscopically examined for skeletal pathologies related to dietary deficiencies and disease. Individuals were separated into age, ancestry, birth (Antebellum, Civil War, Pre-Reconstruction, and Reconstruction), combined ancestry/birth, enslaved versus liberated, and collection cohorts. These groups were statistically evaluated using ANOVA and χ(2) analyses to determine if age, ethnic, and temporal differences existed. Results indicated that African Americans, especially those born during Reconstruction, had significantly higher frequencies of tuberculosis (P = 0.004) and treponematosis (P = 0.006) than Euro-Americans. Historical sources are important in contextualizing why these different ethnic and temporal patterns were present, pointing to environmental conditions related to enslavement, postliberation migration to the industrialized North, crowded urban living conditions, and poor sanitation.     

Advances in the conservation of British mammals, 1954–2004: 50 years of progress with The Mammal Society

1. The Mammal Society was established in 1954 to link amateurs and professionals in promoting the study of mammals. It now directly assists British conservation science, and has fostered The British Deer Society, the National Federation of Badger Groups, The Bat Conservation Trust, the Ungulate Research Group and Sea Watch Foundation. The Society also has strong links with the Zoological Society of London, the Vincent Wildlife Trust and the People's Trust for Endangered Species/Mammals Trust UK, as well as with many other non‐governmental organizations (NGOs) and statutory bodies. 2. The Mammal Society provides fora for discussion, scientific symposia, mammal publications, and practical studies. It has also instigated major advances in the presentation of scientific knowledge through three editions of The Handbook of British Mammals under three successive editors: H.N. Southern, G.B. Corbet and S. Harris. 3. From the 1970s the Society has highlighted conservation concerns (e.g. the decline of otters and persecution and management of badgers), informed legislation, supported many surveys, including harvest mice, pine marten, polecat, small rodents, hares, yellow‐necked mice and foxes, and published authoritative species’ accounts, guides to methodology, Mammal Review, Notes/Communications from The Mammal Society, the annual Current Projects on British Mammals and other scientific and educational material. 4. Country‐wide mammal recording and training (Look Out for Mammals) developed in the 1990s alongside the Endangered British Mammals Fund. The ‘ground breaking’A Red Data Book for British Mammals, and A Review of British Mammals, both drew on Mammal Society expertise, helping to meet the UK Government's conservation responsibilities and emphasizing the growing influence of The Society. Co‐operative monitoring has been developed with the British Trust for Ornithology through the Winter Mammal Monitoring scheme and is further projected with more than 20 NGOs and statutory bodies forming the ‘Tracking Mammals Partnership’. 5. The Mammal Society now advises on UK Biodiversity Action Plans and plays a lead role in UK mammal conservation, highlighting problems and promoting solutions. However, many British mammals are still declining, many are neither legally protected nor subject to national conservation initiatives, and data are still lacking on the status of many terrestrial and most marine species. Much has been done, but there is still much to do.