Long-term changes in lowland calcareous grassland plots using Tephroseris integrifolia subsp. integrifolia as an indicator species

We investigated the changes to calcareous grassland plots within protected sites, and whether Tephroseris integrifolia subsp. integrifolia can act as a useful indicator species for re-visitation studies within vegetation predicted to remain relatively stable. Twenty-two plots located across lowland England and all formerly containing T. integrifolia were re-surveyed following the methodology used in the original survey undertaken in the 1960s. Pseudo-turnover and between-observer bias were minimised by sampling replicate quadrats at each fixed plot using a single surveyor and at a similar time of year as the original survey. Qualitative details concerning grazing management were obtained for all sites. In contrast to other long-term re-visitation studies, all our study plots were intact and retained diverse, herb-rich vegetation, demonstrating the value of site protection. However, there were clear shifts in vegetation composition, most notably where T. integrifolia was absent, as shown by an increase in Ellenberg fertility and moisture signifying nutrient enrichment, and a decrease in the cover of low-growing, light-demanding specialists, with a change likely to be associated predominantly with grazing management. Whereas in the mid-20th century the greatest threat to calcareous grassland was habitat loss, undergrazing or temporary neglect now appears to pose the principal threat. Distinctive species such as T. integrifolia with marked sensitivity to habitat change provide a potentially useful tool for rapid assessment and monitoring of site quality. Focusing monitoring on such species allows non-expert observers to recognise the early stages of habitat degradation, providing, in effect, a “health check” on individual sites and groups of sites

The influences of height and age on waist circumference as an index of adiposity in adults

OBJECTIVES: To assess the influences of height and age on the differences in waist circumference between individuals of different stature. SUBJECTS: 3319 males and 4358 females from four studies in the UK and the Netherlands. MEASUREMENTS: Waist circumference, body weight, height, and age. RESULTS: Linear regression analysis of log10 height as the independent variable on log10 waist as the dependent variable was used to determine the optimal index powers (OIP) (p) to minimize the influence of height in the relationships of waist/height(p). Six out of eight samples of men and women had OIP of height not significantly different from zero, with the remaining two groups had OIP between 0.15-0.58, indicating that height had very limited influence on the differences in waist circumference measurement between individuals. Age adjustment increased the relationship between waist and height, with OIP of 0.19-0.89 in men and 0.02-0.58 in women. Without age adjustment, height explained 0.3-3.5% and 0.1-2.5% variance in waist in men and in women respectively, and the corresponding variances were 0.4-7.5% in men and 0.0-2.6% in women with age adjustment. A similar analysis of weight and height showed the OIP of height in weight/height(p) ratio ranged from 1.32-2.25 in men, and 0.87-1.74 in women without age adjustment, and from 1.47-2.24 in men and 1.25-1.96 in women with age adjustment. CONCLUSION: Height and age had limited influences on the differences in waist between Caucasian subjects of different stature. Waist alone may be used to indicate adiposity or to reflect metabolic risk factors. In contrast, the influence of height on body weight is important