Spiders as surrogate species in ecological monitoring, habitat classification and reserve selection : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Science in Ecology at Massey University, Palmerston North, New Zealand

The use of invertebrates in the monitoring of terrestrial ecosystems was investigated using spiders as a focal group. In a review of previous literature, spiders were found to meet the majority of criteria required of suitable ecological indicators, including high diversity and abundance, a widespread distribution, easy sampling and sorting, relatively low random fluctuation in population sizes and community composition, a range of dispersal abilities, measurable response to habitat change and representation of other taxa. The main weaknesses of spiders as ecological indicators were the lack of taxonomic expertise and sparse knowledge of baseline biology. However, these disadvantages could be rectified and it was concluded that spiders are suitable for further investigation as ecological indicators, involving field trials and hypothesis testing. The spider communities in the litter, herb and shrub layer of eight sites representing four habitat types within a forest successional series were sampled in Pouiatoa State Forest in Northern Taranaki. There were no distinct trends in spider richness or abundance across the successional series. However, spider species and family composition both reflected the successional stage from which they were taken. Site classifications using DCA and cluster analysis were similar when using either plant or spider data. Spider communities demonstrated potential for use in habitat classification of terrestrial ecosystems. Spiders and seven other ground-active invertebrate groups were sampled with pitfall traps from fourteen forest remnants within the Rangitikei Ecological Region to test whether spiders were able to act as indicators of plant and invertebrate diversity. Within-site richness (α-diversity) of spiders was strongly correlated with that of all other invertebrates combined, but spiders were not good predictors of between-site richness (²- diversity) of all other invertebrates. Correlation between the α- and β-diversities of plants and invertebrates were low, indicating that maximising plant diversity in reserve selection might not maximise invertebrate diversity. It is recommended that ground-active invertebrates be included in surveys of potential forest reserves. Spiders are a useful surrogate group for invertebrate communities and could be more widely used in the assessment, monitoring and management of terrestrial ecosystems

On cyclic numbers and an extension of Midy's theorem

In this note we consider fractions of the form 1/m and their floating-point representation in various arithmetic bases. For instance, what is 1/7 in base 2005? And, what about 1/4? We give a simple algorithm to answer these questions. In addition, we discuss an extension of Midy's theorem whose proof relies on elementary modular arithmetic.Comment: 6 pages, aimed at undergraduate student

Factorization of quadratic polynomials in the ring of formal power series over Z\Z

We establish necessary and sufficient conditions for a quadratic polynomial to be irreducible in the ring $Z[[x]]$ of formal power series with integer coefficients. For $n,m\ge 1$ and $p$ prime, we show that $p^n+p^m\beta x+\alpha x^2$ is reducible in $Z[[x]]$ if and only if it is reducible in $Z_p[x]$, the ring of polynomials over the $p$-adic integers.Comment: 15 page

The Misallocation of Resources of Anticipated Inflation

This paper analyzes the effects of anticipated inflation on the resource allocations between production and financial services. We develop a model with heterogeneous workers and two sectors economy. A manufacturing sector producing a final composite good and a financial sector providing monetary management services for manufacturers. Workers in this economy are heterogeneous in their productivity and are free to move between the two sectors. Hence workers with high productivity in the financial sector choose to work in the financial sector, where they can earn high wages, while workers with low productivity prefer to work in the manufacturing sector. In equilibrium, the allocation of workers between the two sectors, i.e., the size of each sector depends, among other factors, on the inflation rate. Higher inflation increases the marginal revenues of financial workers and decrease the marginal revenues of production workers. As a consequence, resources are shifted from the manufacturing sector to the financial sector. That is, the share of the financial services in output increases and production (output) decreases. The resulting decline in manufacturing sector output reduces consumption opportunities and represents costs of inflation. To estimate the change in the production structure and, thus, the costs of inflation we analyze data from 28 countries which had some notable inflation history during the period 1972-1995. We find strong support for the hypothesis that higher inflation increases the share of the financial sector output and employment relative to the manufacturing sector.anticipated inflation, resource allocation, financial sector.