Factors affecting the establishment of Leptospermum scoparium J.R. et G. Forst. (manuka) : a thesis presented in partial fulfillment of the requirements for the degree of Master of Agricultural Science at Massey University

L. scoparium is one of New Zealand's most important weeds of unploughable infertile hill country. The plant is an indigenous shrub, characteristic of the early stages of succession to forest in a wide range of habitats (Cockayne, 1928). In the eight years prior to 1959/60 nearly 40,000 acres of unimproved grassland reverted to scrub, fern and second growth each year. L. scoparium is one of the most important components of the scrub, fern and second growth category. By 1959/60 the total area of reverted land in New Zealand was 5.7 million acres of which 3.65 million were in the North Island. (Rigg, 1962). Control of L. scoparium on unploughable hill country has been limited to pulling, cutting, or cutting and burning, depending on stage of growth. Chemical methods and standing burns have generally proved unsuccessful. Most methods are expensive. Levy (1932, 1940, 1946) postulated that establishment of L. scoparium in pasture could be prevented by good farming techniques. Today there is a growing body of practical evidence to support this hypothesis (Suckling, 1959; New Zealand Farmer 83 (42, 43, 45)). This study was carried out to determine what intrinsic factors favour the establishment of L. scoparium, and the quantitative effect of farm management techniques on this process

"How Big Should the Public Capital Stock Be? The Relationship Between Public Capital and Economic Growth"

Investment in infrastructure is necessary for a strong, flexible, and growing economy. However, the relationship between public capital and economic growth is not linear. At a certain level, the tax burden associated with financing and maintaining public capital reduces the returns to private industry, which, in turn, reduces growth; also, different types of spending have different effects on growth. The short- and long-term growth-maximizing effects of public investment increase as the ratio of public to private capital stock rises to an optimal level (found to be about 61 percent); above that level the growth effects decrease. The public to private ratio is below the optimal level throughout much of the country and government spending is not always directed toward the types of investment that have the most positive effects on growth. Good economic policy requires both increasing the public capital stock and reorienting government spending from consumption to investment in physical capital stock.

Selective Categories and Linear Canonical Relations

A construction of Wehrheim and Woodward circumvents the problem that compositions of smooth canonical relations are not always smooth, building a category suitable for functorial quantization. To apply their construction to more examples, we introduce a notion of highly selective category, in which only certain morphisms and certain pairs of these morphisms are "good". We then apply this notion to the category $\mathbf{SLREL}$ of linear canonical relations and the result ${\rm WW}(\mathbf{SLREL})$ of our version of the WW construction, identifying the morphisms in the latter with pairs $(L,k)$ consisting of a linear canonical relation and a nonnegative integer. We put a topology on this category of indexed linear canonical relations for which composition is continuous, unlike the composition in $\mathbf{SLREL}$ itself. Subsequent papers will consider this category from the viewpoint of derived geometry and will concern quantum counterparts

Analytic solution of Hubbell's model of local community dynamics

Recent theoretical approaches to community structure and dynamics reveal that many large-scale features of community structure (such as species-rank distributions and species-area relations) can be explained by a so-called neutral model. Using this approach, species are taken to be equivalent and trophic relations are not taken into account explicitly. Here we provide a general analytic solution to the local community model of Hubbell's neutral theory of biodiversity by recasting it as an urn model i.e.a Markovian description of states and their transitions. Both stationary and time-dependent distributions are analysed. The stationary distribution -- also called the zero-sum multinomial -- is given in closed form. An approximate form for the time-dependence is obtained by using an expansion of the master equation. The temporal evolution of the approximate distribution is shown to be a good representation for the true temporal evolution for a large range of parameter values.Comment: 10 pages, 2 figure

Metro Raise: Boosting the Earned Income Tax Credit to Help Metropolitan Workers and Families

Argues for increasing the Earned Income Tax Credit and expanding its options in order to help low-income workers and families meet rising costs and to ensure more inclusive economic growth. Estimates the impact of various proposals on metropolitan areas