A Scale‐Sensitive Test of Attraction and Repulsion Between Spatial Point Patterns

There exist a variety of tests for attraction and repulsion effects between spatial point populations, most notably those involving either nearest‐neighbor or cell‐count statistics. Diggle and Cox (1981) showed that for the nearest‐neighbor approach, a powerful test could be constructed using Kendall's rank correlation coefficient. In the present paper, this approach is extended to cell‐count statistics in a manner paralleling the K‐function approach of Lotwick and Silverman (1982). The advantage of the present test is that, unlike nearest‐neighbors, one can identify the spatial scales at which repulsion or attraction are most significant. In addition, it avoids the torus‐wrapping restrictions implicit in the Monte Carlo testing procedure of Lotwick and Silverman. Examples are developed to show that this testing procedure can in fact identify both attraction and repulsion between the same pair of point populations at different scales of analysis.     

Chronicle for 1999

Abstract

Two German maps of southern Africa, one official, the other private, came to the attention of the British government in the 1890s and raised questions of boundary delineation. In both instances, they provoked a response—diplomatic dispute and internal policy decision—but in neither case did the maps do more. They actively initiated contention but were passive devices thereafter.     

Estimation Bias in Spatial Models with Strongly Connected Weight Matrices

This article shows that, for both spatial lag and spatial error models with strongly connected weight matrices, maximum likelihood estimates of the spatial dependence parameter are necessarily biased downward . In addition, this bias is shown to be present in general Moran tests of spatial dependency. Thus, positive dependencies may often fail to be detected when weight matrices are strongly connected. The analysis begins with a detailed examination of downward bias for the extreme case of maximally connected weight matrices. Results for this case are then extended by continuity to a broader range of (appropriately defined) strongly connected matrices. Finally, a simulated numerical example is presented to illustrate some of the practical consequences of these biases.     

Clearances and Clearings: Deforestation in Mesolithic/Neolithic Britain

Clearances, interpreted from pollen records during the Mesolithic and Neolithic of Europe, are generally ascribed to purposive deforestation which is compatible with the transition model, whereby early Neolithic economic strategies are a development of late Mesolithic intensification of wild plant food husbandry. This paper considers the role of natural processes in creating clearings and the role of inadvertent impact of human activity on forest processes, including woodland regeneration. The role of climate, wind-throw and lightning strikes in creating clearings and forest instability is emphasised and the evidence discussed from sites which may be interpreted as resulting from opportunistic human use of natural clearings. Unfortunately, regional pollen diagrams lack sufficient spatial resolution to detect the size of isolated clearings or establish the spatial variation in forest composition that was intimately related both to forest ecology and the effects of subtle human impacts. This may be the major reason for an apparent contradiction between pollen evidence of Neolithic impact and the archaeological record. Moreover, early Neolithic agricultural activity may have been concentrated in valley bottoms, which is undetectable in regional pollen diagrams. Alternative models need to be considered, which include culturally specific exploitation of the local environment, along with the inadvertent ecological repercussions of pre-agricultural and early-agricultural human activities in naturally dynamic woodlands.     

Community-based development, non-governmental organizations and social capital in post-apartheid South Africa

Community-based development strategies are gaining in credibility and acceptance in development circles internationally and notably in post-apartheid South Africa. In parallel, the concept of social capital and the role of supportive nongovernmental organizations are receiving attention as key catalytic elements in encouraging and assisting community-based initiatives. In this paper, a well-documented initiative, the Hertzog Agricultural Co-operative in Eastern Cape province, is re-examined after the passage of several years to assess the impact of social capital and the involvement of a particular non-governmental organization in ensuring the sustainability and economic survival of the project. While both elements have proved critical to the project's life-cycle, particularly in recent years, concerns over possible dependency and project sustainability exist.     

Command Centre Bjorn: the conflict heritage of a Swedish Cold War military installation

This text presents the results of a contemporary archaeological investigation of an important Swedish Cold War installation, Command Centre Bjorn. This centre was connected to the Air Force Attack Squadron and together with the coastal artillery and the navy it constituted a crucial part of the Swedish defence efforts during the Cold War period. The text also discusses questions concerning heritage processes, and it stresses that a contemporary archaeology approach can contribute with new insights into the Cold War and its heritage in Sweden, as well as canalize and offer guidance to the huge public interest in the material remains from this period in Sweden.