This book is the second of two volumes in a series on terrestrial and marine comparisons, focusing on the temporal complement of the earlier spatial analysis of patchiness and pattern (Levin et al. 1993). The issue of the relationships among pattern, scale, and patchiness has been framed forcefully in John Steele’s writings of two decades (e.g., Steele 1978). There is no pattern without an observational frame. In the words of Nietzsche, “There are no facts… only interpretations.”

https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.2307/1941447

The Problem of Pattern and Scale in Ecology: The Robert H. MacArthur Award Lecture

Preservation of natural communities has historically consisted of measures protecting them from physical disturbance. Timber harvests and livestock grazing are usually excluded from preserves, and fire suppression has been practiced—within the U.S. system of national parks, for example. Ecologists and conservationists have come to recognize, however, that many forms of disturbance are important components of natural systems. Many plant communities and species are dependent on disturbance, especially for regeneration (Pickett & White 1985). Preserves should be large enough to allow the natural disturbance regime to operate and to support a mosaic of patches in different stages of disturbance, successional recovery, and community maturation (Pickett & Thompson 1978).

http://www.myxyz.org/phmurphy/dog/DisturbanceDiversityInvasion.pdf

Disturbance, Diversity, and Invasion: Implications for Conservation

Knowledge Management

Since DeLone and McLean (D&M) developed their model of IS success, there has been much research on the topic of success as well as extensions and tests of their model. Using the technique of a qualitative literature review, this research reviews 180 papers found in the academic literature for the period 1992–2007 dealing with some aspect of IS success. Using the six dimensions of the D&M model – system quality, information quality, service quality, use, user satisfaction, and net benefits – 90 empirical studies were examined and the results summarized. Measures for the six success constructs are described and 15 pairwise associations between the success constructs are analyzed. This work builds on the prior research related to IS success by summarizing the measures applied to the evaluation of IS success and by examining the relationships that comprise the D&M IS success model in both individual and organizational contexts.

https://link.springer.com/content/pdf/10.1057%2Fejis.2008.15.pdf

Measuring information systems success: models, dimensions, measures, and interrelationships

Based on the expectancy disconfirmation theory, this study proposes a decomposed technology acceptance model in the context of an e-learning service. In the proposed model, the perceived performance component is decomposed into perceived quality and perceived usability. A sample of 172 respondents took part in this study. The results suggest that users' continuance intention is determined by satisfaction, which in turn is jointly determined by perceived usefulness, information quality, confirmation, service quality, system quality, perceived ease of use and cognitive absorption.

/pdf/understanding-e-learning-continuance-intention-an-extension-33szhub1o6.pdf

Understanding e-learning continuance intention: An extension of the Technology Acceptance Model

DeLone and McLean's 1992 model of information systems success has received much attention amongst researchers This study provides the first empirical test of an adaptation of DeLone and McLean's model in the user-developed application domain The model tested was only partially supported by the data Of the nine hypothesized relationships tested, four were found to be significant and the remainder not significant The model provided strong support for the relationships between perceived system quality and user satisfaction, perceived information quality and user satisfaction, user satisfaction and intended use, and user satisfaction and perceived individual impact This study indicates that user perceptions of information systems success play a significant role in the user-developed application domain There was, however, no relationship between user developers' perceptions of system quality and independent experts' evaluations, and user ratings of individual impact were not associated with organizational impact measured as company performance in a business simulation Further research is required to understand the relationship between user perceptions of IS success and objective measures of success, and to provide a model of IS success appropriate to end user development

User Developed Applications and Information Systems Success: A Test of DeLone and McLean's Model

Virtual learning environments (VLEs) are widespread in higher education today, typically used to deliver instructional materials and facilitate communication within a course. This study aimed to investigate the task–technology fit of VLEs for their two main groups of users: instructors and students, using the VLE WebCT. Task–technology fit, user satisfaction, attitude towards use and anticipated consequences of use were found to be significantly higher for students than for instructors. Instructors were found to have higher perceptions of social norms and higher perceptions of facilitating conditions than students. However, there was no difference between the instructors and students in level of utilization of the VLE. Students perceived that the VLE had higher impacts on their learning compared with instructors' perceptions regarding their teaching. These results suggest that despite high levels of support acknowledged by instructors, they may still be unsure about the contribution of VLEs to their teaching.

How Students and Instructors Using a Virtual Learning Environment Perceive the Fit between Technology and Task

Application of slow release fertiliser to small (0.5x1 m) plots within a serpentine annual grassland community led to significant increases in above-ground biomass and a shift in species relative abundances. In fertilised plots the native forb species which usually dominate the grassland were almost totally replaced by grasses. In the years following initial fertiliser application, a heavy mulch formed from the previous year's grass growth allowed establishment of grass species such as Bromus mollis but significantly reduced forb establishment. Gopher disturbance of fertilised plots in the second and third years of the experiment effectively removed the grass mulch and allowed re-establishment of forb species.

Effects of fertiliser addition and subsequent gopher disturbance on a serpentine annual grassland community

We present a computer model which simulates population processes and spatial patterning in response to gopher disturbance in an annual grassland community. The model includes the processes of seed production, dispersal, germination and seedling survival of four main grassland species. Runs show that soil disturbance by gophers affects both short-term spatial patterning and long-term species composition. The main determinant of species behaviour is their relative seed dispersal distances, and the model is relatively insensitive to initial species distribution or abundances. The model adequately simulated short-term community patterning, and provided predictions of long-term dynamics which can now be tested using longer-term field experiments.

Valerie Hobbs

Papers

User Developed Applications and Information Systems Success: A Test of DeLone and McLean's Model

How Students and Instructors Using a Virtual Learning Environment Perceive the Fit between Technology and Task

Effects of fertiliser addition and subsequent gopher disturbance on a serpentine annual grassland community

Gophers and grassland: a model of vegetation response to patchy soil disturbance

A proposed framework and database for EIA auditing