A generalized mathematical model of ecosystems is
developed. The model begins with the general class of
systems known as state-determined systems, in which the
time-derivative of each state variable is a function of some
subset of the set of all system state variables and
.environmental parameters. A formal basis is...
This work sets forth a reformulation of Levins' loop analysis for the qualitative modeling of complex dynamical systems. Relationships between members of ecological communities can be analyzed through a qualitatively specified community matrix, whereby +1, -1, or 0 represent effects of one species upon another. A contribution is made to...
In this dissertation, new theory and its applications are developed to predict three properties of complex ecological communities: stability, equilibrium response, and non-equilibrium dynamics. First, a graph-theoretic analysis identifies the interconnections in a complex ecosystem that promote or diminish stability (Chapter 2). The hierarchy of interactions that influences stability and...
Conclusion: The first part of this note deals with problems of propagation of error and the latter part with questions commonly identified as "model validation" questions. It is concluded that all validation questions can be resolved into two parts: (1) strategic aspects, involving logical and inferential structures and (2) tactical...
Seasonal trends in forage production and environmental parameters
for five plant community types within a northeastern Oregon riparian zone
were described and modeled using correlation and path analysis. Wet
meadows produced the greatest amount of herbage biomass, followed by moist
bluegrass meadows, gravel bars, forests and dry bluegrass meadows. Trends...
Many problems in ecology and conservation biology can be formulated and solved using machine learning algorithms for multi-label classification. This dissertation addresses three topics related to predicting the distributions of multiple species. It improves existing methods and proposes a new modeling paradigm to address the multi-species, multi-label problem. The first...
Purpose of the Study:
The purpose of this study was to develop and field
test a model for context evaluation of objectives used
in competency-based curricula at the community college
level.
The study:
1. Developed a decision and information matrix that
identified objectives which should be considered
for deletion from...
The primary goal of this research was to identify the impacts that individual agricultural land uses have on fish communities in small streams located in the Willamette Valley of western Oregon. The diverse nature of the land use features of the valley provided a challenging but useful system for the...