Accounting for uncertainty in ecological analysis: the strengths and limitations of hierarchical statistical modeling

Analyses of ecological data should account for the uncertainty in the process(es) that generated the data. However, accounting for these uncertainties is a difficult task, since ecology is known for its complexity. Measurement and/or process errors are often the only sources of uncertainty modeled when addressing complex ecological problems, yet analyses should also account for uncertainty in sampling design, in model specification, in parameters governing the specified model, and in initial and boundary conditions. Only then can we be confident in the scientific inferences and forecasts made from an analysis. Probability and statistics provide a framework that accounts for multiple sources of uncertainty. Given the complexities of ecological studies, the hierarchical statistical model is an invaluable tool. This approach is not new in ecology, and there are many examples (both Bayesian and non-Bayesian) in the literature illustrating the benefits of this approach. In this article, we provide a baseline for concepts, notation, and methods, from which discussion on hierarchical statistical modeling in ecology can proceed. We have also planted some seeds for discussion and tried to show where the practical difficulties lie. Our thesis is that hierarchical statistical modeling is a powerful way of approaching ecological analysis in the presence of inevitable but quantifiable uncertainties, even if practical issues sometimes require pragmatic compromises.

Examining the use of terms "Conservation" "Restoration" and "Preservation" between Natural Resource Professionals and Literature Reviews

ABSTRACT This thesis will determine if there is a discrepancy between how literature defines conservation, preservation, and restoration, and how natural resource professionals define these terms. Interviews were conducted with six professionals from six different agencies that deal with natural resources. These agencies consisted of both government and non-government groups. In addition to interviewing these professionals regarding how they define the terms, they were asked where their work fits into the context of these terms. The interviewees’ responses were then compared with the literature to determine inconsistencies with the use of these terms in the literature and real world settings. The literature and the interviewees have agreed on the term conservation. There are some different points of view about preservation, some see it as ‘no management’ and some others see it as keeping things the same or ‘static.’ Restoration was the term where both the literature and professionals thought of moving an ecosystem from one point of succession or community, to another point on a continuum. The only thing in which they disagree on is the final goal of a restoration project. The literature would suggest restoring the ecosystem to a past historic condition, where the interviewees said to restore it to the best of their abilities and to a functioning ecosystem.