Session 7: Eclectic Innovations

Many authors have pointed out the need to firm up the “fuzzy”ecosystem management paradigm and develop operationally practical processes to allow forest managers to accommodate more effectively the continuing rapid change in societal perspectives and goals. There are three spatial scales where clear, precise, practical ecosystem management processes are needed: the regional assessment scale, the forest-level scale, and the project-level scale. This paper proposes a practical decision analysis process for ecosystem management at the project-level scale. The proposed process is firmly grounded in the body of theory and practice organized in the scientific literature under the heading of multi-objective decision analysis. An illustrative example of this decision analysis process using the Bent Creek Experimental Forest of the Pisgah National Forest near Asheville, NC as a test case is presented.

Keywords: decision analysis, decision support, forest planning, adaptive management, ecosystem management, national forests, analytical hierarchy process (AHP)

^*Presented by H.Michael Rauscher.

Is the Growth/Removals Ratio a Reliable Indicator of Sustainable Harvest Levels?

Stephen P. Prisley

Department of Forestry

Virginia Tech

Blacksburg 24061 USA

Andrew J. Malmquist

Information Technology, Forest Technology Group

Summerville, SC 29483

Abstract

When forest managers and policymakers wish to assess the ability of a given forest resource to support a sustainable level of timber harvests, they frequently use growth/removals ratios developed from forest inventory data. Recently published inventory data for forests of the southern U.S. have documented numerous states in which softwood harvests exceed softwood growth, raising concern over the sustainability of this critical resource.

At the same time, forest managers in the southeast have been investing in a wide range of practices that have dramatically increased the growth rates for softwood plantations. As these growth increases are verified in the field, forest managers respond accordingly with adjustments to management regimes, including shortening of rotation lengths. This, in turn, means that the area of forest harvested annually must increase in a given forest estate to approach a regulated forest condition.

A spreadsheet model has been developed which evaluates the impacts of shortening rotation lengths on the growth/removals ratios for managed forests. The model demonstrates that a temporary imbalance of removals over growth results when the rotation age is shortened. Hence, managers and policymakers should use caution when making inferences or public claims about sustainable harvest levels from growth/removals ratios alone.

^*Presented by Stephen Prisley.

Study Of A Mexico City´S Urban Forest Sample Using Ecological Indexes

Hector J. Vázquez

Department of Systems

Metropolitan Autonomous University

02200 Azcapotzalco Mexico D.F. 2200 Mexico

Grabinsky, Jaime (2). Chacalo, Alicia (3) and Aldama Alejandro(1)

(1). - Department of Systems (hjv@hp9000a1.uam.mx)

(2). - Department of Basic Sciences

(3). - Department of Energy

Metropolitan Autonomous University

Azcapotzalco, Mexico City.

Abstract

For the study of the structure of a biological population or sample a certain number of statistical indexes have been used. Indexes applied to evaluate characteristics such as: Species space distribution, Species diversity in terms of abundance and equitability, interespecific associations , etc. These indexes have the advantage of summarizing several properties in a number. However this advantage, in certain occasions can be inconvenient. For example it is observed that several indexes proposed to evaluate the same characteristic can diverge, in other cases the same value of the index can be obtained for two substantially different samples.

In a study of an urban forest sample of the streets of Mexico City some statistical indexes were applied to evaluate the characteristics mentioned. These indexes had been used in investigations of natural systems.

The results showed some of the inconveniences before commented. It was then preceded to a search of other methods or indicators to better to evaluate the sample. In this work Multivariate Exploratory results of space distribution, abundance, presence-absences and association matrices are presented and compared with the values of the indexes already mentioned. These results gave important elements to give clearer and more useful interpretations of ecological indexes.

^*Presented by Hector J. Vasquez.

Predictive ecosystem mapping: Applications to the management of large forest areas

Dave Downing

Timberline Forest Inventory Consultants

#315-10357 109 St. Edmonton T5JIN3 Canada

Abstract

Ecological land classification is becoming an integral part of forest management in many jurisdictions given the current regulatory and policy environment; the necessity for more accurate estimates of standing timber, long-range sustained yields, and allowable annual cuts; and the benefits of identifying areas that provide the best returns for silvicultural investments. Conventional ecological mapping provides detailed information on ecological conditions within a forest management area, but it takes a long time to complete and is relatively expensive. In the last ten years, significant advances have occurred in both spatial and aspatial predictive modelling approaches to mapping. These "predictive ecosystem mapping" methods capitalize on the knowledge of expert ecologists and use digital information normally available to forest managers such as terrain models and forest cover maps. Characteristics of good predictive ecosystem mapping systems include: the flexibility to adapt to changing information sources and ecological knowledge in a timely and economical fashion; the ability to assign estimates of accuracy to predictions; and the ability to generate explicit traces of the allocation path followed for each prediction. A case study of a forest management area in western Canada demonstrates the benefits of using a commercially available predictive ecosystem mapping system, ELDAR, in support of contemporary forest planning requirements including timber supply analysis, silvicultural planning, and non-timber modeling such as biodiversity and wildlife habitat assessments.

^*Presented by David Downing.

Application Of “Data Modeling” And “Data Model” In Natural Resources And Forest Management

Yujia Zhang and Bruce E. Borders

School of Forest Resources

University of Georgia

Athens 30602-2152 USA

Abstract

Recent developments in database theory and technology, especially in the relational database approach and database management systems (DBMS) provide a powerful tool to construct natural resources and forest database systems using long-term observations. Compared with the traditional database approach, the relational database approach allows data to be stored without unnecessary redundancy, allows data to be accessed and analyzed more efficiently, and provides the flexibility to implement multi-source data. Using DBMS, database users can store and manipulate data in a central computer (server) from a PC by networking, without fear of losing data. Also, users can retrieve data from different data files to make a view containing required information for a particular purpose, which significantly simplifies data analysis. With the help of structured query language, data operations such as data revising and updating, and data analysis can be processed using queries. Data modeling and the data model facilitate construction of a ‘virtual forest’ in the computer that is a comprehensive database including data files from different disciplines of forestry, which helps forest scientists to review complicated relationships among individual components and model forest dynamics.

^*Presented by Yujia Zhang.

Last revised: April 6, 2000

Session 7: Eclectic Innovations

(Moderated by Wade Harrison)

Contents