There are many theoretical approaches to modelling forest systems, but not all of them have valid practical applications. This book reviews current thinking on various models and presents applications in various contexts. Papers have been selected and developed from those presented at aworkshop held in Portugal in June 2002. Topics covered include: Forest reality and modelling strategies Mathematical approaches and reasoning Estimation processes Models, validation and decision under uncertainty Model archives and metadata
Drawing upon a wealth of past research and results, this book provides a comprehensive summary of state-of-the-art methods for empirical modeling of forest trees and stands. It opens by describing methods for quantifying individual trees, progresses to a thorough coverage of whole-stand, size-class and individual-tree approaches for modeling forest stand dynamics, growth and yield, moves on to methods for incorporating response to silvicultural treatments and wood quality characteristics in forest growth and yield models, and concludes with a discussion on evaluating and implementing growth and yield models. Ideal for use in graduate-level forestry courses, this book also provides ready access to a plethora of reference material for researchers working in growth and yield modeling.
The book is designed to be a textbook for university students (MSc-PhD level) and a reference for researchers and practitioners. It is an introduction to dynamic modelling of forest growth based on ecological theory but aiming for practical applications for forest management under environmental change. It is largely based on the work and research findings of the authors, but it also covers a wide range of literature relevant to process-based forest modelling in general. The models presented in the book also serve as tools for research and can be elaborated further as new research findings emerge. The material in the book is arranged such that the student starts from basic concepts and formulations, then moves towards more advanced theories and methods, finally learning about parameter estimation, model testing, and practical application. Exercises with solutions and hands-on R-code are provided to help the student digest the concepts and become proficient with the methods. The book should be useful for both forest ecologists who want to become modellers, and for applied mathematicians who want to learn about forest ecology. The basic concepts and theory are formulated in the first four chapters, including a review of traditional descriptive forest models, basic concepts of carbon balance modelling applied to trees, and theories and models of tree and forest structure. Chapter 5 provides a synthesis in the form of a core model which is further elaborated and applied in the subsequent chapters. The more advanced theories and methods in Chapters 6 and 7 comprise aspects of competition through tree interactions, and eco-evolutionary modelling, including optimisation and game theory, a topical and fast developing area of ecological modelling under climate change. Chapters 8 and 9 are devoted to parameter estimation and model calibration, showing how empirical and process-based methods and related data sources can be bridged to provide reliable predictions. Chapter 10 demonstrates some practical applications and possible future development paths of the approach. The approach in this book is unique in that the models presented are based on ecological theory and research findings, yet sufficiently simple in structure to lend themselves readily to practical application, such as regional estimates of harvest potential, or satellite-based monitoring of growth. The applicability is also related to the objective of bridging empirical and process-based approaches through data assimilation methods that combine research-based ecological measurements with standard forestry data. Importantly, the ecological basis means that it is possible to build on the existing models to advance the approach as new research findings become available.
Offering a fresh perspective on ecological phenomena, this book provides all the information necessary to understand and use the JABOWA simulation model of forest growth. It sets the forest model within the broader context of the science of ecology and the ecological issues that confront society in the management of forests.
Modelling is an important tool for understanding the complexity of forest ecosystems and the variety of interactions of ecosystem components, processes and values. This book describes the hybrid approach to modelling forest ecosystems and their possible response to natural and management-induced disturbance. The book describes the FORECAST family of ecosystem management models at three different spatial scales (tree, stand and landscape), and compares them with alternative models at these three spatial scales. The book will help forest managers to understand what to expect from ecosystem-based forest models; serve as a tool for use in teaching about sustainability, scenario analysis and value trade-offs in natural resources management; and assist policy makers, managers and researches working in assessment of sustainable forest management and ecosystem management. Several real-life examples of using the FORECAST family of models in forest management and other applications are presented from countries including Canada, China, Spain and the USA, to illustrate the concepts described in the text. The book also demonstrates how these models can be extended for scenario and value trade-off analysis through visualization and educational or management games.
The aim of this book is to improve the understanding of forest dynamics and the sustainable management of forest ecosystems. How do tree crowns, trees or entire forest stands respond to thinning in the long term? What effect do tree species mixtures and multi-layering have on the productivity and stability of trees, stands or forest enterprises? How do tree and stand growth respond to stress factors such as climate change or air pollution? Furthermore, in the event that one has acquired knowledge about the effects of thinning, mixture and stress, how can one make that knowledge applicable to decision-making in forestry practice? The experimental designs, analytical methods, general relationships and models for answering questions of this kind are the focus of this book. Given the structures dealt with, which range from plant organs to the tree, stand and enterprise levels, and the processes analysed in a time frame of days or months to decades or even centuries, this book is directed at all readers interested in trees, forest stands and forest ecosystems. This work has been compiled for students, scientists, lecturers, forest planners, forest managers, and consultants.
The world's boreal forests, which lie to the south of the Arctic, are considered to be the Earth's most significant terrestrial ecosystems. A panel of ecologists here provide a synthesis of the important patterns and processes which occur in boreal forests and review the principal mechanisms which control the forest's patterns.
In an lUlffianaged woodland, forest development follows a succession of periods of undisturbed natural growth, interrupted by intermediate loss or damage of trees caused by fire or wind or other natural hazards. In a managed woodland, the most important periodic disturbances are the thinning operations, which are often carried out at regular intervals and which usually have a significant effect on the future evolution of the resource. Thus, a realistic model of forest development includes both natural growth and thinnings. The key to successful timber management is a proper understanding of growth processes, and one of the objectives of modelling forest development is to provide the tools that enable foresters to compare alternative silvicultural treatments. Foresters need to be able to anticipate the consequences of a particular thinning operation. In most cases, total timber volume is not a very appropriate measure for quantifying growth or yields, or changes caused by thinning operations. Yield in economic terms is defined by the dimensions and quality attributes of the harvestable logs, and estimating timber products is a central issue of production-oriented growth and yield research. Introduction 2 Growth modelling is also an essential prerequisite for evaluating the consequences of a particular management action on the future development of an important natural resource, such as a woodland ecosystem.
Modelling is an important tool for understanding the complexity of forest ecosystems and the variety of interactions of ecosystem components, processes and values. This book describes the hybrid approach to modelling forest ecosystems and their possible response to natural and management-induced disturbance. The book describes the FORECAST family of ecosystem management models at three different spatial scales (tree, stand and landscape), and compares them with alternative models at these three spatial scales. The book will help forest managers to understand what to expect from ecosystem-based forest models; serve as a tool for use in teaching about sustainability, scenario analysis and value trade-offs in natural resources management; and assist policy makers, managers and researches working in assessment of sustainable forest management and ecosystem management. Several real-life examples of using the FORECAST family of models in forest management and other applications are presented from countries including Canada, China, Spain and the USA, to illustrate the concepts described in the text. The book also demonstrates how these models can be extended for scenario and value trade-off analysis through visualization and educational or management games.
At the end of the 1970s, when signs of destabilization of forests became visible in Eu rope on a large scale, it soon became obvious that the syndrome called "forest de cline" was caused by a network of interrelated factors of abiotic and biotic origin. All attempts to explain the wide-spread syndrome by a single cause, and there were many of them, failed or can only be regarded as a single mosaic stone in the network of caus es behind the phenomenon. Forest ecosystems are highly complex natural or quasi natural systems, which exhibit different structures and functions and as a conse quence different resilience to internal or external stresses. Moreover, forest ecosys tems have a long history, which means that former impacts may act as predisposing factors for other stresses. The complexity and the different history of forest ecosys tems are two reasons that make it difficult to assess the actual state and future devel opment of forests. But there are two other reasons: one is the large time scale in which forests react, the other is the idiosyncrasy of the reactions on different sites. Due to the slow reaction and the regional complexity of the abiotic environment of forest ecosys tems, a profound analysis of each site and region is necessary to identify the underly ing causes and driving forces when attempting to overcome the destruction of forest ecosystems.
