Models of Tree and Stand Dynamics


Book Description

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.




Modeling Forest Trees and Stands


Book Description

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.




Forest Dynamics, Growth and Yield


Book Description

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.




A Theory of Forest Dynamics


Book Description

Forest succession. Computer models of forest succession. Gap models. Performance of gap models. Patch dynamics in forested mosaics. the biomass respone of landscapes. Categories of dynamic landscapes. Animals and mosaic landescapes. Predicting large-scale consequences of small-scale changes A theory of forest dynamics.







Physiological Ecology of Forest Production


Book Description

Process-based models open the way to useful predictions of the future growth rate of forests and provide a means of assessing the probable effects of variations in climate and management on forest productivity. As such they have the potential to overcome the limitations of conventional forest growth and yield models, which are based on mensuration data and assume that climate and atmospheric CO2 concentrations will be the same in the future as they are now. This book discusses the basic physiological processes that determine the growth of plants, the way they are affected by environmental factors and how we can improve processes that are well-understood such as growth from leaf to stand level and productivity. A theme that runs through the book is integration to show a clear relationship between photosynthesis, respiration, plant nutrient requirements, transpiration, water relations and other factors affecting plant growth that are often looked at separately. This integrated approach will provide the most comprehensive source for process-based modelling, which is valuable to ecologists, plant physiologists, forest planners and environmental scientists. Includes explanations of inherently mathematical models, aided by the use of graphs and diagrams illustrating causal interactions and by examples implemented as Excel spreadsheets Uses a process-based model as a framework for explaining the mechanisms underlying plant growth Integrated approach provides a clear and relatively simple treatment







Modern Approaches in Forest Ecosystem Modelling


Book Description

A review of modern approaches existing nowadays in ecological modelling of forest ecosystems in boreal and temperate forests. The book contains data on contemporary approaches in intensively developed simulation modelling of forest stands, soils and whole ecosystems as well; an analysis of existing spatial forest models and their significance and development; and a comprehensive discussion of theoretical (analytical) models of forest communities. The idea of a system of forest models for more effective solving of different theoretical and practical problems is also discussed. This work is particularly useful in its critical reviewing of modern achievements in forest ecosystem modelling and its discussion of more promising trends of forest modelling with an increase of their practical significance in the near future.




Modeling Carbon Fluxes, Net Primary Production and Light Utilization in Boreal Forest Stands


Book Description

The use of satellite remote sensing for modeling net primary production (NPP) was evaluated in sixty boreal forest stands spanning a range of site conditions. The work included: (i) estimating annual phenological dynamics and photosynthetically active radiation (PAR) interception with remotely sensed spectral measurements, (ii) linking annually absorbed PAR (APAR) to measured NPP and quantifying variability in light use efficiency ("En"), (iii) evaluating sources of variability in "En" via mechanistic modeling of ecophysiology and associated carbon fluxes, particularly through analyses of respiratory carbon costs in relation to assimilation gains (the R: A ratio), (iv) assessing generalization of the results through an investigation of the evidence for evolutionary convergence in "En", the R: A ratio and assimilation per unit APAR (Eg). The analyses showed that observed variability in "En" reflects a decoupling of PAR harvesting and utilization, primarily as a result of differences in the R: A ratio. Links between "En", the R: A ratio and standing above-ground biomass were related to differences the carbon (energy) costs associated with synthesis and maintenance of plant constituents, and longevity (i.e. the payback period on investment in carbon gain). Estimating the R: A ratio from above-ground biomass, in order to compensate for variability in "En", was found to be problematic owing primarily to covariation of R and A with the amount of respiring biomass (i.e. sapwood and foliage). The analyses also showed that the differences in carbon costs between functional types (plants with related life history traits) resulted in convergence on "Eg" rather than en. Variability in "Eg" was, however, introduced by stomatal control at some stressed sites. These findings were supported by the remote sensing and simulation modeling results, and the synthesis of work related to evolutionary ecology. The primary conclusions are that variability in light utilization in these boreal forest stands was determined largely by respiratory carbon costs, and that NPP models based on light harvesting require augmentation with terms that reflect PAR utilization. Possible methods to address these issues, and their implications for NPP modeling over large areas, are discussed.