As we know, forest management is a long-term process that can project forward for more than a hundred years. A sound forest management scheme is a significant precondition to promote sustainable use of forests. Forest management strategies, therefore, should be formulated with great care before they are applied. Knowledge of forest dynamics as well as the ways forests respond to management practices (e.g., thinning, fertilizing) must be considered when formulating a management strategy. In addition obtaining forest resource information at different level of resolution is essential for making both national forest policies and enterprise-level forest management plans. Field measurements can provide accurate information but they are time-consuming and expensive. We need more efficient ways to update forest resource information.
Growth and yield models that produce estimates of stand characteristics at specified points in time provide knowledge for forest management decision making. The primary uses of growth and yield information are: production forecasting, inventory updating, evaluation of silvicultural alternatives, management planning, and harvest scheduling. This topic looks at the models currently used, the whole stand-level, size-class and individual-tree models according to the modeling entity (stand, size class, tree), and discusses their fundamental features such as scope of application, specific usability, and limitations. Some of the prevailing models will be introduced and discussed. I will introduce some of them in my lectures but I would encourage you to explore more on your own.
Video Lectures
View the following video lectures:
2.2.1 Overview of forest growth and yield modeling
2.2.2 Whole stand model
2.2.3 Size class model
2.2.4 Individual tree model
Additional Resources
Weiskittel, A. R., Hann, D. W., Kershaw Jr, J. A., &Vanclay, J. K. (2011). Forest growth and yield modeling. John Wiley & Sons.ISBN-13: 978-0470665008; ISBN-10: 0470665009
Burkhart, H. E., & Tomé, M. (2012). Modeling forest trees and stands. Springer. Retrieved from http://link.springer.com/book/10.1007%2F978-90-481-3170-9Links to an external site. The previous two books provide readers with a comprehensive summary of the current approaches for modeling forest dynamics. In addition they include the preliminaries for producing forest growth and yield models such as forest site evaluation, indices of competition, stand density quantification and growth functions.
Peng, C. (2000). Growth and yield models for uneven-aged stands: past, present and future. Forest ecology and management, 132(2), 259-279. Retrieved from http://www.sciencedirect.com/science/article/pii/S0378112799002297Links to an external site. This article focuses on uneven-aged forest growth and yield modeling. It discusses basic types of models and also demonstrates future trends for modeling uneven-aged forests.
Liang, J., & Picard, N. (2013). Matrix model of forest dynamics: an overview and outlook. Forest Science, 59(3), 359-378. Retrieved from http://jiliang.forestry.wvu.edu/r/download/167726Links to an external site. This article provides a review of matrix model which are applied over a wide number areas. It introduces the general structure of matrix models, summarizes their key properties, evaluates their advantages and limitations and, finally, gives an overview of major challenges and future possibilities.
What is the reason for constructing forest growth and yield models?
What are the main approaches to modeling forest stands?
How do you determine the biological rotation age of an even-aged pure forest stand to get the maximum volume according to growth and yield relationships?
When do you use a space state model? Please describe its advantage over yield tables and compatible growth and yield equations.
What is a matrix model and what are its limitations?
What is an individual-tree model and when is it used?
How do you categorize individual-tree models?
FODE006
Requirements Changed
Topic 2.1: Forest Inventory and Monitoring Topic 2.3: Carbon Accounting and Monitoring