Certified Forester Practice Exam

How is net change in growing stock determined?

1. By comparing height measurements before and after logging

2. Through an estimate of volume lost due to mortality

3. By calculating the net volume difference over a specified time

4. By assessing the spread of tree diseases

The correct answer is: By calculating the net volume difference over a specified time

The net change in growing stock is determined by calculating the net volume difference over a specified time. This approach involves measuring the timber inventory at two different points in time and assessing the changes that have occurred in terms of volume. This method provides a comprehensive view of both growth and losses (due to harvest, mortality, or disease) that affect the overall volume of timber available. Estimating net volume differences allows foresters to understand the dynamics of a forest stand, including growth rates and how management practices influence growing stock. This data is critical for sustainable forest management, as it helps in planning future treatments, ensuring healthy growth, and meeting wood production goals. Other options, while they address aspects of tree health or growth, do not provide a complete picture of net change in growing stock. For instance, assessing tree height before and after logging does not account for changes in volume due to various factors such as growth rates or losses from mortality. Similarly, merely estimating volume lost due to mortality does not capture the full picture of growth versus loss over time. Lastly, evaluating the spread of tree diseases pertains more to health and potential loss factors but does not quantify the overall volume change that defines net change in growing stock.