The Czech National Forest Inventory, the second cycle (2011–2015)

In 2018, ÚHÚL finished all tasks related to the second cycle of the National Forest Inventory (NFI2, 2011–2015), which, thanks to the repeated survey of locations identical with the NFI1, complemented the static character of NFI1 information with development trends (e.g. an estimate of forest land area change, an estimate of growing stock change) and especially with dynamic variables (e.g. an estimate of the amount of felling, gross increment, transitions of land among the various land categories). This information, based on data gathered by repeated surveys of identical locations in the field, had never been published in the Czech Republic. In terms of the second cycle, a new grid of sampling locations was established, which has been surveyed within the currently continuous NFI with a five-year cycle since 2016.

The Czech National Forest Inventory, the third cycle (2016–2020)

Having gained experience, ÚHÚL has got a clear vision in what ways the National Forest Inventory should proceed in the future. A continuous character of the inventory when ongoing data collection takes place with a five-year interval of sample plot re-assessment and parallel result evaluation is preferred. The formerly applied periodic ten-year cycle inventory system has been found inflexible and inefficient. Results from such an NFI setup are available once in a decade, thus becoming gradually outdated. Another issue is the six-year interruption of the NFI process, which disintegrates the expert team of NFI workers and expensive technological devices lie idle. The transition from a periodic to a continuous NFI is also a gradual trend in a number of European countries (Finland, Sweden, France, Austria, etc.).

The intention to change the inventory form was already known before the start of the NFI2. The entire technology of NFI2 data collection and evaluation was prepared to enable the transition to a continuous NFI as early as 2016. This proposal was presented to the Czech Ministry of Agriculture, a guarantor of the Czech NFI. The Ministry accepted and in 2015 entrusted ÚHÚL with the task of carrying out the project called Monitoring the State and Changes of Forest Ecosystems until the next NFI has been launched by a government regulation. The project was devised to follow up on the Czech NFI survey effectively and to enable more frequent and operational provision of the necessary information. A continuous character of the National Inventory brings the following benefits:

• Updated outcomes – it is possible to update the data on the state and changes of forests more often due to the measurement system already set within the NFI2 when, every six months, the whole territory of the CZ is evenly measured (1/10 of the areas).
• The improved accuracy and range of outputs – data obtained by remote sensing methods increase the accuracy and range of outputs. Other specialised surveys can be included in (or excluded from) the continuous NFI according to current needs.
• Lower costs – a continuous inventory allows more efficient use of technology that is used constantly and supplemented as needed.
• Personnel sustainability - the advantage of the continuous NFI is the stabilisation of the expert team, which is constantly involved in data collection and evaluation (unlike the periodic NFI). This ensures further professional development of the Czech NFI.