Determination of the minimum detectable damage caused by wildlife to Czech Republic’s forests.
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SUMMARY:
In recent years, there has been a significant increase in the population of cloven-hoofed (ungulate) game, leading to more damage to forests. Wildlife currently poses a major obstacle to restoring diverse forest ecosystems that can withstand climate change. There are currently no accurate tools to measure the extent of damages caused by wildlife, and there is a lack of comprehensive data for the entire Czech Republic. Decree No. 55/1999 Coll. deals with damages caused by the destruction of forest cover, reduced growth, and diminished quality of forest cover, but there are no comprehensive databases available for the entire country. Additionally, damages caused by the selective feeding habits of game animals, which reduce species diversity and natural forest rejuvenation in many areas, are not currently quantifiable. The Forestry Management Institute (ÚHÚL) has data from comparative test plots that can be used to assess damage, but an updated analysis is needed. The impact of wildlife on the species composition and diversity of forest stands can also be seen as damage to future forest ecosystems. There is no widely accepted methodology for estimating these costs, but they are likely to be greater than quantifiable damages. Also, excessive protection measures, such as fencing, coatings, and individual protection for plantings and young stands against game, can be included in quantifiable costs, although there is no consensus on what constitutes “adequate” versus “excessive” protection.
Based on the data from the National Forest Inventory, conducted by the Forestry Management Institute (ÚHÚL), the minimum provable amount of damage can be estimated as follows:
Financial loss from the reduction of the growth of forest stands: CZK 331 million/year
Financial loss from a reduction in the quality of forest stands: CZK 832 million/year
The financial loss from the destruction of forest stands cannot be determined objectively
Total: 1,163 million CZK/year
The cost of protecting forest areas from the game currently amounts to approximately CZK 1,451 million per year. When factoring this into the calculation, the total amount rises to CZK 2,614 million per year. When considering additional types of damage (as mentioned above), much higher values can be reached. However, these estimates are often based on limited data sources and are subjective and sometimes reflect the limited knowledge of the authors. It’s important to note that the costs associated with quantifying the damage, particularly in cases of minor damage such as browsing, may exceed the actual damage cost. However, this is not necessarily fatal for slightly damaged forest areas. The identifiable amount of financial loss represents a potential that could be applied if damage assessments were conducted across all forest lands in the Czech Republic.
JUSTIFICATION:
In the Czech Republic and throughout Europe, forest ecosystems are impacted by various factors that negatively affect their growth, production, species composition, stand density, and overall stability, particularly in light of ongoing climate changes. Biotic factors can include wild animals, including game as defined by Act No. 449/2001 Coll., on hunting, as amended. There has been a significant increase in the hunting of wild ungulates in recent decades, corresponding to the rise in their populations in rural areas. This population surge is considered overpopulation in many areas based on current definitions, not only in the Czech Republic but also in other Central and Western European countries (Carpio et al., 2021; Valente et al., 2020).
The increase in population has led to an increased risk of conflicts between wildlife and human activities, which includes damage to forest stands. There are ongoing discussions about how to calculate the amount of damage to forest stands, along with a growing demand for legislative changes to the Hunting Act. The goal is to harmonize the different components of the environment to prevent excessive damage in the future. Determining the amount of damage is a complex task, as it involves various aspects such as damage to wood production and quality, damage to biodiversity due to changes in species composition, and damage related to the long-term stability and resistance of the stand to harmful agents.
The Czech legal system regulates the procedure for calculating financial loss in Decree No. 55/1999 Coll. This decree, also known as the Damage Decree, outlines the method for calculating the amount of damage or harm caused to forests. When calculating the amount of damage to forest stands, the Damage Decree addresses damage from the destruction of forest stands (Section 8), damage from a reduction in the growth of forest stands (Section 9), and damage from a reduction in the quality of forest stands (Section 11). The decree also considers damage caused by animals, but it does not encompass the total damage to forest ecosystems. Additionally, it accounts for indirect damage resulting from extraordinary and more costly measures (§ 14).
Currently, it is difficult to accurately determine the financial loss to the forests in the Czech Republic due to the lack of relevant data sets. The Forest Management Institute offers some data on the level of damage within the National Forest Inventory cycle, which can be used to estimate the amount of damage. However, the primary goal of the National Forest Inventory is not to determine the financial quantification of damages to forest stands. It is possible to calculate and claim a minimal amount of damage based on existing legislation, but the actual damage is likely to be higher. The total damage consists of various individual damage categories, which are listed below.
Financial loss from the reduction of the growth of forest stands
The financial loss due to the reduction of forest growth caused by ungulates nibbling on tree shoots was calculated using data from the Institute for Forest Management Institute Brandýs nad Labem. The data was obtained from the National Forest Inventory for the period 2016 to 2020 and was published at the seminar “Methodology for deriving the amount of minimum hunting of ungulates” on April 26, 2023. Although there is ongoing increase in the number of ungulates, this data source is currently the most reliable. The calculated values in this document only consider damage to the terminal browsing of trees up to a height of 1.3 meters, excluding damage from lateral browsing.
Based on NIL3, the determined annual rate of damage to the terminal top ranges from 15.5% (Norway spruce) to 50.6% (other hardwoods). For the calculation, the value of the acreage of the restored forest area for the period of the last 5 years for which data is available (2017 to 2021; Report on the state of the forest and forest management of the Czech Republic in 2021) was considered, for individual tree species. The total area of forested area for this time period was more than 144,000 ha. As part of the calculation, the assumption of taste within 5 years from the establishment of the stand was considered. However, in extreme conditions with an enormous occurrence of ungulates, these stands can be sensitive to the browsing even more than 20 years after establishment, so these are again the minimum values considered. In addition, the minimum hectare numbers of the given tree species were used as part of the calculation. Damaged production areas of individual tree species according to the afforested area were assigned decree values of financial loss stated in CZK/m2. On the basis of the above-mentioned procedure, the total minimum provable amount of damage caused by browsing on forested areas was set at 331 million CZK/year. It should be emphasized again that this is a minimal damage that is only related to artificially regenerated areas, not to areas that have been regenerated by natural regeneration. The calculation also does not include the natural regeneration of forest trees located under the parent stand. Even here, however, there is demonstrably a considerable negative influence on the natural renewal by the taste of the terminal shoot.
Financial loss from a reduction in the quality of forest stands
Financial loss resulting from a decrease in the quality of forest stands due to biting and peeling can be determined using the procedure specified in the damage decree. The calculation must be performed separately for each affected area, taking into account the specific data of damaged stands. It is necessary to work with the age of the stand in which the damage occurred, obtained from the provided data, and to consider the value of washing, set at 110 years for deciduous trees and 100 years for conifers. Additionally, creditworthiness data, using the average value for the entire Czech Republic, must be considered to calculate the damage from the reduction in the quality of forest stands. Moreover, a minimum condition of extent needs to be fulfilled, requiring a continuous area of mechanical damage greater than 25 cm2 or damage exceeding 10% of the circumference of the trunk. When evaluating according to the specified procedure, damage that reaches at least 1/8 of the circumference of the stem is considered.
The financial loss due to the decreased quality of forest stands was calculated based on previous data from ÚHÚL using NIL2 data, amounting to CZK 832 million per year. It’s important to note the limitations of this calculation. The calculation only takes into account the reduction in forest stand quality due to wood material deterioration from stem rot or other factors. Recent research has shown a decrease in production capacity in recent years, with severely damaged trees only reaching approximately one-third of the values of undamaged trees. Additionally, the resistance of spruce trees to climatic factors has been significantly impaired, while Scots pine has shown considerable resistance to this type of damage in research. Different tree species react differently to this type of damage. The calculated amount should be seen as a conservative but demonstrable value that could be annually applied within the Czech Republic if calculated by all forest owners.
The financial loss from the destruction of forest stands
Under the current damage decree, it is possible to calculate damage from the destruction of forest cover based on § 8. This damage is caused by animals through various behaviours such as uprooting seedlings by wild boars, beating them out with clawed animals, strong biting that disables damaged trees (especially forest pine) from performing economic functions, or massive peeling and biting that causes subsequent mortality of the damaged trees. Although relevant data sources for the Czech Republic do not record the number of damaged trees or those at risk of mortality, the long-term experience of employees at the Forestry and Game Management Research Institute suggests that this damage across the entire Czech Republic could amount to tens or hundreds of millions of crowns per year. However, the calculation does not include damage from the destruction of forest stands for objectivity and to highlight the minimal, but provable value of the amount of damage.
Costs incurred for the protection of forest stands
The Czech Republic does not have a comprehensive database that summarizes all the costs incurred to protect forest stands against the negative effects of wildlife. However, we can use the data from the state enterprise Czech Republic Forests (Lesy České republiky – LČR), which owns and manages about 54% of the forest land. The state enterprise carefully summarizes the costs incurred for the protection of forest stands. The annual costs for protecting forest stands on the property of LČR are listed below:
Fencing of young forest stands: CZK 578,721,282 (construction, but also repair and disposal of fences)
Protection of forest stands against game: CZK 197,203,559 (coatings, spraying, individual protection, KSP)
Forest protection against game: CZK 8,400,659 (branching, oats, repellents)
A TOTAL of CZK 784,325,500
It is estimated that the costs of protecting forest stands in the entire Czech Republic from wildlife effects can total approximately 1,451 million CZK/year. It’s important to note that some of these costs were incurred over an extended period for activities to secure the forest stands due to animal browsing. According to Section 14 of the Damages Decree, it is possible to claim a portion of these damages. However, current data does not allow for an exact determination of the amount that can be claimed.
Conclusion
We determined the total financial loss to forest stands by analysing legislative documents and data sets. Based on the available National Forest Inventory data, we have calculated the minimum financial loss of 1,163 million CZK/year due to damage by taste, browsing, and peeling. This amount could be incurred annually if owners follow a strict procedure. When factoring in the costs of protecting forest stands from the negative effects of game, the total amount comes to approximately 2,614 million CZK/year.
Limits of the evaluation conducted
As previously emphasized at the start of this review, the Czech Republic does not currently possess a comprehensive dataset to accurately ascertain the overall damage caused by game. It is essential to undertake a separate, long-term research initiative with the specific objective of determining the complete extent of damage caused by animals in the forest.
The Forest Management Institute collected data to estimate the minimum amount of damage caused by animals such as browsing and peeling. However, in practice, forest owners typically don’t calculate or claim compensation for such damages. Assessing the damage is challenging and requires field monitoring that can strain staff resources. For example, the Forest Management Institute claimed CZK 28,314,911 for damages from 01/07/2022 to 30/06/2023, but the actual amount is believed to be higher. Similar data is reported by the Czech Statistical Office, which indicates that forest owners received around CZK 55 million in 2022 from hunting tenants for damages caused by game. It’s important to note that calculated damage doesn’t necessarily mean a threat to the stand’s development. It’s essential to consider the adequacy of the damage, proper care for the stand, and the number of individuals in the stand. In practice, it’s crucial to find a balance between the complexity of quantifying the damage, the real risk to the stand’s development, and the expected financial loss in CZK when claiming compensation.
The calculated value does not include financial loss caused by destruction, although this damage occurs. The calculation of this type of damage would likely correspond to an amount in the order of tens or hundreds of millions of crowns per year. Due to the absence of relevant documents, damage from extraordinary and more costly measures was also not quantified. The determined damage also does not include impacts on the stability of forest stands, reduced resistance to ongoing climate change, and other ecological damage.
The processed assessment also highlights the annual expenditure for protecting forest stands from damage caused by wild animals. The majority of this expenditure is on fencing for young forest stands. It’s worth noting that the subsidy covers these costs for the owners, regardless of how effective the expenditure actually is. In practice, this means there’s no check to determine if it’s necessary to fence off the restored areas, i.e., whether there’s truly an increased risk of animal damage. This is particularly relevant in post-disaster areas with tens of hectares of regenerated stands, where there are tens to hundreds of thousands of artificially and naturally regenerated individuals. Damage by animals on a significant portion of these areas doesn’t necessarily pose a threat to the continued successful development of the vegetation, and the placement of fencing can be completely inappropriate. However, to support this argument, we only have the personal experiences of professionals and not precise data.
The relationship between damage caused by free-living ungulates and the abundance of game, including its species composition and sexual structure, is an important factor to consider. Currently, there has been no research conducted on this relationship in the Czech Republic. However, this data is crucial for sustainable planning of game hunting to ensure a socially acceptable level of annual damage to the forest. Project support is needed to carry out this research.
The study was last updated on 7/11/2024.
Acknowledgement
Thanks go primarily to the responsible staff of the Forestry Management Institute (ÚHÚL) for providing the NIL data files, and at the same time to the responsible staff of the state enterprise Lesy České republiky (LČR).
Literature cited
Carpio, A. J., Apollonio, M., & Acevedo, P. (2021). Wild ungulate overabundance in Europe: contexts, causes, monitoring and management recommendations. In Mammal Review (Vol. 51, Issue 1, pp. 95–108). Blackwell Publishing Ltd. https://doi.org/10.1111/mam.12221
Cukor, J., Vacek, Z., Linda, R., Vacek, S., Marada, P., Šimůnek, V., & Havránek, F. (2019). Effects of bark stripping on timber production and structure of Norway spruce forests in relation to climatic factors. Forests, 10(4). https://doi.org/10.3390/f10040320
Cukor, J., Vacek, Z., Linda, R., Vacek, S., Šimůnek, V., Macháček, Z., Brichta, J., & Prokůpková, A. (2022). Scots pine (Pinus sylvestris L.) demonstrates a high resistance against bark stripping damage. Forest Ecology and Management, 513, 120182. https://doi.org/10.1016/j.foreco.2022.120182
Vacek, Z., Cukor, J., Linda, R., Vacek, S., Šimůnek, V., Brichta, J., Gallo, J., & Prokůpková, A. (2020). Bark stripping, the crucial factor affecting stem rot development and timber production of Norway spruce forests in Central Europe. Forest Ecology and Management, 474. https://doi.org/10.1016/j.foreco.2020.118360
Valente, A. M., Acevedo, P., Figueiredo, A. M., Fonseca, C., & Torres, R. T. (2020). Overabundant wild ungulate populations in Europe: management with consideration of socio-ecological consequences. In Mammal Review (Vol. 50, Issue 4, pp. 353–366). Blackwell Publishing Ltd. https://doi.org/10.1111/mam.12202