Eker Remzi, PhD

In terms of engineering standards, the dimensions of hydraulic structures such as culverts on forest roads should have the capability to drain the expected maximum discharge for a 50-year return period during their lifespan (i.e., 20 years). In Turkey, Talbot’s formula, as empirical method, has commonly been used in determining the required cross-sectional area (CSA) of the structures. However, in practice, forest road engineers in Turkey do not pay enough attention to their construction with required dimensions calculated by Talbot’s formula. In the present study, the Hydrological Engineering Centre – River Analysis System (HEC-RAS) model was used to evaluate the dimensions of installed structures in terms of their ability to drain maximum discharges, with the aim of determining the required dimensions for those that could not meet this requirement. To this purpose, the 6+000 km forest road No. 410 in Acısu Forest Enterprise, Gerede Forest Directorate (Bolu, Turkey) was selected as the study area. In total, 15 small watersheds crossed by the forest road were delineated, with only six of them having cross-drainage structures. The HEC-RAS model geometry was generated by manual unmanned aerial vehicle (UAV) flights at altitudes of 5–15 m, providing very high spatial resolution (<1 cm). The maximum discharges of the watersheds were estimated for the HEC-RAS model using the Rational, Kürsteiner, and Soil Conservation Service-Curve Number (SCS-CN) methods. Maximum discharges of 0.18–6.03 were found for the Rational method, 0.45–4.46 for the Kürsteiner method, and 0.25–7.97 for the SCS-CN method. According to the HEC-RAS hydraulic model CSA simulations, most of the installed culvert CSAs calculated by Talbot’s formula were found to be incapable of draining maximum discharges. The study concluded that the HEC-RAS model can provide accurate and reliable results for determining the dimensions of such structures for forest roads.

With recent technological development, photo-optical measurement systems in mobile devices have been increasingly used for automatic wood volume estimation because of their ease of use and efficiency. This study aimed to evaluate the use of photo-optical mobile apps for measuring solid wood volume of the stack in Turkish forestry practices. For this study, 21 log stacks were measured using the traditional technique and two photo-optical mobile apps – iFovea Pro and Timbeter. A strong correlation was found between the traditionally measured solid wood volume of the stack and the volume estimated using both photo-optical apps, the number of logs in the stack, and the mean diameter of the stack. The estimated number of trees from the two apps and manual measurement were not statistically different. However, statistical differences were observed between all three measurement approaches for the mean diameter of the stack. Also, statistical test results indicated mixed results for estimated solid wood volume in the stack. In addition, the study tested whether both apps correctly measure the diameter of the logs in the stack. Thus, manually measured diameter of the randomly selected 50 trees within 21 stacks was compared to the log diameters measured automatically using both mobile apps. The results indicated no statistical difference between the three measurement approaches. The study results are promising for using photo-optical mobile apps in Turkish forestry in terms of transition to digital forestry. However, there are still opportunities to improve the capabilities of the method through further analysis of estimating stack volume using the image from both sides of the logs considering different quality and diameter classes with bark conditions.

The life and robustness of forest roads depend on their protection from the harmful effects of water coming into the road surface. In particular, the deterioration of the road surface affects the safe navigation of vehicles and traffic safety. This situation requires that the surface be stable on forest roads. The aim of the study is to examine whether surface deterioration (erosion and accumulation) on forest roads due to the drainage problem of water falling on the road surface can be minimized by open-top culverts and to determine their effectiveness. These are used in three separate trial blocks every 25 m (A parcels; total of 3 parcels), every 50 m (B parcels; total of 3 parcels) and control block (C). Volumetric erosion and accumulation in these blocks was compared by UAV for about 3 years and the effectiveness of the open-top culverts was examined by this method. A 500 m section of the forest road coded 001 of the Kardüz Forest Operations Directorate (Düzce/Türkiye) was examined in the study. As a result, erosion and accumulation in all blocks have been found to have a dynamic course. It was determined that this mobility was greater in the control block than in the blocks with open-top culverts installed at intervals of 25 m and 50 m. The mean Z values for the blocks showed that the deterioration in the control block (C) was higher than in the blocks with 25 m and 50 m open culverts. The volumetric deterioration rate was 5 times higher in the control block than in the block installed at 25 m interval (A plots) and 2 times higher than in the block installed at 50 m interval (B plots). Similarly, the areal deterioration rate was 3.3 times higher in the control block than in the block installed at 25 m interval (A plots) and 1.4 times higher than in the block installed at 50 m interval (B plots). These results showed the effectiveness of open-top culverts and it was also determined that the open-top culverts installed at 25 m intervals were more effective than the open-top culverts established at 50 m intervals. In addition, according to the statistical analysis, a statistically significant difference was found between the erosion volume in the blocks. Open-top culverts should be used against forest road surface deterioration and UAV technology should be used for deterioration detection.

The life and robustness of forest roads depend on their protection from the harmful effects of water coming into the road surface. In particular, the deterioration of the road surface affects the safe navigation of vehicles and traffic safety. This situation requires that the surface be stable on forest roads. The aim of the study is to examine whether surface deterioration (erosion and accumulation) on forest roads due to the drainage problem of water falling on the road surface can be minimized by open-top culverts and to determine their effectiveness. These are used in three separate trial blocks every 25 m (A parcels; total of 3 parcels), every 50 m (B parcels; total of 3 parcels) and control block (C). Volumetric erosion and accumulation in these blocks was compared by UAV for about 3 years and the effectiveness of the open-top culverts was examined by this method. A 500 m section of the forest road coded 001 of the Kardüz Forest Operations Directorate (Düzce/Türkiye) was examined in the study. As a result, erosion and accumulation in all blocks have been found to have a dynamic course. It was determined that this mobility was greater in the control block than in the blocks with open-top culverts installed at intervals of 25 m and 50 m. The mean Z values for the blocks showed that the deterioration in the control block (C) was higher than in the blocks with 25 m and 50 m open culverts. The volumetric deterioration rate was 5 times higher in the control block than in the block installed at 25 m interval (A plots) and 2 times higher than in the block installed at 50 m interval (B plots). Similarly, the areal deterioration rate was 3.3 times higher in the control block than in the block installed at 25 m interval (A plots) and 1.4 times higher than in the block installed at 50 m interval (B plots). These results showed the effectiveness of open-top culverts and it was also determined that the open-top culverts installed at 25 m intervals were more effective than the open-top culverts established at 50 m intervals. In addition, according to the statistical analysis, a statistically significant difference was found between the erosion volume in the blocks. Open-top culverts should be used against forest road surface deterioration and UAV technology should be used for deterioration detection.

Natural and human-induced disturbances are major drivers of the decline and loss of vulnerable species worldwide. Among these, fires are particularly disruptive as they can devastate entire ecosystems. Assessing the likelihood and severity of such disturbances on plant communities is crucial for the management and conservation of biodiversity. This study aims to analyze fire susceptibility using the Maximum Entropy (MaxEnt) model to evaluate the potential impacts of fires on the biodiversity of a lowland forest in Azerbaijan. The research was conducted as part of the project on the evaluation of Red Book species in Azerbaijan based on IUCN categories and criteria. In this study, 21 rare plant species found in the Samur-Yalama National Park (SYNP) were assessed for fire susceptibility, as they have been significantly affected by fires in recent years. The fire susceptibility analysis included 12 driving factors, categorized into topographic, vegetation, and climatic factors, and identified 564 wildfire incidents. Model performance was evaluated using the AUC value, which was 0.855, indicating good model accuracy. Fire susceptibility was classified into three categories: low, moderate, and high. According to the results, 12,642 hectares (60.82%) of the SYNP area fall under low susceptibility, 5532 hectares (26.62%) under moderate susceptibility, and 2611 hectares (12.56%) under high susceptibility. Rare plant species in SYNP were evaluated based on their fire susceptibility. It was found that Alcea kusariensis (Iljin ex Grossh.) Iljin, Anacamptis morio subsp. picta (Loisel.) Jacquet & Scappat., Equisetum hyemale L., Orchis purpurea Huds., Pinus brutia var. eldarica (Medw.) Silba, Platanus orientalis L., Punica granatum L., and Quercus castaneifolia C.A.Mey are located in areas classified as having high susceptibility.

Natural and human-induced disturbances are major drivers of the decline and loss of vulnerable species worldwide. Among these, fires are particularly disruptive as they can devastate entire ecosystems. Assessing the likelihood and severity of such disturbances on plant communities is crucial for the management and conservation of biodiversity. This study aims to analyze fire susceptibility using the Maximum Entropy (MaxEnt) model to evaluate the potential impacts of fires on the biodiversity of a lowland forest in Azerbaijan. The research was conducted as part of the project on the evaluation of Red Book species in Azerbaijan based on IUCN categories and criteria. In this study, 21 rare plant species found in the Samur-Yalama National Park (SYNP) were assessed for fire susceptibility, as they have been significantly affected by fires in recent years. The fire susceptibility analysis included 12 driving factors, categorized into topographic, vegetation, and climatic factors, and identified 564 wildfire incidents. Model performance was evaluated using the AUC value, which was 0.855, indicating good model accuracy. Fire susceptibility was classified into three categories: low, moderate, and high. According to the results, 12,642 hectares (60.82%) of the SYNP area fall under low susceptibility, 5532 hectares (26.62%) under moderate susceptibility, and 2611 hectares (12.56%) under high susceptibility. Rare plant species in SYNP were evaluated based on their fire susceptibility. It was found that Alcea kusariensis (Iljin ex Grossh.) Iljin, Anacamptis morio subsp. picta (Loisel.) Jacquet & Scappat., Equisetum hyemale L., Orchis purpurea Huds., Pinus brutia var. eldarica (Medw.) Silba, Platanus orientalis L., Punica granatum L., and Quercus castaneifolia C.A.Mey are located in areas classified as having high susceptibility.