Annals of Forest Research

Plant species richness and conservation status of protected and unprotected areas of Kohat District, Northern Pakistan

Muhammad Zamin, Muhammad Adnan, Shaheen Begum, Waheed Murad, Sardar Khan — Thu, 15 May 2025 00:00:00 +0000

Kohat, located in northern Pakistan, holds ecological importance due to its distinct climate, diverse vegetation, and conservation concerns. This study hypothesizes that protected areas exhibit higher plant diversity and biomass than unprotected areas, primarily due to the impact of protection measures on domestic and wild animal activities. We assessed the abundance and diversity of native vegetation across 25 plots in protected and unprotected areas. Our findings revealed 67 native plant species, including 39 herbs, 18 shrubs, and 10 trees. Key tree species such as Grewia opptiva, Vachellia nilotica, and Senegalia modesta demonstrated higher basal areas in protected areas. In contrast, shrub species like Rhazya stricta, Withania coagulans, and Gymnosporia royleana exhibited higher densities in these areas. Species of conservation concern, such as critically endangered W. coagulans and nearly threatened G. royleana, were more prevalent in protected areas, suggesting the effectiveness of conservation measures. Additionally, locally important and consumable medicinal plant species, including Ajuga bracteosa, Amaranthus viridis, Peganum harmala, Sonchus arvensis, and Zygophyllum indicum revealed substantial abundance, richness, and distribution within protected areas. In conclusion, the study indicates that conservation measures, particularly protected areas, play a crucial role in safeguarding and preserving native plant communities and enhancing species richness.

Structural features of Peleș Park Forest: managing for ecosystem services provision

Șerban Chivulescu, Diana Pitar, Ștefan Petrea, Bogdan Apostol, Ovidiu Badea — Mon, 12 May 2025 00:00:00 +0000

The Peleș Park Forest (PPF), a semi-natural peri-urban forest near Sinaia, Romania, is essential in providing ecological benefits and improving human well-being through recreation. As the urban population grows and stress-related health problems increase, green spaces are increasingly recognised for their restorative functions, including air purification, temperature regulation and mental health improvement. This study aims to develop a sustainable management framework that reconciles forest conservation with recreational value use by assessing forest structure, evaluating tourism-related stressors, and proposing adaptive management strategies. We assessed forest structure through tree diameter, height, volume, and crown health measurements, applying principal component analysis (PCA) to identify the main structural drivers. The results revealed a strong correlation between tree diameter and height, modulated by species composition and site conditions. They showed pronounced crown defoliation in the upper canopy layers, particularly among trees of lower wood quality. The findings suggest that uneven-aged stand structures, which support biodiversity and ecological resilience, are subject to tourism-related pressures such as soil compaction and vegetation damage.

Tree stem mean diameter reduction factor prediction through advanced modeling approaches

Maria Diamantopoulou — Thu, 17 Jul 2025 00:00:00 +0000

Sustainable management of natural resources relies on accurate modelling of forest attributes to prevent degradation. This study explores advanced modelling techniques, including Artificial Neural Networks (ANN) and Support Vector Regression (SVR), for estimating the mean stem diameter reduction factor (taper) of standing fir trees (Abies x borisii-regis Matff.). These methods are compared against traditional non-linear regression model (NLR), developed using the Levenberg-Marquardt optimization algorithm. The ANN models employ cascade correlation, generalized regression, and Bayesian regularization back-propagation architectures, while the ε-SVR approach is assessed for its robustness. The results show that support vector regression (ε-SVR) achieved the lowest relative errors in model fitting, improving by 0.60% over cascade correlation and generalized regression and by 0.67% over Bayesian regularization. Regarding generalization ability, the ε-SVR model performed best, with a relative error of 4.90%, which was slightly lower than cascade correlation (by 0.1%), generalized regression (by 0.01%), and Bayesian regularization (by 0.04%). A comparative analysis between machine learning approaches and standard regression revealed that the ε-SVR model had the lowest mean error (0.0715), while the non-linear regression (NLR) model showed a higher mean error of 0.0955, which means 1.35 times greater. These findings highlight the strong capability of machine learning methods in accurately estimating and predicting the diameter reduction factor of trees, effectively capturing its non-linear behaviour compared to traditional regression models. Overall, this study underscores the potential of advanced machine learning techniques to enhance accuracy and adaptability in sustainable forest management.

Physiological and biochemical adjustments of the assimilatory system of advance regeneration of Norway spruce to cutting-induced changes in the environment

Mon, 30 Jun 2025 00:00:00 +0000

Various forestry practices (shelterwood systems, selective felling) promoted for the natural regeneration of Norway spruce can speed up the emergence of the advanced growth. Overstory removal can cause drastic environmental changes, resulting in the death of newly regenerated trees or blocking their growth. We studied changes in the content of photosynthetic pigments, parameters of chlorophyll a fluorescence, activity of antioxidant system enzymes in the needles of 20-year-old advance regeneration of Norway spruce and alteration of xylem radial growth rate in response to abrupt cutting-induced changes in the environment. Cutting led to inhibition of photochemical activity (the maximum photochemical efficiency of PSII (Fv/Fm), quantum yield of photosystem II (Y(II)) and relative electron transport rate (ETR) decreased), rearrangement of the pigment system (the content of chlorophyll a (Chl a) and chlorophyll b (Chl b) decreased, chlorophyll a/b (Chl a/b) ratio increased) and a sharp rise in non-photochemical quenching (NPQ). A year later, after clear-cutting, the needles had adapted to the new conditions. Low NPQ level was associated with increased Chl a content and Chl a/b ratio and upregulation of antioxidant enzymes. The activity of photochemical processes increased (Fv/Fm, Y(II), and ETR) and the radial xylem increment was promoted significantly. When using forestry practices involving overstory removal, it is necessary to consider that light intensity increase, associated reduction of air and soil humidity, as well as an increase in the air temperature, can have a negative effect on advance regeneration of Norway spruce growth after cutting down, effect that is reversed after one year.

Field assessment of synthetic attractants and traps for the cerambycid beetles Tetropium castaneum L. and Tetropium fuscum (F.) in the Eastern Carpathians, Romania

Nicolai Olenici, Iuliana Vasian — Mon, 30 Jun 2025 00:00:00 +0000

Tetropium species, significant forest pests in some countries, are expected to pose an even more significant threat in the context of climate change and biological invasions. The potential impact is substantial, making detecting their presence and monitoring their populations crucial. The research presented in the paper aimed to test the response of adults of Tetropium castaneum (Linnaeus,1758) and Tetropium fuscum (Fabricius, 1787) to synthetic attractants similar to those used in other countries (two experiments) and to verify the effectiveness of three types of traps in their capture (one experiment). The experiments were conducted in six freshly clear-cutting areas located in spruce or mixed stands in the northern part of the Eastern Carpathians. In the first two experiments, carried out between 2015 and 2016, we investigated the response to fuscumol, both alone and in combination with host tree volatiles (monoterpenes and ethanol) released at different rates. We also tested a combination of (-)-alpha-pinene, ethanol, and aggregative pheromone of Ips typographus (C.Linnaues, 1758). Barrier traps were used in these initial experiments. The third experiment, conducted in 2017, evaluated the effectiveness of Crosstrap, Barrier, and MultiWit traps, all baited with lures of fuscumol, (-)-alpha-pinene, and ethanol. Numerous specimens of both species were caught in all experiments, namely 7,824-10,466 T. castaneum and 1,041-1,215 T. fuscum. The sex ratio (M/F) varied from 1:1.02 to 1.36:1 for the first species and from 1:1.03 to 1.55:1 for the second. All the baits tested were found to be significantly attractive to the adults of both species. The differences in average catches recorded in traps baited with fuscumol or combinations of attractants were statistically significant compared to those in unbaited traps. Additionally, the catches from traps baited with fuscumol and host volatiles differed significantly from those baited with fuscumol alone. However, there were no significant differences in the average catches of traps baited only with fuscumol compared to those baited with (-)-alpha-pinene, ethanol, and synthetic I. typographus pheromone. Baits containing fuscumol primarily attracted female insects, but when baits with host volatiles were added to those containing fuscumol, the proportion of males in the total catches increased. The Crosstrap and Barrier traps captured significantly more specimens of T. castaneum and T. fuscum than the MultiWit traps, with capture rates 3.20 to 5.57 times higher for T. castaneum and 4.81 to 8.56 times higher for T. fuscum. However, the differences between the Crosstrap and Barrier traps were not statistically significant. Fuscumol baits, whether used independently or alongside host tree volatiles, demonstrate significant attractiveness to beetles of both Tetropium species in Romania. Adding monoterpenes and ethanol lures creates a powerful synergistic effect, remarkably enhancing the allure of fuscumol, particularly for T. fuscum compared to T. castaneum. Moreover, a combination of (-)-alpha-pinene, ethanol, and aggregative pheromone of Ips typographus matches the attractiveness of fuscumol lures, making it an effective alternative. For effective detection and monitoring of Tetropium native or exotic species, fuscumol lures in conjunction with host volatile baits and Crosstrap or Barrier traps are recommended. This approach improves population monitoring and ensures reliable results.

Mapping the monetary value of forest-based recreation: a case study in the Italian Carnic Prealps

Carlotta Sergiacomi, Alessandro Paletto — Mon, 30 Jun 2025 00:00:00 +0000

In the last decades, ecosystem services are increasingly of interest to the scientific community and policy makers, due to their ability to improve people’s physical and mental well-being. To better target forest management interventions, it is important to assign a spatially explicit monetary value to ecosystem services provided by forests. This study aims to defined a procedure to assess and map the monetary values of outdoor recreational in a case study in the north-east of Italy (Cansiglio Orientale forest). For that purpose, a zonal Travel Cost Method and a spatial analysis were implemented in order to map the outdoor recreation value in different forest areas. During the summer 2023, 118 questionnaires were collected through face-to-face administration on the site. The results showed an annual consumer surplus of 13,961,789 € that corresponds to 15.36 € per visit per person. According to the spatial analysis, accommodation facilities, points of interest, and roads and paths network are the elements that most affect the distribution of the outdoor recreation value.

Variation in strobilus and cone production in clonal seed orchards of Anatolian black pine

Mon, 30 Jun 2025 00:00:00 +0000

Anatolian black pine [Pinus nigra Arnold subsp. pallasiana (Lamb.) Holmboe] is an economically and ecologically important forest tree species with a natural distribution of 4.2 million ha, 32% of which is unproductive due to forest fire and other damages in Turkish forestry. The species is widely used in afforestation and conversion of unproductive forests by deploying genetically improved seed from seed orchards because of high adaptation capability to various environmental conditions, and a target species of national tree breeding programme of Anatolian black pine. Estimated variation in reproductive characters can be used as an important guide for managing of seed orchards. The number of cones, female and male strobili were studied in three seed orchards established in 1991, 1993 and 1985 composed of 30, 30 and 34 clones each. Five grafts of each clone were evaluated from each seed orchard for three consecutive years (2022-2024). This study estimated the variation of broad-sense heritability (H2) and the correlation among cone and strobili production at the graft and clone level. Positive and significant (p<0.05) relations were calculated between female and male strobili within year in all orchards both ramet and clone levels, together with significant (p<0.05) relations among years for cone productions in the orchards. Significant (p<0.05) differences were found for the characters among clones and among years within orchard. Year x clone and clone x ramet interactions were generally significant (p<0.05) for the characters. Female strobili seemed a good predictor for cone production. However, the heritability in broad sense was mostly on average below 0.5 for the characters in each seed orchard except of female strobili in an orchard in year-24. It indicated that the reproductive characters under environmental control, and they could give to reflect to management practices.

Fertility variability among clones and genetic diversity of seed crops at seed orchards of Chamaecyparis obtusa in South Korea

Ji-Min Park, Ye-Ji Kim, Koeun Jeon, Kyu-Suk Kang — Mon, 30 Jun 2025 00:00:00 +0000

Chamaecyparis obtusa (Siebold & Zucc.) Endl., commonly known as Japanese cypress or hinoki cypress, is widely cultivated for its high-quality timber and ornamental use. Despite its economic and ecological importance, the species faces challenges in adapting to various climates, necessitating the distribution of high-quality seeds and seedlings. This study aims to enhance the genetic improvement and stability of seed production by analyzing fertility characteristics and genetic traits from two clonal seed orchards of C. obtusa in two locations (Gochang and Seogwipo), South Korea. We examined patterns of strobilus and cone production from 2020 to 2022, assessed effective parent numbers, genetic diversity, and heritability estimates, and analyzed parental contribution for the reproductive traits. Results indicated significant annual variation in strobilus and cone production among clones, with higher male fertility variance than female parents. The effective parent number and genetic diversity were generally maintained sustainably, though Seogwipo showed slightly lower diversity. The study underscores the need for management practices to balance clonal contributions, and sustain long-term productivity and genetic diversity in the seed orchards of C. obtusa. Future research should focus on understanding environmental influences on clonal contributions and refining selection criteria for superior clones in the advanced generation breeding program.

Development of acorn discrimination model for warm-temperature evergreen oaks using hyperspectral analysis

Gye-Hong Cho, Yeji Kim, Koeun Jeon , Kyu-Suk Kang — Mon, 30 Jun 2025 00:00:00 +0000

We used hyperspectral analysis to distinguish between acorns of Japanese red oak (Quercus acuta Thunb.) and ring-cup oak (Quercus glauca Thunb.), two closely related species of the evergreen oaks. To accomplish this, 631 Japanese red oak acorns and 505 ring-cupped oak acorns were collected from the seed orchard in Jeju Island, Korea, and hyperspectral imaging was performed. Two types of hyperspectral devices, Corning and Korea Spectral Products (KSP), were used to calibrate images and extract regions of interest. Average spectra were obtained from the extracted regions of interest, and morphological variables were added to the Corning data to form a dataset. Partial least square (PLS) was used as the learning model, Standard normal variate, Multiplicative scatter correction, and Savitzky-Golay filtering were applied as preprocessing techniques, and competitive adaptive reweighted sampling and successive projection algorithm were applied as variable selection techniques ; and the combination of preprocessing method, the number of PLS components, and the number of selected variables were optimized.. The lightweight model was generated from the selected variables, and the performance was improved by combining the morphological variables. As a result, the lightweight model based on Corning dataset showed 45~85% accuracy, and the lightweight model based on the KSP dataset showed 75~90% accuracy. The model utilizing morphological variables in the Corning-based lightweight model showed a high accuracy of 98-100%, so we were able to discriminate the acorns of evergreen oaks between Q. acuta and Q. glauca. The results of this study are expected to serve as a basis for future model development for seed classification of hybrid oak acorns.

Sentinel-2 and environmental data as predictors of the spatiotemporal dynamics of bark beetle (Coleoptera: Scolytinae) - induced tree mortality in natural spruce forests

Matúš Pivovar, Pavel Mezei, Renata Ďuračiová, Rastislav Jakuš — Mon, 30 Jun 2025 00:00:00 +0000

Biotic and abiotic disturbances affect forest ecosystems. Unlike sudden disturbances, bark beetle outbreaks are a gradual process. Bark beetle outbreak triggered by windstorm in Norway spruce (Picea abies) forests was analysed over a 6-year period (2016-2021) in mountainous conditions (890-2,100 m a.s.l.) with deep valleys and high ridges. The disturbance extent and dynamics were assessed via remote sensing (Sentinel-2 imagery) using a supervised maximum likelihood classification. Topographical variables, bark beetle-related spatial metrics and spectral indices were assessed for predictor importance for their influence on bark beetle-caused disturbance dynamics by boosted regression trees. The overall accuracy of the classification ranged from 87-92% (Kappa 0.84-0.89). Bark beetle spots were initiated mainly at relatively high altitudes and preferentially on exposed terrain. Spectral indices, such as the red-edge normalized difference vegetation index (RENDVI), played a consistent role across various years in predicting spot initiation. With respect to the spread of bark beetle spots, distance emerged as the most influential predictor across all years. Additionally, elevation and RENDVI had notable impacts on spot spreading. In the case of bark beetle spot initialization, the importance of different factors varied among years whereas for spot spreading distance was the most influential for each year.

A case study on forest practitioners’ perspectives on climate extremes: consensus on impacts and conflicts in responses

Florian Knutzen, Averbeck Paul, Karsten Haustein, Oliver Frör, Markus Groth — Mon, 30 Jun 2025 00:00:00 +0000

Climate extremes present significant challenges to the German forestry sector, impacting forest ecosystems, biodiversity, and overall forest health. This study examines the perspectives of forest practitioners regarding the impacts of climate extremes, such as drought, heat waves, storms, and heavy rainfall, as well as their proposed responses and potential conflicts. Utilizing a transdisciplinary approach, semi-structured interviews were conducted with 28 forest practitioners. The findings reveal that over 89% of practitioners acknowledge drought as the most significant climate extreme affecting forests, highlighting its detrimental impacts on tree health and forest ecosystems. Drought-related damage since 2018 has also resulted in significant economic losses and necessitates large-scale reforestation. Notably, two divergent management approaches were identified: those prioritizing wood production (FWP) tend to focus on economic viability and timber management strategies, while those emphasizing protection and recreation (FPR) concentrate on ecological sustainability and biodiversity conservation. There is a broad consensus on the impacts of climate change, but responses remain contested. Both groups agree on the importance of promoting mixed, multi-layered forest stands to enhance resilience to climate extremes. However, important differences remain: the FWP group advocates active interventions and favors conifer species such as spruce for economic reasons, while the FPR group emphasizes natural processes and prefers native species like beech. Although climate adaptation serves as a shared rationale, their underlying priorities differ considerably. These insights underscore the need for integrating diverse perspectives in forest management to effectively address the complexities of climate change, facilitating collaborative approaches that address both economic aspects and environmental co-benefits through integrated forest management.