Oriental Beech Forests Research Articles

Assessing the effect of plot size on species diversity in a mixed oriental beech forest

Assessing the effect of plot size on species diversity in a mixed oriental beech forest

Effects of Thinning Practices on Soil Properties and Arbuscular Mycorrhizal Fungi in Natural Pure Oriental Beech Forests

Thinning intensities in Fagus orientalis Lipsky. stands may influence the soil properties, arbuscular mycorrhizal (AM) fungi symbiosis, and their interaction through soil quality enhancement. We aimed to investigate the impact of four thinning intensities—control (no thinning); moderate (15%), moderately intense (35%), and intense thinning (55%)—implemented five years ago in pure oriental beech forests. In this context, the percentage indicates the proportion of trees removed by each thinning intensity, based on the total number of trees before thinning. Our focus encompassed soil physical–chemical properties, AM fungi community composition, and root colonization. At the intense thinning sites, the soil organic carbon, total nitrogen, available potassium, AMF spore density, and root colonization increased by 209.7, 88.9, 115.8, 404.9, and 448.5%, respectively, when compared to the control sites. This suggests a potential rise in AMF spore density and root colonization—a vital aspect for natural regeneration. These findings highlight the importance of considering management practices in forest systems that can enhance the root system in a sustainable manner to improve plant performance, soil fertility, and symbiosis with AM fungi.

Drivers of wood-inhabiting fungal diversity in European and Oriental beech forests.

The hyperdiverse wood-inhabiting fungi play a crucial role in the global carbon cycle, but often are threatened by deadwood removal, particularly in temperate forests dominated by European beech (Fagus sylvatica) and Oriental beech (Fagus orientalis). To study the impact of abiotic drivers, deadwood factors, forest management and biogeographical patterns in forests of both beech species on fungal composition and diversity, we collected 215 deadwood-drilling samples in 18 forests from France to Armenia and identified fungi by meta-barcoding. In our analyses, we distinguished the patterns driven by rare, common, and dominant species using Hill numbers. Despite a broad overlap in species, the fungal composition with focus on rare species was determined by Fagus species, deadwood type, deadwood diameter, precipitation, temperature, and management status in decreasing order. Shifting the focus on common and dominant species, only Fagus species, both climate variables and deadwood type remained. The richness of species within the deadwood objects increased significantly only with decay stage. Gamma diversity in European beech forests was higher than in Oriental beech forests. We revealed the highest gamma diversity for old-growth forests of European beech when focusing on dominant species. Our results implicate that deadwood retention efforts, focusing on dominant fungi species, critical for the decay process, should be distributed across precipitation and temperature gradients and both Fagus species. Strategies focusing on rare species should additionally focus on different diameters and on the conservation of old-growth forests.

Changes in carbon stocks according to stand development stages in oriental beech forests in the Marmara Region of Türkiye.

This study was conducted to determine the changes in carbon stocks of oriental beech (Fagus orientalis) according to stand development stage in the Marmara Region of Türkiye. For this purpose, sample plots were taken from a total of 32 areas encompassing four stand development stages (young, middle age, mature and overmature stand). The diameter at breast height and height of all trees in the sample plots were measured, and only three dominant trees's ages per plot were determined. Aboveground carbon stock was calculated using equations developed for beech forests, while the coefficients in the Agriculture, Forestry and Other Land Use guide were used to determine belowground carbon stocks. A soil pit was dug in each plot and soil samples were taken at different depths (0-10, 10-30, 30-60, 60-100cm). In addition, litters were sampled from four different 25 × 25cm sections in each plot, and then the physical and chemical properties of the soil and litters were analysed. The variations in carbon stocks in above- and below-ground tree mass, litter and soil, and in ecosystem carbon stocks according to development stage were examined by analysis of variance and Duncan test, and the relationships between the carbon stocks were investigated by correlation analysis. Aboveground (AG) and belowground (BG) tree, soil and ecosystem carbon stocks showed significant differences between the four stand development stages (P < 0.05), but not the litter carbon stocks (P > 0.05). AG and BG tree and ecosystem carbon stocks increased with progressive stand development stages, while the soil carbon stock was the highest at the young stage. These findings will contribute to the preparation of forest management plans and the national greenhouse gas inventory.

Comparison of tree species diversity, deadwood volume and regeneration of managed and old-growth Oriental beech (Fagus orientalis L.) forests in Eastern Georgia

Abstract Main stand characteristics and tree species composition were studied in managed and old-growth Oriental beech (Fagus orientalis L.) forests in eastern Georgia (Caucasus). Oriental beech dominates both the regeneration layer and the upper story in old-growth forest. In managed forests, Caucasian hornbeam (Carpinus orientalis) and Oriental beech co-dominate the tree layer as well as the regeneration layer. Tree species diversity and deadwood proportion are higher in managed forests than in old-growth forests. However, the absolute deadwood proportion is similar in both studied forest types. Hence, deadwood proportion is not a suitable indicator to assess the naturalness or management intensity of forests in the study area. The observed proportions of Caucasian hornbeam in managed forests raise concerns about the sustainable use of beechwood in the long term. Harvesting hornbeam and smaller removals of beech are recommended to maintain the uneven-aged forest ecosystem, with Oriental beech as the dominant tree species. The established long-term study plots are important to observe and improve future stand development and forest management.

Developing a Structural Complexity Index for Oriental Beech Forests in Northern Iran

Abstract The structural complexity index (SCI) has become an important metric for forest managers to monitor ecosystem services and conservation value in a wide variety of forest types. In this study, we developed an SCI for an unmanaged mixed Fagus orientalis Lipsky forest in northern Iran, which incorporated structural information specific to mature and old-growth forests. Our results showed that we were able to develop an SCI for this forest that would assist managers to make conservation decisions in a forest where large overstory trees and small understory trees are equally important. The SCI was significantly positively correlated with the density of five minor tree species (Acer velutinum Boiss., Acer cappadocicum Gled., Tilia begoniifolia Chun &amp; H.D. Wong, Quercus castaneifolia C.A. Mey., and Prunus avium L.) and the density of large ([50 cm &amp;lt; diameter at breast height {DBH} &amp;lt; 75 cm]) and very large (DBH &amp;gt; 75 cm) overstory trees. The SCI remains a highly flexible tool for forest conservation and decision making and may assist with decisions about forest management in response to climate change and shifting disturbance regimes. Study Implications: Forest managers have begun to use the structural complexity index (SCI) to assess the successful achievement of conservation management objectives. In many mature, mixed-species forests, large trees, minor species, and understory tree species are important structural components. In this study, we demonstrate that reduction of the minimum diameter used for sampling trees and careful selection of the variables used to calculate SCI results in a valuable metric for making conservation decisions. The advantage of SCI as a forest decision tool is that forest managers are able to adjust the inputs used to calculate SCI to reflect specific management objectives or monitoring goals.

Drivers of tree-related microhabitat profiles in European and Oriental beech forests

Tree-related microhabitats (TreMs) provide a quantitative indicator of habitat heterogeneity in forests, including beech (Fagus) forests. However, systematic analyses of the factors driving TreM diversity and composition in Fagus sylvatica and F. orientalis forests are lacking. In this study, the TreMs of beech forests on 203 plots of 22 forest sites (production and old-growth forest) across the full longitudinal range of both species were assessed following a standardized TreM protocol. A unified diversity and ordination framework based on Hill numbers was applied to account for unobserved TreM types and to extend the sensitivity of our findings focusing from rare to dominant TreMs. The composition of TreM assemblages was mostly determined by Fagus species and elevation, a surrogate for climate, and with focus on dominant TreMs by DBH, whereas old-growth versus production forest had no effect. The coverage of detected TreMs per plot increased with the number of trees assessed and DBH, but was lower in old-growth than in production forests. When standardized for sampling coverage, the diversity of rare and dominant TreM types was higher in old-growth than in production forests, but increased with elevation only focusing on dominant TreMs. These findings corroborate regional studies showing a higher TreM diversity in old-growth forests. Moreover, they demonstrate the importance of focusing conservation efforts on forests of both Fagus species and at different elevations, covering the full range of TreM assemblages. Future studies comparing TreM diversity in different forests should standardize diversity by sample coverage, as currently done in many biodiversity studies.

Determination of the amount of litterfall according to the development stages and of the carbon stock input into the litter in the oriental beech forests in the Marmara Region

Bu çalışma Marmara Bölgesi’ndeki doğu kayını ormanlarında gelişim çağlarına göre dökülme miktarlarını ve bu yolla ölü örtüye giren karbon stoklarını ortaya koymak amacıyla yapılmıştır. Denemeler, b (d1,3=8,0-19,9 cm), c (d1,3=20,0-35,9 cm) ve d (d1,3=36,0-51,9 cm) gelişim çağında bulunan, bakı, yükselti, eğim, yamaç konumu ve meşcere gelişimi bakımından farklılık gösteren toplam 18 alanda tesis edilmiştir. Her deneme alanına beş adet 50×50 cm ebadında kapan kurulmuş ve üç yıl boyunca aylık olarak dökülme materyalleri toplanmıştır. Araziden alınan dökülme materyalleri laboratuvarda bileşenlerine (yaprak, dal, kabuk, diğer) ayrılarak 65 °C’de sabit ağırlığa ulaşıncaya kadar kurutulmuş ve tartılmıştır. Daha sonra öğütülen örneklerde karbon analizi yapılmıştır. Kapanlardan elde edilen dökülme bileşenlerine ait kütleler hektara çevirme katsayısı kullanılarak bir hektar alandaki dökülme miktarları elde edilmiş daha sonra bu değerler analizler sonucu elde edilen karbon yoğunlukları ile çarpılarak bir hektar alanda dökülme sonucu ölü örtüye katılan karbon stokları hesaplanmıştır. Elde edilen veriler varyans, korelasyon ve aşamalı çoklu regresyon analizleri ile değerlendirilmiştir. Araştırma sonuçlarına göre, gelişim çağının ilerlemesine bağlı olarak dökülme miktarı artmış ve toplam dökülme 3959 ile 5698 kg/ha/yıl arasında değişmiştir. Dökülmeye ait ağırlıklı karbon oranı %50,3 olarak belirlenmiştir. Toplam dökülme ile ölü örtüye giren C stoku gelişim çağlarına göre 1988-2857 kg/ha/yıl arasında değişmektedir. Kayın ormanlarındaki toplam dökülme meşcere özellikleri, iklim özellikleri ve fizyografik faktörler ile tahmin edilmiştir. Elde edilen modeller kullanılarak yöredeki ve benzer yetişme ortamlarındaki kayın meşcerelerinde yıllık dökülme miktarı tahmin edilebilir. Bu araştırma ile ortaya konulan bulgular arazi kullanımı, arazi kullanımı değişikliği ve ormancılık sektörünün uzun dönemli hedefleri arasında yer alan modelleme çalışmalarında kullanılabilir.

Comparison of plant diversity between managed and unmanaged forests in Haftkhal, Mazandaran Province, North of Iran

Abstract. Kiasari MSh, Sagheb-Talebi Kh, Rahmani R, Ghelichnia H. 2023. Comparison of plant diversity between managed and unmanaged forests in Haftkhal, Mazandaran Province, North of Iran. Asian J For 7: 106-113. The relationship of plant diversity with silvicultural practices has not been fully understood for the oriental beech forests (Fagus orientalis Lipsky), which is a widespread forest tree in the Hyrcanian Region, Iran. The implementation of appropriate forestry practices in the oriental beech forests is therefore crucial in terms of sustainable forest management. Hence, assessing the impacts of silvicultural practices on plant diversity is essential with the regard to sustainable forest management. This study aimed to compare plant species diversity between two managed and unmanaged forest stands in Mazandaran Province, Iran. Forest inventory in an area of 131 ha was performed using in a systematic random sampling with a 150 × 200 m grid size. In addition, the area of sampling was 100 m2 (10 × 10 m). Twenty and thirty sampling plots were established in managed (compartment No. 8) and unmanaged (compartment No. 36) forests, respectively. Shannon-Wiener and Simpson Indices were used to calculate plant species diversity, while Margalef and Sheldon indices were used to determine species richness and evenness, respectively. The results revealed that 50 and 56 plant species were found in managed and unmanaged forests, respectively. Rosaceae, Asteraceae, and Fabaceae were the main families in these studied areas. This study showed that the diversity and richness of plants in the managed forest slightly increased compared to the unmanaged forest. On the other hand, the evenness of plants in the managed forest slightly decreased compared to the unmanaged forest. Changes in plant diversity indices between managed and unmanaged forests were not statistically significant. This research showed that forest management of oriental beech forests using the single-tree selection cutting has not reduced or weakened the diversity of plant species in the managed forest compared to the unmanaged forest.

An epizootic by a new nucleopolyhedrovirus variant on the Pale tussock larvae (Lepidoptera: Lymantriidae) in oriental beech forest

Dasychira pudibunda is a defoliating forest pest, and it caused an outbreak in oriental beech forests in Bursa, Turkey, in 2019. Examination of collected dead larvae revealed that the body contents were liquefied as in baculovirus infections. Transmission electron microscopy showed that the isolate had many nucleocapsids in an envelope in the occlusion bodies. The isolate was named Dasychira pudibunda nucleopolyhedrovirus-T1 (DapuNPV-T1). Host range studies showed that DapuNPV-T1 was virulent to lymantriid insects. The fact that few pests were found in the surveys conducted in the region between 2020-2022 shows that the epidemic was suppressed seriously by DapuNPV-T1 in 2019.

Soil properties and fine root morphological traits in relation to soil particle-size fractions in a broad-leaved beech (Fagus orientalis Lipsky) forest

Soil particle-size fractions play an important influence soil physico-chemical properties, microbial biomass processes as well as fine roots morphological traits in beech forest ecosystem. The objectives of study were to determine how soil texture interacts with soil physico-chemical properties and microbial biomass as well as fine roots traits in oriental beech forest in Guilan province, northern Iran. Five subplots of 400 m2 were randomly selected at a plot of 1 ha. At five different locations, soil samples were collected at depth of 0–20 cm and fine root samples were also taken from beech trees. Results indicated that clay content was positively correlated with carbon, carbon/nitrogen (C/N) ratio, and moisture, but negatively correlated with nitrogen (N) and phosphorous (P). Silt values had significant positive correlation with C/N, and negative correlation with N and P. The microbial biomass carbon/carbon (MBC/C) ratio in soil increased significantly with clay, but microbial biomass nitrogen (MBN) decreased significantly with increasing clay. The MBC/C ratio decreased significantly with sand values in soil at depth 0–20 cm. Results showed that silt value of soil profile was negatively correlated with MBN, but positively with MBN/N ratio. Soil acidic phosphatase concentration was negatively correlated with clay content, but soil alkaline phosphatase was positively correlated with silt. Clay and sand contents were positively correlated with fine root density, fine root biomass, fine root length, and surface root area. Sand content was negatively correlated with fine root volume. The results of research, considering the correlation between soil particle-size fractions and some soil characteristics as well as fine root traits, show that soil texture in oriental beech forest can play an important role in forest stand dynamics.

Comparison of Basal Area and Trees Abundance for Estimating Tree Diversity in Beech Forests (Case Study: Guilan, Masal, Northern Iran)

Measuring tree species diversity is necessary to manage forest resources sustainably and to better understand the economic consequences to changes in species diversity due to management. This research aimed at comparing the basal area and trees abundance for evaluating tree species diversity in oriental beech (Fagus orientalis Lipsky) forests (Guilan, Masal, Northern Iran). For this study, compartment 515 was selected, and then data were collected through the random-systematic method with a grid dimension of 150×150 m in an area of 50 ha, and lozenge shape with the sizes of 400; 800; 1,000; 1,200; 1,600; 2,000; 2,500; and 5,000 m2 was established. In total, 160 sampling plots were taken. In each plot, the diameter at breast height (DBH≥7.5 cm) of all trees was measured. Diversity and evenness indices were estimated applying different variables (the basal area and the trees abundance) separately. The results elucidated that the error percentage of Mac Arthur’s N1, Hill’s N2 indices, and Simpson's evenness, was lower using basal area compare to the trees abundance. The result of Camargo, Nee, and Smith-Wilson evenness indices revealed that the error percentage by using the trees abundance was lower than the amount of basal area. We recommend using the basal area for estimating tree species diversity.

Managed vs. unmanaged Fagus orientalis Lipsky forests: Structure and diversity of natural regeneration in northern Iran

The predominant natural disturbance regime within an old-growth Oriental beech (Fagus orientalis Lipsky) forest has been imitated in order to continue the forest cover. It is unclear how much the silvicultural characteristics of regeneration in a managed forest differ from those in an unmanaged old-growth forest subject only to natural dynamics. In this study, we compared important quantitative (e.g. height, collar diameter, crown width, length of spring shoot on the main stem and length of the uppermost internodes) and qualitative (e.g. healthy, mode of branching and stem form) silvicultural characteristics of beech saplings within the gaps between an unmanaged old-growth Oriental beech compartment and a managed forest in the northern Iran ten years after a single harvest entry using a single-tree selection. Canopy gaps larger than 100 m&lt;sup&gt;2&lt;/sup&gt; with visible remnants of gapmakers (i.e. stumps) were included in this study. The saplings’ characteristics of both compartments were within typical ranges for an old-growth beech forest. Small, but important differences were also observed. The value of beech saplings’ density in the managed compartment (4.9 ± 0.7 SE) was significantly (P &amp;lt; 0.05) higher than the unmanaged one (3.4 ± 0.6 SE). Conversely, the value of the Menhinick Richness index in the unmanaged one (0.96 ± 0.05 SE) was significantly (P &amp;lt; 0.01) higher than the managed compartment (0.80 ± 0.04 SE). The sapling spring shoot length in the unmanaged compartment (13.3 ± 1.7 SE) was also significantly (P &amp;lt; 0.01) higher than the managed one (7.3 ± 0.7 SE). Relying on beech trees in a managed compartment will hamper the stability of future forest stands. The imitation of the old growth forest must be complete. To increase the resistance of the forest stands to adverse conditions, pay attention to the tree species richness at the time of marking.

The impact of consecutive, shelter and single tree selection system on quantitative characteristics of oriental beech forest in the Muzisay section forest, plan of Haftkhal2, Neka forest

ارزیابی روش‌های مدیریتی در جنگل برای تعیین شیوۀ مناسب مدیریت پایدار ضروری است. به همین دلیل برخی از پارامترهای کمی جنگلی که به‌صورت متوالی ابتدا به شیوۀ تدریجی ‌پناهی و سپس تک‌گزینی بهره‌برداری شدند و پارسل شاهد مقایسه شد. برای این منظور پارسل شاهد و بخش‌هایی از پارسل‌های مجاور آن در راشستان‌های سری موزیسای جنگل‌های هفت‌خال نکا انتخاب شدند. نمونه‌برداری در شبکه‌ای به ابعاد 150 در 200 متر در قطعات ده‌آری صورت گرفت. قطر برابرسینۀ همۀ درختان قطورتر از 5/12 سانتی‌متر و ارتفاع 8 درخت اندازه‌گیری شد. نتایج نشان داد که از سال 1380 تا سال 1398 فراوانی راش در پارسل‌های بهره‌برداری‌شده از 51/81 درصد به 2/96 درصد افزایش و فراوانی ممرز از 41/14 درصد به 9/2 درصد کاهش یافت. فراوانی راش در پارسل شاهد از 9/89 درصد به 7/93 درصد رسید، ولی در فراوانی ممرز تغییری ایجاد نشد. متوسط تعداد در هکتار، در پارسل شاهد از 5/275 اصله به 83/245 اصله کاهش یافت، ولی در پارسل‌های بهره‌برداری‌شده از 32/259 اصله به 81/315 اصله افزایش یافت. حجم در هکتار در قطعات بهره‌برداری‌شده از 47/481 سیلو به 31/426 سیلو کاهش یافت، ولی در پارسل شاهد از 4/454 سیلو به 27/528 سیلو در هکتار افزایش یافت. هر دو عرصۀ تحت بررسی دارای ساختار ناهمسال تقریبا منظم بودند. ساختار حجمی در هر دو عرصه نزدیک به نرمال بوده است. در مجموع به‌جز قطر برابرسینه، تفاوت بین پارسل شاهد و توده‌های بهره‌برداری‌شده در دیگر پارامترهای تحت بررسی معنی‌دار نشد. در واقع بهره‌برداری از جنگل به شیوۀ تک‌گزینی در جنگل تحت بررسی سبب تخریب نشد.

Forest floor and soil properties in different development stages of Oriental beech forests

Native to Eurasia, Eastern Europe, and Western Asia, Oriental beech (Fagus orientalis Lipsky) stands extend from the north-western part of Turkey, the eastern part of the Caucasus Mountains in Georgia and Russia to the Alborz Mountains in Iran. The effect of different development stages of beech stands on the forest floor and soil characteristics are so far almost unknown. For this purpose, the Langa forest that is located in northern Iran was investigated to detect the effect of forest development on major traits of soil biology and related soil characteristics. For this aim, 45 forest floors and soil samples (15 samples per each development stage i.e. initial, optimal, and decay stage) were analysed. In addition, the water content, temperature, and biological dynamics were monitored over the different development stages in summer and fall. Among the considered independent factors, the development stage of beech had the largest explanatory power for the variations of the soil water content (34.7%), total earthworm density and biomass (29.6% and 32.3%, respectively), Acarina (30.3%), nematode (64.3%), protozoa (57.7%), bacteria, (62.8%), fungi (59.5%), basal respiration (53.0%), substrate-induced respiration (53.8%), microbial biomass carbon (30.4%), microbial biomass nitrogen (36.0%), microbial biomass phosphorous (59.1%) and net nitrification rate (19.1%). Soil temperature (42.5%), collembola density (18.2%), net ammonification rate (29.9%), and net N mineralization rate (2.1%) were predominantly determined by the seasons. With the ageing of the forest stands, soil fertility, biota abundance, and soil function were enhanced. To figure out the most vital soil features affecting C and N sequestrations, a stepwise regression model was applied. Carbon sequestration correlated positively to N, the C/N ratio, and negatively to porosity, and the nematode abundance. In addition, nitrogen sequestration correlated positively to C, the sand content, and fine root biomass and negatively to the C/N ratio, soil porosity, and aggregate stability. Although all forest stages of the Oriental beech have an important ecological role and their place in the evolutionary process, the old-growth (i.e. decay) stage is especially important for the soil functions exhibiting the highest fertility and biological relevance. The understanding of ecological changes within different development stages can be helpful in forest management and the evaluation of silvicultural methods.

Species Diversity of Trees and Forest Floor Plants in Oriental beech Forest Types of Shastkalate Educational and Research Forest, Gorgan)

Species Diversity of Trees and Forest Floor Plants in Oriental beech Forest Types of Shastkalate Educational and Research Forest, Gorgan)

Assessing selected microhabitat types on living trees in Oriental beech (Fagus orientalis L.) dominated forests in Iran

On the selected sites in the investigated Oriental beech ( Fagus orientalis L.) dominated forests in Iran with an extensive individual tree selection system, tree microhabitats (MH) are more influenced by tree level factors such as tree species and DBH than by plot level factors such as plot basal area or size and species diversity. Despite the ecological importance of tree microhabitats for biodiversity, there is a lack of information about the occurrence of microhabitat features in Hyrcanian forests in Northern Iran. The aims of this study were to assess selected MH types on living trees in forests managed with an individual tree selection system and forests unmanaged since at least 30 years and to study the effect of tree and plot level factors on their occurrence. A total of 120 circular sample plots were used to collect tree level microhabitat information at six different sites in Oriental beech forests in Iran. Pairs of managed and recently unmanaged forests were located at six sites. Generalized linear mixed models were employed to analyze (i) the effect of management on microhabitat occurrence, and (ii) to explain the occurrence of microhabitats at tree level. There was no significant difference in total number of assessed microhabitats per ha in forests managed with a low-intensity management regime with individual tree selection versus recently unmanaged forests (no management intervention for at least 30 years). Stem cavity with decay was by far the most frequent microhabitat type in managed (16.5 per ha) as well as in recently unmanaged forests (14.2 per ha). Hornbeam and oak trees have a higher probability to host microhabitats (bark loss, woodpecker cavity, and stem cavities) than the dominant oriental beech. Suppressed trees indicated by basal area of larger trees have a lower probability to show bark loss and conks of fungi. Models of microhabitat occurrence on trees have potential to support the development of management guidelines to foster biodiversity.

Tree-Related Microhabitats: A Comparison of Managed and Unmanaged Oriental Beech–Dominated Forests in Northern Iran

Abstract Tree-related microhabitats (TreMs) provide ecological niches in features for a variety of species in forests and are suitable indicators of biodiversity for certain taxa. The study objective was to compare the abundance and occurrence of TreMs in managed versus unmanaged Oriental beech (Fagus orientalis Lipsky) forests of northern Iran to quantify the effect of forest management on biodiversity indicators. We inventoried 3,954 trees to identify the number of trees with TreMs and quantify the occurrence of different types of TreMs. Managed forests averaged 25 trees with TreMs per hectare, and unmanaged forests averaged 41 trees with TreMs per hectare. In both forests, larger-diameter trees (≥50 centimeters diameter at breast height [dbh]) had more TreMs than smaller-diameter trees. TreMs were found on trees larger than a minimum size (32 centimeters dbh) and were more common on trees in poor health, as indicated by vitality class. According to our findings, managed forests have a lower diversity of TreMs than unmanaged forests. However, if management plans in deciduous forests include the retention of large-diameter trees during harvesting events, it is possible to balance providing TreMs within the forest while maintaining growth of economically valuable timber. Study Implications Forest biodiversity is time and labor intensive to quantify, and researchers have begun using tree-related microhabitats (TreMs) as a proxy for biodiversity. This study found TreMs occurred at lower abundances but had a similar occurrence of TreM groupings (cavities, injuries and wounds, deformation/growth form, and epiphytes) in managed Oriental beech (Fagus orientalis Lipsky) forests compared with unmanaged Oriental beech forests. Managed hardwood stands provided 25 TreMs per hectare, which is similar to numbers recommended for managing for biodiversity, and thus it may be possible to promote TreM creation and retention as an opportunity to increase forest biodiversity while also managing forests for timber production. Abundance of TreMs was associated with large-diameter trees and low-vitality trees (poor health). In deciduous forests managed for timber production, the retention of large-diameter trees is likely to align more closely with other management objectives than the retention of trees in poor health.

Replacing an oriental beech forest with a spruce plantation impacts nutrient concentrations in throughfall, stemflow, and O layer

Aim of study: To measure the nutrient leaching from canopy and the O layer in a natural oriental beech (Fagus orientalis Lipsky) forest and a Norway spruce (Picea abies) plantation.Materials and methods: From mid-July to early November, 2013, we measured throughfall (TF) (n=45), stemflow (SF) (n=12) and leaching from the O layer (n = 30) in a 0.5 ha sample plot in the Caspian region, Mazandaran province in northern Iran.Main results: Concentrations of PO43-, Na+, Mg2+, Ca2+ and K+ in the throughfall and the O layer in both beech and spruce forests significantly increased relative to gross rainfall. Concentrations of Ca2+ and Na+ in TF and SF were significantly higher in the spruce forest compared with the beech forest. Furthermore, in both forests, cumulative fluxes of all studied elements (with the exception of NH4+ and NO3-) during the study period were statistically different from those of GR (P&lt;0.05).Research highlights: This study demonstrates that changing from a natural beech forest to a spruce plantation significantly alters nutrient fluxes exiting the canopy and the O layer. This information provides essential information on how planting exotic species will affect nutrient cycles in this region.Keywords: Beech forest; Norway spruce plantation; Throughfall; Nutrient leaching; O layer.

Common ground among beech forest development stages: Matrix versus stage‐typical live tree structure

AbstractQuestionsDoubt has recently been shed on the validity of the European patch mosaic‐forest life cycle model involving the assignment of stages of development to natural forests. To partially explain the inconsistency in development stage assignment, we ask: does the high neighborhood‐scale structural heterogeneity inherent to old‐growth beech forests subject to small‐scale gap dynamics transcend development stages?LocationNatural Oriental beech (Fagus orientalis Lipsky) forests in four regions of the Elborz Mountain range in northern Iran.MethodsNatural tree neighborhoods at three different scales (ca. 112, 508, and 1,228 m2) were identified within 1.0 ha plots in each of the three main development stages (Initial, Optimum, Decay) in each region using the spatially explicit Delaunay‐triangulation‐based floating neighborhood approach. The diameter distribution across all neighborhoods in all three stages was summarized using Principal Components Analysis. Neighborhoods exhibiting shared structure among stages were identified as those within one standard deviation of the centroid of the 2D ordination space.ResultsShared neighborhoods, which were highly heterogeneous with a weakly rotated sigmoid size class structure, were found to consistently occur in ca. 10%–20% of neighborhoods in all three development stages. Only neighborhoods more than one, and particularly more than two, standard deviations from the centroid differed among development stages in size class structure, with stage‐typical distributions observed in each development stage (i.e., negative exponential in the Initial stage, normal in the Optimum, and bimodal in the Decay).ConclusionsRegardless of development stage, forested beech stands subject to a small‐scale disturbance regime share a common core of tree neighborhoods with similar, heterogeneous live tree structure. We conjecture that this structure reflects temporal and spatial variation in gap dynamics, with variously aged but relatively newer gap patches with relatively high within‐patch homogeneity nested within a matrix of the highly heterogeneous neighborhoods that develop in the absence of recent disturbance.