Acer Velutinum Research Articles

The Effects of Soil Compaction on the Growth and Architecture of the Seedlings of Species Commonly Used for Afforestation in Iran

The aim of the present study was to elucidate the effects of soil compaction on the seedlings of two species of deciduous (Acer velutinum and Alnus subcordata) and evergreen trees (Pinus eldarica and Pinus nigra) in terms of above- and below-ground morphology in a greenhouse. Six soil compaction levels were applied: the lowest intensity (control), very low, low, moderate, heavy, and very heavy. The results showed that there were different effects according to the species. These effects were on lateral root length, stem diameter, leaf dry biomass, SSL (specific stem length), SRL (specific root length), LMR (leaf mass ratio), RMR (root mass ratio), SMR (stem mass ratio), and R/S (root-to-shoot ratio). The results showed that soil penetration resistance (SPR) had a significant effect on seedling variables such as lateral root length, stem diameter, leaf dry biomass, and SRL (p < 0.05). A. velutinum seedlings have the highest values of growth variables compared to three other species, followed by A. subcordata seedlings. The two evergreen species, Pinus eldarica and Pinus nigra, have the lowest values of these growth variables. It is worth noting that we found that deciduous species had enhanced growth up to a moderate compaction level (1.3 MPa), while the growth decreased at an SPR that was higher than this value.

Consequence of habitat specificity: a rising risk of habitat loss for endemic and sub-endemic woody species under climate change in the Hyrcanian ecoregion

Endemic species are more impacted by climate change than other taxa. However, assessing the vulnerability of endemics to these changes in some regions, such as the Hyrcanian forest, is limited, despite its importance for biodiversity and ecosystem function. To address the question of expected habitat shifts under climate change across the Hyrcanian ecoregion, we built an ensemble of species distribution models (SDM) under two emission scenarios (RCP 4.5 and RCP 8.5) for 15 endemic woody taxa. To identify the potential priority conservation areas, we also applied a spatial prioritization approach. Overall, our results suggest that the impacts of climate change are more severe on the eastern parts of the region (Golestan) and the Talysh Mountains (north-western Hyrcanian ecoregion) with over 85% and 34% loss of suitable habitats over the next 80 years. The central part of the Alborz Mountains (Mazandaran) and some areas in the Talysh Mountains could be potential climatic refugia under the future conditions for endemic taxa. The most prominent changes are expected for Ruscus hyrcanus, Gleditsia capsica, Acer velutinum, Frangula grandifolia, and Buxus hyrcana. The worrying predicted loss of suitable habitats for most studied taxa would dramatically affect the stability and resilience of forests, threatening thus biodiversity of the Hyrcanian ecoregion. We present the first estimation of the potential risks involved and provide useful support for regional climate-adaptation strategy, indicating potential conservation priority areas for maintaining and preserving its resources. Notably, only 13.4% of areas designated for conservation and management under climate change will be located within the current Hyrcanian protected areas, yet the majority of these areas are classified as low priority.

Estimation of bark water storage capacity of broad- and needle-leaved trees planted in a semi-arid climate zone

In forest ecosystems, measurement of bark water storage capacity (BWSC) is required for determining the amount of rainfall interception and understanding throughfall and stemflow processes. We compared the bark roughness coefficient (BRC) and BWSC of even-aged, widely-planted, broad-leaved and needle-leaved species in the Chitgar Forest Park, near Tehran, Iran. Bark samples (n = 10 per species) were extracted from three needle-leaved species (Cupressus arizonica, Thuja orientalis, and Pinus eldarica) and two broad-leaved species (Acer velutinum and Robinia pseudoacacia). The highest and lowest BWSC was found to be for A. velutinum and P. eldarica trees, respectively (0.63 vs. 0.32 g cm−3). Among the studied species, R. pseudoacacia had the highest BRC (0.69), and the lowest was found to be for A. velutinum species (0.03). The whole tree bole BWSC ranged from 156.8 L for P. eldarica to 14.6 L for A. velutinum. The results suggested that A. velutinum may provide more stemflow to the forest floor due to its small size, low BRC and subsequent low whole tree bole BWSC. These findings significantly contribute to our understanding of rainfall partitioning dynamics and ecohydrological processes associated with stemflow from trees. This improved understanding will help managers in selecting tree hydrologic characteristics that align with their objectives in forestry treatments, afforestation plans and establishment of vegetation in urban park settings within drylands.

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 & H.D. Wong, Quercus castaneifolia C.A. Mey., and Prunus avium L.) and the density of large ([50 cm < diameter at breast height {DBH} < 75 cm]) and very large (DBH > 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.

Environment-friendly waterborne fire retardants for protection of wood and bark against fire flames

Flame retardancy was induced in maple (Acer velutinum) and ash (Fraxinus excelsior) wood and bark by means of mixtures consisting of bio-based materials such as starch (S) and glue (G) and water-based paint, MINWAX (M) in two different combined formulations with perlite (P) as the main fire retardant. The selected wood species as solid wood with two different treatable surfaces (with and without bark) were examined. The lowest and the highest mass loss occurred in the untreated-ash and untreated-maple wood samples with bark, while the lowest weight percent gain was related to PSGM-treated ash wood samples with bark, and the highest weight percent gain was related to PSGM-treated maple wood samples without bark. The lowest time to ignition and glowing point time were measured in the untreated-maple wood samples without bark, and the highest of them were measured in the PSGM-treated ash wood samples without bark. The effect of bark in the treated- and untreated-maple samples on the time to ignition and glowing point time was greater than the bark of treated- and untreated-ash samples, respectively. There was not any significant relationship between actual retention, weight percent gain, and mass loss for all treatments. However, there was significant difference between the individual and interaction agents on fire retardancy of treated and untreated samples.

Two new Phyllocoptine species (Acariformes: Eriophyidae: Phyllocoptinae) from northern Iran

Two new Phyllocoptine species (Eriophyidae: Phyllocoptinae) including Shevtchenkella acerutinis sp. nov. and Epitrimerus cupresservirens sp. nov. were collected from Acer velutinum Boiss. (Sapindaceae) and Cupressus sempervirens L. (Cupressaceae), respectively in Sari county, Mazandaran province, North of Iran. They are described and illustrated. This is the first report of eriophyoid mite species in association with Acer velutinum and Cupressus sempervirens plants.

Effects on soil physicochemical properties and seedling growth in mixed high forests caused by cable skidder traffic

The use of wheel skidders for timber extraction from tree stump to roadside landing has become more and more widespread. Although the use of wheel skidders has the advantages of high production and reduced extraction costs, it also damages the soil and impedes forest regeneration. The main purpose of this study was to investigate the effect of machine traffic using the Timberjack 450C (two, six and 15 passes) on two slope classes (SC) of skid trails. A low slope is considered to be <20% and a high slope is at >20%. The effects on soil physicochemical properties and seedling growth (alder, Alnus subcordata C.A. Mey. and maple, Acer velutinum Boiss.) in natural mixed beech stands in the Hyrcanian forests in Northern Iran were observed and studied. The results showed that the different factors of traffic intensity (TI) and SC had a significant impact on soil physicochemical properties and subsequent seedling growth. After two machine passes in a low TI on both low and high slopes, soil bulk density (BD) increased by 49.3% and 59.2% and penetration resistance increased by 30.5% and 38.5%, while total porosity decreased by 19.5% and 23.5%. The forest floor decreased by 30.9% and 42%, organic carbon decreased by 25.6% and 39.4%, nitrogen decreased by 18.5% and 26.3%, phosphorus decreased by 14.1% and 23%, and potassium decreased by 10.7% and 24.2%, respectively as compared with the control area. Our results indicated additional BD increments after two, six and 15 machine passes of 49.3%, 17.9% and 8.3% in the low slope, respectively, and 59.2%, 16.5% and 7.1% in the high slope, respectively. The mean of the germination rate (GR) of alder and maple seedlings in the control area was 58.3% and 46.1%, respectively, while after two, six and 15 passes, the GR of alder seedlings reduced to 50%, 46.4% and 37.5%, respectively, while that of maple seedlings reduced to 36.1%, 28.6% and 25.6%, respectively. Additionally, after two machine passes, stem length, main root length, and total dry biomass decreased by 28.7%, 34.9% and 34% in alder seedlings, respectively, and 27.9%, 27.6% and 33.3% in maple seedlings, respectively. Comparison of the response of the two seedling species to soil compaction showed that although alder had a higher GR than maple, the root growth of maple was higher than that of alder.

Effect of Different Vegetation Restoration on Recovery of Compaction-Induced Soil Degradation in Hyrcanian Mixed Forests: Influence on Soil C and N Pools and Enzyme Activities

Reforestation with native and non-native tree species is one of the most effective strategies to cope with climate change, and is also the most effective management method for solving soil erosion problems in degraded forests around the world. The current research investigates three skid trails, which were planted with three species in the clearcutting areas, in comparison with a natural forest of hornbeam (CB; Carpinus betulus L.) and velvet maple (AV; Acer velutinum Boiss.) and degraded land without trees (DL), as well as evaluates the recovery of soil characteristics in the skid trails in response to the planting of native species, including black alder (Alnus glutinosa (L.) Gaertn.), and non-native species, including eastern cottonwood (Populus deltoides L.) and Italian cypress (Cupressus sempervirens L. var. horizontalis (Mill.) Gord.) in a mid-term period of 25 years, in the Hyrcanian forests in northern Iran. Significantly higher litter nitrogen (N), phosphorus (P), and potassium (K) were detected in the plantation of black alder (AG), whereas the lowest values were measured under the DL treatment. Soil physio-chemical properties significantly differed among treatments, except silt content. Among the soil chemical properties, N storage and available nutrients of P and K under the black alder plantation were fully restored as compared to the value observed at the hornbeam and velvet maple (CB-AV) stand over a 25-year period after soil disturbance and planting. Over a 25-year period after logging operations, soil biological and microbial properties of carbon and nitrogen, and enzyme activity in the black alder plantation were partially recovered, but these values have not returned to pre-harvest level at the CB-AV treatment as control. Overall, these results suggested that black alder had greater positive effects on the recovery of soil properties than other trees due to the faster litter decomposition as a N-fixing species, and its labile substrate with low organic C and high N concentration. Therefore, black alder reforestation should be increase in future ecosystem restoration in the area influenced by logging operations.

МОНІТОРИНГ ПОСУХОСТІЙКОСТІ ІНТРОДУКОВАНИХ ВИДІВ ВИСОКОРОСЛИХ ДЕРЕВПІСЛЯ ЗМІНИ КЛІМАТИЧНИХ УМОВ УРБОПРОСТОРІВ

Background. Landscaping of urban environments significantly mitigates the negative effects of "urban heat islands", which in turn has a positive effect on many aspects of human life. Therefore, the purpose of our research was to identify droughttolerant rare and decorative species of woody plants with further recommendation for their inclusion in the ecosystems of the urban environment. Methods. For research, we selected from the collections of the Botanical Garden named after acad. O.V. Fomina 25 highly decorative species of trees with a height from 10 to 50 m, which come from temperate and continental climate zones. Among them, 14 species are uncommon and 11 species are widespread in mass culture in the Polissia and Forest-Steppe zone of Ukraine. The drought resistance test was conducted twice: in early June and also in early September. Relative drought resistance was assessed by following parameters: tissue hydration and water loss per unit time. Results. According to the results of the study, most of the 25 species of tall trees showed a high or average level of drought resistance. The most drought-resistant light-loving and shade-tolerant species were recommended. Species that may require additional care during cultivation (Phelodendron amurense and Styphnolobium japonicum) have been identified, which must be taken into account when landscaping urban areas. Conclusions. Among shade-tolerant trees, the following species can be recommended for cultivation in urban conditions as highly drought-resistant: Acer mandshuricum, Acer velutinum, Corylus colurna and Prunus padus. The following light-loving plants turned out to be the most drought-resistant: Liriodendron chinense, Ginkgo biloba, Acer saccharinum, Catalpa bignonioides, Catalpa fargesii and Tilia europea.

Acer velutinum Bioss. (velvet maple) seedlings are more tolerant to water deficit than Alnus subcordata C.A. Mey. (Caucasian alder) seedlings

Drought stress is a major environmental factor limiting plant growth. Selection of drought-tolerant plants is of critical importance in vegetation restoration and forestation programs. Alnus subcordata and Acer velutinum are two valuable, dominant, and endemic species in the Hyrcanian forests. There are fast-growing species and significant diffuse-porous hardwood in afforestation and reforestation. One-year old seedlings of both species were exposed to four water shortage treatments (100, 75, 50 and 25% of field capacity (FC) chosen as control, mild, moderate, and severe) for 12 weeks. Thereafter, their morphological characteristics such as height and basal area, total and organs biomass (root, stem, and leaf), leaf area (LA), specific leaf area (SLA), leaf area ratio (LAR), as well as physiological and biochemical characteristics such as relative water content (RWC), content of chlorophyll, free proline and malondialdehyde (MDA), and superoxide dismutase (SOD) and peroxidase (POD) activity were measured. The results showed that when exposed to reduced water availability, plants’ height, basal diameter, total and organs biomass, LA, LAR, RWC and chlorophyll content decreased, but their proline concentration, MDA content, SOD, and POD activity increased in both species. The root to shoot ratio (R/S) and root mass ratio (RMR) increased at 50 and 25% FC treatments in A. subcordata, whereas no significant difference was found in A. velutinum under drought treatments. SLA increased significantly at 50% FC in A. velutinum and decreased in A. subcordata under drought treatments compared to control treatment. A. velutinum showed more proline content, RWC, POD, and lower increase in MDA content than A. subcordata under moderate treatment. Therefore, A. velutinum appears to possess a better mechanism to cope drought stress. The drought tolerance of A. velutinum may enhance its potential for climatic adaptations under drier conditions with the ongoing climatic change.

The performance of the reformulated Gash rainfall interception model in the Hyrcanian temperate forests of northern Iran

• Reformulated Gash Analytical models (RGAM) applied for seven reforestations. • Models need frequent numbers of rainfall to estimate rainfall interception loss. • RGAM is advisable for predicting interception with small numbers of rain storms. • Ecohydrological parameters dramatically differs between studied stands. Modeling rainfall interception ( I ) is fundamental for understanding the forests’ role in ecohydrological processes in local and regional scales. This research examines the Reformulated Gash Analytical Model (RGAM) applicability for estimating I in seven dissimilar plantations ( Acer velutinum , Quercus castaneifolia , Pinus brutia , Picea abies , and Cupressus sempervirens L. var horizontalis ) in the four reforested areas across the Hyrcanian temperate forests, northern Iran. Field measurements were performed from May-2012 to March-2014 for 167 distinct throughfall and gross rainfall observations. According to our results, the effects of inter-species variation on I value was evident, as P. abies might be the most excellent among the five frequently used tree species for planting project in temperate forests if the primary goal of plantation is to decrease erosion and surface runoff as it intercepted and evaporated more rainfall than other species. Our findings showed that in terms of average-based calculation, the mean of free throughfall coefficient ( p ) value in evergreen needle-leaved reforestations (0.47) was lower than those calculated for deciduous broad-leaved reforestations (0.59), and vice versa for the canopy storage capacity ( S ; 1.85 mm vs . 1.36 mm, respectively), and mean of the ratio of evaporation rate to the mean of rainfall intensity during saturated canopy conditions ( E ¯ / R ¯ ; 0.45 vs . 0.38, respectively). The RGAM satisfactorily estimated I for all species (except for A. velutinum stand), because the estimation error of I was lower than 15% and the Nash–Sutcliffe efficiency was equal to or higher than 0.87. In conclusion, using data from a short time study period to derive canopy ecohydrological parameters as well as modeling I by the RGAM is advisable in reforestation areas across the Hyrcanian temperate forests and regions with similar forest and meteorological attributes.

Variation in Carbon Sequestration and Soil Properties in Relation to Stand Age in Maple and Alder Plantations

ABSTRACT Increased CO2 levels caused by human activities (e.g., fossil fuel consumption and deforestation) has become a major concern for climate change and caused environmental problems. Afforestation/reforestation can help mitigate CO2 emission in the atmosphere by sequestering atmospheric carbon (C) in tree biomass. Herein, the above- and below-ground C sequestration of two pioneer tree species, including Acer velutinum Bioss and Alnus glutinosa L plantation stands of 25 (A25) and 35 (A35) years old were studied. The mean annual growth of diameter at breast height (cm/year) was significantly higher in A35 than A25, while the mean growth of height (m/year) was significantly higher in A25. The total and mean annual growth of the tree biomass and C storage (root and trunk) was significantly higher in A35. The amount of soil C sequestration in A35 was also significantly higher than in A25. The above-ground C sequestration and the annual average of C sequestration of the trees were positively correlated with soil moisture, pH, nitrogen, and phosphorus. Our study illustrates the benefits of considering stand age in the growth and developmental patterns of forest ecosystems in estimating terrestrial C stocks.

Identification of the Most Common Allergens of Acer velutinum Pollen.

Pollens have been identified as potent inducers of allergic diseases worldwide. Acer velutinum (Persian maple) tree is an important source of allergic pollens in Iran. This study aimed to identify the immunoglobulin E (IgE)-reactive components of A. velutinum pollen extract in patients with maple allergy. We aimed to evaluate its allergenic components; using IgE in the serum of patients with maple allergy. Twenty-two patients with a clinical history of reaction and a positive skin-prick test to maple pollen extract were included in this study. Identification of IgE-binding proteins in A. velutinum pollen extract was performed by immunoblotting using sera from sensitive patients. A protein band with a molecular weight of around 70 kDa was the most IgE-reactive allergen in A. velutinum pollen extract detected by this method. Identification of a protein with a molecular weight of about 70kDa, as the most reactive allergen of A. velutinum pollen extract, can be considered as a potential allergen for designing diagnostic kits or as a target for immunotherapy of allergic patients with maple allergy.

Soil fauna communities and microbial activities response to litter and soil properties under degraded and restored forests of Hyrcania

Reforestation has long been the best practice to restore degraded forests due to human interventions. In this paper we investigated the effect of forest degradation (DNF) along with reforestation using 4 endemic species (Alnus subcordata, ASP; Acer velutinum, AVP; Cupressus sempervirens, CSP; Quercus castaneifolia Mey, QCP) on forest’s soil chemical and biological indicators compared to a close-to-virgin natural forest (VNF). For this study, a total of 24 physico-chemical and 25 biological and microbial indicators were measured in soils of all 6 forest stands along with the litter properties. Results showed that the lowest soil quality was observed under DNF, CSP, and QCP which was the result of forest cover degradation in DNF and low litter quality, especially low pH and high C:N, in CSP and QCP. Soil fauna communities were significantly affected by tree species. We found two times higher density of earthworms in VNF compared to ASP, but in DNF the density was 5 times lower than VNF. We found no epigeic earthworms in QCP, CSP and DNF and no endogeic earthworms in DNF. Acarina and Collembola density was high in VNF and ASP, but they showed significant differences (VNF>ASP), and their density sharply decreased in other stands, especially in CSP (3 times lower than VNF) and DNF (8 to 10 times lower than VNF). Nematode density was statistically equal in VNF, ASP, and AVP, but significantly lower in other stands. Protozoa, bacteria and fungi densities were significantly higher in VNF and ASP (VNF>ASP) compared to each other and other forest stands. Basal respiration, substrate induced respiration, microbial biomass N and P, and carbon availability index was also higher in VNF and ASP compared to other stands. Although VNF has the best condition because of old forest cover and high diversity, ASP soil showed significant improvements, demonstrating the importance of litter quality in soil restoration. Restoration effectiveness ranking of the four tested species on soil improvement are therefore ASP>AVP>QCP>CSP. The significant improvement of soil quality under ASP compared to other reforestated stands, only after 3 decades, emphasizes the importance of tree species selection and litter quality on soil chemical and biological restoration.

Effect of nitrogen addition on soil CO2 efflux and fine root biomass in maple monocultures of the hyrcanian region

• Key message Nitrogen (N) addition (10 and 15 g N m −2 year −1 as dissolved \({\mathbf{N}\mathbf{H}}_{4}{\mathbf{N}\mathbf{O}}_{3}\) ) significantly increased the CO 2 efflux from the forest soil and the fine root biomass in a maple (Acer velutinum Bioss.) plantation. Following a seasonal pattern, soil CO 2 efflux showed an exponential relationship with the fine root biomass and soil temperature. • Context The effect of increased atmospheric Nitrogen (N) deposition on forest soil CO2 efflux is still unclear in the Hyrcanian forests and has received considerable attention in the context of global climate change.• Aims Aims of this study were to determine how soil CO2 efflux and fine root biomass change after N addition in a maple (Acer velutinum Bioss.) plantation.• Methods Since the wet N deposition in these areas is 3–5 g N m−2 year−1, four treatments including N1 (5 g N m−2 year−1), N2 (10 g N m−2 year−1), N3 (15 g N m−2 year−1), and N0 (control) were selected. Twelve plots (10 × 20 m) were established, and a \({\mathrm{NH}}_{4}{\mathrm{NO}}_{3}\) solution was sprayed monthly below the trees’ canopy for 1 year. Soil temperature, moisture, and soil CO2 efflux were measured monthly with static dark closed chambers. Fine root biomass was seasonally measured by soil sampling at the same depth.• Results Soil temperature, moisture, and soil CO2 efflux were affected by different levels of N addition. Soil CO2 efflux significantly increased with N addition, and N3 displayed the highest rate (174 ± 16.1 mg CO2-C m−2 h−1). Fine root biomass increased significantly in N3.• Conclusion The predicted levels of N deposition in such plantations will probably lead to enhanced CO2 efflux from soils in reforested areas close to industrial sites in the Hyrcanian forest.

Development of individual tree growth and yield model across multiple contrasting species using nonparametric and parametric methods in the Hyrcanian forests of northern Iran

The Hyrcanian forests of Iran contain many species-rich communities that can only be maintained through an understanding of the renewal and development of these forests. Located in the Jojadeh section of the Farim forest in northern Iran, individual tree growth of five distinct species [(Oriental beech (Fagus orientalis Lipsky), chestnut-leaved oak (Quercus castaneifolia Coss. ex J.Gay), Persian maple (Acer velutinum Boiss.), common hornbeam (Carpinus betulus L.) and Caucasian alder (Alnus subcordata C.A.Mey.)] were measured on 313 permanent sample plots (0.1 ha) over a 10-year period (2003–2013). In this analysis, various tree-level predictions were investigated using the available data with application of parametric models and two artificial neural networks [i.e., the multilayer perceptron (MLP) and radial basis function (RBF) networks]. Individual tree diameter growth models showed a robust negative relationship with basal area in larger trees, which was relatively consistent across species. A total height model indicated that the examined species did not differ for a given set of covariates. In the survival model, the survival probability of Oriental beech was lower than the other species, while the ingrowth model revealed sapling density of all species increased with greater basal area. The artificial neural network based on the MLP was superior for all models and predicted more accurately than the RBF. Furthermore, the models based on the MLP were also superior to the parametric individual tree models developed using mixed-effect regression. The use of these developed models in forest planning and management is imperative, particularly for uneven-aged stands, but assessment of long-term projection behavior across the contrasting statistical approaches used is warranted despite the general superiority of the nonparametric models.

The effects of roadside on composition of tree communities in forests of West Guilan Province, Iran

Forest roads are one of the main affecting factors on diversity and composition of plant species. This study aimed to investigate the effects of forest road on composition of tree communities of forests in west of Guilan Province, Iran. Therefore, in two age classes (0-10 and 10-20 years old) of forest roads with five different distances from the road edge, totally, 240 sample plots (150 square meters) were taken by line transect method. The results showed that the relative importance of Fagus orientalis, Quercus castaneifolia and Acer velutinum trees on roads with lower age (0-10 years old) was higher than those with higher age (10-20 years old). The results also indicated that on the newly-constructed roads, the presence of pioneer species (Alnus subcordata and A. cappadocicum) became lower than the other species by moving from the roadside into the forest. In this study, the species importance values of A. subcordata, A. cappadocicum, and A. velutinum decreased from roadside to the forest interior. The results also showed that the Simpson’s diversity and evenness indexin old roads were higher than the young ones. The results of ANOVA analysis showed that by increasing distance from the road, the species diversity and richness declined, while species evenness elevated. The results indicated that there are higher dead trees on the roadside (0-30 and 31-60 m) compared to the inside of forest.

Orius (Heterorius) linnavuorii (Hemiptera: Heteroptera: Anthocoridae), a New Species from Iran

A new species, Orius (Heterorius) linnavuorii Moulet, Ghahari & Ostovan sp. nov. (Hemiptera: Heteroptera: Anthocoridae), is described from Semnan Province (Iran). The species was collected on Acer velutinum, and confirmed as a predator of Asterobemisia atraphaxius. A checklist of 18 Iranian Orius species is provided.

Long-term afforestation effect and help to optimize degraded forest lands and reducing climate changes

The present study examined the forest floor, soil properties, and dynamics of greenhouse gas fluxes in 23-years old stands of alder (Alnus subcordata C. A. M.), maple (Acer velutinum Bioss.), cypress (Cupressus sempervirens L. var. horizontalis), and pine (Pinus nigra) sites in northern Iran. A degraded natural forest (DNF) with sparse trees including Parrotia persica C. A. M., Carpinus betulus L., and Diospyros lotus L. located near the afforested stands was selected as the control region. Fifteen forest floor and topsoil (0–15 cm) samples per site were taken and analyzed in the laboratory. In addition, the seasonal changes in the fluxes of CO2, CH4, and N2O were studied over a year. The quality of the forest floor differed among the sites, indicating the highest N, and the lowest C concentrations in the alder stand. The soil bulk density, pH, available nutrients (P, Ca, and Mg), earthworm activities and microbial biomass N were significantly higher in the alder stand with organic C being the least. The microbial biomass C did not differ among the studied sites, whereas the total N was significantly higher in the alder ≈ maple sites having the minimum C/N ratios. High contents of water were found in the DNF site. The highest CO2 (0.31 mg CO2 m−2 d−1) and N2O (0.42 mg N2O m−2 d−1) fluxes were observed in the DNF site. The CH4 flux showed higher amounts in the DNF ≈ cypress ≈ pine (0.12, 0.11 and 0.07 mg CH4 m−2 d−1, respectively) sites than in the maple ≈ alder (−0.05, and − 0.04 mg CH4 m−2 d−1, respectively) plantations. The highest values of all fluxes were measured in August, whereas the lowest were detected in February. This research recommends a plantation with suitable native broad-leaved species along with a forestation management plan to rehabilitate the forests of the DNF area.

Morphology, Growth and Architecture Response of Beech (Fagus orientalis Lipsky) and Maple Tree (Acer velutinum Boiss.) Seedlings to Soil Compaction Stress Caused by Mechanized Logging Operations

The Caspian forests of Iran were monitored and evaluated for forest natural regeneration after logging activities for more than a decade. This large area has a substantial ecological, environmental and socio-economic importance. Ground based skidding is the most common logging method in these forests and soil compaction is the most critical consequence of this method. One of the current main topics and important emerging issue in forest research of the last decade are discussed in this study. Soil compaction has major influences on growth and/or mortality rates of forest seedlings. This study has lasted for over ten years so as to have a clear overview related to forest natural regeneration after logging activities. We monitored and evaluated physical soil properties (bulk density, penetration resistance and total porosity) and their effects on maple and beech seedlings on 10-year-old skid trails in the Iranian Caspian forests. Results obtained from evaluating the impact of skid trails within the aforementioned three soil physical parameters were significant; bulk density increased by 12.6% on log skidded routes (between two skidder tires on skid trail) and 36.1% on tire tracks, compared to non-skid trails (1.19 g/cm3), penetration resistance increased by 68% on log skidded routes and 220% on tire tracks, compared to non-skid trails (0.25 MPa), total porosity decreased by 12.8% on log skidded routes and 30.9% on tire tracks, compared to non-skid trails (54%). Among the morphological parameters, lateral root length (LRL) and root penetration depth (RPD) showed the highest decrease at soil compaction compared to the control (decrease in LRL: 60% in maple and 44% in beech; decrease in RPD: 56% in both maple and beech); the main response of growth parameters to soil compaction was found in roots (decrease in dry mass of 36% both in maple and beech); architectural parameters were also influenced by soil compaction, and the response of both seedling species was more evident in the ratio of main root to stem length (RRS) (reduction in RRS 42% in maple, 33% in beech); the ratio of RPD to main root length (RPL) also showed a great reduction (reduction in RPL 20% in maple 33% in beech). Physical soil properties, changes in other environmental properties of skid trails, created differences in beech and maple seedling growth between the skid trails and non-skid trails. This was closely related to the physiological characteristics of the two species studied. Beech seedlings reacted well to a moderate uncovering but they needed little disturbed soil, even if there was a very mixed bedding. Maple seedlings reacted better than beech seedlings to the uncovering and soil disturbance. The effects of the skid trail on morphology, growth and architecture of maple seedlings in the Hyrcanian beech forests showed that the maple, as a seedling, is a suitable species for maintaining the physical properties of skid trails after logging operations in the beech stands in the Caspian forests of Iran.