Forests

17 pages, 1102 KiB

Open AccessArticle

Management of Needle-Eating Caterpillars Associated with Pinus massoniana and P. merkusii in Vietnam

by Dao Ngoc Quang, Pham Quang Thu, Nguyen Minh Chi, Le Van Binh, Nguyen Quoc Thong, Nguyen Hoai Thu, Vo Dai Nguyen and Bernard Dell

Forests 2021, 12(11), 1610; https://doi.org/10.3390/f12111610 - 22 Nov 2021

Cited by 3 | Viewed by 1979

Abstract

Pine tussock moth (Dasychira axutha Collenette (Lymantriidae)) and masson pine caterpillar (Dendrolimus punctatus Walker (Lasiocampidae)) cause serious damage to Pinus massoniana and P. merkusii plantations in Vietnam. An integrated pest management (IPM) program is required to control these pests. Therefore, this [...] Read more.

Pine tussock moth (Dasychira axutha Collenette (Lymantriidae)) and masson pine caterpillar (Dendrolimus punctatus Walker (Lasiocampidae)) cause serious damage to Pinus massoniana and P. merkusii plantations in Vietnam. An integrated pest management (IPM) program is required to control these pests. Therefore, this study was undertaken to identify damage thresholds and to evaluate control options for implementing IPM in the Northeast and North Central regions of Vietnam. Three damage thresholds were considered: <25%, 25%–50% and >50% loss of leaf area. Control options were manual collection of eggs and pupae and the use of light traps and biological agents. An initial IPM model was developed for each pest and these gave control efficacies of 82.4% (Da. axutha on P. massoniana) and 77.8% (De. punctatus on P. merkusii). Six extended IPM models were undertaken by forest companies giving pest control efficacies of 79.2%–85.9%. The collection of pine resin provides an important source of income to local communities and the resin yield in the IPM models increased by 20.9%–22.7% compared to untreated control plots. The IPM protocols would help in developing policies that promote a more sustainable management of forest pests in Vietnam, thus reducing dependence on the use of insecticides of environmental and public health concerns. Full article

(This article belongs to the Section Forest Ecology and Management)

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20 pages, 20142 KiB

Open AccessArticle

Availability and Environmental Performance of Wood for a Second-Generation Biorefinery

by Cecilia Rachid-Casnati, Fernando Resquin and Leonidas Carrasco-Letelier

Forests 2021, 12(11), 1609; https://doi.org/10.3390/f12111609 - 22 Nov 2021

Cited by 2 | Viewed by 2014

Abstract

The current global climate change, the 2030 Agenda, and the planetary boundaries have driven new development strategies, such as the circular economy, bioeconomy, and biorefineries. In this framework, this study analyzes the potential availability and sustainability of the wood supply chain for a [...] Read more.

The current global climate change, the 2030 Agenda, and the planetary boundaries have driven new development strategies, such as the circular economy, bioeconomy, and biorefineries. In this framework, this study analyzes the potential availability and sustainability of the wood supply chain for a small-scale biorefinery aiming at producing 280–300 L of bioethanol per ton of dry biomass, consuming 30,000 t of dry biomass per year harvested in a 50 km radius. This wood production goal was assessed from Eucalyptus grandis stands planted for solid wood in northeastern Uruguay. Moreover, to understand the environmental performance of this biomass supply chain, the energy return on investment (EROI), carbon footprint (CF), and potential soil erosion were also assessed. The results showed that the potential wood production would supply an average of 81,800 t of dry mass per year, maintaining the soil erosion below the upper threshold recommended, an EROI of 2.3, and annual CF of 1.22 kg CO

_{2 - e q}

m

^{- 3}

(2.6 g CO

_{2 - e q}

MJ

^{- 1}

). Combined with the environmental performance of the bioethanol biorefinery facility, these results would show acceptable values of sustainability according to EU Directive 2009/28/ec because the bioethanol CF becomes 1.7% of this petrol’s CF. Full article

(This article belongs to the Collection Sustainable Forest Management: Past, Present, Future)

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13 pages, 1018 KiB

Open AccessArticle

Remediation of Pb and Cd Polluted Soils with Fulvic Acid

by Aslihan Esringü, Metin Turan and Asli Cangönül

Forests 2021, 12(11), 1608; https://doi.org/10.3390/f12111608 - 22 Nov 2021

Cited by 7 | Viewed by 1692

Abstract

Heavy metal pollution is among the important environmental problems in the world. Many techniques have already been used to remove the heavy metals such as lead (Pb) and cadmium (Cd). Among them, the phytoremediation method is an environmentally friendly and green technology. This [...] Read more.

Heavy metal pollution is among the important environmental problems in the world. Many techniques have already been used to remove the heavy metals such as lead (Pb) and cadmium (Cd). Among them, the phytoremediation method is an environmentally friendly and green technology. This study was carried out to determine the efficiency of fulvic acid (FA) application in removing Pb and Cd from polluted soil using Tagetes eracta L. and Zinnia elegans Jacq. ornamental plants. The results indicated that, FA application, number of flower per plants, and plant fresh weight of Tagetes eracta plants and Zinnia elegans plants increased 187.5%, 104.5% and 155.5%, 57.7%, respectively with application of 7000 mg L⁻¹ FA at 100 mg kg⁻¹ Pb pollution condition, whereas 42.85%, 16.5%, and 44.4–36.1% with application of 7000 mg L⁻¹ FA at 30 mg kg^±1 Cd pollution condition, respectively. With the FA application in the Zinnia elegans plant, the root part has accumulated 51.53% more Pb than the shoot part. For Cd, the shoot part accumulated 35.33% more Cd than the root. The effect of FA application on superoxide dismutase (SOD), peroxidase (POD) and, catalase (CAT) of the Tagetes eracta were decreased as 32.7%, 33.1%, and 35.1% for Pb, 21.2%, 25.1%, and 26,1%, for Cd, and 15.1%, 22.7%, and 37.7% for Pb, and 7.55%, 18.0%, and 18.8% for Cd were in Zinnia elegans respectively. In conclusion, Tagetes eracta and Zinnia elegans can not be recommended for remediation of Pb and Cd polluted area, but FA can be recommended for Pb and Cd stabilization in polluted soil. Full article

(This article belongs to the Special Issue Modern Techniques of the Technogenic Affected Areas Restoration: Approaches and Solutions)

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9 pages, 2087 KiB

Open AccessCommunication

Timber Properties and Cellulose Crystallites Size in Pine Wood Cut in Different Sawing Patterns after Pretreatment with CH₃COOH and H₂O₂ and Densification

by Andi Detti Yunianti, S Suhasman, A Agussalim, Musrizal Muin and Heru Arisandi

Forests 2021, 12(11), 1607; https://doi.org/10.3390/f12111607 - 22 Nov 2021

Viewed by 1717

Abstract

One process to improve wood quality is densification or wood surface compression. Our study analyzed the changes in some basic properties of pine wood, including its anatomical structure, density, modulus of elasticity (MOE), and dimensions of cellulose crystallites, after densification following soaking pretreatment [...] Read more.

One process to improve wood quality is densification or wood surface compression. Our study analyzed the changes in some basic properties of pine wood, including its anatomical structure, density, modulus of elasticity (MOE), and dimensions of cellulose crystallites, after densification following soaking pretreatment in CH₃COOH and H₂O₂ at a concentration of 20%. Samples were sawn in radial and tangential directions for analysis of the wood. The results showed a change in the shape of tracheid cells from hexagonal to oval, as well as damage to the ray cell constituents on the tangential surface. The thickness decrease of the samples was in accordance with the target, which meant that spring-back was short. In general, the tangential boards had a higher density than the radial boards, with a lower MOE and crystallite dimensions. Our findings showed that the densified tangential board was stronger than the radial board. Full article

(This article belongs to the Special Issue Advanced Technologies in Physical and Mechanical Wood Modification)

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12 pages, 3398 KiB

Open AccessArticle

Radiata Pine Wood Treated with Copper Nanoparticles: Leaching Analysis and Fungal Degradation

by María Graciela Aguayo, Claudia Oviedo, Laura Reyes, José Navarrete, Liset Gómez, Hugo Torres, Gonzalo Gaviño and Ejnar Trollund

Forests 2021, 12(11), 1606; https://doi.org/10.3390/f12111606 - 21 Nov 2021

Cited by 10 | Viewed by 2456

Abstract

Radiata pine is the main wood species used in the Chilean construction industry, but it must be protected due to its low natural durability. Chemical protection of wood by impregnation allows for a more efficient utilization of the forest resources by extending its [...] Read more.

Radiata pine is the main wood species used in the Chilean construction industry, but it must be protected due to its low natural durability. Chemical protection of wood by impregnation allows for a more efficient utilization of the forest resources by extending its useful life. The use of nanoparticles in wood protection has garnered great interest during the last decade, due to their unique physicochemical properties, different from those of larger sized materials. In this research, the impregnation of radiata pine wood with copper nanoparticles (CuNP) was studied in terms of retention, penetration, leaching, and its protective effect against wood rot fungi growth according to EN 113, AWPA A3-91, A9-18, and E11-16. Penetration analysis confirmed a uniform distribution across the wood, with total penetration in the impregnated samples with the highest concentration solution of CuNP. Retention values of the impregnated wood increased proportionally with the concentration of nanoparticles evaluated by EDXRF. Leaching analysis showed copper removal during the first hours of the test, with a constant leaching rate up to 144 h. Impregnated wood mass loss (ML) due to exposure to Gloeophyllum trabeum and Rhodonia placenta fungi were significantly reduced regardless of the CuNP concentration or fungi tested, with an ML smaller than 5% and smaller than 14% for leached samples. Full article

(This article belongs to the Special Issue Evaluation and Protection of Wood and Wood Products)

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Graphical abstract

11 pages, 2205 KiB

Open AccessArticle

Tree Regeneration Patterns on Contrasting Slopes at Treeline Ecotones in Eastern Tibet

by Lili Zheng, Peili Shi, Tiancai Zhou, Ge Hou, Minghua Song and Feihai Yu

Forests 2021, 12(11), 1605; https://doi.org/10.3390/f12111605 - 20 Nov 2021

Cited by 4 | Viewed by 1719

Abstract

Alpine treelines are projected to shift upslope in response to climate warming, but empirical studies have yielded inconsistent results, with both upshifted and stable alpine treelines. Additionally, treelines on different slope aspects of the same mountain can differ. Thus, for a better understanding [...] Read more.

Alpine treelines are projected to shift upslope in response to climate warming, but empirical studies have yielded inconsistent results, with both upshifted and stable alpine treelines. Additionally, treelines on different slope aspects of the same mountain can differ. Thus, for a better understanding of the mechanisms of treeline formation and treeline responses to climate change, we need to elucidate the population dynamics at treelines on different slope aspects. Here, we quantified the population dynamics of Balfour spruce (Picea likiangensis var. rubescens) at treeline ecotones on contrasting north- and east-facing slopes on the eastern Tibetan Plateau based on field surveys. The alpine treeline positions of Balfour spruce have not advanced toward higher altitudes on the contrasting slopes in recent decades. Compared with the east-facing slope, more recruits occurred on the north-facing slope above the present treeline, indicating a more favorable regeneration condition. However, on the north-facing slope, the individual growth rate of Balfour spruce was lower, and the number of adult trees above the present treeline was higher than that on the east-facing slope. Thus, slope aspects mediate a trade-off between the growth and survival of treeline species, explaining the absence of an impact of slope aspects on treeline responses to climate change. Our results highlight the importance of considering the effect of topography on population dynamics in predicting alpine treeline dynamics under the scenario of climate change. Full article

(This article belongs to the Section Forest Ecology and Management)

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21 pages, 4081 KiB

Open AccessArticle

Growth Recovery and Phenological Responses of Juvenile Beech (Fagus sylvatica L.) Exposed to Spring Warming and Late Spring Frost

by Kristine Vander Mijnsbrugge, Jessa May Malanguis, Stefaan Moreels, Amy Lauwers, Arno Thomaes, Luc De Keersmaeker and Kris Vandekerkhove

Forests 2021, 12(11), 1604; https://doi.org/10.3390/f12111604 - 20 Nov 2021

Cited by 5 | Viewed by 1871

Abstract

Global change increases the risk of extreme climatic events. The impact of extreme temperature may depend on the tree species and also on the provenance. Ten provenances of Fagus sylvatica L. were grown in a common garden environment in Belgium and subjected to [...] Read more.

Global change increases the risk of extreme climatic events. The impact of extreme temperature may depend on the tree species and also on the provenance. Ten provenances of Fagus sylvatica L. were grown in a common garden environment in Belgium and subjected to different temperature treatments. Half of the one year old seedlings were submitted to a high thermal stress in the spring of the first year, and all plants were exposed to a late spring frost in the second year. The high-temperature treated plants displayed reduced growth in the first year, which was fully compensated (recovery with exact compensation) in the second year for radial growth and in the third year for height growth. Frost in the spring of the second year damaged part of the saplings and reduced their growth. The frost damaged plants regained the pre-stress growth rate one year later (recovery without compensation). The high temperature treatment in the first year and the frost damage in the second year clearly influenced the phenological responses in the year of the event and in the succeeding year. Little population differentiation was observed among the provenances for growth and for phenological responses. Yet, a southern provenance, a non-autochthonous provenance (original German provenance that was planted in Belgium about a century ago) and a more continental provenance flushed earlier than the local Atlantic provenances in the year of the frost event, resulting in more frost damage. Some caution should therefore be taken when translocating provenances as an anticipation of the predicted climate warming. Full article

(This article belongs to the Special Issue Vulnerability of Forests to Climate Variability and Change)

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13 pages, 2694 KiB

Open AccessArticle

Growth and Nitrogen Retranslocation of Nutrient-Loaded Clonal Betulaalnoides Transplanted with or without Fertilization

by Lin Chen, Yue Ma, Hua Li, Ji Zeng, Bernard Dell and Zhaoying Li

Forests 2021, 12(11), 1603; https://doi.org/10.3390/f12111603 - 20 Nov 2021

Viewed by 1223

Abstract

Nutrient loading can improve the growth and nutrient content of nursery-grown Betula alnoides Buch.-Ham. ex D. Don, but it is unknown whether nutrient loading enhances growth and nutrient uptake after transplanting. Plants were grown with three nutrient loading treatments (N100, N200, and N400; [...] Read more.

Nutrient loading can improve the growth and nutrient content of nursery-grown Betula alnoides Buch.-Ham. ex D. Don, but it is unknown whether nutrient loading enhances growth and nutrient uptake after transplanting. Plants were grown with three nutrient loading treatments (N100, N200, and N400; 100, 200, and 400 mg N per plant as ¹⁵N-urea) in nursery containers and then transplanted into plastic pots, with or without controlled-release fertilizer (F0 and F10, 0 and 10 g per plant). The N400 plants had a smaller size but higher nitrogen concentration relative to the N100 and N200 plants before transplanting. However, 180 days after transplanting, the N200 and N400 plants had superior root collar diameter, root length, and root area compared to the N100 plants, due to an increase in ¹⁵N retranslocation to new stems and new leaves. Moreover, transplant fertilization (F10) enhanced the height, root collar diameter, root length, and plant dry mass, but not nitrogen concentration or retranslocation, relative to F0. We recommend that medium- and high-dose nutrient loading is implemented in B. alnoides nurseries to optimize growth after transplanting. Additional fertilizer at transplanting may be advantageous in supporting growth, owing to the rapid depletion of nutrient reserves after planting out in the field. Full article

(This article belongs to the Section Forest Ecology and Management)

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13 pages, 2283 KiB

Open AccessArticle

The Radial Growth of Picea wilsonii Was More Restricted by Precipitation Due to Climate Warming on Mt. Guandi, China

by Xiaoxia Huang, Xiaoneng Sun, Yuan Jiang, Feng Xue, Minghao Cui, Shoudong Zhao and Muyi Kang

Forests 2021, 12(11), 1602; https://doi.org/10.3390/f12111602 - 20 Nov 2021

Cited by 2 | Viewed by 1589

Abstract

Transitional climate zones (TCZ) are characterized by instability due to rapid changes in climate and biological variables, and trees growing there are particularly sensitive to climate change. Therefore, knowledge about the shifted relationships of tree growth in response to climate warming will shape [...] Read more.

Transitional climate zones (TCZ) are characterized by instability due to rapid changes in climate and biological variables, and trees growing there are particularly sensitive to climate change. Therefore, knowledge about the shifted relationships of tree growth in response to climate warming will shape regional forest conservation and management strategies. China has experienced rapid warming in recent decades. However, how tree growth in semihumid to semiarid regions, such as the Guandi Mountains, responds to more sophisticated changes in the hydrothermal combination is not yet clear. In this study, we used tree-ring width data from three sites along an elevational gradient in the Guandi Mountains to present the response of Picea wilsonii Mast. radial growth to increasing temperature and elevational differences in the relationship between tree growth and climate. The results indicated that the Guandi Mountains have experienced rapid warming with a clear trend toward aridity. From 1959 to 1995, the radial growth of P. wilsonii was mainly influenced by temperature, while it was controlled by both temperature and precipitation after rapid warming in 1996. From 1959 to 2017, this species showed a generally consistent growth–climate relationship at different elevations in the Guandi Mountains. However, the radial growth of trees at higher elevations had a higher climatic correlation than at lower elevations, and it was more conditioned by higher summer temperatures and precipitation in December of the previous year. These results suggested that P. wilsonii was more susceptible to drought and high temperatures due to a warming climate and that more attention should be devoted to forest management, especially the adverse consequences of summer drought on P. wilsonii. Full article

(This article belongs to the Special Issue Response of Forests to Climate Change: Tree-Ring Analysis and Wood Anatomy)

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14 pages, 4317 KiB

Open AccessArticle

Single-Track Bike Trails in the Moravian Karst as Part of Forest Recreation

by Petr Hrůza, Petr Pelikán and Lucie Olišarová

Forests 2021, 12(11), 1601; https://doi.org/10.3390/f12111601 - 19 Nov 2021

Cited by 5 | Viewed by 1893

Abstract

Recently, cycling has become a popular recreation activity, and mountain biking provides an experience that is sought by an increasing number of people. Bike trails constructed for mountain bikers in access areas lead mostly through the forest and provide not only an extraordinary [...] Read more.

Recently, cycling has become a popular recreation activity, and mountain biking provides an experience that is sought by an increasing number of people. Bike trails constructed for mountain bikers in access areas lead mostly through the forest and provide not only an extraordinary riding experience but the opportunity to admire the surrounding nature. The reason for constructing such trails from a landowner’s point of view is to help keep bikers’ movements within a defined access area and to ensure adjacent areas are left free for other forest functions. It also helps distribute groups of visitors with other interests to other parts of the forest. This is what we call “controlled recreation”. In this example, it means that if cyclists come to the locality to use the bike trails, they should ride only along the designated trails; however, they may leave these trails and ride on the surrounding land. This article studied the movements of bikers in an accessible area of the Moravian Karst and the regulation of their movements by controlled recreation. Attendance in the area was measured using automatic counters. These were placed at the entry points to the accessible area and just behind the routes where the trails branch off. The results showed that bikers mostly stayed on the formal routes and that the trails were effective, i.e., there was no uncontrolled movement of bikers into the surrounding forest stands. We also noted the time of day that cyclists were active. These results can be used to better plan work in the forest, for example, harvesting and logging. To further the suitable development of accessible areas of the forest, we also compared the usual size of trail areas in two other European countries and the increasing width of bike trails due to the transverse slope of the terrain. Full article

(This article belongs to the Special Issue Forest Recreation and Landscape Protection)

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13 pages, 23374 KiB

Open AccessArticle

Evolution of Human Salivary Stress Markers during an Eight-Hour Exposure to a Mediterranean Holm Oak Forest. A Pilot Study

by Albert Bach, Jose Joaquin Ceron, Roser Maneja, Joan Llusià, Josep Penuelas and Damián Escribano

Forests 2021, 12(11), 1600; https://doi.org/10.3390/f12111600 - 19 Nov 2021

Cited by 5 | Viewed by 2270

Abstract

The current study analyses the evolution of different human stress markers during an 8 h exposure to a Mediterranean Holm oak forest. We conducted a pre-post study with thirty-one subjects in which saliva samples were collected before the exposure (baseline) and after 1, [...] Read more.

The current study analyses the evolution of different human stress markers during an 8 h exposure to a Mediterranean Holm oak forest. We conducted a pre-post study with thirty-one subjects in which saliva samples were collected before the exposure (baseline) and after 1, 2, 4 and 8 h. Our results show: (A) a significant decrease in cortisol saliva concentrations from the second hour until the end compared to basal time; (B) a significant increase in alpha amylase activity after the first hour of exposure compared to basal time that remained elevated during the rest of the study; (C) a significant decrease in IgA from the fourth hour of exposure compared to the basal time. These findings indicate an effect of forest exposure in salivary biomarkers of stress and provide relevant data for the scientific and healthcare community encouraging further research in the field. Full article

(This article belongs to the Special Issue The Dynamic Interaction between People and Forest Ecosystems)

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22 pages, 4624 KiB

Open AccessArticle

Dead or Alive: Drivers of Wind Mortality Initiate Multiple Disturbance Regime in a Temperate Primeval Mountain Forest

by Ivana Vašíčková, Pavel Šamonil, Jakub Kašpar, Andrea Román-Sánchez, Tomáš Chuman and Dušan Adam

Forests 2021, 12(11), 1599; https://doi.org/10.3390/f12111599 - 19 Nov 2021

Cited by 1 | Viewed by 1725

Abstract

The driving forces of tree mortality following wind disturbances of mountain mixed European temperate forests belongs among issues not comprehensively resolved. Hence, we aimed to elucidate the key factors of tree resistance to historical severe disturbance events in the Boubínský Primeval Forest, one [...] Read more.

The driving forces of tree mortality following wind disturbances of mountain mixed European temperate forests belongs among issues not comprehensively resolved. Hence, we aimed to elucidate the key factors of tree resistance to historical severe disturbance events in the Boubínský Primeval Forest, one of the oldest forest reserves in the Czech Republic. By using spatially explicit tree census, dendrochronological and soil data, we study spatial and temporal patterns of past disturbances and mathematically compared selected characteristics of neighboring trees that were killed by a severe storm in 2017 and those that remained undisturbed. The tendency of trees toward falling was primarily driven edaphically, limiting severe events non-randomly to previously disturbed sites occupied by hydromorphic soils and promoting the existence of two spatially-separated disturbance regimes. While disturbed trees usually recruited in gaps and experienced only one severe release event, surviving trees characteristically regenerated under the canopy and were repeatedly released. Despite the fact that disturbed trees tended to reach both lower ages and dimensions than survivors, they experienced significantly higher growth rates. Our study indicates that slow growth with several suppression periods emerged as the most effective tree strategy for withstanding severe windstorms, dying of senescence in overaged life stage. Despite the selective impact of the Herwart storm on conifer population, we did not find any difference in species sensitivity for most characteristics studied. We conclude that the presence of such ancient, high-density wood trees contributes significantly to the resistance of an entire stand to severe storms. Full article

(This article belongs to the Section Forest Ecology and Management)

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19 pages, 7673 KiB

Open AccessArticle

Morpho-Histology, Endogenous Hormone Dynamics, and Transcriptome Profiling in Dacrydium Pectinatum during Male Cone Development

by Wenju Lu, Enbo Wang, Weijuan Zhou, Yifan Li, Zhaoji Li, Xiqiang Song, Jian Wang, Mingxun Ren, Donghua Yang, Shaojie Huo, Ying Zhao and Haiying Liang

Forests 2021, 12(11), 1598; https://doi.org/10.3390/f12111598 - 19 Nov 2021

Cited by 2 | Viewed by 1960

Abstract

Dacrydium pectinatum de Laubenfels is a perennial gymnosperm species dominant in tropical montane rain forests. Due to severe damages by excessive deforestation, typhoons, and other external forces, the population of the species has been significantly reduced. Furthermore, its natural regeneration is poor. To [...] Read more.

Dacrydium pectinatum de Laubenfels is a perennial gymnosperm species dominant in tropical montane rain forests. Due to severe damages by excessive deforestation, typhoons, and other external forces, the population of the species has been significantly reduced. Furthermore, its natural regeneration is poor. To better understand the male cone development in D. pectinatum, we examined the morphological and anatomical changes, analyzed the endogenous hormone dynamics, and profiled gene expression. The morpho-histological observations suggest that the development of D. pectinatum male cone can be largely divided into four stages: microspore primordium formation (April to May), microspore sac and pollen mother cell formation (July to November), pollen mother cell division (January), and pollen grain formation (February). The levels of gibberellins (GA), auxin (IAA), abscisic Acid (ABA), cytokinin (CTK), and jasmonic acid (JA) fluctuated during the process of male cone development. The first transcriptome database for a Dacrydium species was generated, revealing >70,000 unigene sequences. Differential expression analyses revealed several floral and hormone biosynthesis and signal transduction genes that could be critical for male cone development. Our study provides new insights on the cone development in D. pectinatum and the foundation for male cone induction with hormones and studies of factors contributing to the species’ low rate of seed germination. Full article

(This article belongs to the Special Issue Emerging Principles of Tree Biology in the Omics Era)

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12 pages, 3255 KiB

Open AccessArticle

Particleboards from Recycled Pallets

by Ján Iždinský, Ladislav Reinprecht and Zuzana Vidholdová

Forests 2021, 12(11), 1597; https://doi.org/10.3390/f12111597 - 19 Nov 2021

Cited by 11 | Viewed by 2129

Abstract

Worldwide production of wooden pallets continually increases, and therefore in future higher number of damaged pallets need to be recycled. One way to conveniently recycle pallets is their use for the production of particleboards (PBs). The 3-layer PBs, bonded with urea-formaldehyde (UF) resin, [...] Read more.

Worldwide production of wooden pallets continually increases, and therefore in future higher number of damaged pallets need to be recycled. One way to conveniently recycle pallets is their use for the production of particleboards (PBs). The 3-layer PBs, bonded with urea-formaldehyde (UF) resin, were prepared in laboratory conditions using particles from fresh spruce logs (FSL) and recycled spruce pallets (RSP) in mutual weight ratios of 100:0, 80:20, 50:50 and 0:100. Particles from RSP did not affect the moisture properties of PBs, i.e., the thickness swelling (TS) and water absorption (WA). The mechanical properties of PBs based on particles from RSP significantly worsened: the modulus of rupture (MOR) in bending from 14.6 MPa up to 10 MPa, the modulus of elasticity (MOE) in bending from 2616 MPa up to 2012 MPa, and the internal bond (IB) from 0.79 MPa up to 0.61 MPa. Particles from RSP had only a slight negative effect on the decay resistance of PBs to the brown-rot fungus Serpula lacrymans, while their presence in surfaces of PBs did not affect the growth activity of moulds at all. Full article

(This article belongs to the Special Issue Composites from Recycled and Modified Woods – Technology, Properties, Application)

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12 pages, 2555 KiB

Open AccessArticle

Closed-Canopy Tropical Forests of Hainan, (China) Are Resilient against Invasive Herbs and Shrubs

by Xiaobo Yang, Long Li, Xiaobo Lv, Wenqi Luo, Donghai Li, Caiqun Liang, Alison K. S. Wee and Wenxing Long

Forests 2021, 12(11), 1596; https://doi.org/10.3390/f12111596 - 19 Nov 2021

Cited by 1 | Viewed by 1441

Abstract

The successful establishment of many plants in tropical forests often depends on species-specific adaptations related to light availability and forest successional stage. Species that are present in early successional stages generally do not occur in later successional stages. In this study, we documented [...] Read more.

The successful establishment of many plants in tropical forests often depends on species-specific adaptations related to light availability and forest successional stage. Species that are present in early successional stages generally do not occur in later successional stages. In this study, we documented the diversity, distribution, and abundance of terrestrial invasive plants across the (sub)tropical island of Hainan, China, and tested the germination of specific invasive plants in forested environments. In 97 transects positioned randomly across the island, we found nine invasive herb and shrub species were present in all human-modified habitats but not in intact forest interiors. In separate forest-specific transects, we documented a sharp drop in the abundance of invasive plants >5 m into the forest. High numbers of invasive plant seeds germinated from the soil seed bank sampled at the forest edge, but very few seeds germinated from soil sampled any distance into the forest. Finally, in experiments with four focal invasive plant species, overall germination rates were low; and much lower in shaded sites compared to full gap sites. In conclusion, our findings demonstrated that invasive herbs and shrubs do not yet form a serious threat to native species in the closed-canopy forests of Hainan. Full article

(This article belongs to the Section Forest Ecology and Management)

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13 pages, 2831 KiB

Open AccessArticle

Early Growth Responses of Larix kaempferi (Lamb.) Carr. Seedling to Short-Term Extreme Climate Events in Summer

by Nam-Jin Noh, Gwang-Jung Kim, Yowhan Son and Min-Seok Cho

Forests 2021, 12(11), 1595; https://doi.org/10.3390/f12111595 - 19 Nov 2021

Cited by 2 | Viewed by 1824

Abstract

Extreme climate events such as heat waves, drought, and heavy rainfall are occurring more frequently and are more intense due to ongoing climate change. This study evaluated the early growth performance of one-year-old Larix kaempferi (Lamb.) Carr. seedlings under open-field extreme climate conditions [...] Read more.

Extreme climate events such as heat waves, drought, and heavy rainfall are occurring more frequently and are more intense due to ongoing climate change. This study evaluated the early growth performance of one-year-old Larix kaempferi (Lamb.) Carr. seedlings under open-field extreme climate conditions including experimental warming and different precipitation regimes. We recorded the survival rate, root collar diameter, height, biomass, shoot-to-root ratio, and seedling quality index using nine treatments (three temperature levels, i.e., control, warming by 3 °C and by 6 °C, × three precipitation levels, i.e., control, drought, and heavy rainfall) in July and August 2020. The survival rate of seedlings did not differ between treatments, showing high values exceeding 94% across treatments. The measured shoot height was largest under warming by 3 °C and high rainfall, indicating that moderate warming increased seedling height growth in a moist environment. Heavy rainfall decreased stem volume by 21% and 25% under control and warming by 6 °C treatments, respectively. However, drought manipulation using rain-out shelters did not decrease the growth performance. Overall, extreme climate events did not affect the survival rate, biomass, shoot-to-root ratio, and seedling quality index of L. kaempferi. We thus conclude that, regarding growth responses, L. kaempferi seedlings may be resistant to short-term extreme warming and drought events during summer. Full article

(This article belongs to the Special Issue Impact of Extreme Weather Events on Forest Functions)

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12 pages, 3184 KiB

Open AccessArticle

Chemical Characterization of Waterlogged Charred Wood: The Case of a Medieval Shipwreck

by Eirini Mitsi, Stamatis Boyatzis and Anastasia Pournou

Forests 2021, 12(11), 1594; https://doi.org/10.3390/f12111594 - 19 Nov 2021

Cited by 1 | Viewed by 1721

Abstract

In 2008, a medieval wooden shipwreck was discovered at the port of Rhodes, Greece. The shipwreck was party burned, presenting a challenge for conservators, as uncharred, semi-charred and charred waterlogged wood were often encountered on the same piece of timber. In seeking the [...] Read more.

In 2008, a medieval wooden shipwreck was discovered at the port of Rhodes, Greece. The shipwreck was party burned, presenting a challenge for conservators, as uncharred, semi-charred and charred waterlogged wood were often encountered on the same piece of timber. In seeking the most appropriate conservation method for this unusual material, its chemical characterization was considered necessary. This study examined the chemistry of the three dominant wood conditions found in the wreck. Fourier transform infrared spectroscopy and X-ray diffraction analysis were implemented in comparison to reference samples. Energy dispersive analysis was also used for assessing the inorganic composition of each condition. Moreover, for charred and semi-charred wood, proximate analysis was undertaken. Results obtained regarding the organic moieties of the waterlogged archaeological material, demonstrated that charred samples were chemically comparable to charcoals, semi-charred material showed similarity to thermally modified wood, whereas uncharred waterlogged wood was proven to have an analogous chemistry to biodeteriorated wood. Elemental analysis results also diversified among the three shipwreck’s conditions. Sulfur, iron, and oxygen decreased in charred areas, whereas carbon increased. Proximate analysis showed that ash and fixed carbon content increased with charring, whereas volatile mater decreased. This work proved major chemical differences among shipwreck timbers’ conditions owing to different degree of charring. These are anticipated to influence not only conservation methods’ efficacy, but also the post-treatment behavior of the material. Further investigation is needed for correlating the chemistry of the archaeological material to its physical properties in order to contribute to practical aspects of conservation. Full article

(This article belongs to the Special Issue Historical Wood: Structure, Properties and Conservation)

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13 pages, 1652 KiB

Open AccessArticle

Effects of Temperature, Scarification, Stratification, Phytohormones, and After-Ripening on the Dormancy and Germination of Eucommia ulmoides Oliv. Seeds

by Shiming Deng, Zhijun Deng, Xiaofeng Wang, Hai Lu and Hua Xue

Forests 2021, 12(11), 1593; https://doi.org/10.3390/f12111593 - 19 Nov 2021

Cited by 3 | Viewed by 1849

Abstract

Eucommia ulmoides Oliv., the only member of the family Eucommiaceae, is endemic to China and has great development and utilization prospects. The seeds of E. ulmoides show dormancy but the underlying mechanism remains unknown. The aim of this study was to determine [...] Read more.

Eucommia ulmoides Oliv., the only member of the family Eucommiaceae, is endemic to China and has great development and utilization prospects. The seeds of E. ulmoides show dormancy but the underlying mechanism remains unknown. The aim of this study was to determine the cause of the seed dormancy and provide fundamental knowledge for the breeding, genetic improvement, and conservation of the germplasm resources of this species. According to the seed dormancy classification system developed by Jerry M. Baskin and Carol C. Baskin, we compared the germination percentage between intact seeds and isolated embryos, constructed water absorption curves, and evaluated the germination of seeds treated with scarification, cold/warm-moist stratification, after-ripening during dry storage, and gibberellic acid (GA₃). The results showed that the intact seeds germinated only at 10 °C with a low germination percentage of 13.3% whereas the isolated embryos had a high normal germination percentage among a wider range of temperatures. According to the results from the scarified seeds, half seeds, and intact seeds, the seed coat significantly restricted the embryo water absorption. The scarification, after-ripening, cold/warm-moist stratification, and GA₃ treatments promoted seed germination. Among them, cold-moist stratification was the most effective method and the temperature range of seed germination increased in both directions from 10 °C with prolonged stratification. The germination percentage increased significantly at constant temperatures with the highest germination percentage of 93.7 ± 0.3% at 10 °C and a light/dark cycle after 90 days of cold-moist stratification. Therefore, the freshly harvested E. ulmoides seeds exhibited a combinational dormancy comprising physical and Type 3 non-deep physiological dormancy, causing limited embryo water absorption by the seed coat and a low embryo growth potential. Given the unique phylogenetic characteristics and utility of E. ulmoides, our findings should promote studies of seed dormancy evolution and the development and application of E. ulmoides germplasm resources. Full article

(This article belongs to the Section Forest Ecophysiology and Biology)

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12 pages, 3513 KiB

Open AccessArticle

Plant Regeneration and In Vitro Growth Performance of Male-Sterile Somatic Plantlets of Sugi (Japanese Cedar, Cryptomeria japonica) Derived from Different Embryogenic Cell Lines

by Momi Tsuruta, Tsuyoshi E. Maruyama, Saneyoshi Ueno, Takumi Kaneeda and Yoshinari Moriguchi

Forests 2021, 12(11), 1592; https://doi.org/10.3390/f12111592 - 18 Nov 2021

Cited by 1 | Viewed by 1818

Abstract

With the spread of pollinosis caused by sugi (Japanese cedar, Cryptomeria japonica) pollen, the use of pollen-free somatic seedlings of sugi is expected in Japan. However, there is a lack of knowledge on the relationship between the abilities during somatic embryogenesis, initial [...] Read more.

With the spread of pollinosis caused by sugi (Japanese cedar, Cryptomeria japonica) pollen, the use of pollen-free somatic seedlings of sugi is expected in Japan. However, there is a lack of knowledge on the relationship between the abilities during somatic embryogenesis, initial in vitro growth traits, and subsequent growth of somatic seedlings. In the present study, we provide the first basic information on somatic embryo maturation efficiency, somatic embryo germination, and plantlet conversion frequencies, as well as on in vitro growth performance of pollen-free somatic plantlets derived from different embryogenic cell lines (ECLs). Somatic embryo maturation efficiency varied from 34 to 514 cotyledonary embryos per plate and the average for the 19 ECLs tested was 244 embryos per plate. Subsequently, the overall average rates of somatic embryo germination and conversion among ECLs were 87.8% and 85.3%, respectively. The results of in vitro growth performance of pollen-free somatic plantlets showed significant differences in growth rate among ECLs. Full article

(This article belongs to the Special Issue Application of Biotechnology Techniques on Tree Species)

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17 pages, 6096 KiB

Open AccessArticle

Chemical Components of Fungus Comb from Indo-Malayan Termite Macrotermes gilvus Hagen Mound and Its Bioactivity against Wood-Staining Fungi

by Dodi Nandika, Lina Karlinasari, Arinana Arinana, Irmanida Batubara, Putri Sari Sitanggang, Djoko Santoso, Lucia Dhiantika Witasari, Yanti Rachmayanti, Dikhi Firmansyah, I Ketut Sudiana and Desca Medika Hertanto

Forests 2021, 12(11), 1591; https://doi.org/10.3390/f12111591 - 18 Nov 2021

Cited by 8 | Viewed by 2697

Abstract

Recently, the architectural and physical properties of the fungus comb from subterranean termite Macrotermes gilvus Hagen (Isoptera: Termitidae) mounds had been studied and it is important to determine its chemical profile as well as to evaluate its anti-staining-fungi activity. The results showed that [...] Read more.

Recently, the architectural and physical properties of the fungus comb from subterranean termite Macrotermes gilvus Hagen (Isoptera: Termitidae) mounds had been studied and it is important to determine its chemical profile as well as to evaluate its anti-staining-fungi activity. The results showed that fungus comb of M. gilvus has a high crude ash (30.57%), fiber (25.46%), starch (7.76%), protein (5.80%, 5.53% amino acid), acid-insoluble ash (3.45%), and fat (0.73%). It also contained phenol hydroquinone, steroids, terpenoids, and saponin compounds. Seventeen amino acids were identified via high-performance liquid chromatography analysis, of which arginine, leucine, glutamate, and aspartic acid were the majority. According to gas chromatography-mass spectrometry analysis, the n-hexane extract consists of several types of fatty acid derivatives. Meanwhile, the ethyl acetate (EtOAc) extracts were primarily phenol groups with 1,2,3-propanetriol (glycerol) at the highest relative concentration. Four fungus-comb extracts (n-hexane, EtOAc, MeOH, and water) inhibited the Aspergillus foetidus fungus, with inhibition rates ranging from 24.17% to 100% and EtOAc extract as the most active extract. It appears that EtOAc extracts from the M. gilvus fungus comb can be considered an active ingredient source of novel organic fungicide in preventing wood-staining fungi attacks on susceptible wood. Full article

(This article belongs to the Special Issue Evaluation and Protection of Wood and Wood Products)

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18 pages, 3477 KiB

Open AccessArticle

Exploring the Effects of Thinning on Cunninghamia lanceolata Lamb. Carbon Allocation in Southwestern China Using a Process-Based Model

by Hao Yang, Ziyan Liao, Angang Ming and Ning Miao

Forests 2021, 12(11), 1590; https://doi.org/10.3390/f12111590 - 18 Nov 2021

Viewed by 1607

Abstract

We investigated the effects of thinning intensity on the carbon allocation of Cunninghamia lanceolata Lamb. Hook by analyzing the stand growth and carbon content of a plantation under three thinning intensities (I: 70%; II: 50%; III: 30%) and with no thinning treatment. Using [...] Read more.

We investigated the effects of thinning intensity on the carbon allocation of Cunninghamia lanceolata Lamb. Hook by analyzing the stand growth and carbon content of a plantation under three thinning intensities (I: 70%; II: 50%; III: 30%) and with no thinning treatment. Using the carbon balance framework of the CROwn BASe (CROBAS) model and multi-source inventory data, we calibrated the parameters of the CROBAS-C. lanceolata (CROBAS-CL) model to simulate the carbon content in the plantation. We validated the CROBAS-CL model by comparing the predicted stand diameter at breast height (DBH) and stand height (H) with the measured values. Finally, the predicted stand carbon was compared with the soil carbon to assess the dynamics and allocation of ecosystem carbon content. Overall, our findings suggest that the predicted stand carbon of CROBAS-CL satisfies the statistical test requirements: the deviation of height and DBH predicted by the CROBAS-CL model from the measured height and DBH are less than 0.087 m and 0.165 cm, respectively. These results confirm that the model is useful for a dynamic prediction of stand carbon in C. lanceolata plantations. Based on the results of the proposed model, we determine that Thinning III (30% thinning intensity) is beneficial for the growth of C. lanceolata plantations and improving soil carbon sequestration. Additionally, the simulated carbon storage of an individual tree in the C. lanceolata plantation gradually increased with the tree age. Our study provides a strong reference for the efficient operation and management of C. lanceolata plantations in southwestern China. Full article

(This article belongs to the Special Issue Carbon Stock and Sequestration in Forest Ecosystems)

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17 pages, 1961 KiB

Open AccessEditor’s ChoiceArticle

Effects of Early, Small-Scale Nitrogen Addition on Germination and Early Growth of Scots Pine (Pinus sylvestris) Seedlings and on the Recruitment of the Root-Associated Fungal Community

by David Castro, Andreas N. Schneider, Mattias Holmlund, Torgny Näsholm, Nathaniel R. Street and Vaughan Hurry

Forests 2021, 12(11), 1589; https://doi.org/10.3390/f12111589 - 18 Nov 2021

Cited by 3 | Viewed by 2630

Abstract

Scots pine (Pinus sylvestris L.) is one of the most economically important species to the Swedish forest industry, and cost-efficient planting methods are needed to ensure successful reestablishment after harvesting forest stands. While the majority of clear-cuts are replanted with pre-grown seedlings, [...] Read more.

Scots pine (Pinus sylvestris L.) is one of the most economically important species to the Swedish forest industry, and cost-efficient planting methods are needed to ensure successful reestablishment after harvesting forest stands. While the majority of clear-cuts are replanted with pre-grown seedlings, direct seeding can be a viable option on poorer sites. Organic fertilizer has been shown to improve planted seedling establishment, but the effect on direct seeding is less well known. Therefore, at a scarified (disc trencher harrowed) clear-cut site in northern Sweden, we evaluated the effect of early, small-scale nitrogen addition on establishment and early recruitment of fungi from the disturbed soil community by site-planted Scots pine seeds. Individual seeds were planted using a moisture retaining germination matrix containing 10 mg nitrogen in the form of either arginine phosphate or ammonium nitrate. After one growing season, we collected seedlings and assessed the fungal community of seedling roots and the surrounding soil. Our results demonstrate that early, small-scale N addition increases seedling survival and needle carbon content, that there is rapid recruitment of ectomycorrhizal fungi to the roots and rhizosphere of the young seedlings and that this rapid recruitment was modified but not prevented by N addition. Full article

(This article belongs to the Special Issue Tree Host – Microbial Interactions)

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12 pages, 2487 KiB

Open AccessArticle

Anthropogenic Disturbances Shape Soil Capillary and Saturated Water Retention Indirectly via Plant Functional Traits and Soil Organic Carbon in Temperate Forests

by Shufang Liu, Zuoqiang Yuan, Arshad Ali, Anvar Sanaei, Zikun Mao, Fan Ding, Di Zheng, Shuai Fang, Zhaojie Jia, Zhao Tao, Fei Lin, Ji Ye, Xugao Wang and Zhanqing Hao

Forests 2021, 12(11), 1588; https://doi.org/10.3390/f12111588 - 18 Nov 2021

Cited by 3 | Viewed by 1872

Abstract

Soil’s water-physical properties support essential soil water retention functions for driving water distribution and availability, which is vital for plant growth and biogeochemical cycling. However, the question concerning how tree compositions and their interactions with other abiotic factors modulate soil’s water-physical properties in [...] Read more.

Soil’s water-physical properties support essential soil water retention functions for driving water distribution and availability, which is vital for plant growth and biogeochemical cycling. However, the question concerning how tree compositions and their interactions with other abiotic factors modulate soil’s water-physical properties in disturbed forests remains poorly understood. Based on observational data from nine permanent forest sites (18,747 trees and 210 plots) in the northeast of China, where forests once undergone three different levels of anthropogenic logging disturbance, we evaluated how multiple biotic (i.e., tree diversity and functional trait composition) and abiotic (soil texture and soil organic carbon) factors influence water-physical properties (i.e., in terms of soil capillary water retention (WC) and soil saturated water retention (WS)) in temperate forests. We found that the impacts of logging disturbance on soil water-physical properties were associated with improved tree diversity, acquisitive functional traits, and SOC. These associated attributes were also positively related to WC and WS, while there was no significant effect from soil texture. Moreover, disturbance indirectly affected soil water-physical properties mainly by functional traits and SOC, as acquisitive functional traits significantly mediate the effect from disturbance on WC and SOC mediates the influence from disturbance on WS. Finally, our results emphasize the potential relationships of tree composition with SOC and soil water retention as compared with soil texture and hence suggest that plants can actively modulate their abiotic contexts after disturbance, which is meaningful for understanding forest health and resistance. Full article

(This article belongs to the Special Issue Plant-Soil Interactions under Abiotic or Biotic Stresses)

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15 pages, 6517 KiB

Open AccessArticle

Land Cover and Land Use Change Decreases Net Ecosystem Production in Tropical Peatlands of West Kalimantan, Indonesia

by Imam Basuki, J. Boone Kauffman, James T. Peterson, Gusti Z. Anshari and Daniel Murdiyarso

Forests 2021, 12(11), 1587; https://doi.org/10.3390/f12111587 - 18 Nov 2021

Cited by 5 | Viewed by 2413

Abstract

Deforested and converted tropical peat swamp forests are susceptible to fires and are a major source of greenhouse gas (GHG) emissions. However, information on the influence of land-use change (LUC) on the carbon dynamics in these disturbed peat forests is limited. This study [...] Read more.

Deforested and converted tropical peat swamp forests are susceptible to fires and are a major source of greenhouse gas (GHG) emissions. However, information on the influence of land-use change (LUC) on the carbon dynamics in these disturbed peat forests is limited. This study aimed to quantify soil respiration (heterotrophic and autotrophic), net primary production (NPP), and net ecosystem production (NEP) in peat swamp forests, partially logged forests, early seral grasslands (deforested peat), and smallholder-oil palm estates (converted peat). Peat swamp forests (PSF) showed similar soil respiration with logged forests (LPSF) and oil palm (OP) estates (37.7 Mg CO₂ ha⁻¹ yr⁻¹, 40.7 Mg CO₂ ha⁻¹ yr⁻¹, and 38.7 Mg CO₂ ha⁻¹ yr⁻¹, respectively), but higher than early seral (ES) grassland sites (30.7 Mg CO₂ ha⁻¹ yr⁻¹). NPP of intact peat forests (13.2 Mg C ha⁻¹ yr⁻¹) was significantly greater than LPSF (11.1 Mg C ha⁻¹ yr⁻¹), ES (10.8 Mg C ha⁻¹ yr⁻¹), and OP (3.7 Mg C ha⁻¹ yr⁻¹). Peat swamp forests and seral grasslands were net carbon sinks (10.8 Mg CO₂ ha⁻¹ yr⁻¹ and 9.1 CO₂ ha⁻¹ yr⁻¹, respectively). In contrast, logged forests and oil palm estates were net carbon sources; they had negative mean Net Ecosystem Production (NEP) values (−0.1 Mg CO₂ ha⁻¹ yr⁻¹ and −25.1 Mg CO₂ ha⁻¹ yr⁻¹, respectively). The shift from carbon sinks to sources associated with land-use change was principally due to a decreased Net Primary Production (NPP) rather than increased soil respiration. Conservation of the remaining peat swamp forests and rehabilitation of deforested peatlands are crucial in GHG emission reduction programs. Full article

(This article belongs to the Special Issue Forest-Atmosphere Interactions)

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22 pages, 4950 KiB

Open AccessArticle

Influence of Edaphic Salinity on Leaf Morphoanatomical Functional Traits on Juvenile and Adult Trees of Red Mangrove (Rhizophora mangle): Implications with Relation to Climate Change

by Alejandra Robles Sánchez, José Ernesto Mancera Pineda, Xavier Marquínez Casas and Jairo Humberto Medina Calderón

Forests 2021, 12(11), 1586; https://doi.org/10.3390/f12111586 - 18 Nov 2021

Cited by 8 | Viewed by 2238

Abstract

Rhizophora mangle L. is one of the most distributed species of neotropical mangroves. The species exhibits great phenological variability that is associated with saline concentrations of the sediment where it grows. Among the organs that are most affected by interstitial and tidal water [...] Read more.

Rhizophora mangle L. is one of the most distributed species of neotropical mangroves. The species exhibits great phenological variability that is associated with saline concentrations of the sediment where it grows. Among the organs that are most affected by interstitial and tidal water salinity concentrations are the leaves. Since the hypersalinity generates water deficiency, it changes photosynthetic and hydraulic processes of the plant. To understand the relationship between the variation in leaf blade parameters and the water stress generated by salinity in two growth stages, morphoanatomical functional traits were quantified in leaves of juveniles and adults of R. mangle in three structurally different mangrove forests with different ranges of natural salinity (Oligohaline: 5.8–11.7 practical salinity units (PSU); Euhaline: 9.2–35.6 PSU and 23.9–47.7 PSU). We hypothesized that water stress caused by salinity generates modification in conductivity, water-storage, and photosynthetic tissues. Our results showed a greater number of morphoanatomical traits affected by salinity in juveniles compared to adults, greater variability in the traits associated with water accumulation and transport. Adults and juveniles subjected to higher values of salinity had traits more tolerant of variability in this factor, allowing superior adaptation to environments with high water deficit than individuals originating in oligohaline environments. This difference in adaptability to salinity between populations of R. mangle may imply different responses to climate change, where populations of oligohaline origin will be more susceptible to hypersalinization resulting from this phenomenon, while populations of euhaline origin could more effectively tolerate the aquatic stresses caused, allowing a prolongation of their permanence and the provision of their ecosystem services over time. Full article

(This article belongs to the Special Issue Advances in Mangrove Ecology)

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12 pages, 1761 KiB

Open AccessArticle

Effects of Exogenous Ethylene and Cobalt Chloride on Root Growth of Chinese Fir Seedlings under Phosphorus-Deficient Conditions

by Hui Zhang, Nemin Wang, Shanshan Zheng, Min Chen, Xiangqing Ma and Pengfei Wu

Forests 2021, 12(11), 1585; https://doi.org/10.3390/f12111585 - 17 Nov 2021

Cited by 2 | Viewed by 1720

Abstract

Studying the effects of different concentrations of ethephon on morphological and physiological changes in the roots of Chinese fir (Cunninghamia lanceolata Lamb. Hook.) seedlings under P deficiency can reveal the internal adaptive mechanisms of these plants under nutrient stress. Herein, we investigated [...] Read more.

Studying the effects of different concentrations of ethephon on morphological and physiological changes in the roots of Chinese fir (Cunninghamia lanceolata Lamb. Hook.) seedlings under P deficiency can reveal the internal adaptive mechanisms of these plants under nutrient stress. Herein, we investigated the effects of different ethephon and cobalt chloride concentrations under normal P supply and P deficiency. A significant effect (p < 0.05) of exogenous additive application was observed on the development of Chinese fir root length, surface area, and volume. These root development indices showed maximum values when the ethephon concentration was 0.01 g kg⁻¹ under normal P supply and P deficiency, and they were significantly different from those under 0.04 g kg⁻¹ ethephon treatment. Similarly, the indices showed maximum values when CoCl₂ concentration was 0.01 g kg⁻¹ under P deficiency and was significantly different (p < 0.01) from those under 0.2 g kg⁻¹ CoCl₂ treatment. Under normal P supply, an increase in ethephon concentration caused superoxide dismutase (SOD; E.C. 1.15.1.1) activity to decrease and peroxidase (POD; E.C. 1.11.1.X) activity to increase gradually. Conversely, CoCl₂ addition (0.01 g kg⁻¹) promoted SOD and POD activities under P deficiency. There were no significant differences (p > 0.05) in malondialdehyde content of seedlings among ethephon or CoCl₂ treatments. In conclusion, ethylene plays a significant role in adaptative mechanisms underlying stress resistance in plants, prompting them to respond to P starvation and improving seedlings’ tolerance to P-deficient conditions. Full article

(This article belongs to the Special Issue Abiotic and Biotic Stress in Forest and Plantation Trees)

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14 pages, 5528 KiB

Open AccessArticle

Colonization Pattern of Abandoned Croplands by Quercus pyrenaica in a Mediterranean Mountain Region

by Antonio J. Pérez-Luque, Francisco J. Bonet-García and Regino Zamora

Forests 2021, 12(11), 1584; https://doi.org/10.3390/f12111584 - 17 Nov 2021

Cited by 3 | Viewed by 1714

Abstract

Land abandonment is a major global change driver in the Mediterranean region, where anthropic activity has played an important role in shaping landscape configuration. Understanding the woodland expansion towards abandoned croplands is critical to develop effective management strategies. In this study, we analyze [...] Read more.

Land abandonment is a major global change driver in the Mediterranean region, where anthropic activity has played an important role in shaping landscape configuration. Understanding the woodland expansion towards abandoned croplands is critical to develop effective management strategies. In this study, we analyze the colonization pattern of abandoned croplands by Quercus pyrenaica in the Sierra Nevada mountain range (southern Spain). We aimed to assess differences among populations within the rear edge of the Q. pyrenaica distribution. For this purpose, we characterized (i) the colonization pattern of Q. pyrenaica, (ii) the structure of the seed source (surrounding forests), and (iii) the abundance of the main seed disperser (Eurasian jay, Garrulus glandarius). The study was conducted in five abandoned croplands located in two representative populations of Q. pyrenaica located on contrasting slopes. Vegetation plots within three habitat types (mature forest, edge-forest and abandoned cropland) were established to compute the abundance of oak juveniles. The abundance of European jay was determined using data of bird censuses (covering 7 years). Our results indicate that a natural recolonization of abandoned croplands by Q. pyrenaica is occurring in the rear edge of the distribution of this oak species. Oak juvenile abundance varied between study sites. Neither the surrounding-forest structure nor the abundance of jays varied significantly between study sites. The differences in the recolonization patterns seem to be related to differences in the previous- and post-abandonment management. Full article

(This article belongs to the Section Forest Ecology and Management)

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12 pages, 1424 KiB

Open AccessArticle

Thinning Effect of C Sequestration along an Elevation Gradient of Mediterranean Pinus spp. Plantations

by Antonio M. Cachinero-Vivar, Guillermo Palacios-Rodríguez, Miguel A. Lara-Gómez and Rafael M. Navarro-Cerrillo

Forests 2021, 12(11), 1583; https://doi.org/10.3390/f12111583 - 17 Nov 2021

Cited by 5 | Viewed by 1623

Abstract

Forests are key elements in mitigating the effects of climate change due to the fact of their carbon sequestration capacity. Forest management can be oriented to optimise the carbon sequestration capacity of forest stands, in line with other productive objectives and the generation [...] Read more.

Forests are key elements in mitigating the effects of climate change due to the fact of their carbon sequestration capacity. Forest management can be oriented to optimise the carbon sequestration capacity of forest stands, in line with other productive objectives and the generation of ecosystem services. This research aimed to determine whether thinning treatments have a positive influence on the growth patterns of some of the main Mediterranean pine species and, therefore, on their Carbon (C) fixation capacity, both in terms of living biomass and soil organic carbon. The results obtained show that C sequestration capacity (biomass and SOC) increased at higher thinning intensities due to the induced alterations in tree growth patterns. We observed almost a 1.5-fold increase in P. nigra and P. sylvestris, respectively, and over a two-fold increase in P. pinaster under heavy thinning treatments; SOC stocks were affected by the intensity of the thinning treatments. These results can contribute to improving silvicultural practices aimed at C sequestration in forest plantations located in dry areas of the Mediterranean. Full article

(This article belongs to the Special Issue Adaptive Forest Management to Climatic Change)

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16 pages, 1228 KiB

Open AccessArticle

Composed Indicator of Community Forest Governance in San Miguel Topilejo, Mexico City

by Susana Aguilar-Martínez and Esteban Valtierra-Pacheco

Forests 2021, 12(11), 1582; https://doi.org/10.3390/f12111582 - 17 Nov 2021

Cited by 2 | Viewed by 1380

Abstract

Community Forest Governance is a process of building agreements and decision-making about rules and norms for the use and access to forest resources of common use. The main objective of this study was to know the level of governance about the management and [...] Read more.

Community Forest Governance is a process of building agreements and decision-making about rules and norms for the use and access to forest resources of common use. The main objective of this study was to know the level of governance about the management and conservation of the forest of the agrarian community of San Miguel Topilejo, in Southern Mexico City. A survey was applied to a representative sample of 58 community members. The level of governance is determined by a composed indicator that includes criteria and specific indicators of social capital, collective action, and local organization. The main finding shows that social capital is low because there is little cohesion between community members. Community collective action shows a lack of cooperation and coordination to enforce norms and sanctions in the use of forest resources. The level of organization is low because the structure of positions and roles is very basic and not specialized. The conclusion is that the level of governance is low because this community has no clear common objectives, there is a lack of well-established norms and sanctions, and there is a lack of involvement of owners in the decision-making process and management of forest resources of common use. Full article

(This article belongs to the Special Issue Political Ecology of Forests Ecosystem Services)

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9 pages, 1925 KiB

Open AccessArticle

Dimensional Stability of Treated Sengon Wood by Nano-Silica of Betung Bamboo Leaves

by Istie Rahayu, Fitria Cita Dirna, Akhiruddin Maddu, Wayan Darmawan, Dodi Nandika and Esti Prihatini

Forests 2021, 12(11), 1581; https://doi.org/10.3390/f12111581 - 17 Nov 2021

Cited by 2 | Viewed by 1724

Abstract

Sengon (Falcataria moluccana Miq.) is one of the fastest growing wood that is broadly planted in Indonesia. Sengon wood has inferior wood properties, such as a low density and dimensional stability. Therefore, sengon wood requires a method to improve its wood quality [...] Read more.

Sengon (Falcataria moluccana Miq.) is one of the fastest growing wood that is broadly planted in Indonesia. Sengon wood has inferior wood properties, such as a low density and dimensional stability. Therefore, sengon wood requires a method to improve its wood quality through wood modification. One type of wood modification is wood impregnation. On the other hand, Betung Bamboo leaves are considered as waste. Betung Bamboo leaves contain silica. Based on several researches, nano-SiO₂ could improve fast-growing wood qualities. According to its perfect solubility in water, monoethylene glycol (MEG) is used in the study. The objectives are to evaluate the impregnation treatment (MEG and nano-silica originated from betung bamboo leaves) in regard to the dimensional stability and density of 5-year-old sengon wood and to characterize the treated sengon wood. MEG, MNano-Silica 0.5%, MNano-Silica 0.75%, and MNano-Silica 1% were used as impregnation solutions. The impregnation method was started with 0.5 bar of vacuum for 60 min, followed by 2.5 bar of pressure for 120 min. The dimensional stability, density, and characterization of the samples were studied through the use of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results show that the treatment had a significant effect on the dimensional stability and density of sengon wood. Alterations in the morphology of treated sengon wood were observed through the full coverage of the pits on the vessel walls (SEM analysis results) and the detection of ethylene (FTIR analysis results) and silica (XRD and FTIR analysis results). Overall, the 0.75% MNano-Silica treatment was the most optimal treatment for increasing the dimensional stability and density of 5-year-old sengon wood. Full article

(This article belongs to the Special Issue Advanced Technologies in Physical and Mechanical Wood Modification)

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