Forests

18 pages, 3639 KiB

Open AccessArticle

Product Quality Measurement, Dynamic Changes, and the Belt and Road Initiative Distribution Characteristics: Evidence from Chinese Wooden Furniture Exports

by Lu Wan, Nannan Ban, Yizhong Fu and Luyao Yuan

Forests 2022, 13(7), 1153; https://doi.org/10.3390/f13071153 - 21 Jul 2022

Cited by 2 | Viewed by 2364

Abstract

As the most important forest product in the export of China, wooden furniture is facing increasingly fierce international competition and has a strong need for quality improvement. Based on the endogenous determination model of quality, this paper measures the quality of Chinese wooden [...] Read more.

As the most important forest product in the export of China, wooden furniture is facing increasingly fierce international competition and has a strong need for quality improvement. Based on the endogenous determination model of quality, this paper measures the quality of Chinese wooden furniture in exports from 1998 to 2017, by using product-level trade data of BACI CEPII. From the perspectives of the overall and sub-category quality, it examines the characteristics of dynamic changes in the product quality and its regional distribution of “the Belt and Road Initiative” countries. The results show that the quality of Chinese wooden furniture in exports is lower than that of wood-based panels and paper products. It remains stable after a slight increase from 2001 to 2005, but the quality level is always low. Among the sub-categories, wooden furniture not for kitchens, offices, or bedrooms has the lowest quality, while wooden office furniture has the highest one. The three dominant sub-categories that account for a high export share are all low in quality, while the small proportion sub-categories are all of higher quality, implying a strong imbalance. In particular, the quality of the main export products, upholstered wooden seats and wooden furniture not for kitchen, office, or bedroom use, has continued to decline, highlighting the plight of the quality growth of Chinese wooden furniture. For the BRI markets, the quality of Chinese wooden furniture exported to the region has declined slightly since 2012. However, different markets have shown different characteristics in the quality level and the direction of change. In terms of quality level, the qualities of wooden furniture exported to Malaysia, Israel, the United Arab Emirates, Vietnam, and the Philippines are relatively high. In terms of changing trends, the qualities of wooden furniture to Malaysia, Thailand, Indonesia, and Israel are showing a rising trend. In this case, accurately identifying the quality of different export categories of furniture products and their changing characteristics can help furniture enterprises make better production and operation decisions, promote the formation of a good business environment, and foster new comparative advantages and international competitiveness. Full article

(This article belongs to the Section Wood Science and Forest Products)

► Show Figures

Figure 1

21 pages, 3650 KiB

Open AccessArticle

Gene Flow and Recruitment Patterns among Disjunct Populations of Allocasuarina verticillata (Lam.) L.A.S. Johnson

by Yong Zhang, Nigel England, Linda Broadhurst, Lan Li, Chonglu Zhong and David Bush

Forests 2022, 13(7), 1152; https://doi.org/10.3390/f13071152 - 21 Jul 2022

Viewed by 1509

Abstract

Allocasuarina verticillata (Lam.) L.A.S. Johnson is a widespread species in south-eastern Australia providing vegetation cover, protecting fragile soils and providing food for birds. Understanding the effects of gene flow on the recruitment patterns, genetic differentiation and structure of fragmented populations provides fundamental guidelines [...] Read more.

Allocasuarina verticillata (Lam.) L.A.S. Johnson is a widespread species in south-eastern Australia providing vegetation cover, protecting fragile soils and providing food for birds. Understanding the effects of gene flow on the recruitment patterns, genetic differentiation and structure of fragmented populations provides fundamental guidelines to underpin plant conservation strategies and activities. In this study, four spatially disjunct populations of A. verticillata were sampled to explore the effects of population size, reproductive patterns and pollen and seed dispersal on among-population genetic diversity, genetic differentiation and structure, using field survey and microsatellite marker techniques. It was found that stands of A. verticillata were predominantly sexually reproductive, but asexual reproduction through root suckering was an additional mode of reproduction. The reproductive success of A. verticillata is positively correlated with the effective population size rather than actual population size. The reduction in effective population size and increment of spatial isolation resulted in lower genetic diversity and higher inbreeding coefficient of progenies. Moderate pairwise genetic differentiation and weak genetic structure were identified. The results suggest that exogenous, wind-mediated pollen flow provides some maintenance of genetic diversity in the isolated stands. Seed dispersal appears mainly to be over short distances (i.e., within populations), but the infrequent transport of seeds between disjunct locations cannot be ruled out as another factor that may help maintain genetic diversity. Full article

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

► Show Figures

Figure 1

9 pages, 5569 KiB

Open AccessArticle

Experimental Study of Intra-Ring Anatomical Variation in Populus alba L. with Respect to Changes in Temperature and Day-Length Conditions

by Kei’ichi Baba, Yuko Kurita and Tetsuro Mimura

Forests 2022, 13(7), 1151; https://doi.org/10.3390/f13071151 - 21 Jul 2022

Cited by 2 | Viewed by 1622

Abstract

There are various studies on annual ring structural variations in plants grown in the field under varying meteorological statistics. However, related experimental approach is limited, hitherto. In this study, complete artificial conditions with growth chambers were adopted to evaluate the influence of day [...] Read more.

There are various studies on annual ring structural variations in plants grown in the field under varying meteorological statistics. However, related experimental approach is limited, hitherto. In this study, complete artificial conditions with growth chambers were adopted to evaluate the influence of day length and temperature on intra-ring structure formation. The basic artificial growing conditions have been previously reported as “shortened annual cycle system”, which consisted of the following three stages mimicking seasons approximately: Stage 1, spring/summer; Stage 2, autumn; and Stage 3, winter. This system shortens an annual cycle of Populus alba to 5 months. In this study, Stage 2 was modified in two ways: one was a condition in which the temperature was fixed and the day length was gradually shortened, and the other was a condition with a fixed day length and gradually lowered temperature. In the former condition, the cell wall of fibers thickened from the middle of the ring, and the vessel diameter became smaller from the same position. The wood in the latter condition appeared more natural in terms of wall thickness and vessel shape; however, the thickness of the wall reduced in the starting position of Stage 2. It may have been caused by the shortage of material for cell production under a high temperature but a short day length. Full article

(This article belongs to the Special Issue Wood Growth and Structure)

► Show Figures

Figure 1

20 pages, 2558 KiB

Open AccessArticle

Development of Variable-Density Yield Models with Site Index Estimation for Korean Pines and Japanese Larch

by Daesung Lee and Jungkee Choi

Forests 2022, 13(7), 1150; https://doi.org/10.3390/f13071150 - 21 Jul 2022

Cited by 1 | Viewed by 1354

Abstract

The objectives of this study were to develop site index and variable-density yield models for Korean red pine (Pinus densiflora Siebold & Zucc.), Korean white pine (P. koraiensis S. & Z.), and Japanese larch (Larix kaempferi (Lamb.) Carrière) in Korea. [...] Read more.

The objectives of this study were to develop site index and variable-density yield models for Korean red pine (Pinus densiflora Siebold & Zucc.), Korean white pine (P. koraiensis S. & Z.), and Japanese larch (Larix kaempferi (Lamb.) Carrière) in Korea. The data were collected between 2012 and 2021 from repeatedly measured empirical plots in each target stand in the North Central region of Korea: Gangwon and North Gyeongsang provinces. To develop the site index for each species, a dominant height growth model by species was developed using the Chapman–Richards function. The site index was computed with a base age of 40 years and used as an independent variable to predict the stand volume. To develop the variable-density yield models, three stand density variables, the stand age, and the site index were applied. The stand density variables used were the stand basal area, the number of trees per hectare, and the relative density. All the models were successfully developed with significant parameters and reasonable fit statistics, and the residuals analyzed presented unbiased scatter plots. Yield models with the stand basal area, or the number of trees, can be used to predict the stand volume. The yield model with relative density was flexible to apply across the stand age because the input of the absolute stand density was not required. Model simulation and comparisons with other studies also supported the applicability of the models developed in this study. The models were found to be highly applicable for predicting and simulating these targeted stands, particularly in Korea. Full article

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

► Show Figures

Figure 1

17 pages, 5660 KiB

Open AccessArticle

Influence of Strip Clearcuts, Deer Exclusion and Herbicide on Initial Sapling Recruitment in Northern Hardwood Forests

by Stefan F. Hupperts, Christopher R. Webster, Robert E. Froese, Brandon Bal and Yvette L. Dickinson

Forests 2022, 13(7), 1149; https://doi.org/10.3390/f13071149 - 21 Jul 2022

Cited by 1 | Viewed by 1442

Abstract

Sapling recruitment in hardwood forests is often suppressed by overstory shade, interspecific competition, and browsing pressure from white-tailed deer (Odocoileus virginianus Zimmerman). In some northern hardwood stands, these three interacting factors may cause persistent recruitment failure of the dominant canopy species, sugar [...] Read more.

Sapling recruitment in hardwood forests is often suppressed by overstory shade, interspecific competition, and browsing pressure from white-tailed deer (Odocoileus virginianus Zimmerman). In some northern hardwood stands, these three interacting factors may cause persistent recruitment failure of the dominant canopy species, sugar maple (Acer saccharum Marsh.), into the sapling size class. In this study, we compared initial (two-year) sugar maple and hophornbeam (Ostrya virginiana ((Mill.) K. Koch) seedling and sapling recruitment in strip clearcuts to strip selection cuts, with combinations of herbicide and deer exclosures, in a northern hardwood forest with limited sugar maple sapling recruitment. We found that sugar maple sapling recruitment was higher in exclosures, particularly in strip clearcuts. Moreover, mixed models predicted that exclosures in strip clearcuts with herbicide tended to benefit sugar maple sapling recruitment, especially when the pre-treatment density was less than ~1500 stems ha⁻¹. Sapling density of hophornbeam was also promoted in exclosure plots but was negatively affected by herbicide. Graminoid and Rubus spp. cover was also limited by herbicide following harvest, potentially alleviating constraints on future sugar maple sapling recruitment. Our findings indicate that sugar maple sapling recruitment in strip clearcuts is similar to strip selection cuts unless browsing pressure and interspecific competition are also alleviated. Full article

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

► Show Figures

Figure 1

14 pages, 7392 KiB

Open AccessArticle

Effects of Land Use Conversion on the Soil Microbial Community Composition and Functionality in the Urban Wetlands of North-Eastern China

by Yining Wu, Weifeng Gao, Yu Zou, Haiyan Dong, Fei Yu, He Wang and Cheng Zong

Forests 2022, 13(7), 1148; https://doi.org/10.3390/f13071148 - 21 Jul 2022

Cited by 4 | Viewed by 1919

Abstract

Urban wetlands are undergoing intensive conversion from natural wetlands to farmlands, woodlands, and even alkaline land. This study aimed to determine the effects of land conversion on soil microbial communities of urban wetlands in the hinterland of Songnen Plain, Northeastern China. Soil samples [...] Read more.

Urban wetlands are undergoing intensive conversion from natural wetlands to farmlands, woodlands, and even alkaline land. This study aimed to determine the effects of land conversion on soil microbial communities of urban wetlands in the hinterland of Songnen Plain, Northeastern China. Soil samples were collected from various sites of Longfeng wetland, including swamp wetland (SW), meadow wetland (MW), woodland (WL), farmland (FL), and alkaline land (AL). High-throughput sequencing followed by bioinformatic analysis was conducted to evaluate the structure, composition, and function of soil bacterial and fungal communities. The most dominant bacterial and fungal phylum among the land-use types were Proteobacteria and Ascomycota, respectively. In addition, the bacterial diversity and functions varied significantly across different land-use types. However, no remarkable differences in fungal communities were observed under various land-use types. Edaphic parameters, including exchange sodium percent (ESP) and total nitrogen (TN), remarkably influenced the abundance and diversity of soil microbial communities. These results show that land-use type shapes various aspects of soil microbial communities, including soil physicochemical properties, microbial taxa structure, potential functional genes, and correlation with environmental factors. This study provides reliable data to guide land use management and supervision by decision-makers in this region. Full article

(This article belongs to the Special Issue Application of Microbes in Landscape Restoration)

► Show Figures

Figure 1

11 pages, 1359 KiB

Open AccessArticle

Shrubs Should Be Valued: The Functional Traits of Lonicera fragrantissima var. lancifolia in a Qinling Huangguan Forest Dynamics Plot, China

by Anxia Han, Jing Qiu, Ruoming Cao, Shihong Jia, Zhanqing Hao and Qiulong Yin

Forests 2022, 13(7), 1147; https://doi.org/10.3390/f13071147 - 21 Jul 2022

Cited by 1 | Viewed by 1381

Abstract

Previous studies have focused on the functional traits of trees, while undergrowth shrubs have not received the same attention. We collected 97 shrubs from 6 habitats in 3 diameter classes to measure the functional traits of Lonicera fragrantissima var. lancifolia, which is [...] Read more.

Previous studies have focused on the functional traits of trees, while undergrowth shrubs have not received the same attention. We collected 97 shrubs from 6 habitats in 3 diameter classes to measure the functional traits of Lonicera fragrantissima var. lancifolia, which is one of the dominant species in the shrub layer of the Qinling Huangguan plot. We found that leaf thickness (LT) decreased with an increase in diameter classes. Other functional traits did not change significantly with the diameter classes. Most of the functional traits changed with the habitats, which may be influenced by topography and soil. On the whole, Lonicera fragrantissima var. lancifolia showed low variation, which indicates that its growth was stable and good. The relationships between functional traits within species was in accordance with the leaf economic spectrum. The positive correlation between soil total nitrogen (STN) and C:N verified the “nutrition luxury hypothesis”. Full article

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

► Show Figures

Figure 1

13 pages, 2426 KiB

Open AccessArticle

Spatial and Temporal Evolution of Ecosystem Service Value in Shaanxi Province against the Backdrop of Grain for Green

by Kai Li and Beiying Zhang

Forests 2022, 13(7), 1146; https://doi.org/10.3390/f13071146 - 20 Jul 2022

Cited by 4 | Viewed by 1442

Abstract

The Grain for Green Project (GGP) has influenced Shaanxi Province’s land-use pattern, resulting in a shift in ecosystem service value (ESV). Exploring the spatial and temporal evolution of the pattern of land use and ESV in Shaanxi Province, before and after the project’s [...] Read more.

The Grain for Green Project (GGP) has influenced Shaanxi Province’s land-use pattern, resulting in a shift in ecosystem service value (ESV). Exploring the spatial and temporal evolution of the pattern of land use and ESV in Shaanxi Province, before and after the project’s implementation, can give a theoretical foundation for regional land-use planning. For this study, we used the transfer matrix and the value equivalent approaches to investigate the influence of project implementation on the spatial distribution and evolution of patterns of land use and ESV in Shaanxi Province based on four periods of land-use data from 1990 to 2020. The results suggest the following: (1) Farmland, forestland, and grassland were the most common land-types in Shaanxi Province. Farmland, forestland, and grassland in Shaanxi Province were all altered dramatically over the research period due to the GGP. Farmland was turned mostly into forestland and grassland, and forestland and grassland areas progressively grew. (2) The ESVs in Shaanxi Province were USD 3802.82, 3814.90, 3836.20, and 3806.50 billion in 1990, 2000, 2010, and 2020, respectively. The most value was supplied by hydrological management, while water resources provided the lowest value. Forestland and grassland were the most valuable land-types in high-value locations, whereas built-up land was the most valuable land-type in low-value areas. (3) While the GGP has increased the ESV of forestland and grassland, it has harmed the acreage of other land-types, resulting in a decline in the total ESV in Shaanxi Province. Full article

(This article belongs to the Section Forest Economics, Policy, and Social Science)

► Show Figures

Figure 1

8 pages, 1367 KiB

Open AccessCommunication

Microbial Residue Distribution in Microaggregates Decreases with Stand Age in Subtropical Plantations

by Yanli Jing, Xuechao Zhao, Shengen Liu, Peng Tian, Zhaolin Sun, Longchi Chen and Qingkui Wang

Forests 2022, 13(7), 1145; https://doi.org/10.3390/f13071145 - 20 Jul 2022

Cited by 2 | Viewed by 1456

Abstract

Soil microbial residues contribute to the majority of stable soil organic carbon (SOC) pools, and their distribution among aggregate fractions determines long-term soil carbon (C) stability and, consequently, soil productivity. However, how microbial residue accumulation and distribution respond to stand age remains unexplored. [...] Read more.

Soil microbial residues contribute to the majority of stable soil organic carbon (SOC) pools, and their distribution among aggregate fractions determines long-term soil carbon (C) stability and, consequently, soil productivity. However, how microbial residue accumulation and distribution respond to stand age remains unexplored. To fill this knowledge gap, we investigated microbial residues in bulk soil and soil aggregate fractions under a chronosequence of Chinese fir (Cunninghamia lanceolata [Lamb.] Hook) plantations with stands aged 3, 17, 27, and 36 years. The results showed that microbial residues in topsoil did not change across the different stand ages, but the residues in the subsoil increased from 3 to 17 years of age and then remained constant. Moreover, microbial residue distribution in microaggregates decreased with stand age, and the residue distribution in small macroaggregates was lower at age 17 years than at other stand ages. The effect of stand age on microbial residue distribution was due to the fact of their effect on aggregate distribution but not microbial residue concentrations in aggregate fractions. Collectively, our results indicate that microbial residue stability decreased with stand age, which has significant implications for the management of SOC in subtropical plantations. Full article

(This article belongs to the Special Issue Carbon Fluxes and Production in Forest Ecosystems)

► Show Figures

Figure 1

16 pages, 2463 KiB

Open AccessArticle

Comparative Study of Plywood Boards Produced with Castor Oil-Based Polyurethane and Phenol-Formaldehyde Using Pinus taeda L. Veneers Treated with Chromated Copper Arsenate

by Estefani Sugahara, Bruno Casagrande, Felipe Arroyo, Victor De Araujo, Herisson Santos, Emerson Faustino, Andre Christoforo and Cristiane Campos

Forests 2022, 13(7), 1144; https://doi.org/10.3390/f13071144 - 20 Jul 2022

Cited by 5 | Viewed by 2229

Abstract

Plywood is widely used in civil construction. Due to the importance of preservation and gluing in bio-composites, this study compares the influence of a chemical treatment with CCA (chromated-copper-arsenate) on Pinus taeda L. wood veneers to produce two plywood types using phenol-formaldehyde (PF) [...] Read more.

Plywood is widely used in civil construction. Due to the importance of preservation and gluing in bio-composites, this study compares the influence of a chemical treatment with CCA (chromated-copper-arsenate) on Pinus taeda L. wood veneers to produce two plywood types using phenol-formaldehyde (PF) and castor oil-based polyurethane (PU). Four different treatments were performed to analyze both varieties’ physical and mechanical properties. As a result, an improvement in the properties of the treated panels was observed. Lower moisture contents and better interactions caused by less thickness swelling and water absorption were identified in the PU-based plywoods. The treatment with CCA was efficient, improving these properties when they were compared to the reference panels. Most treatments evidenced increases in the modulus of elasticity and modulus of rupture for both adhesives when the CCA treatment was applied to the veneers. Comparing the resins, the PF showed the best values of modulus of elasticity. All treatments met the requirements defined by the Brazilian standard document for the glue line shear. Full article

(This article belongs to the Special Issue Frontiers in Modification of Wood and Wood-Based Composites)

► Show Figures

Figure 1

15 pages, 3152 KiB

Open AccessArticle

(Re)Designing Urban Parks to Maximize Urban Heat Island Mitigation by Natural Means

by Victor L. Barradas, Jennifer A. Miranda, Manuel Esperón-Rodríguez and Monica Ballinas

Forests 2022, 13(7), 1143; https://doi.org/10.3390/f13071143 - 20 Jul 2022

Cited by 5 | Viewed by 2966

Abstract

Urban trees play a key role in mitigating urban heat by cooling the local environment. However, the cooling benefit that trees can provide is influenced by differences in species traits and site-specific environmental conditions. Fifteen dominant urban tree species in parks from Mexico [...] Read more.

Urban trees play a key role in mitigating urban heat by cooling the local environment. However, the cooling benefit that trees can provide is influenced by differences in species traits and site-specific environmental conditions. Fifteen dominant urban tree species in parks from Mexico City were selected considering physiological traits (i.e., transpiration and stomatal conductance) and aesthetic and morphological characteristics. Species’ physiological performance was measured to explore the potential of trees to reduce urban heat load. Data were collected over a 4-week period in the months of April and May 2020, the warmest and driest months of the year in Mexico City. We used the Thermal UrbaN Environment Energy (TUNEE) balance model to calculate the cooling benefit of each species and the number of individuals necessary to reduce local air temperature. The highest midday transpiration was registered for Liquidambar styraciflua L. (0.0357 g m⁻² s⁻¹) and the lowest for Buddleja cordata H.B.K (0.0089 g m⁻² s⁻¹), representing an energy consumption and cooling potential of 87.13 and 21.69 J m⁻² s⁻¹, respectively. Similarly, the highest stomatal conductance was recorded for L. styraciflua., whereas the lowest was recorded for B. cordata. Based on the species transpiration rates and aesthetic characteristics, we developed a proposal and outline for a 50 × 50 m urban park (i.e., park community) consisting of six species with 19 individuals, and according to the TUNEE model, the proposed arrangement can reduce air temperature up to 5.3 °C. Our results can help urban planners to (re)design urban parks to mitigate urban heat while increasing urban tree diversity in parks. Full article

(This article belongs to the Special Issue Urban Forests and Landscape Ecology—Series II)

► Show Figures

Figure 1

19 pages, 2924 KiB

Open AccessArticle

Crown Structure Metrics to Generalize Aboveground Biomass Estimation Model Using Airborne Laser Scanning Data in National Park of Hainan Tropical Rainforest, China

by Chenyun Li, Zhexiu Yu, Shaojie Wang, Fayun Wu, Kunjian Wen, Jianbo Qi and Huaguo Huang

Forests 2022, 13(7), 1142; https://doi.org/10.3390/f13071142 - 20 Jul 2022

Cited by 4 | Viewed by 1845

Abstract

Forest aboveground biomass (AGB) is an important indicator for characterizing forest ecosystem structures and functions. Therefore, how to effectively investigate forest AGB is a vital mission. Airborne laser scanning (ALS) has been demonstrated as an effective way to support investigation and operational applications [...] Read more.

Forest aboveground biomass (AGB) is an important indicator for characterizing forest ecosystem structures and functions. Therefore, how to effectively investigate forest AGB is a vital mission. Airborne laser scanning (ALS) has been demonstrated as an effective way to support investigation and operational applications among a wide range of applications in the forest inventory. Moreover, three-dimensional structure information relating to AGB can be acquired by airborne laser scanning. Many studies estimated AGB from variables that were extracted from point cloud data, but few of them took full advantage of variables related to tree crowns to estimate the AGB. In this study, the main objective was to evaluate and compare the capabilities of different metrics derived from point clouds obtained from ALS. Particularly, individual tree-based alpha-shape, along with other traditional and commonly used plot-level height and intensity metrics, have been used from airborne laser scanning data. We took the random forest and multiple stepwise linear regression to estimate the AGB. By comparing AGB estimates with field measurements, our results showed that the best approach is mixed metrics, and the best estimation model is random forest (R² = 0.713, RMSE = 21.064 t/ha, MAE = 15.445 t/ha), which indicates that alpha-shape may be a good alternative method to improve AGB estimation accuracy. This method provides an effective solution for estimating aboveground biomass from airborne laser scanning. Full article

(This article belongs to the Special Issue New Insights into Remote Sensing of Vegetation Structural Parameters)

► Show Figures

Figure 1

16 pages, 2981 KiB

Open AccessArticle

The Effects of Biochar on Microbial Community Composition in and Beneath Biological Soil Crusts in a Pinus massoniana Lamb. Plantation

by Jinping Wang, Rongzhen Huang, Liqin Zhu, Hongzhi Guan, Lijing Lin, Huanying Fang, Mengjia Yang, Shaohui Ji, Xianhua Zou and Xin Li

Forests 2022, 13(7), 1141; https://doi.org/10.3390/f13071141 - 20 Jul 2022

Cited by 8 | Viewed by 1905

Abstract

Biological soil crusts (BSCs) hold promise for reducing soil erosion in subtropical forest plantations, and microorganisms profoundly affect the formation and development of BSCs. The effects of biochar as a soil conditioner on the diversity and structure of soil microbial communities in BSCs [...] Read more.

Biological soil crusts (BSCs) hold promise for reducing soil erosion in subtropical forest plantations, and microorganisms profoundly affect the formation and development of BSCs. The effects of biochar as a soil conditioner on the diversity and structure of soil microbial communities in BSCs are largely unknown. Therefore, our aim was to determine how biochar might improve microbial community composition and BSC function. Herein, a field experiment was conducted in a P. massoniana plantation; the addition of biochar was the treatment, and no biochar addition was the control (CK). Soil microbial communities associated with moss BSCs (in and beneath BSCs) with and without the addition of biochar were analyzed by Illumina sequencing technology. The results showed that Acidobacteria (28.35%), Proteobacteria (22.53%), Actinobacteria (17.41%), and Chloroflexi (16.74%) were the dominant bacterial phyla, whereas Basidiomycota (70.00%) and Ascomycota (22.76%) were the dominant fungal phyla in BSCs. The soil bacterial and fungal OTU number and richness in BSCs were higher than those beneath BSCs. The relative abundances of Acidobacteria, Chloroflexi, and Basidiomycota were higher in BSCs than beneath BSCs, whereas the relative abundances of Actinobacteria, Firmicutes, Ascomycota, and Chytridiomycota showed the opposite trend. Beneath BSCs, biochar addition increased the soil bacterial OTU number and richness (ACE index and Chao1) but decreased the soil fungal OTU number and richness. Biochar had little effect on soil microbial community structures in BSCs; however, beneath BSCs, it significantly increased the relative abundances of Acidobacteria, Chloroflexi, and Basidiomycota and significantly decreased the relative abundances of Actinobacteria, Firmicutes, Ascomycota, and Chytridiomycota. Biochar-induced changes in soil microbial communities were related to soil environmental factors, especially urease activity, organic matter content, pH, total nitrogen content, and sucrase activity. We demonstrated the different effects of biochar on soil microbial communities in and beneath the BSCs of subtropical forest plantations; these findings provided new insights into soil stabilization with BSCs below the forest canopy in subtropical regions. Full article

(This article belongs to the Special Issue Soil Microorganisms in Forests: Biodiversity, Ecological Function, and Biogeography)

► Show Figures

Figure 1

14 pages, 3314 KiB

Open AccessArticle

Terpene Production Varies in Pinus thunbergii Parl. with Different Levels of Resistance, with Potential Effects on Pinewood Nematode Behavior

by Xin-Yu Wang, Xiao-Qin Wu, Tong-Yue Wen, Ya-Qi Feng and Yan Zhang

Forests 2022, 13(7), 1140; https://doi.org/10.3390/f13071140 - 20 Jul 2022

Cited by 4 | Viewed by 1528

Abstract

Determining the mechanisms of pine wilt disease (PWD) resistance in Pinus is a popular research topic, but information on volatile organic substances (VOS) and their role in PWD is lacking. Whether the difference in VOS among Pinus thunbergii parl. that have different levels [...] Read more.

Determining the mechanisms of pine wilt disease (PWD) resistance in Pinus is a popular research topic, but information on volatile organic substances (VOS) and their role in PWD is lacking. Whether the difference in VOS among Pinus thunbergii parl. that have different levels of resistance with pine wood nematodes (PWNs) is the reason for the differing resistance needs to be studied. In this study, resistant P. thunbergii introduced from Japan and susceptible P. thunbergii native to China were used to investigate the effects of different lines inoculated with PWN. We determined the expression levels of the terpene synthesis-related genes geranylgeranyl diphosphate synthase (GGPPS), 3-hydroxy-3-methylglutaryl-coenzyme A reductase 1 (HMDH1), two kinds of alpha-farnesene synthase (PT) genes. The types and the relative percentage content of terpenoids in the pine needles were also determined by gas chromatography coupled with mass spectrometry (GC-MS). Results show that the growth, population size and migration of PWNs were significantly inhibited. The expression of terpene synthesis genes in the resistant P. thunbergii was higher than that in the susceptible one. The analysis of terpenoids revealed a total of 41 terpenoids, of which resistant P. thunbergii contained 39 and susceptible P. thunbergii only 28; 14 terpenoids were specific to resistant P. thunbergii, in which 8 of the terpenoids were constitutive terpenes and 6 were inducible terpenes. There were 3 terpenes unique to the susceptible P. thunbergii, and only 1 inducible terpene. Our results showed that the reduction in the expression of disease symptom and suppression of PWNs in resistant P. thunbergii was likely related to differences in the types and content of resistance-related substances in the trees. This study does not specifically connect elevated compounds in resistant P. thunbergii to resistance to PWN and assays should be conducted to establish direct effects of terpenoids on pinewood nematode activity and reproduction. Full article

(This article belongs to the Section Forest Health)

► Show Figures

Figure 1

23 pages, 10331 KiB

Open AccessArticle

Research on Tree Ring Micro-Destructive Detection Technology Based on Digital Micro-Drilling Resistance Method

by Xueyang Hu, Yili Zheng, Da Xing and Qingfeng Sun

Forests 2022, 13(7), 1139; https://doi.org/10.3390/f13071139 - 19 Jul 2022

Cited by 3 | Viewed by 1611

Abstract

Micro-drilling resistance method is a widely used tree ring micro-destructive detection technology. To solve the problem that the detection signal of the analog micro-drilling resistance method has excessive noise interference and cannot intuitively identify tree ring information, this research proposes a digital micro-drilling [...] Read more.

Micro-drilling resistance method is a widely used tree ring micro-destructive detection technology. To solve the problem that the detection signal of the analog micro-drilling resistance method has excessive noise interference and cannot intuitively identify tree ring information, this research proposes a digital micro-drilling resistance method and provides a recommended hardware implementation. The digital micro-drilling resistance method adopts the photoelectric encoder instead of ADC as the signal sampling module. Through the theoretical analysis of the DC motor characteristic, the PWM closed-loop speed control, the detection principle of the digital method is given. Additionally, the experimental equipment that can complete the detection of the digital method and the analog method simultaneously is designed to carry out comparative experiments. The experimental results show that: (1) The detection results of the digital method have a better-quality signal which can intuitively identify the tree rings. (2) The average correlation coefficient reaches 0.9365 between the detection results of the digital method and the analog method. (3) The average Signal-to-Noise Ratio (SNR) of the digital method is 39.0145 dB, which is 19.2590 dB higher than that of the analog method. The average noise interference energy in the detection result of the digital method is only 1.27% of the analog method. In summary, hardware implementation of the digital micro-drilling resistance method can correctly reflect the tree ring information and significantly improve the signal quality of the micro-drilling resistance technology. This research is helping to improve the identification accuracy of micro-drilling resistance technology, and to develop the application of tree ring micro-destructive detection technology in the high-precision field. Full article

(This article belongs to the Special Issue Electronics, Close-Range Sensors and Artificial Intelligence in Forestry)

► Show Figures

Figure 1

15 pages, 3452 KiB

Open AccessArticle

Quantifying Vegetation Stability under Drought in the Middle Reaches of Yellow River Basin, China

by Xiaoliang Shi, Fei Chen, Hao Ding, Yi Li and Mengqi Shi

Forests 2022, 13(7), 1138; https://doi.org/10.3390/f13071138 - 19 Jul 2022

Cited by 3 | Viewed by 1620

Abstract

Under the background of climate warming, the increase in the frequency and severity of drought leads to vegetation facing severe challenges. A comprehensive and systematic assessment of the stability of vegetation under drought stress in the middle reaches of Yellow River basin (MRYRB) [...] Read more.

Under the background of climate warming, the increase in the frequency and severity of drought leads to vegetation facing severe challenges. A comprehensive and systematic assessment of the stability of vegetation under drought stress in the middle reaches of Yellow River basin (MRYRB) will help to grasp the characteristics of vegetation response to drought. In this study, the normalized difference vegetation index (NDVI) was used to achieve quantitative and qualitative assessments of vegetation stability to drought, and the smoothed monthly standardized precipitation evapotranspiration index (SPEI) was used to describe the characteristics of drought events in 2005/2006 and identified vegetation stability parameters using a standardized anomaly of NDVI across space, which included the resistance duration, resilience duration, drought threshold, and lag time. Vegetation was dominated by less resistance and less resilience. The 2005/2006 drought event affected most of the study area, and vegetation growth was inhibited. The duration of vegetation resistance over 100 days accounted for 65.7%, and vegetation in 89.4% of the regions could return to normal within 100 days. The drought threshold of vegetation gradually decreased from northwest to southeast, and the lag time was mainly concentrated from 1 to 3 months. These findings contribute to a better understanding of the effects of drought on the environment, as well as scientific references for reducing ecological, economic, and social losses in future droughts, and promoting ecological environmental governance and high-quality development in the MRYRB. Full article

(This article belongs to the Section Forest Meteorology and Climate Change)

► Show Figures

Figure 1

16 pages, 9998 KiB

Open AccessArticle

Phenological Shifts of the Deciduous Forests and Their Responses to Climate Variations in North America

by Zixuan Li, Husheng Fang, Jianguang Tu, Xiaolei Li and Zongyao Sha

Forests 2022, 13(7), 1137; https://doi.org/10.3390/f13071137 - 19 Jul 2022

Cited by 2 | Viewed by 1988

Abstract

Forests play a vital role in sequestering carbon dioxide from the atmosphere. Vegetation phenology is sensitive to climate changes and natural environments. Exploring the patterns in phenological events of the forests can provide useful insights for understanding the dynamics of vegetation growth and [...] Read more.

Forests play a vital role in sequestering carbon dioxide from the atmosphere. Vegetation phenology is sensitive to climate changes and natural environments. Exploring the patterns in phenological events of the forests can provide useful insights for understanding the dynamics of vegetation growth and their responses to climate variations. Deciduous forest in North America is an important part of global forests. Here we apply time-series remote sensing imagery to map the critical dates of vegetation phenological events, including the start of season (SOS), end of season (EOS), and growth length (GL) of the deciduous forests in North America during the past two decades. The findings show that the SOS and EOS present considerable spatial and temporal variations. Earlier SOS, delayed EOS, and therefore extended GL are detected in a large part of the study area from temporal trend analysis over the years, though the magnitude of the trend varies at different locations. The phenological events are found to correlate to the environmental factors and the impact on the vegetation phenology from the factors is location-dependent. The findings confirm that the phenology of the deciduous forests in North America is updated such as advanced SOS and delayed EOS in the last two decades and the climate variations are likely among the driving forces for the updates. Considering that previous studies warn that shifts in vegetation phenology could reverse the role of forests as net emitters or net sinks, we suggest that forest management should be strengthened to forests that experience significant changes in the phenological events. Full article

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

► Show Figures

Figure 1

27 pages, 9698 KiB

Open AccessArticle

Analysis of the Influence of Forests on Landslides in the Bijie Area of Guizhou

by Yu Zhang, Chaoyong Shen, Shaoqi Zhou and Xuling Luo

Forests 2022, 13(7), 1136; https://doi.org/10.3390/f13071136 - 19 Jul 2022

Cited by 13 | Viewed by 1925

Abstract

Forests are an important part of the ecological environment, and changes in forests not only affect the ecological environment of the region but are also an important factor causing landslide disasters. In order to correctly evaluate the impact of forest cover on landslide [...] Read more.

Forests are an important part of the ecological environment, and changes in forests not only affect the ecological environment of the region but are also an important factor causing landslide disasters. In order to correctly evaluate the impact of forest cover on landslide susceptibility, in this paper, we build an evaluation model for the contribution of forests to the landslide susceptibility of different grades based on survey data for forest land change in Bijie City and landslide susceptibility data, and discuss the effects of forest land type, origin, age group, and dominant tree species on landslide susceptibility. We find that forests play a certain role in regulating landslide susceptibility: compared with woodland, the landslide protection ability of shrubland is stronger. Furthermore, natural forests have a greater inhibitory effect on landslides than artificial forests, and compared with young forest, mature forest and over-mature forest, middle-aged forest and near-mature forest have stronger landslide protection abilities. In addition, the dominant tree species in different regions have different impacts on landslides. Coniferous forests such as Chinese fir and Cryptomeria fortunei in Qixingguan and Dafang County have a low ability to prevent landslides. Moreover, the soft broad tree species found in Qianxi County, Zhijin County, Nayong County and Jinsha County are likely to cause landslides and deserve further research attention. Additionally, a greater focus should be placed on the landslide protection of walnut economic forests in Hezhang County and Weining County. Simultaneously, greater attention should be paid to the Cyclobalanopsis glauca tree species in Weining County because the area where this tree species is located is prone to landslides. Aiming at addressing the landslide susceptibility existing in different forests, we propose forest management strategies for the ecological prevention and control of landslides in Bijie City, which can be used as a reference for landslide susceptibility prevention and control. Full article

(This article belongs to the Special Issue Landslides in Forests around the World: Causes and Mitigation)

► Show Figures

Figure 1

20 pages, 3585 KiB

Open AccessArticle

Fire Impact on Carbon Pools and Basic Properties of Retisols in Native Spruce Forests of the European North and Central Siberia of Russia

by Viktor V. Startsev, Evgenia V. Yakovleva, Ivan N. Kutyavin and Alexey A. Dymov

Forests 2022, 13(7), 1135; https://doi.org/10.3390/f13071135 - 19 Jul 2022

Cited by 3 | Viewed by 1556

Abstract

Fires play an important role in the modern dynamics of boreal ecosystems. The article presents the results of studying the effect of old fires on soils and soil organic matter (SOM) of native spruce forests that were last affected by fires in the [...] Read more.

Fires play an important role in the modern dynamics of boreal ecosystems. The article presents the results of studying the effect of old fires on soils and soil organic matter (SOM) of native spruce forests that were last affected by fires in the previous 100 to 200 years. The studies were carried out in the European north-east of Russia (Komi Republic) and Central Siberia (Krasnoyarsk region). The objects of the study were typical Glossic Stagnic Retisol (Siltic, Cutanic). The time after the fire was determined by dendrochronological methods. Data on the content of water-soluble organic matter and densimetric fractions of soils were obtained; carbon and nitrogen stocks were calculated. The content of polycyclic aromatic hydrocarbons (PAHs) was established to characterize the effect of fires. Pyrogenic carbonaceous inclusions were morphologically diagnosed 200 years after the fire. In this regard, it is proposed to distinguish a “pyrogenic” subtype for soils with pronounced signs of pyrogenesis. Carbon stocks in soils of the Komi Republic varied from 5.7 to 15.7 kg C m⁻², and soils of the Krasnoyarsk region had an accumulation of 6.9–12.5 kg C m⁻². The contribution of the pyrogenic horizon Epyr to the total carbon and nitrogen stocks was 9–45%. It is suggested that pyrogenic carbon (PyC) can accumulate in light densimetric fractions (fPOM_<1.6 and oPOM_<1.6). The analysis of PAH content showed their high concentrations in the organic and upper mineral horizons of the studied soils (24 to 605 ng g⁻¹). The coefficient FLA (fluoranthene)/(FLA+PYR(pyrene)) was the most useful to diagnose the pyrogenic origin of PAHs in the studied Retisols. Full article

(This article belongs to the Special Issue Soil Organic Matter and Nutrient Cycling in Forests)

► Show Figures

Figure 1

19 pages, 12194 KiB

Open AccessArticle

Measuring and Modeling the Effect of Strip Cutting on the Water Table in Boreal Drained Peatland Pine Forests

by Leena Stenberg, Kersti Leppä, Samuli Launiainen, Annamari (Ari) Laurén, Hannu Hökkä, Sakari Sarkkola, Markku Saarinen and Mika Nieminen

Forests 2022, 13(7), 1134; https://doi.org/10.3390/f13071134 - 19 Jul 2022

Cited by 1 | Viewed by 1670

Abstract

Strip-cutting management has been proposed as an alternative to clear-cuts in drained boreal peatland pine (Pinus sylvestris L.) forests. We explored the hydrological feasibility of strip cutting, that is, under which conditions the post-harvest water table (WT) in peat remains sufficiently deep [...] Read more.

Strip-cutting management has been proposed as an alternative to clear-cuts in drained boreal peatland pine (Pinus sylvestris L.) forests. We explored the hydrological feasibility of strip cutting, that is, under which conditions the post-harvest water table (WT) in peat remains sufficiently deep (here, a WT of −0.35 m during the late growing season) to enable undisturbed tree growth. We approached the question by (1) measuring the WTs in a harvested strip and an adjacent unharvested stand in peatland forests in southern Finland and (2) by simulating the WTs in different strip cut layouts, unharvested peatland, and clear-cut cases using a process-based hydrological model. The measured WTs were, on average, 0.06–0.12 m closer to the peat surface in the harvested strips than in the unharvested stands. The hydrological feasibility of strip cutting increased along with increasing site productivity and improving climate conditions. Strip cutting resulted in the rise in the WTs of adjacent unharvested stands, which can have undesired consequences. Depending on the stand density and strip cut layout, the share of the well-drained area in the harvested strips was slightly larger or even two times larger compared to a complete clear-cut of the forest. Narrow strips (here, 13 m in width) indicated better drainage in the harvested area than wider (20–30 m in width) strips. Even though strip cutting has limited capacity to maintain efficient drainage in the harvested strip on low hydraulic conductivity peat, the increase in the WT was smaller than after clear-cut. Full article

(This article belongs to the Special Issue Forest Management, Hydrology and Biogeochemistry Modelling)

► Show Figures

Figure 1

16 pages, 4599 KiB

Open AccessArticle

Comparative Research on Forest Fire Image Segmentation Algorithms Based on Fully Convolutional Neural Networks

by Ziqi Wang, Tao Peng and Zhaoyou Lu

Forests 2022, 13(7), 1133; https://doi.org/10.3390/f13071133 - 19 Jul 2022

Cited by 15 | Viewed by 2486

Abstract

In recent years, frequent forest fires have plagued countries all over the world, causing serious economic damage and human casualties. Faster and more accurate detection of forest fires and timely interventions have become a research priority. With the advancement in deep learning, fully [...] Read more.

In recent years, frequent forest fires have plagued countries all over the world, causing serious economic damage and human casualties. Faster and more accurate detection of forest fires and timely interventions have become a research priority. With the advancement in deep learning, fully convolutional network architectures have achieved excellent results in the field of image segmentation. More researchers adopt these models to segment flames for fire monitoring, but most of the works are aimed at fires in buildings and industrial scenarios. However, there are few studies on the application of various fully convolutional models to forest fire scenarios, and comparative experiments are inadequate. In view of the above problems, on the basis of constructing the dataset with remote-sensing images of forest fires captured by unmanned aerial vehicles (UAVs) and the targeted optimization of the data enhancement process, four classical semantic segmentation models and two backbone networks are selected for modeling and testing analysis. By comparing inference results and the evaluation indicators of models such as mPA and mIoU, we can find out the models that are more suitable for forest fire segmentation scenarios. The results show that the U-Net model with Resnet50 as a backbone network has the highest segmentation accuracy of forest fires with the best comprehensive performance, and is more suitable for scenarios with high-accuracy requirements; the DeepLabV3+ model with Resnet50 is slightly less accurate than U-Net, but it can still ensure a satisfying segmentation performance with a faster running speed, which is suitable for scenarios with high real-time requirements. In contrast, FCN and PSPNet have poorer segmentation performance and, hence, are not suitable for forest fire detection scenarios. Full article

(This article belongs to the Section Forest Inventory, Modeling and Remote Sensing)

► Show Figures

Figure 1

22 pages, 5153 KiB

Open AccessArticle

Loss of Relict Oak Forests along Coastal Louisiana: A Multiyear Analysis Using Google Earth Engine

by Paurava Thakore, Parusha Raut and Joydeep Bhattacharjee

Forests 2022, 13(7), 1132; https://doi.org/10.3390/f13071132 - 18 Jul 2022

Cited by 1 | Viewed by 1663

Abstract

Coastal forests along the southeastern Gulf of Mexico are known to be diminishing at an alarming rate. The live-oak dominant chenier forests of southeast Louisiana are amongst those exhibiting the steepest declines. The remnant stands have experienced numerous hurricanes and intense storm events [...] Read more.

Coastal forests along the southeastern Gulf of Mexico are known to be diminishing at an alarming rate. The live-oak dominant chenier forests of southeast Louisiana are amongst those exhibiting the steepest declines. The remnant stands have experienced numerous hurricanes and intense storm events in recent years, calling into question the current status and immediate future of this imperiled natural resource. Despite their noted ecological and physiographic importance, there is a lack within national geographic data repositories of accurate representations of forest loss and wetland extent for this region. Supervised machine learning algorithms in the Google Earth Engine were used to classify and process high-resolution National Agricultural Image Product (NAIP) datasets to create accurate (>90%) tree cover maps of the Louisiana Chenier Plains in Cameron and Vermilion Parishes. Data from three different years (2003, 2007, and 2019) were used to map 2302 km² along the southwestern coast of Louisiana. According to the analyses, there was a 35.73% loss of forest cover in this region between 2003 and 2019. A majority of the land-use change was from tree cover to saltmarsh, with losses in pastoral land also documented. We found variable rates of loss with respect to elevation. Forest cover losses corresponded strongly to rises in mean sea level. These findings deliver a baseline understanding of the rate of forest loss in this region, highlighting the reduction and potentially the eventual extirpation of this imperiled ecosystem. Full article

(This article belongs to the Section Forest Inventory, Modeling and Remote Sensing)

► Show Figures

Figure 1

12 pages, 2596 KiB

Open AccessArticle

Nematicidal Properties and Chemical Composition of Pinus rigida Mill. Resin against Pinewood Nematodes

by Hwan-Su Hwang, Yi-Re Kim, Jung-Yeon Han and Yong-Eui Choi

Forests 2022, 13(7), 1131; https://doi.org/10.3390/f13071131 - 18 Jul 2022

Cited by 3 | Viewed by 1403

Abstract

Pitch pine (Pinus rigida Mill.) is native to North America and has a strong resistance to pine wood nematodes (PWNs). The PWN resistance mechanism of this tree species has yet to be discovered. In this work, we found that the spreading of [...] Read more.

Pitch pine (Pinus rigida Mill.) is native to North America and has a strong resistance to pine wood nematodes (PWNs). The PWN resistance mechanism of this tree species has yet to be discovered. In this work, we found that the spreading of inoculated PWNs in the branch of P. rigida was significantly suppressed compared to those in the branches of Pinus densiflora (Sieb. et Zucc.) and Pinus koraiensis (Sieb. et Zucc.). Dipping of PWNs in the resins isolated from P. rigida significantly suppressed the PWN mobility and conferred significantly higher PWN mortality compared to those in the resins from P. densiflora and P. koraiensis. All PWNs dipped in P. rigida resin were killed after six days, but more than 50% of the PWNs dipped in the resin from P. densiflora, and P. koraiensis were still alive after six days. The phytochemical analysis of resins revealed that P. rigida resin contained little or no amount of sesquiterpenes compared to those from P. densiflora and P. koraiensis. However, P. rigida resin contained rich amounts of diterpenes, among which dehydroabietic aldehyde, methyl dehydroabietate, and methyl abietate were uniquely detected. Particularly, two pinosylvin stilbenes (trans and cis-3,5-dimethoxystilbene) were accumulated in P. rigida resin, which were not detected in the resins from P. densiflora and P. koraiensis. cis-3,5-Dimethoxystilbene showed high nematicidal activity but not in trans-3,5-dimethoxystilbene. Conclusively, PWN resistance of P. rigida may be due to the toxic chemicals in the resin, in which cis-3,5-dimethoxystilbene may contribute to PWN toxicity. This work is the first demonstration that resin from PWN-resistant P. rigida directly affected PWN mobility and mortality, probably due to toxic phytochemicals in the resin. Full article

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

► Show Figures

Figure 1

12 pages, 2448 KiB

Open AccessArticle

Income and Insurability as Factors in Wildfire Risk

by Matthew Robert Auer and Benjamin Evan Hexamer

Forests 2022, 13(7), 1130; https://doi.org/10.3390/f13071130 - 18 Jul 2022

Cited by 3 | Viewed by 6141

Abstract

The increasing frequency of destructive wildfire incidents in the United States, particularly in the West, is well-documented, and the key causal variables are increasingly well understood. Among stakeholders with heightened concerns about risks from destructive wildfire are insurance companies and the homeowners they [...] Read more.

The increasing frequency of destructive wildfire incidents in the United States, particularly in the West, is well-documented, and the key causal variables are increasingly well understood. Among stakeholders with heightened concerns about risks from destructive wildfire are insurance companies and the homeowners they insure. The cancellation and nonrenewal of insurance due to wildfire risk has received media attention in the wake of major wildfire seasons, particularly in California. However, less attention has been directed to wildfire-related risks borne by lower-income policy holders, specifically. For example, the probability of maintaining or replacing an at-risk policy increases when a homeowner invests in fire protection measures. However, these investments are comparatively costly for lower-income homeowners. The present research aims to identify regions in the lower 48 states where moderate and high wildfire risk, lower income, and insurability are coterminous risks. The concentration of at-risk homes in counties with comparatively high wildfire hazard potential and comparatively higher poverty rates are considered. This paper also considers how the concentrated market share of insurance underwriting may pose a risk to lower income homeowners, considering the overlap between highly concentrated insurance markets and states with high wildfire risk and higher poverty rates. Full article

(This article belongs to the Special Issue New Challenges in Framework for Forest Fire Control)

► Show Figures

Figure 1

13 pages, 2709 KiB

Open AccessArticle

Forest Fire Prediction with Imbalanced Data Using a Deep Neural Network Method

by Can Lai, Shucai Zeng, Wei Guo, Xiaodong Liu, Yongquan Li and Boyong Liao

Forests 2022, 13(7), 1129; https://doi.org/10.3390/f13071129 - 18 Jul 2022

Cited by 12 | Viewed by 2771

Abstract

Forests suffer from heavy losses due to the occurrence of fires. A prediction model based on environmental condition, such as meteorological and vegetation indexes, is considered a promising tool to control forest fires. The construction of prediction models can be challenging due to [...] Read more.

Forests suffer from heavy losses due to the occurrence of fires. A prediction model based on environmental condition, such as meteorological and vegetation indexes, is considered a promising tool to control forest fires. The construction of prediction models can be challenging due to (i) the requirement of selection of features most relevant to the prediction task, and (ii) heavily imbalanced data distribution where the number of large-scale forest fires is much less than that of small-scale ones. In this paper, we propose a forest fire prediction method that employs a sparse autoencoder-based deep neural network and a novel data balancing procedure. The method was tested on a forest fire dataset collected from the Montesinho Natural Park of Portugal. Compared to the best prediction results of other state-of-the-art methods, the proposed method could predict large-scale forest fires more accurately, and reduces the mean absolute error by 3–19.3 and root mean squared error by 0.95–19.3. The proposed method can better benefit the management of wildland fires in advance and the prevention of serious fire accidents. It is expected that the prediction performance could be further improved if additional information and more data are available. Full article

(This article belongs to the Section Natural Hazards and Risk Management)

► Show Figures

Figure 1

15 pages, 3655 KiB

Open AccessArticle

Heritage Trees as an Important Sanctuary for Saproxylic Beetles in the Central European Landscape: A Case Study from Litovelské Pomoraví, Czech Republic

by Oto Nakládal, Václav Zumr, Jiří Remeš, Markéta Macháčová and Vítězslava Pešková

Forests 2022, 13(7), 1128; https://doi.org/10.3390/f13071128 - 18 Jul 2022

Cited by 3 | Viewed by 2354

Abstract

Intensive forest and agroforestry management has greatly reduced the biodiversity of saproxylic organisms. Large trees are one of the most important refuges of saproxylic beetles. These large trees that grow outside and inside the forest are declining in the wider landscape. Heritage trees [...] Read more.

Intensive forest and agroforestry management has greatly reduced the biodiversity of saproxylic organisms. Large trees are one of the most important refuges of saproxylic beetles. These large trees that grow outside and inside the forest are declining in the wider landscape. Heritage trees are one of the essential groups of beneficial trees in the landscape. We investigated saproxylic beetles associated with 35 selected oak heritage trees in Litovelské Pomoraví in the eastern Czech Republic. The study aimed to investigate the distribution of saproxylic beetles on trees growing inside or at the edge of forest stands, or on free-growing heritage trees. The other studied variables were the height, DBH, and light condition (sunny or shady) of heritage trees. The results showed that sunny habitats were the only significant factor found for all saproxylic species. However, the significance of increasing tree trunk dimension was found for the endangered species. Diversity indices q = 0 (species richness) and q = 1 (exponential of Shannon entropy index) were also higher for sunny trees, while solitary trees showed a high Shannon index value despite the low number of samples. Redundancy analysis of saproxylic species showed that the preferred habitats of most species were sunny massive solitary oaks. The results indicated that strictly protected heritage trees scattered in the landscape are crucial sanctuaries for many species—especially in landscapes where there are not enough suitable habitats for saproxylic beetles. Finding, conserving, and protecting these rare types of massive trees in the landscape has a significant impact on the conservation of saproxylic beetle biodiversity. Full article

(This article belongs to the Special Issue Silviculture Measures Needed to Keep Up with Changes in Forests)

► Show Figures

Figure 1

14 pages, 2878 KiB

Open AccessArticle

Influences of Shading on Ascorbic Acid Biosynthesis of Blackcurrant (Ribes nigrum L.)

by Huixin Gang, Danni Zhang, Xiaojuan Sun, Junwei Huo and Dong Qin

Forests 2022, 13(7), 1127; https://doi.org/10.3390/f13071127 - 17 Jul 2022

Cited by 1 | Viewed by 1473

Abstract

Cultivation conditions may greatly affect fruit quality, especially in the accumulation of functional metabolites. Blackcurrant fruits (Ribes nigrum L.) have high ascorbic acid (AsA) concentrations. The purpose of the current study was to investigate the influence of different shading treatments (full sunlight, [...] Read more.

Cultivation conditions may greatly affect fruit quality, especially in the accumulation of functional metabolites. Blackcurrant fruits (Ribes nigrum L.) have high ascorbic acid (AsA) concentrations. The purpose of the current study was to investigate the influence of different shading treatments (full sunlight, and 40% and 60% sunlight) on the fruits’ maturity, and on the levels of fruit firmness, soluble solid, AsA, and enzyme activity involved in AsA biosynthesis and recycling in two blackcurrant (Ribes nigrum) cultivars, ‘Heifeng’ and ‘Adelinia’. Shading conditions of 40% and 60% sunlight delayed fruit ripening and increased fruit firmness in both ‘Adelinia’ and ‘Heifeng’. Soluble solids in ‘Adelinia’ were markedly reduced by shading compared with ‘Heifeng’. Compared with full sunlight, the AsA content was significantly decreased in the ripe fruits under the 40% and 60% shading treatments. Additionally, the AsA content was decreased during the fruit development process under the 60% shading treatment, which was associated with the reduced activity of the enzymes monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione oxidoreductase (GR), ascorbate peroxidase (APX), and L-galactose dehydrogenase (GalDH) involved in the biosynthesis and recycling pathway of AsA. The correlation analysis results showed that the activity of MDHAR, DHAR, GR, APX, and GalDH was significantly positively correlated with AsA concentrations during the 60% shading treatment in ‘Adelinia’ and ‘Heifeng’ fruits, suggesting that AsA biosynthesis and recycling were affected and the two cultivars have similar mechanisms to deal with shading. Our results not only provide a better understanding of the regulation mechanism of AsA accumulation under shading, but also provide a theoretical basis for taking effective cultivation measures aimed at the improvement of AsA levels in blackcurrant fruits. Full article

(This article belongs to the Special Issue Physiological Responses of Trees to Biotic and Abiotic Stresses)

► Show Figures

Figure 1

15 pages, 1431 KiB

Open AccessArticle

Motivations and Trade-Offs for Sustainability in Family Forestry and Tourism Firms: A Cross-National Survey

by William Nikolakis, Doina Olaru, Lisandro Roco and René Reyes

Forests 2022, 13(7), 1126; https://doi.org/10.3390/f13071126 - 17 Jul 2022

Viewed by 1322

Abstract

Family firms are the foundation of economies across the world. Yet, little is understood about what motivates sustainability in these firms, particularly in developing economies. In this study, we examine family forestry and tourism firms in Chile and India and use a novel [...] Read more.

Family firms are the foundation of economies across the world. Yet, little is understood about what motivates sustainability in these firms, particularly in developing economies. In this study, we examine family forestry and tourism firms in Chile and India and use a novel stated-choice method to understand preferences for sustainability and the trade-offs with profit maximization, law and regulation, and family relations (among others). There were heterogeneous preferences across the sample, with respondents favoring financial outcomes and viewing regulation negatively. Respondents preferred positive environmental impacts, and this was significantly favored by tourism firms. Forestry firms were particularly focused on maintaining satisfactory family relationships, where there was stronger family involvement in the firm’s management decisions. Indian respondents were more likely to prefer the expansion option in the choice study (financial outcomes), while Chileans preferred the eco-labeling choice (sustainability), suggesting more supportive sustainability norms in Chile. Chileans were more likely to exceed legal compliance in their choice selection and favored positive environmental impacts more. Overall, tourism firms were larger in terms of revenues and favored the eco-labeling choice with positive environmental impacts but with minimal regulations, while forestry favored expansion. These differences may be driven by the resources available to tourism firms for supporting sustainability measures and the importance of sustainability to their business models. Policies to support sustainability among family firms must account for their heterogeneity and must provide supports and incentives rather than regulations to facilitate sustainability. Full article

(This article belongs to the Section Forest Economics, Policy, and Social Science)

► Show Figures

Figure 1

20 pages, 12203 KiB

Open AccessArticle

Spring and Autumn Phenology in Sessile Oak (Quercus petraea) Near the Eastern Limit of Its Distribution Range

by Ioana Maria Gafenco (Pleșca), Bogdan Ionuț Pleșca, Ecaterina Nicoleta Apostol and Neculae Șofletea

Forests 2022, 13(7), 1125; https://doi.org/10.3390/f13071125 - 17 Jul 2022

Cited by 3 | Viewed by 1967

Abstract

Due to the visible and predictable influence of climate change on species’ spatial distributions, the conservation of marginal peripheral populations has become topical in forestry research. This study aimed to assess the spring (budburst, leaf development, and flowering) and autumn (leaf senescence) phenology [...] Read more.

Due to the visible and predictable influence of climate change on species’ spatial distributions, the conservation of marginal peripheral populations has become topical in forestry research. This study aimed to assess the spring (budburst, leaf development, and flowering) and autumn (leaf senescence) phenology of sessile oak (Quercus petraea), a species widespread across European forests close to its ranges’ eastern limit. This study was performed in Romania between spring 2017 and 2020, and it included a transect with three low-altitude populations, a reference population from its inner range, and a sessile oak comparative trial. The temperature was recorded to relate changes to phenophase dynamics. We identified small variations between the reference and peripheral populations associated with climatic conditions. In the peripheral populations, budburst timing had day-of-year (DOY) values <100, suggesting that sessile oak may be more susceptible to late spring frost. Furthermore, we found spring phenophase timing to be more constant than autumn senescence. Moreover, budburst in the sessile oak comparative trial had obvious longitudinal tendencies, with an east to west delay of 0.5–1.4 days per degree. In addition, budburst timing influenced leaf development and flowering, but not the onset of leaf senescence. These findings improve our understanding of the relationship between spring and autumn phenophase dynamics and enhance conservation strategies regarding sessile oak genetic resources. Full article

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

► Show Figures

Figure 1

11 pages, 1494 KiB

Open AccessArticle

Protocol for In Vitro Propagation of Salix acmophylla (Boiss.). Studies on Three Ecotypes

by Maurizio Capuana, Werther Guidi Nissim and Joshua D. Klein

Forests 2022, 13(7), 1124; https://doi.org/10.3390/f13071124 - 17 Jul 2022

Cited by 5 | Viewed by 1854

Abstract

Salix acmophylla Boiss. has a traditional role in several regions of the Middle East and the Indian subcontinent. As with many other woody species, the development of methods for fast propagation and ex situ conservation of this species is needed. We describe for [...] Read more.

Salix acmophylla Boiss. has a traditional role in several regions of the Middle East and the Indian subcontinent. As with many other woody species, the development of methods for fast propagation and ex situ conservation of this species is needed. We describe for the first time a micropropagation protocol of three S. acmophylla ecotypes. The best results for shoot proliferation were obtained by culturing the shoot explants on Woody Plant Medium (WPM) containing benzyladenine (BA) 5 μM, but it was also observed that proliferation can be further enhanced by the separation of the shoot tip from the underlying internodes, followed by their respective culture on BA- or activated-charcoal-containing medium. Thidiazuron or zeatin did not enhance shoot proliferation. The rooting of shoots occurred spontaneously, but for the ecotype with a lower propensity for rooting, treatment with 5 μM indolebutyric acid (IBA) increased rooting percentage. Genetic differences were evident in rooting success, but not in shoot development of the tested ecotypes in response to in vitro cultural conditions. Full article

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

► Show Figures

Figure 1

Journal Menu

Journal Browser

Forests, Volume 13, Issue 7 (July 2022) – 188 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI