Forests

17 pages, 614 KiB

Open AccessArticle

Two Male Poplar Clones (Populus × euramericana ‘Siyang-1’ and Populus deltoides ‘Nanlin 3804’) Exhibit Distinctly Different Physiological Responses to Soil Water Deficit

by Lintao Tang, Pei Cao, Shuo Zhang, Xiaopeng Liu, Xiaomin Ge and Luozhong Tang

Forests 2024, 15(7), 1142; https://doi.org/10.3390/f15071142 (registering DOI) - 29 Jun 2024

Viewed by 40

Abstract

Poplar is a globally important industrial tree species due to its fast growth and abundant applications. However, poplars require sufficient water during the growing season, and drought usually limits their production. Drought caused by climate change poses a serious threat to widely planted [...] Read more.

Poplar is a globally important industrial tree species due to its fast growth and abundant applications. However, poplars require sufficient water during the growing season, and drought usually limits their production. Drought caused by climate change poses a serious threat to widely planted poplar plantations, making it crucial to clarify and improve the drought resistance of poplars. We employed two male poplar clones, namely, Siyang-1 (Populus × euramericana ‘Siyang-1’) and NL3804 (Populus deltoides ‘Nanlin 3804’), to investigate the growth and physiological responses of these clones to soil drought stress within 25 days. Under drought treatment, both clones experienced a significant reduction in height growth and biomass accumulation, with Siyang-1 exhibiting a more substantial decrease. Under drought treatment, Siyang-1 allocated more assimilates to roots than NL3804. Compared with Siyang-1, NL3804 wilted earlier and had a significantly higher wilting coefficient (p < 0.05). Siyang-1 had higher peroxidase (POD) activity in leaves under drought stress, while NL3804 had a greater increase in membrane permeability. Drought stress increased P absorption and decreased K absorption in both clones but had no significant effect on N absorption. The translocation of limited N and K resources into the stems and roots, as well as the increased uptake of P by the roots, can contribute to defending against drought for poplars. Siyang-1 enhances its drought resistance by modulating its nutrient status and slowing its growth rate, whereas NL3804 accumulates more biomass in the drought stage but perishes sooner, due to imbalances in water and antioxidant systems. Full article

(This article belongs to the Special Issue Abiotic Stress in Tree Species)

19 pages, 5048 KiB

Open AccessArticle

Responses of Physiological Traits and Soil Properties in Pinus thunbergia and Euonymus japonicus Saplings under Drought and Cadmium (Cd) Stress

by Shan Li, Jing Wang, Sen Lu, Huan Li and Junkang Guo

Forests 2024, 15(7), 1141; https://doi.org/10.3390/f15071141 (registering DOI) - 29 Jun 2024

Viewed by 105

Abstract

Pinus thunbergii and Euonymus japonicus are two species commonly found in arid and semi-arid areas; however, their responses in terms of physiological traits and soil properties under drought and cadmium (Cd) stress are not clear. In this study, we carried out single and [...] Read more.

Pinus thunbergii and Euonymus japonicus are two species commonly found in arid and semi-arid areas; however, their responses in terms of physiological traits and soil properties under drought and cadmium (Cd) stress are not clear. In this study, we carried out single and combined stress treatments consisting of drought and Cd on saplings of P. thunbergii and E. japonicus and investigated the responses in terms of the physiological traits and soil properties of both species. For both species, under single Cd stress, Cd was observed in both the xylem and phloem, while the root Cd²⁺ flow rate fluctuated at different levels of Cd stress. Under both single and combined stress, as the stress level increased, the abscisic acid (ABA) content of the leaves and roots increased significantly, while the indole-3-acetic acid (IAA) content of the leaves and roots decreased significantly. Moreover, the non-structural carbohydrate (NSC) content of the leaves, stems, and roots, as well as the leaf chlorophyll content, decreased significantly. Under drought stress, the xylem water potential and hydraulic conductivity significantly decreased, which was exacerbated by Cd stress; this led to a more significant decrease in water potential and hydraulic conductivity under the combined stresses. Meanwhile, no significant changes in the conduit lumen diameter and double-wall thickness were observed, except for the double cell wall thickness of the P. thunbergii tracheid, which increased. In addition, both the single stresses and the combined stress of drought and Cd induced significant changes in the soil properties of the two species, i.e., the ammonium nitrogen, nitrate nitrogen, and effective phosphorus of the soil increased significantly, and the increase in content was more significant under combined stress. The diversity of the soil microbial community of P. thunbergii saplings significantly increased, while no change was found in its microbial community abundance under the single stresses and combined stress; however, the diversity and abundance of the soil microbial community in E. japonicus saplings showed the opposite pattern, which indicates that the effect of Cd on soil microorganisms is more significant than the effect of drought. The activity of sucrase and catalase in P. thunbergii soil fluctuated under the single stress and combined stress when compared, and the activity of sucrase in the soil of the E. japonicus species decreased. However, its catalase activity increased significantly under the single drought and Cd stress and combined stress when compared. We found that the combined stresses exacerbated the effects of the single stress in both species. Our study provides more detailed information on the responses in terms of the physiological traits and soil properties of the two species under single and combined stress consisting of drought and Cd. Full article

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

23 pages, 10665 KiB

Open AccessArticle

The Impact of Artificial Afforestation on the Soil Microbial Community and Function in Desertified Areas of NW China

by Yan Li, Lamei Jiang, Hongfei Yuan, Eryang Li and Xiaodong Yang

Forests 2024, 15(7), 1140; https://doi.org/10.3390/f15071140 (registering DOI) - 29 Jun 2024

Viewed by 123

Abstract

Afforestation is a widely used method of controlling desertification globally as it significantly impacts the soil quality, microbial community structure, and function. Investigating the effects of various artificial vegetation restoration models on soil microbial communities is crucial in understanding the mechanisms involved in [...] Read more.

Afforestation is a widely used method of controlling desertification globally as it significantly impacts the soil quality, microbial community structure, and function. Investigating the effects of various artificial vegetation restoration models on soil microbial communities is crucial in understanding the mechanisms involved in combating desertification. However, research on this topic in arid, desertified regions is limited. In this study, we collected soil samples from two types of artificial forests (single species and mixed species) and bare desert soils in desertified areas of Northwest China to explore the impact of afforestation on soil nutrients, the microbial community composition, network relationships, and carbohydrate degradation abilities using metagenomic sequencing techniques. Our findings indicate that afforestation significantly enhances the soil moisture, total carbon, available phosphorus, and total nitrogen levels. The soil under mixed-species forests exhibited significantly higher levels of total carbon, total phosphorus, available phosphorus, and total nitrogen than that under single-species forests. Following afforestation, the populations of Pseudomonadota, Acidobacteriota, and Cyanobacteria increased significantly, whereas Actinomycetota decreased markedly. In single-species forests, Pseudomonadota and Bacillota were enriched, whereas Chloroflexota, Planctomycetota, and Acidobacteriota were more prevalent in mixed-species plantations. Afforestation increases the complexity and stability of microbial community networks. Afforestation enhances microbial metabolic activity, particularly increasing the abundance of carbon degradation functional genes in forest soils compared to bare desert soils. Mixed-species plantations outperform single-species forests in enhancing carbohydrate metabolism, amino acid metabolism, and the biodegradation and metabolism of xenobiotics. The abundance of functional genes associated with the degradation of starch, cellulose, hemicellulose, chitin, and pectin in mixed-species forests was significantly greater than in single-species plantations. Our study shows that mixed-species afforestation effectively improves the soil quality, enhances the stability of soil microbial communities, and bolsters the carbon cycle in arid regions prone to desertification. The reciprocal relationship between microorganisms and plants may serve as an intrinsic mechanism by which mixed-species afforestation more effectively controls desertification. Full article

(This article belongs to the Section Forest Soil)

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18 pages, 5485 KiB

Open AccessArticle

Stress Wave Hybrid Imaging for Detecting Wood Internal Defects under Sparse Signals

by Xiaochen Du, Yilei Zheng and Hailin Feng

Forests 2024, 15(7), 1139; https://doi.org/10.3390/f15071139 (registering DOI) - 29 Jun 2024

Viewed by 119

Abstract

Stress wave technology is very suitable for detecting internal defects of standing trees, logs, and wood and has gradually become the mainstream technology in this research field. Usually, 12 sensors are positioned equidistantly around the cross-section of tree trunks in order to obtain [...] Read more.

Stress wave technology is very suitable for detecting internal defects of standing trees, logs, and wood and has gradually become the mainstream technology in this research field. Usually, 12 sensors are positioned equidistantly around the cross-section of tree trunks in order to obtain enough stress wave signals. However, the arrangement of sensors is time-consuming and laborious, and maintaining the accuracy of stress wave imaging under sparse signals is a challenging problem. In this paper, a novel stress wave hybrid imaging method based on compressive sensing and elliptic interpolation is proposed. The spatial structure of the defective area is reconstructed by using the advantages of compressive sensing in sparse signal representation and solution of stress waves, and the healthy area is reconstructed by using the elliptic space interpolation method. Then, feature points are selected and mixed for imaging. The comparative experimental results show that the overall imaging accuracy of the proposed method reaches 89.7%, and the high-quality imaging effect can be guaranteed when the number of sensors is reduced to 10, 8, or even 6. Full article

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

13 pages, 13437 KiB

Open AccessArticle

Pinus banksiana Lamb. Regeneration Patterns in a Lacustrine Dune System

by Jonathan C. Danielson, Adam R. Warrix, Madison E. Lehman, Andrew C. Lehman and Jordan M. Marshall

Forests 2024, 15(7), 1138; https://doi.org/10.3390/f15071138 (registering DOI) - 29 Jun 2024

Viewed by 107

Abstract

Successional patterns in lacustrine sand dunes along Lake Superior begin with grass-dominated plant communities leading to the establishment of Pinus banksiana Lamb. as initial forests. Using maximum entropy models, we predicted P. banksiana seedling and sapling patterns within the Grand Sable Dunes, Pictured [...] Read more.

Successional patterns in lacustrine sand dunes along Lake Superior begin with grass-dominated plant communities leading to the establishment of Pinus banksiana Lamb. as initial forests. Using maximum entropy models, we predicted P. banksiana seedling and sapling patterns within the Grand Sable Dunes, Pictured Rocks National Lakeshore, USA, based on slope, aspect, forest basal area, and vegetation types. Across the different vegetation types, there were variable probabilities of seedling and sapling occurrence. For both seedlings and saplings, the higher likelihoods of occurrence were observed in coastal pine barrens vegetation types. P. banksiana regeneration is occurring in the Grand Sable Dunes in the absence of fire, with seedlings establishing and saplings being recruited in a variety of vegetation types. With the greatest probabilities in barrens, there is likely a relationship with seed source and canopy density. Understanding regeneration patterns in dune ecosystems is necessary to predict the future forest arrangement and colonization of P. banksiana into the dunes. These results contribute insights into the dynamics of plant communities in lacustrine dune systems, specifically the establishment of P. banksiana seedlings in various vegetation types. Continued forest establishment and increasing P. banksiana density will influence endangered species and non-native species management strategies for Pictured Rocks National Lakeshore. Full article

(This article belongs to the Special Issue Impact of Disturbance on Forest Regeneration and Recruitment)

19 pages, 6886 KiB

Open AccessArticle

SIMCB-Yolo: An Efficient Multi-Scale Network for Detecting Forest Fire Smoke

by Wanhong Yang, Zhenlin Yang, Meiyun Wu, Gui Zhang, Yinfang Zhu and Yurong Sun

Forests 2024, 15(7), 1137; https://doi.org/10.3390/f15071137 (registering DOI) - 29 Jun 2024

Viewed by 109

Abstract

Abstract: Forest fire monitoring plays a crucial role in preventing and mitigating forest disasters. Early detection of forest fire smoke is essential for a timely response to forest fire emergencies. The key to effective forest fire monitoring lies in accounting for the [...] Read more.

Abstract: Forest fire monitoring plays a crucial role in preventing and mitigating forest disasters. Early detection of forest fire smoke is essential for a timely response to forest fire emergencies. The key to effective forest fire monitoring lies in accounting for the various levels of forest fire smoke targets in the monitoring images, enhancing the model’s anti-interference capabilities against mountain clouds and fog, and reducing false positives and missed detections. In this paper, we propose an improved multi-level forest fire smoke detection model based on You Only Look Once v5s (Yolov5s) called SIMCB-Yolo. This model aims to achieve high-precision detection of forest fire smoke at various levels. First, to address the issue of low precision in detecting small target smoke, a Swin transformer small target monitoring head is added to the neck of Yolov5s, enhancing the precision of small target smoke detection. Then, to address the issue of missed detections due to the decline in conventional target smoke detection accuracy after improving small target smoke detection accuracy, we introduced a cross stage partial network bottleneck with three convolutional layers (C3) and a channel block sequence (CBS) into the trunk. These additions help extract more surface features and enhance the detection accuracy of conventional target smoke. Finally, the SimAM attention mechanism is introduced to address the issue of complex background interference in forest fire smoke detection, further reducing false positives and missed detections. Experimental results demonstrate that, compared to the Yolov5s model, the SIMCB-Yolo model achieves an average recognition accuracy (mAP50) of 85.6%, an increase of 4.5%. Additionally, the mAP50-95 is 63.6%, an improvement of 6.9%, indicating good detection accuracy. The performance of the SIMCB-Yolo model on the self-built forest fire smoke dataset is also significantly better than that of current mainstream models, demonstrating high practical value. Full article

(This article belongs to the Special Issue Forest Fires Prediction and Detection—2nd Edition)

14 pages, 848 KiB

Open AccessArticle

Changes in Soil Hydrological Retention Properties and Controlling Factors on Shaded and Sunny Slopes in Semi-Arid Alpine Woodlands

by Qi Liu, Zhaoming Chen, Shengli Wang, Tiantian Liang, Zhongyuan Gao and Yinwen Dong

Forests 2024, 15(7), 1136; https://doi.org/10.3390/f15071136 (registering DOI) - 29 Jun 2024

Viewed by 97

Abstract

Slope orientation significantly influences soil’s physicochemical properties and the soil hydrological environment. However, the regulatory mechanisms and effects, particularly in semi-arid highlands, remain poorly understood. This study investigated soil physicochemical and hydrological properties on shaded and sunny slopes. Results indicated that in the [...] Read more.

Slope orientation significantly influences soil’s physicochemical properties and the soil hydrological environment. However, the regulatory mechanisms and effects, particularly in semi-arid highlands, remain poorly understood. This study investigated soil physicochemical and hydrological properties on shaded and sunny slopes. Results indicated that in the 0–20 cm soil layer, the water-holding capacity was higher on sunny slopes, while water retention in the 10–20 cm layer was significantly higher on shaded slopes. This suggests that vegetation on shaded slopes experiences less soil erosion due to higher topsoil water retention. Additionally, slope orientation altered soil properties: the electrical conductivity (EC) of the 0–20 cm soil layer was significantly higher on shaded slopes. Nutrient elements such as Ca, Cu, and Zn were also relatively higher on shaded slopes, whereas soil organic matter was significantly lower compared to sunny slopes. Overall, soil water-holding capacity and supply were primarily controlled by EC, followed by capillary porosity and nutrient elements like Ca, Mn, and Fe. Therefore, slope orientation has a significant effect on soil hydrological properties, with stronger topsoil water retention on shaded slopes. These findings offer valuable insights for vegetation restoration in semi-arid highland ecosystems. Full article

(This article belongs to the Special Issue Physical, Chemical and Biological Properties of Soil for Ecological and Environmental Restoration)

20 pages, 5043 KiB

Open AccessArticle

Spatio-Temporal Analysis of Erosion Risk Assessment Using GIS-Based AHP Method: A Case Study of Doğancı Dam Watershed in Bursa (Türkiye)

by Esin Erdoğan Yüksel, Ömer Faruk Karan and Abdullah Emin Akay

Forests 2024, 15(7), 1135; https://doi.org/10.3390/f15071135 (registering DOI) - 29 Jun 2024

Viewed by 101

Abstract

Soil erosion, one of the most serious phenomena in watershed management, can be estimated based on various criteria. Land use change is one of the most important factors affecting the susceptibility of soil erosion. In this study, the effect of land use change [...] Read more.

Soil erosion, one of the most serious phenomena in watershed management, can be estimated based on various criteria. Land use change is one of the most important factors affecting the susceptibility of soil erosion. In this study, the effect of land use change on soil erosion risk in two plan periods (2005 and 2017) was investigated using Analytical Hierarchy Process (AHP) and Geographic Information Systems (GIS) for the forest planning units in the Doğancı Dam Watershed, located in Bursa, Türkiye. Eight criteria were evaluated including erosion-related slope, bedrock type, land use/land cover, precipitation, relative relief, aspect, drainage frequency, and density. According to the results, the most effective factor in soil erosion was slope (0.29), while bedrock type and land use/land cover ranked second with 0.19. It was found that full closure forests were characterized by high erosion resistance (0.3), while bare land was characterized as the most sensitive area to erosion (0.39). In terms of spatio-temporal changes in a 12-year period, the areas in the medium and high erosion risk decreased, while low and very low-risk areas increased. The ROC method showed a satisfactory accuracy of 72.8% and 80.2% for the 2005 and 2017 erosion risk maps, respectively. Full article

(This article belongs to the Topic Spatial Patterns of Disaster Risk Assessment via Remote Sensing)

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26 pages, 1401 KiB

Open AccessArticle

Evaluation of the Restoration Effects of Rooftop Greening Areas Created by Applying an Ecological Restoration Method

by Dong Uk Kim, Songhie Jung, Gyung Soon Kim, Bong Soon Lim and Chang Seok Lee

Forests 2024, 15(7), 1134; https://doi.org/10.3390/f15071134 (registering DOI) - 28 Jun 2024

Viewed by 232

Abstract

Green roofs provide various ecosystem services, including habitats for diverse organisms in urban areas where natural space is very scarce. This study aims to evaluate the restoration effects of green roofs created by applying an ecological restoration method to reinforce habitat function. The [...] Read more.

Green roofs provide various ecosystem services, including habitats for diverse organisms in urban areas where natural space is very scarce. This study aims to evaluate the restoration effects of green roofs created by applying an ecological restoration method to reinforce habitat function. The reference ecosystem selected for the ecological restoration of a roof was a Korean red pine stand established on Mt. Bulam, considering the soil depth, light, moisture conditions, etc., compared with the roof’s environmental conditions. Ecological restoration was carried out by planting two-year-old pine seedlings and scattering surface soil collected from the pine stands. The pine trees showed geometrical growth in height and diameter and a high water-use efficiency. The ecological restoration of the green roofs demonstrated an ecological function for improving the urban climate through the mitigation of the urban heat island effect and high productivity, showing different functions depending on the greening method. The composition and diversity of vegetation and insects at the ecological restoration site were similar to those at the reference site, whereas the landscape architecture sites, which were created using the landscape architecture method, were different from the reference site. These results confirm that applying the ecological restoration method for rooftop greening resulted in better biological habitat function than applying existing landscape architecture methods. Full article

(This article belongs to the Section Forest Soil)

23 pages, 2031 KiB

Open AccessArticle

Individual Tree Identification and Segmentation in Pinus spp. Stands through Portable LiDAR

by Ana Solares-Canal, Laura Alonso, Juan Picos and Julia Armesto

Forests 2024, 15(7), 1133; https://doi.org/10.3390/f15071133 (registering DOI) - 28 Jun 2024

Viewed by 217

Abstract

Forest inventories are essential for sustainable forest management. In inventories at the tree level, all the information is linked to individuals: species, diameter, height, or spatial distribution, for example. Currently, the implementation of Portable LiDAR (PLS) is being studied, aiming to digitalize forest [...] Read more.

Forest inventories are essential for sustainable forest management. In inventories at the tree level, all the information is linked to individuals: species, diameter, height, or spatial distribution, for example. Currently, the implementation of Portable LiDAR (PLS) is being studied, aiming to digitalize forest environments and increase the reliability of forest observations. Performing automatic individual tree identification (ITD) and segmentation (ITS) is essential for the operational implementation of PLS in forestry. Multiple algorithms have been developed for performing these tasks in LiDAR point clouds. Their performance varies according to the LiDAR system and the characteristics of the stand. In this study, the performance of several ITD and ITS algorithms is analyzed in very high-density PLS point clouds in Pinus species stands with a varying presence of understory, shrubs, and branches. The results showed that ITD methods based on finding trunks are more suitable for tree identification in regular stands with no understory. In the ITS process, the methods evaluated are highly conditioned by the presence of understory and branches. The results of this comparison help to identify the most suitable algorithm to be applied to these types of stands, and hence, they might enhance the operability of PLS systems. Full article

(This article belongs to the Special Issue Application of Close-Range Sensing in Forestry)

20 pages, 6330 KiB

Open AccessArticle

Forest Canopy Height Retrieval Model Based on a Dual Attention Mechanism Deep Network

by Zongze Zhao, Baogui Jiang, Hongtao Wang and Cheng Wang

Forests 2024, 15(7), 1132; https://doi.org/10.3390/f15071132 (registering DOI) - 28 Jun 2024

Viewed by 235

Abstract

Accurate estimation of forest canopy height is crucial for biomass inversion, carbon storage assessment, and forestry management. However, deep learning methods are underutilized compared to machine learning. This paper introduces the convolutional neural network–bidirectional long short-term memory (CNN-BiLSTM) model and proposes a Convolutional [...] Read more.

Accurate estimation of forest canopy height is crucial for biomass inversion, carbon storage assessment, and forestry management. However, deep learning methods are underutilized compared to machine learning. This paper introduces the convolutional neural network–bidirectional long short-term memory (CNN-BiLSTM) model and proposes a Convolutional Neural network–spatial channel attention–bidirectional long short-term memory (CNN-SCA-BiLSTM) model, incorporating dual attention mechanisms for richer feature extraction. A dataset comprising vegetation indices and canopy height data from forest regions in Luoyang, specifically within the 8–20 m range, is used for a comparative analysis of multiple models, with accuracy evaluated based on the mean absolute error (MAE), root mean square error (RMSE), and coefficient of determination (R²). The results demonstrate that (1) the CNN-BiLSTM model exhibits strong potential (MAE = 1.6554 m, RMSE = 2.2393 m, R²= 0.9115) and (2) the CNN-SCA-BiLSTM model, while slightly less efficient (<1%), demonstrates improved performance. It reduces the MAE by 0.3047 m, the RMSE by 0.6420 m, and increases the R² value by 0.0495. Furthermore, the model is utilized to generate a canopy height map (MAE = 5.2332 m, RMSE = 7.0426 m) for Henan in the Yellow River Basin for the year 2022. The canopy height is primarily distributed around 5–20 m, approaching the accuracy levels of global maps (MAE = 4.0 m, RMSE = 6.0 m). Full article

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

19 pages, 2598 KiB

Open AccessArticle

Disturbance Effect of Highway Construction on Vegetation in Hexi Corridor, North-Western China

by Zhenhua Han, Luqing Zhang, Fenxiang Zhang, Jian Zhou and Song Wang

Forests 2024, 15(7), 1131; https://doi.org/10.3390/f15071131 (registering DOI) - 28 Jun 2024

Viewed by 162

Abstract

The ecological environment of the Hexi Corridor in China is fragile owing to its unique geographical conditions. Since the 21st century, the construction of highway projects in the Hexi Corridor has increased with the implementation of China’s western development policy. The impact of [...] Read more.

The ecological environment of the Hexi Corridor in China is fragile owing to its unique geographical conditions. Since the 21st century, the construction of highway projects in the Hexi Corridor has increased with the implementation of China’s western development policy. The impact of highway construction on vegetation along roads is uncertain and requires attention. In this study, the normalized difference vegetation index (NDVI) was obtained based on remote sensing data, and the correlations between the vegetation index, climate changes, and highway construction from 2000 to 2019 were analyzed. The results showed that the NDVI of the Hexi Corridor showed a significant increasing trend, and the spatial difference was obvious, which was largely controlled by climatic conditions. Generally, the vegetation index was negatively correlated with temperature, but positively correlated with precipitation, and the correlation between the NDVI and precipitation was greater than that of temperature. The impact of highways on vegetation is a long-term process. In the eastern region of the Hexi Corridor, where the ecological environment is better, highway construction promoted vegetation development. However, in the western region with high desertification, the damage caused by highway construction to vegetation was serious, and the recovery rate of degraded vegetation was slow after the completion of highway construction. Although the vegetation development in the Hexi Corridor was mainly affected by precipitation, in the western region, highway construction was the main factor controlling vegetation disturbance within a certain range on both sides, and its contribution to vegetation disturbance reached 60%. The research results can improve understanding of the disturbance effect of highway construction on vegetation in arid areas. Full article

(This article belongs to the Special Issue Application of Remote Sensing in Vegetation Dynamic and Ecology)

19 pages, 6089 KiB

Open AccessArticle

Physiological Response to Low-Temperature Stress and Cold Resistance Evaluation of Ziziphus jujuba var. spinosa Clones from Different Provenances

by Biao Li, Yuncheng Zhang, Ying Kang, Yijin Wang, Ruilin Liu, Qingbai Liu and Shengjun Dong

Forests 2024, 15(7), 1130; https://doi.org/10.3390/f15071130 (registering DOI) - 28 Jun 2024

Viewed by 142

Abstract

To investigate the low-temperature adaptability of different provenances of Ziziphus jujuba var. Spinosa, we used 21 clones from seven provenances as experimental materials and observed the changes in physiological and biochemical indicators and the characteristics of anatomical structures under low-temperature stress. A [...] Read more.

To investigate the low-temperature adaptability of different provenances of Ziziphus jujuba var. Spinosa, we used 21 clones from seven provenances as experimental materials and observed the changes in physiological and biochemical indicators and the characteristics of anatomical structures under low-temperature stress. A comprehensive evaluation of their cold resistance was conducted using the membership function method. As the temperature decreased, the relative electrical conductivity (REC) of clone 89 became stable and had the lowest LT₅₀ value (−44.04 °C). The cold-resistant Z. jujuba var. spinosa had a higher bound water/free water (BW/FW) ratio and antioxidant enzyme activity and accumulated large quantities of osmotic regulatory substances. Higher xylem, phloem, and xylem–cortex ratios and greater conduit density enhanced the cold resistance of Z. jujuba var. spinosa. The membership function values of clones 89, 90, 91, 604, and 612 were greater than 0.6, indicating that they could be evaluated as resources with the potential for low-temperature resistance. The cold resistance rankings for the different provenances were as follows: Kazuo, Liaoning > Jiaxian, Shaanxi > Fuxing, Heibei > Changqing, Shandong > Neiqiu, Heibei > Yanchuan, Shaanxi > Xiaxian, Shanxi. These results provide a scientific basis for the rapid and accurate identification of cold resistance in Z. jujuba var. spinosa resources and the breeding and cultivation of new cold-resistant varieties of this subspecies. Full article

(This article belongs to the Special Issue Abiotic and Biotic Stress Responses in Trees Species)

23 pages, 2463 KiB

Open AccessArticle

Analysis of Long-Term Vegetation Trends and Their Climatic Driving Factors in Equatorial Africa

by Isaac Kwesi Nooni, Faustin Katchele Ogou, Nana Agyemang Prempeh, Abdoul Aziz Saidou Chaibou, Daniel Fiifi Tawiah Hagan, Zhongfang Jin and Jiao Lu

Forests 2024, 15(7), 1129; https://doi.org/10.3390/f15071129 (registering DOI) - 28 Jun 2024

Viewed by 151

Abstract

Understanding vegetation seasonality and its driving mechanisms improves decision-making in the management of ecological systems in a warming global climate. Using multiple statistical methods (i.e., trend analysis, abrupt changes, and partial correlation analysis), this study analyzed the spatiotemporal variations in the Normalized Difference [...] Read more.

Understanding vegetation seasonality and its driving mechanisms improves decision-making in the management of ecological systems in a warming global climate. Using multiple statistical methods (i.e., trend analysis, abrupt changes, and partial correlation analysis), this study analyzed the spatiotemporal variations in the Normalized Difference Vegetation Index (NDVI) in the Equatorial Africa (EQA) region and their responses to climate factors from 1982 to 2021. The NDVI values declined at a rate of 0.00023 year⁻¹, while the precipitation (P) and mean temperature (TMEAN) values increased at rates of 0.22 mm year⁻¹ and 0.22 °C year⁻¹, respectively. The mean minimum temperature (TMIN) had a higher rate of 0.2 °C year⁻¹ than the mean maximum temperature (TMAX) at 0.02 °C year⁻¹. An abrupt change analysis showed that the TMAX, P, and NDVI breakpoints occurred in 2000, 2002, and 2009, respectively; TMEAN and TMIN breakpoints occurred in 2001. The NDVI trends declined in forest and cropland areas but increased in shrubland and grassland areas. The summer NDVI trends declined for all vegetation types and were reversed in the winter season. The NDVI positively correlated with the P (r = 0.50) and TMEAN (r = 0.60). All seasonal analyses varied across four seasons. A temporal analysis was conducted using partial correlation analysis (PCR), and the results revealed that TMIN had a greater impact on the NDVI (PCR = −0.45), followed by the TMAX (PCR = 0.31) and then the P (PCR = −0.19). The annual trend showed that areas with significant greening were consistent with stronger wetter and weaker warming trends. Both precipitation and temperature showed a positive relationship with vegetation in semi-arid and arid regions but a negative relationship with humid regions. Our findings improve our insight into scientific knowledge on ecological conservation. Full article

(This article belongs to the Special Issue Modeling Forest Response to Climate Change)

18 pages, 1670 KiB

Open AccessArticle

Biochar Application Improved Sludge-Amended Landscape Soil Fertility Index but with No Added Benefit in Plant Growth

by Shuangshuang Chu, Mengrui Xiao, Weixin Peng, Fengling Long, Daoming Wu, Dongnan Hu and Shucai Zeng

Forests 2024, 15(7), 1128; https://doi.org/10.3390/f15071128 (registering DOI) - 28 Jun 2024

Viewed by 116

Abstract

Co-application of sewage sludge (SS) with biochar in landscape/forestry soil is a common strategy for enhancing soil fertility and reducing the bioavailability of potential toxic elements (PTEs) derived from SS, such as Cd, Pb, Cu, Zn, and Ni. However, due to variability of [...] Read more.

Co-application of sewage sludge (SS) with biochar in landscape/forestry soil is a common strategy for enhancing soil fertility and reducing the bioavailability of potential toxic elements (PTEs) derived from SS, such as Cd, Pb, Cu, Zn, and Ni. However, due to variability of biochar quality and uncertainties in responses of different plant species, whether the co-application benefits the landscape/forestry plant system remains elusive. Here, we tested the effectiveness of three types of biochar (SS-derived biochar (SB), rice straw-derived biochar (RB), and litter-derived biochar (LB)), which were added to soil amended with SS at 50% (w/w) at rates of 1.5%, 3%, and 4.5% as growth media for the landscape plant Aglaonema modestum (A. modestum). We analyzed the substrate’s physicochemical properties and assessed the alleviation of phytotoxicity by biochar application. A significant increase in the fertility index of substrate was observed in all the treatments with biochar addition. The addition of biochar reduced the potential mobility of PTEs while increasing their residual fraction in media. Nonetheless, it has been found that the addition of biochar has ineffective or even negative effects on A. modestum growth (height, biomass, root length) and nutrient absorption. Importantly, the reduction in root biomass and the increased activity of root antioxidant enzymes (SOD, POD, CAT, and MDA) indicate contamination stress of biochar on the roots of A. modestum. Toxic elements of concern—namely Cu, Cd, and Pb—were not significantly higher in tissues of A. modestum saplings planted in biochar-SS-amended soil. However, elevated levels of other elements that may pose toxicity concerns, such as Ni and Zn, increased in tissues at high biochar dosages. Based on the Entropy–Weight TOPSIS method, it was further confirmed that compared to the treatment without biochar, all treatments except for 3.0% LB application resulted in poorer A. modestum comprehensive growth. Our results emphasize the need for detailed research on the response of specific plants to biochar in specific environments, including plant adaptability and the unexplored toxicity of biochar, to understand the large variations and mechanisms behind these ineffective or negative effects before the large-scale co-utilization of SS and biochar in landscape/forestry soils. Full article

(This article belongs to the Topic Effect of Heavy Metals on Plants, 2nd Volume)

15 pages, 1316 KiB

Open AccessArticle

Effect of Gastrodia elata Bl Cultivation under Forest Stands on Runoff, Erosion, and Nutrient Loss

by Shuyuan Yang and Jianqiang Li

Forests 2024, 15(7), 1127; https://doi.org/10.3390/f15071127 (registering DOI) - 28 Jun 2024

Viewed by 126

Abstract

(1) Background: The understory planting of Chinese herbal medicine is a common soil and water conservation farming measure, and this approach makes full use of the natural conditions of the understory. However, a large number of studies on soil erosion have focused on [...] Read more.

(1) Background: The understory planting of Chinese herbal medicine is a common soil and water conservation farming measure, and this approach makes full use of the natural conditions of the understory. However, a large number of studies on soil erosion have focused on the simulation of natural indoor conditions, and there are very few investigations on soil erosion caused by understory planting in the field. This study aims to investigate the effects of different slopes on soil and water and nitrogen–phosphorus nutrient loss from understory planting of Gastrodia elata Bl by changing the vegetation structure and soil structure of forest land. (2) Methods: To reveal the nitrogen and phosphorus loss and flow and sediment characteristics of the understory planting of Gastrodia elata Bl, runoff plots were set up in a field, and three surface slopes (5°, 15°, and 20°) were designed to collect runoff sediments and compare the soil and water loss between the natural slopes and those with Gastrodia elata Bl. This provides a basis for the restoration of vegetation cover and the enhancement of soil fertility. (3) Results: The total loss of soil, water, nitrogen, and phosphorus in the forested land with Gastrodia elata Bl increased significantly compared with that in the natural forested land, and the greater the slope was, the greater the loss was. (4) Conclusions: Planting Gastrodia elata Bl should be avoided in areas with steep slopes and serious soil erosion. However, some soil and water conservation engineering measures can be taken, such as the construction of retaining walls, drainage ditches, etc., to minimize the scouring and erosion of soil by rainwater. Full article

(This article belongs to the Special Issue Carbon, Nitrogen, and Phosphorus Storage and Cycling in Forest Soil)

17 pages, 1882 KiB

Open AccessArticle

Comparative Transcriptome Analysis of Different Mulberry Varieties to Reveal Candidate Genes and Small Secreted Peptides Involved in the Sclerotiniose Response

by Li Liu, Zixuan Guo, Xiaoru Kang, Shan Li, Shuai Huang, Longyan Zheng, Rumeng Fu, Keermula Yidilisi and Nan Chao

Forests 2024, 15(7), 1126; https://doi.org/10.3390/f15071126 (registering DOI) - 28 Jun 2024

Viewed by 136

Abstract

Mulberry sclerotiniose is a devastating fungal disease of mulberry fruit and has been a limitation for the utility of mulberry fruits and the diversified development of sericulture. In the present study, we presented a workflow for screening candidate sclerotiniose-resistance genes and small secreted [...] Read more.

Mulberry sclerotiniose is a devastating fungal disease of mulberry fruit and has been a limitation for the utility of mulberry fruits and the diversified development of sericulture. In the present study, we presented a workflow for screening candidate sclerotiniose-resistance genes and small secreted peptides (SSPs) based on a genome-wide annotation of SSPs and comparative transcriptome analysis of different mulberry varieties. A total of 1088 SSPs with expression evidence were identified and annotated in mulberry. A comprehensive analysis of the sclerotiniose-related RNA sequencing datasets showed that photosynthesis, plant hormone signaling, and metabolic pathways were the main pathways involved in the response to sclerotiniose. Fifty-two candidate sclerotiniose-response genes (SRGs), including 15 SSPs, were identified based on comparative transcriptome analysis. These SRGs are mainly involved in the hormone signaling pathway and cell wall biogenesis. Transient overexpression in tobacco and the knock-down of five SRGs affected the resistance against Ciboria shiraiana. MaMYB29, MaMES17, and MaSSP15 were primarily determined as negative regulators of plant resistance to C. shiraiana infection. Our results provide a foundation for controlling sclerotiniose in mulberry using genetic engineering and biological approaches such as spraying antifungal peptides. Full article

(This article belongs to the Section Genetics and Molecular Biology)

19 pages, 1188 KiB

Open AccessArticle

Functional Traits Affect the Contribution of Individual Species to Beta Diversity in the Tropical Karst Seasonal Rainforest of South China

by Yanping Wang, Bing Wang, Jianxing Li, Fang Lu, Wanglan Tao, Dongxing Li, Yili Guo, Nianwu Tang, Xiankun Li and Wusheng Xiang

Forests 2024, 15(7), 1125; https://doi.org/10.3390/f15071125 (registering DOI) - 28 Jun 2024

Viewed by 130

Abstract

In a community, due to the different characteristics of each species, their contributions to community beta diversity may vary. Quantifying the contribution of each species to overall beta diversity (SCBD) is essential for explaining the patterns of beta diversity. However, there is currently [...] Read more.

In a community, due to the different characteristics of each species, their contributions to community beta diversity may vary. Quantifying the contribution of each species to overall beta diversity (SCBD) is essential for explaining the patterns of beta diversity. However, there is currently limited research linking SCBD with species functional traits, and how species functional traits influence SCBD remains unclear. This study is based on tree census data, species functional traits, and environmental variables from a 15 ha permanent monitoring plot in a tropical karst rainforest in south China. By calculating species-specific SCBD based on abundance and presence–absence data, as well as functional distinctiveness and species ecological niche characteristics (niche position and niche width), we applied structural equation modeling (SEM) to analyze how functional traits, distinctiveness, and niche characteristics jointly influence SCBD. The results revealed that SCBD based on abundance is positively correlated with occupancy and abundance, whereas SCBD based on presence–absence data exhibits a hump-shaped relationship with occupancy and abundance. Species ecological niche characteristics directly influence SCBD, with species occupying central ecological niches having a negative effect on SCBD and niche width having a positive effect. Functional traits and functional distinctiveness indirectly impact SCBD through their influence on species ecological niche characteristics. SEM models based on the presence–absence data provide higher explanatory power. In summary, in the seasonal rainforest communities of northern tropical karst regions in China, the combined effects of species’ functional traits, functional distinctiveness, and ecological niche characteristics determine SCBD. This not only contributes to a deeper understanding of how species traits influence β-diversity, making SCBD a more applicable tool for biodiversity conservation, but also allows for the development of more effective biodiversity protection strategies by elucidating the link between SCBD and ecosystem multifunctionality. Full article

(This article belongs to the Special Issue Biodiversity in Forests: Management, Monitoring for Conservation)

28 pages, 9302 KiB

Open AccessArticle

Predicted Future Changes in the Mean Seasonal Carbon Cycle Due to Climate Change

by Mauro Morichetti, Elia Vangi and Alessio Collalti

Forests 2024, 15(7), 1124; https://doi.org/10.3390/f15071124 - 28 Jun 2024

Viewed by 189

Abstract

Through photosynthesis, forests absorb annually large amounts of atmospheric CO₂. However, they also release CO₂ back through respiration. These two, opposite in sign, large fluxes determine how much of the carbon is stored or released back into the atmosphere. The [...] Read more.

Through photosynthesis, forests absorb annually large amounts of atmospheric CO₂. However, they also release CO₂ back through respiration. These two, opposite in sign, large fluxes determine how much of the carbon is stored or released back into the atmosphere. The mean seasonal cycle (MSC) is an interesting metric that associates phenology and carbon (C) partitioning/allocation analysis within forest stands. Here, we applied the 3D-CMCC-FEM model and analyzed its capability to represent the main C-fluxes, by validating the model against observed data, questioning if the sink/source mean seasonality is influenced under two scenarios of climate change, in five contrasting European forest sites. We found the model has, under current climate conditions, robust predictive abilities in estimating NEE. Model results also predict a consistent reduction in the forest’s capabilities to act as a C-sink under climate change and stand-aging at all sites. Such a reduction is predicted despite the number of annual days as a C-sink in evergreen forests increasing over the years, indicating a consistent downward trend. Similarly, deciduous forests, despite maintaining a relatively stable number of C-sink days throughout the year and over the century, show a reduction in their overall annual C-sink capacity. Overall, both types of forests at all sites show a consistent reduction in their future mitigating potential. Full article

(This article belongs to the Special Issue Modeling Forest Response to Climate Change)

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11 pages, 26107 KiB

Open AccessArticle

Spatial Distribution of Forest Soil Base Elements (Ca, Mg and K): A Regression Kriging Prediction for Czechia

by Vincent Yaw Oppong Sarkodie, Radim Vašát, Karel Němeček, Vít Šrámek, Věra Fadrhonsová, Kateřina Neudertová Hellebrandová, Luboš Borůvka and Lenka Pavlů

Forests 2024, 15(7), 1123; https://doi.org/10.3390/f15071123 - 28 Jun 2024

Viewed by 330

Abstract

Base cations have declined within European forests due to leaching, accelerated by atmospheric acid deposition. This study aims at predicting the spatial distribution of pseudototal content of Ca, Mg, and K for coniferous, broadleaved and mixed forest stands. A harmonised database of about [...] Read more.

Base cations have declined within European forests due to leaching, accelerated by atmospheric acid deposition. This study aims at predicting the spatial distribution of pseudototal content of Ca, Mg, and K for coniferous, broadleaved and mixed forest stands. A harmonised database of about 7000 samples from the top mineral layer of 0–30 cm from the entire forest areas of the Czech Republic was used. A regression kriging model was used for spatial prediction of the content of the elements. The influence of the covariates used for the prediction was assessed using generalized additive models for location scale and shape (GAMLSS). The variance explained by the model was best for Ca with the R² of 0.32, the R² for Mg was 0.30, and the R² for K was 0.26. Model fitting assessed by the ratio of performance to inter-quartile distance (RPIQ) showed K as the best fit with a value of 1.12, followed by Mg with the value 0.87, and Ca with 0.25. Ca exhibited the best prediction fit for the GAMLSS, compared with K and Mg, based on their AIC matrix values. The predicted spatial distribution in this study provides information for policy and will provide information for the sustainable management of forests. Full article

(This article belongs to the Special Issue Monitoring and Modelling of Soil Properties in Forest Ecosystems)

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18 pages, 7211 KiB

Open AccessArticle

Geospatial Analysis of Relief Degree of Land Surface in the Forest-Steppe Ecotone in Northern China

by Lili Hu, Zhongke Feng, Chaoyong Shen, Yue Hai, Yiqiu Li, Yuan Chen, Panpan Chen, Hanyue Zhang, Shan Wang and Zhichao Wang

Forests 2024, 15(7), 1122; https://doi.org/10.3390/f15071122 - 28 Jun 2024

Viewed by 187

Abstract

The Relief Degree of Land Surface (RDLS) is an important index to evaluate regional environment. It has a significant effect on the local climate, geologic hazards, the path and speed of fire spreading, the migrations of wild animals, and the runoff [...] Read more.

The Relief Degree of Land Surface (RDLS) is an important index to evaluate regional environment. It has a significant effect on the local climate, geologic hazards, the path and speed of fire spreading, the migrations of wild animals, and the runoff path and speed of precipitation. The forest-steppe ecotone in northern China is one of ecological fragile zones. In-depth study of the RDLS of the forest-steppe ecotone in northern China will help to implement ecological projects scientifically and promote the construction of the national ecological security barrier. The Shuttle Radar Topography Mission (SRTM-GL1 30 m) data were used to determine the optimal analysis window for RDLS based on the mean change-point method, and the elevation difference was extracted based on the window analysis method. The RDLS model was used to extract RDLS of the forest-steppe ecotone and analyzed with the help of a spatial auto-correlation model. The correlation between mean elevation, relative elevation difference, and RDLS was also analyzed. The results show that the optimal analysis window size for RDLS was 29 × 29, corresponding to an area of 0.76 km². The RDLS under the optimal analysis window extracted from SRTM-GL1 (30 m) ranged from 0.084 to 3.516. The RDLS had significant spatial clustering, with high RDLS mainly distributed in the mountainous areas and low RDLS mainly distributed in mountain-to-plain transition zone; the RDLS between different administrative units and different watersheds had obvious variability. Overall, the RDLS was characterized as decreasing, increasing, and then decreasing from the south to north, while it was high in the west and low in the east. And the RDLS was linearly positively correlated with mean elevation and relative elevation difference. In the future, the implementation of major ecological projects in the forest-steppe ecotone in northern China, such as soil and water conservation, afforestation tree species selection, ecological corridor design, ecological management, geological disaster prevention, and forest fire prevention, should fully consider the local topographic conditions. These research results can provide topographic references for the implementation of ecological planning and engineering in this area and similar areas. It contributes to sustainable development and maximization of ecological benefits and promotes the establishment of a national ecological security barrier. Full article

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

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17 pages, 1666 KiB

Open AccessArticle

Improving Otsu Method Parameters for Accurate and Efficient in LAI Measurement Using Fisheye Lens

by Jiayuan Tian, Xianglong Liu, Yili Zheng, Liheng Xu, Qingqing Huang and Xueyang Hu

Forests 2024, 15(7), 1121; https://doi.org/10.3390/f15071121 - 27 Jun 2024

Viewed by 198

Abstract

The leaf area index (LAI) is an essential indicator for assessing vegetation growth and understanding the dynamics of forest ecosystems and is defined as the ratio of the total leaf surface area in the plant canopy to the corresponding surface area below it. [...] Read more.

The leaf area index (LAI) is an essential indicator for assessing vegetation growth and understanding the dynamics of forest ecosystems and is defined as the ratio of the total leaf surface area in the plant canopy to the corresponding surface area below it. LAI has applications for obtaining information on plant health, carbon cycling, and forest ecosystems. Due to their price and portability, mobile devices are becoming an alternative to measuring LAI. In this research, a new method for estimating LAI using a smart device with a fisheye lens (SFL) is proposed. The traditional Otsu method was enhanced to improve the accuracy and efficiency of foreground segmentation. The experimental samples were located in Gansu Ziwuling National Forest Park in Qingyang. In the accuracy parameter improvement experiment, the variance of the average LAI value obtained by using both zenith angle segmentation and azimuth angle segmentation methods was reduced by 50%. The results show that the segmentation of the front and back scenes of the new Otsu method is more accurate, and the obtained LAI values are more reliable. In the efficiency parameter improvement experiment, the time spent is reduced by 17.85% when the enhanced Otsu method is used to ensure that the data anomaly rate does not exceed 10%, which improves the integration of the algorithm into mobile devices and the efficiency of obtaining LAI. This study provides a fast and effective method for the near-ground measurement of forest vegetation productivity and provides help for the calculation of forest carbon sequestration efficiency, oxygen release rate, and forest water and soil conservation ability. Full article

(This article belongs to the Special Issue Deep Learning Techniques for Forests Parameter Retrieval and Accurate Tree Modeling from Remote Sensing Data—Volume Ⅱ)

16 pages, 4560 KiB

Open AccessArticle

Stand Age and Climate Change Effects on Carbon Increments and Stock Dynamics

by Elia Vangi, Daniela Dalmonech, Mauro Morichetti, Elisa Grieco, Francesca Giannetti, Giovanni D’Amico, Mahdi (Andre) Nakhavali, Gherardo Chirici and Alessio Collalti

Forests 2024, 15(7), 1120; https://doi.org/10.3390/f15071120 - 27 Jun 2024

Viewed by 270

Abstract

Carbon assimilation and wood production are influenced by environmental conditions and endogenous factors, such as species auto-ecology, age, and hierarchical position within the forest structure. Disentangling the intricate relationships between those factors is more pressing than ever due to climate change’s pressure. We [...] Read more.

Carbon assimilation and wood production are influenced by environmental conditions and endogenous factors, such as species auto-ecology, age, and hierarchical position within the forest structure. Disentangling the intricate relationships between those factors is more pressing than ever due to climate change’s pressure. We employed the 3D-CMCC-FEM model to simulate undisturbed forests of different ages under four climate change (plus one no climate change) Representative Concentration Pathways (RCP) scenarios from five Earth system models. In this context, carbon stocks and increment were simulated via total carbon woody stocks and mean annual increment, which depends mainly on climate trends. We find greater differences among different age cohorts under the same scenario than among different climate scenarios under the same age class. Increasing temperature and changes in precipitation patterns led to a decline in above-ground biomass in spruce stands, especially in the older age classes. On the contrary, the results show that beech forests will maintain and even increase C-storage rates under most RCP scenarios. Scots pine forests show an intermediate behavior with a stable stock capacity over time and in different scenarios but with decreasing mean volume annual increment. These results confirm current observations worldwide that indicate a stronger climate-related decline in conifers forests than in broadleaves. Full article

(This article belongs to the Special Issue Modeling Forest Response to Climate Change)

18 pages, 6957 KiB

Open AccessArticle

Genome-Wide Identification of MYB Gene Family in Peach and Identification of MYBs Involved in Carotenoid Biosynthesis

by Fengyi Liu, Jiarui Zheng, Yuwei Yi, Xiaoyan Yang, Leiyu Jiang, Jiabao Ye, Weiwei Zhang and Feng Xu

Forests 2024, 15(7), 1119; https://doi.org/10.3390/f15071119 - 27 Jun 2024

Viewed by 182

Abstract

Carotenoids are naturally occurring tetraterpenoids that play a key role in fruit coloration, and yellow peaches are one of the best sources of carotenoid intake. MYB transcription factors are one of the largest families in plants and play an important role in the [...] Read more.

Carotenoids are naturally occurring tetraterpenoids that play a key role in fruit coloration, and yellow peaches are one of the best sources of carotenoid intake. MYB transcription factors are one of the largest families in plants and play an important role in the regulation of plant secondary metabolite biosynthesis. However, peach MYB family genes have not been fully analyzed, and in particular, MYBs that regulate carotenoid biosynthesis have not been fully characterized. In this study, 190 peach MYB genes, containing 68 1R-MYBs, 118 2R-MYBs, 3 3R-MYBs, and 1 4R-MYB, were identified at the genome level using bioinformatics methods. These 190 MYBs were classified into 27 subfamilies based on their phylogenetic relationships with Arabidopsis thaliana MYB family members, and they were unevenly distributed across eight chromosomes. MYB genes of the same subfamily exhibit similar but not identical gene structures and conserved motifs. The promoter regions contain cis-acting elements associated with stress response, hormone response, and plant growth and development. There were 54 collinear pairs of MYB genes in the peach genome, compared with 233 and 221 collinear pairs with Rosa chinensis and Arabidopsis, respectively. Thirteen differentially expressed genes in the carotenoid biosynthesis pathway in yellow peach were identified by transcriptome sequencing and contained MYB binding sites on their promoters. Based on a phylogenetic analysis, we identified 13 PpMYBs that may be involved in carotenoid biosynthesis, and a correlation analysis revealed that they regulate carotenoid accumulation by positively or negatively regulating the expression of carotenoid biosynthetic genes. Further degradome sequencing screened that mdm-miR858 was able to target PpMYB17 and PpMYB126 involved in the regulation of carotenoid biosynthesis. Our findings provide new insights into the potential role of MYB transcription factors in carotenoid biosynthesis and provide a theoretical basis for their molecular mechanisms. Full article

(This article belongs to the Special Issue Genome-Wide Identification and Expression Analysis for the Genetic Improvement of Forest Plants)

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27 pages, 3622 KiB

Open AccessArticle

Automated Shape Correction for Wood Composites in Continuous Pressing

by Yunlei Lv, Yaqiu Liu, Xiang Li, Lina Lu and Adil Malik

Forests 2024, 15(7), 1118; https://doi.org/10.3390/f15071118 - 27 Jun 2024

Viewed by 162

Abstract

Abstract: The effective and comprehensive utilization of forest resources has become the theme of the global “dual-carbon strategy”. Forestry restructured wood is a kind of wood-based panel made of wood-based fiber composite material by high-temperature and high-pressure restructuring–molding, and has become an important [...] Read more.

Abstract: The effective and comprehensive utilization of forest resources has become the theme of the global “dual-carbon strategy”. Forestry restructured wood is a kind of wood-based panel made of wood-based fiber composite material by high-temperature and high-pressure restructuring–molding, and has become an important material in the field of construction, furniture manufacturing, as well as derivative processing for its excellent physical and mechanical properties, decorative properties, and processing performance. Taking Medium Density Fiberboard (MDF) as the recombinant material as the research object, an event-triggered synergetic control mechanism based on interventional three-way decision making is proposed for the viscoelastic multi-field coupling-distributed agile control of the “fixed thickness section” in the MDF continuous flat-pressing process, where some typical quality control problems of complex plate shape deviations including thickness, slope, depression, and bump tend to occur. Firstly, the idea of constructing the industrial event information of continuous hot pressing based on information granulation is proposed, and the information granulation model of the viscoelastic plate shape process mechanism is established by combining the multi-field coupling effect. Secondly, an FMEA-based cyber granular method for diagnosing and controlling the plate thickness diagnosis and control failure information expression of continuous flat pressing is proposed for the problems of plate thickness control failure and plate thickness deviation defect elimination that are prone to occur in the continuous flat-pressing process. The precise control of the plate thickness in the production process is realized based on event-triggered control to achieve the intelligent identification and processing of the various types of faults. The application test is conducted in the international mainstream production line of a certain type of continuous hot-pressing equipment for the production of 18 mm plate thickness; the synergistic effect is basically synchronized after 3 s, the control accuracy reaches 30%, and the average value of the internal bond strength is 1.40, which ensures the integrity of the slab. Practical tests show that the method in the actual production is feasible and effective, with detection and control accuracy of up to ± 0.05 mm, indicating that in the production of E0- and E1-level products, the rate of superior products can reach more than 95%. Full article

(This article belongs to the Special Issue New Development of Smart Forestry: Machine and Automation)

17 pages, 2990 KiB

Open AccessArticle

Assembly and Comparative Analysis of the Complete Mitochondrial Genome of Ilex rotunda Thunb.

by Yuanjian Wang, Gang Cui, Kaifeng He, Kewang Xu, Wei Liu, Yuxiao Wang, Zefu Wang, Shasha Liu and Changwei Bi

Forests 2024, 15(7), 1117; https://doi.org/10.3390/f15071117 - 27 Jun 2024

Viewed by 167

Abstract

Ilex rotunda Thunb. stands as a representative tree species in subtropical evergreen broad–leaved forests, widely distributed across southeast Asia. This species holds significant value in forestry due to its ecological resilience and adaptability. Although researchers have conducted in–depth research on the plastid genome [...] Read more.

Ilex rotunda Thunb. stands as a representative tree species in subtropical evergreen broad–leaved forests, widely distributed across southeast Asia. This species holds significant value in forestry due to its ecological resilience and adaptability. Although researchers have conducted in–depth research on the plastid genome (plastome) of I. rotunda, the mitochondrial genome (mitogenome) of this species has remained undocumented. In the present study, we successfully sequenced and assembled the I. rotunda mitogenome. The mitogenome has a circular structure and is 567,552 bp in total length, with a GC content of 45.47%. The composition of the mitogenome encompasses 40 protein–coding genes, along with 3 rRNA genes and 19 tRNA genes. Notably, the mitogenome exhibits a universal distribution of repetitive sequences, but the total length of repeats contributes to a relatively small proportion (4%) of the whole mitogenome, suggesting that repeats do not serve as the primary cause of the amplification of the Ilex mitogenomes. Collinear analysis indicates that the I. rotunda mitogenome is very conservative within Aquifoliales species. Additionally, our research identified 51 fragments of plastid genomic DNA, which have migrated from the plastome into the mitogenome, with five genes from the plastome remaining intact. Eventually, the phylogenetic analyses based on the plastomes and mitogenomes of 36 angiosperms determine the Aquifoliales to be the basal group in the campanulids. This study establishes the bedrock for prospective investigations in molecular breeding research. Full article

(This article belongs to the Section Genetics and Molecular Biology)

18 pages, 5179 KiB

Open AccessArticle

Accumulation Pattern and Potential Ecological Risk of Heavy Metals in Topsoil as Affected by Diverse Sources in Different Ecosystems in Western Dabie Mountain

by Tao Yang, Feng Wu, Minxuan Luo, Jiatai Xiong, Xiaoli Nie, Fan Cao, Yunzhao Ruan, Fu Li, Wubiao Huang, Tao Liang and Yujing Yang

Forests 2024, 15(7), 1116; https://doi.org/10.3390/f15071116 - 27 Jun 2024

Viewed by 180

Abstract

Soil heavy metal (HM) control has become a pressing global ecological and environmental issue, with a significant focus on the western Dabie Mountain in China, a region that is recognized for its ecological barriers and water sources. We analyzed the concentrations, pollution status, [...] Read more.

Soil heavy metal (HM) control has become a pressing global ecological and environmental issue, with a significant focus on the western Dabie Mountain in China, a region that is recognized for its ecological barriers and water sources. We analyzed the concentrations, pollution status, and potential ecological risks of 10 HMs (i.e., Cu, +Pb, Zn, Cr, Ni, Co, Cd, As, Hg, and Mn) in the topsoil of different ecosystems in this region. The effects of four soil groups (Anthrosol, Fluvisols, Gleysol, and Alisols) and three soil texture types (sandy, clayey, and loamy soils) on the above aspects were also analyzed. Positive Matrix Factorization (PMF) models were performed to identify and quantify the potential sources and contribution rates of these HMs. Results showed that the level of HM pollution may be negligible, and there was no potential ecological risk. Of all metals, Pb and Cd exhibited the highest levels of pollution. The potential ecological risk associated with soil HMs decreased from croplands to urban and further to forests. Cu and Co were more likely to accumulate in Anthrosols, while Alisols were more likely to accumulate Pb, Cd, and Hg and had a higher overall potential ecological risk. The overall risk in clayey and loamy soils is both higher than in sandy soils. The HM accumulation in topsoil was closely related to the soil organic matter and clay contents. The potential main sources of HMs in this region can be agricultural activities, soil parent material, mining, industrial activities, and vehicle emissions. These findings suggest that special attention should be paid to soil Pb and Cd in western Dabie Mountain. Future efforts can focus on reducing mining, smelting, and industrial emissions, as well as strengthening the research on the migration patterns and mechanisms of HMs. Full article

(This article belongs to the Special Issue Soil Chemistry in Forestry and Agroforestry Systems—Heavy Metal Pollution)

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13 pages, 3704 KiB

Open AccessArticle

New Role in the 5-HT Receptor: The Sex Attracting of Bursaphelenchus mucronatus

by Wenyi Liu, Rui Ma, Jing Chen, Quan Li, Kai Guo, Hudie Shao and Jiafu Hu

Forests 2024, 15(7), 1115; https://doi.org/10.3390/f15071115 - 27 Jun 2024

Viewed by 182

Abstract

Bursaphelenchus mucronatus is the sibling species of B. xylophilus, which causes pine wilt disease. Sex pheromone-mediated mating behavior underlies the development of B. xylophilus populations. The study of the molecular mechanism of sex pheromone receptor genes is vital for the control of [...] Read more.

Bursaphelenchus mucronatus is the sibling species of B. xylophilus, which causes pine wilt disease. Sex pheromone-mediated mating behavior underlies the development of B. xylophilus populations. The study of the molecular mechanism of sex pheromone receptor genes is vital for the control of B. xylophilus. The pivotal role of the 5-HT receptor ser-1 in Caenorhabditis elegans’s mating has been demonstrated, but there is little known in B. mucronatus and B. xylophilus. In our study, the molecular features and biological functions of Bmu-ser-1 are explored. qPCR results showed that Bmu-ser-1 was expressed at all ages, especially at J2 and J4, with significantly high expression. Notably, the expression levels in males were significantly higher than that in females. The results of in situ hybridization suggest that the Bmu-ser-1 gene was expressed at the site of the digestive system during the embryonic stage, the whole body during the J2 stage, and mainly at the end of the germinal primordium during the J3 stage, as well as centrally in the vulva of females and in the gonads and tail of males during the J4 and adult stages. The RNAi results indicate a significant decrease in hatchability and stagnation at the J1 stage after interference. Treated J2 had reduced motility and stunted growth. Males after interference showed mismatch and females showed spawning difficulties. Sexual arousal experiments further validated Bmu-ser-1 as a receptor gene for males receiving female sex pheromones. Collectively, our findings strongly suggest that the Bmu-ser-1 gene has a classical role, the control of nematode growth; and a novel role involved in mating. The study on the molecular mechanisms of growth and reproduction in B. mucronatus could provide a reference for understanding the population expansion and disease epidemics of B. xylophilus. Full article

(This article belongs to the Section Forest Health)

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27 pages, 10472 KiB

Open AccessArticle

Predictive Model for Bark Beetle Outbreaks in European Forests

by Ángel Fernández-Carrillo, Antonio Franco-Nieto, María Julia Yagüe-Ballester and Marta Gómez-Giménez

Forests 2024, 15(7), 1114; https://doi.org/10.3390/f15071114 - 27 Jun 2024

Viewed by 315

Abstract

Bark beetle outbreaks and forest mortality have rocketed in European forests because of warmer winters, intense droughts, and poor management. The methods developed to predict a bark beetle outbreak have three main limitations: (i) a small-spatial-scale implementation; (ii) specific field-based input datasets that [...] Read more.

Bark beetle outbreaks and forest mortality have rocketed in European forests because of warmer winters, intense droughts, and poor management. The methods developed to predict a bark beetle outbreak have three main limitations: (i) a small-spatial-scale implementation; (ii) specific field-based input datasets that are usually hard to obtain at large scales; and (iii) predictive models constrained by coarse climatic factors. Therefore, a methodological approach accounting for a comprehensive set of environmental traits that can predict a bark beetle outbreak accurately is needed. In particular, we aimed to (i) analyze the influence of environmental traits that cause bark beetle outbreaks; (ii) compare different machine learning architectures for predicting bark beetle attacks; and (iii) map the attack probability before the start of the bark beetle life cycle. Random Forest regression achieved the best-performing results. The predicted bark beetle damage reached a high robustness in the test area (F1 = 96.9, OA = 94.4) and showed low errors (CE = 2.0, OE = 4.2). Future improvements should focus on including additional variables, e.g., forest age and validation sites. Remote sensing-based methods contributed to detecting bark beetle outbreaks in large extensive forested areas in a cost-effective and robust manner. Full article

(This article belongs to the Special Issue Ecology and Management of Forest Pests—2nd Edition)

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16 pages, 15192 KiB

Open AccessArticle

Long-Term Effects of Mistletoe Removal on Radial Growth of Semi-Arid Aleppo Pine Forests

by Ester González de Andrés, Cristina Valeriano and J. Julio Camarero

Forests 2024, 15(7), 1113; https://doi.org/10.3390/f15071113 - 27 Jun 2024

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Abstract

Mistletoes are hemiparasites that modify how trees cope with drought by impairing the relationships between water, carbon, and nutrients within the tree. Thus, mistletoes endanger the vitality and persistence of trees in drought-prone regions, such as the Mediterranean Basin. Here, we evaluated radial [...] Read more.

Mistletoes are hemiparasites that modify how trees cope with drought by impairing the relationships between water, carbon, and nutrients within the tree. Thus, mistletoes endanger the vitality and persistence of trees in drought-prone regions, such as the Mediterranean Basin. Here, we evaluated radial growth patterns and drought sensitivity of Aleppo pine (Pinus halepensis Mill.) trees from which mistletoe was removed ca. two decades ago (MRTs) with control; currently infested trees (MCTs) from a semi-arid region in NE Spain. Growth showed negative trends in both tree classes since the 1980s concurrent with progressive aridification and aggravated by mistletoe infestation, as indicated by the positive effect of mistletoe removal on the growth of MRT trees. Water availability during the previous autumn and winter and current spring and early summer drove growth. Climate–growth correlations were similar between tree classes before treatment, but after mistletoe removal, precipitation became significant in MCT trees but not in MRT trees. Likewise, the impact of drought on growth changed through time: it increased until the late 20th century and then decreased in the MRT trees, which showed higher resistance and resilience against post-treatment droughts. This study provides evidence of the long-term positive effect of mistletoe removal on radial growth in semi-arid pine forests. Full article

(This article belongs to the Special Issue Response of Forest Trees to Drought)

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Forests, Volume 15, Issue 7 (July 2024) – 70 articles

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