Forests

Wu, Yansheng;Wang, Yanchao;Niu, Weitao;Zhang, Pengfei;Wu, Lina;Li, Huan;Wang, Senghu

doi: 10.3390/f14030439pmid: N/A

Fitting mathematical models to describe the influence of topographic factors and coexisting plants on wild jujube distribution was performed to provide a scientific basis for wild jujube forestation. Investigation quadrats, with straight-line distances between adjacent quadrats of longer than 100 m, were set up in areas of wilderness or low human disturbance, which were rich in wild plant species. Data concerning altitude, slope aspect, slope position and slope degree of each investigation quadrat, as well as the type and number of coexisting wild plants, were collected. Based on this, correlations with the average number, occurrence probability and density of wild jujube and these variables were analyzed, and data models were established. Results of analyses show that topographic factors such as altitude, aspect, gradient, slope and position, play an important role in the distribution of wild jujube; and that Vitex negundo var. heterophylla (Franch.) Rehd. coexistence is related to wild jujube distribution. Both average number and occurrence probability of wild jujube conform to a GaussAmp model with altitude. The highest average number was recorded at 581.24 ± 13.78 m above sea level, and the highest occurrence probability at 462.53 ± 36.67 m above sea level. Average number and occurrence probability of wild jujube were fit to a linear model with slope aspect—with mathematical slope 0.49 ± 0.16—indicating that wild jujube is a light-loving and drought-tolerant plant. Average number and density of wild jujubes were fit to GaussAmp models with slope position. The highest average number and the highest density of wild jujube appears on the upper part of the middle slope. Wild jujube occurrence probability was correlated to slope degree in a quadratic equation model. With an increase in slope degree, the distribution number of wild jujube increased sharply. The survey data of slope position and slope degree further reinforced the observed drought-resistance qualities of wild jujube. Average number and density of wild jujubes were correlated to the number of Vitex negundo var. heterophylla by quadratic equation models. No other plants investigated conformed to a statistically significant relationship with wild jujube distribution. Our results suggest altitude, slope aspect, slope position and slope degree play an important role in wild jujube distribution, and that Vitex negundo var. heterophylla is an important coexistent plant species for wild jujube.

Žigon, Jure;Pavlič, Matjaž

doi: 10.3390/f14030440pmid: N/A

Flame treatment is an ancient technique for surface protection of wood. Further processing of charred wood elements depends on aesthetic and protective requirements. This study presents some general properties and weathering behaviour of the Norway spruce (Picea abies (L.) Karst.) and the European larch (Larix decidua Mill.), protected by variations of sanding, charring, charring + brushing, and coating treatments. Charring and charring + brushing reduced the original mass of the samples by up to 8% and notably changed their colour (ΔE* ≤ 75). A study of chemical properties showed that charring dehydrated the wood and degraded lignin and hemicelluloses. The surface roughness of the wood after charring and charring + brushing increased by as much as 560%, while coating with waterborne acrylic high build stain had no effect on the roughness of these surfaces. The type of surface treatment of the wood did not affect the uptake of the coating in the wood samples, but the uncoated and coated spruce wood absorbed more water than larch wood. Higher water absorption was observed in the samples treated by charring, and it decreased when the char layer was removed by brushing. The film of a waterborne high build stain reduced water uptake only for surfaces treated by sanding and charring + brushing. Larch wood exhibited higher surface hardness (EHz ≤ 1.70 MPa) than spruce wood (EHz ≤ 0.89 MPa), with the brittle char layer reducing the determined hardness of the tested surfaces. During two years of natural weathering, the char layer was removed from the wood surface, even if the samples were additionally coated. The greatest colour changes during weathering were observed on samples treated by sanding (ΔE* ≤ 60) and sanding + coating (ΔE* ≤ 33), followed by samples treated with charring + brushing (ΔE* ≤ 10) and samples treated with charring (ΔE* ≤ 9). In summary, treating wood by charring in combination with brushing was the best wood protection technique.

Qiu, Hanqing;Zhang, Huaiqing;Lei, Kexin;Hu, Xingtao;Yang, Tingdong;Jiang, Xian

doi: 10.3390/f14030441pmid: N/A

Accurate, efficient, impersonal harvesting models play a very important role in optimizing stand spatial structural and guiding forest harvest practices. However, existing studies mainly focus on the single-objective optimization and evaluation of forest at the stand- or landscape-level, lacking considerations of tree-level neighborhood interactions. Therefore, the study explored the combination of the PSO algorithm and neighborhood indices to construct a tree-level multi-objective forest harvest model (MO-PSO) covering multi-dimensional spatial characteristics of stands. Taking five natural secondary forest plots and thirty simulated plots as the study area, the MO-PSO was used to simulate and evaluate the process of thinning operations. The results showed that the MO-PSO model was superior to the basic PSO model (PSO) and random thinning model Monte Carlo-based (RD-TH), DBH dominance (DOMI), uniform angle (ANGL), and species mingling (MING) were better than those before thinning. The multi-dimensional stand spatial structure index (L-index) increased by 1.0%~11.3%, indicating that the forest planning model (MO-PSO) could significantly improve the spatial distribution pattern, increase the tree species mixing, and reduce the degree of stand competition. In addition, under the four thinning intensities of 0% (T1), 15% (T2), 30% (T3), and 45% (T4), L-index increased and T2 was the optimal thinning intensity from the perspective of stand spatial structure overall optimization. The study explored the effect of thinning on forest spatial structure by constructing a multi-objective harvesting model, which can help to make reasonable and scientific forest management decisions under the concept of multi-objective forest management.

Čabalová, Iveta;Krilek, Jozef;Kačík, František;Lagaňa, Rastislav;Jurczyková, Tereza

doi: 10.3390/f14030442pmid: N/A

This article deals with the possibility of valorizing wood waste from grapevine cultivation of the varieties Pesecká leánka (white graft) and Frankovka modrá (red graft), grown in Slovakia. From the point of view of chemical composition, two methods (water and ethyl alcohol) were performed for the determination of extractives, acid-insoluble (Klason) lignin, and structural carbohydrates, and FTIR spectra of the grape samples were recorded. Mechanical strength, compression test parallel to the grain, and morphological properties (fiber length, width, and shape factor using a fiber tester) were carried out. The energy potential of grapevines was evaluated by determining the calorific value. According to the results, the relatively high content of carbohydrates (54.19%–55.27%) provides a prerequisite for acid or enzymatic hydrolysis to produce monosaccharides or second-generation bioethanol. FTIR spectra confirmed the higher content of lignin and cellulose in red grapes. The compression strength of grape cuttings (37.34 MPa—red; 32.34 MPa—white) was comparable to the strength of softwood species; hence, these wastes can be used for particleboard or fiberboard production. Average fiber length is comparable to non-wood species; thus, grape cutting can be used for pulp and paper production. The calorific value of grape cuttings ranged from 18.68 MJ·kg−1 (white) to 18.91 MJ·kg−1 (red), with pellets having 16.96 MJ·kg−1. The energetic potential of grape cuttings was comparable to that of other wooden materials; on the other hand, the ash content of pellets from grape cuttings (10.54%) greatly exceeded the limit given by the EN ISO 17225-1 standard, which is a significant disadvantage to pellets used for heating.

Fernandes, Luís;Paiva, Diana;Roxo, Ivo;Fernandes, Ana Rita;Ribeiro, Dina;Ribeiro, Henrique;Portugal, António

doi: 10.3390/f14030443pmid: N/A

Fusarium circinatum is one of the many threats to forests and Pinus nurseries all over the world, being classified as a quarantine organism by several organizations and governing bodies, such as the European and Mediterranean Plant Protection Organization (EPPO) and the European Union (EU), with associated phytosanitary measures in place to prevent its spread through the various means of dispersal. One such means of dispersal is the water used for irrigation in nurseries, which can contain fungal propagules. Three different treatments, namely, Desogerme, Intra Hydrocare and sodium hypochlorite (NaClO), were tested for their efficacy in eliminating F. circinatum spores in water at several concentrations. Those that showed 100% disinfection rates were selected for further assays regarding seed germination and water quality impact. From these studies, Desogerme 1% and Intra Hydrocare 4% were then selected for large-scale seed germination and plant certification assays in nurseries, where they showed promising results in regard to the prevention of infections in nurseries, and in this way, contribute to the efforts of mitigating this disease.

O’Neill, Leo;Fulé, Peter Z.;Hofstetter, Richard W.

doi: 10.3390/f14030444pmid: N/A

Pandora moths (Coloradia pandora subsp. davisi Barnes and Benjamin) have been observed to reach epidemic populations on the Kaibab Plateau, resulting in relatively small, localized defoliation events of ponderosa (Pinus ponderosa Lawson). We reconstructed the historical pandora moth outbreak regime using tree rings and forest health records to explore how exogenous factors, climate, and fire, are related to outbreak dynamics close to the driest range of ponderosa pine. We collected eight tree-ring chronologies dating back 400 years, geographically dispersed around the plateau, and inferred past outbreaks by comparison with non-host tree-ring chronologies, weather records, and historical observations. Eleven outbreaks were detected between 1744 and the present, many of them occurring at all the sites. Outbreaks were found to be synchronous, typically lasting 10 years at 25-year intervals. Interruption of the frequent fire regime that prevailed prior to 1880 was associated with a shift to shorter, less frequent outbreaks. Dry to wet oscillations in climate were correlated with outbreak initiations. Pandora moth outbreaks appear to have been an intrinsic part of the Kaibab Plateau’s forest ecosystems, though more research is needed to understand outbreak effects on the ecosystem and future directions of the moth–host relationship under climate warming.

Wu, Weiguang;Zhu, Ying;Wang, Yifei

doi: 10.3390/f14030445pmid: N/A

Zhejiang Province, charged with the task of opening “an important window”, should take the lead in the implementation of the national “carbon peak, carbon neutral” strategy. The intention of this study is to start from the intersection of economics and geography, and on the basis of GIS analysis, use the spatial Dubin model to study the spatio-temporal evolution trend, key influencing factors, and spatial spillover effects of forest carbon sequestration in 72 districts and counties of Zhejiang Province from 2000 to 2020, to provide a theoretical and practical reference for how to formulate regional synergistic forest sink enhancement measures and help Zhejiang achieve the goal of carbon neutrality. The conclusions are as follows: (1) From 2000 to 2020, the overall growth of forest carbon sequestration in all regions and counties of Zhejiang Province was relatively high, but the regional differences were large. The concentration center and range moved to the southwest. (2) If the spatial effect is considered, the increase of per capita GDP, road density, and deforestation will reduce the forest carbon sequestration, and the conservation of ecological public welfare forests will have a significant positive relationship with the forest carbon sequestration.

Nowakowska, Justyna Anna;Belbahri, Lassaâd;Oszako, Tomasz

doi: 10.3390/f14030446pmid: N/A

Forests are a vital component of the natural environment as they support biodiversity, sequester carbon, play a key role in biogeochemical cycles, and produce the organic matter necessary for terrestrial organisms [...]

Vatandaşlar, Can;Bettinger, Pete;Gutierrez Garzon, Alba Rocio;Merry, Krista;Boston, Kevin;Lee, Taeyoon;Uzu, Joshua

doi: 10.3390/f14030447pmid: N/A

Forest management plans often suggest that economic, ecological, and/or social sustainability will be achieved if the proposed management actions are followed. Using forest plans developed by the US Department of Agriculture Forest Service and the Republic of Turkey, the purposes of this study were to (i) extract those statements that suggest sustainability will be achieved and (ii) assess whether there exist statistical differences between the two countries’ plans and the emphases of the findings. A content analysis and non-parametric statistical tests were employed to measure the frequency of a set of terms related to sustainability and to estimate significant differences in the use of sustainability terms in the plans sampled. Results suggest that ecological aspects are dominant in forest plans from both countries. While silviculture, sustained yield, and multiple use were the most frequently used terms in Turkish plans, the occurrences of conservation and recreation were significantly higher in US plans (p < 0.001). These findings suggest that the differences in the plans’ emphases could be attributable to the importance of Turkey’s forests for the wood production-related needs of Turkish society, whereas US national forests might no longer be seen as an important wood supply base but instead have been given a more “passive” forest use.

Yang, Ying;Xiong, Kangning;Huang, Huiqiong;Xiao, Jie;Yang, Biliang;Zhang, Yu

doi: 10.3390/f14030448pmid: N/A

The achievement of eco-product value and the growth of eco-industry can boost the economic advancement of karst areas. The findings of a statistical analysis of 520 relevant studies reveal the following: (1) From a time series perspective, the amount of papers increase with each wave of research; (2) contents mainly concentrate on four aspects, namely, ecosystem services supply (8.46%), value accounting (10.58%), value realization (37.88%), and eco-industry (30.38%); (3) the study areas are primarily concentrated in Asia (85.96%), Europe (7.12%), and North America (4.04%), most of which are located in China’s karst areas with vulnerable ecological environments and regions that are aware of eco-product values; and (4) research frontiers are reflected through four aspects of the ecosystem, namely, services supply, value accounting, value realization, and the eco-industry. Based on the analysis in this paper, it can be concluded that paths, mechanisms, and models for eco-product value realization are still slow. Therefore, to support the growth of karst agroforestry ecosystem services, it is imperative to further research the capacity of agroforestry ecosystem services supply, value accounting systems, ecological compensation mechanisms, the value realization models of eco-products, and the formation mechanism of eco-industries.