Latest articles in this journal
Forests, Volume 14; https://doi.org/10.3390/f14061154
Nitrogen deposition can change the soil in N and C cycling processes. However, a general understanding of how N deposition changes C and N mineralization has not yet been reached. Soil organic C and N mineralization beneath the dominant shrubs of Haloxylon ammodendron and between the shrubs in response to two levels of N addition (2.5 gN m−2 and 5 gN m−2 per year) were investigated in the 1st, 4th, and 9th year of N addition in a temperate desert of northern China. N addition promoted soil N mineralization (RmN), and the nitrification rate (RNN) increased C mineralization in the interplant and decreased it beneath shrubs. N addition increased soil microbial biomass C (Cmic), N (Nmic), and PLFAs in the interplant, and decreased it beneath shrubs. RmN and RNN were related to Nmic, and RCM was related to Cmic and the total PLFAs. N addition increased the fungal biomass alongside the ratio of fungal to bacterial PLFAs in the interplants while decreasing them beneath shrubs. Our results support how N addition can increase soil N mineralization and nitrification, but the effects on soil C mineralization are dependent on the amount of nitrogen addition, the soil’s available carbon content, and water. Finally, the divergent responses of microbial communities to N addition between microsites suggest that the “fertile islands” effects on nutrients and microbial biomass are important when estimating feedbacks of C and N cycling to projected N deposition in the desert ecosystem.
Forests, Volume 14; https://doi.org/10.3390/f14061153
This article reviews the potential of uncoated Norway spruce as a façade material. Aspects such as natural durability, permeability properties, impact of density, and product dimensions are discussed. The review concludes that a careful design of the product is needed due to the intrinsic properties of the spruce species. Natural photodegradation will occur but has been proven not to impact spruce to a greater degree than other species. The optimal choice for a Norway spruce panel would be made of heartwood without juvenile tissues, with a vertical growth ring orientation. The selection of density is, however, unclear since low density reduces crack formation but could facilitate favourable levels of moisture for fungal colonisation. Additionally, the width of the growth ring has an unpredictable effect on the formation of cracks when the effect of early and latewood interaction cooperates with the effect of density.
Forests, Volume 14; https://doi.org/10.3390/f14061152
The organic nature of wood makes it susceptible to abiotic and biotic degradation. Impregnation with chemical products is the most common method of protection. Only inorganic borates combine the unique set of properties that make them well suited for wood protection: they are insecticidal, fungicidal and flame retardants. In this work, zinc borate is suspended in an ammonia solution and applied in depth to wood. Its resistance to leaching is evaluated. The product is tested against rot fungi (Gloeophyllum trabeum and Trametes versicolor) and a xylophagous insect (Anobium punctatum). The results verify its effectiveness as a wood protector, while leaching less than other borate-based products.
Forests, Volume 14; https://doi.org/10.3390/f14061151
Recreational ecosystem services (RESs) are the diverse recreational opportunities provided by nature to humans, which contribute to the improvement of public health and social well-being. The use of online social media is an efficient method for quantifying public perceptions of recreational ecosystem services (RESs) delivered by a given landscape. With the continuously changing demand for nature-focused outdoor recreational activities since COVID-19, camping has become the fastest-growing outdoor leisure activity in megacities and a key indicator for how people perceive and value the RESs provided by the landscape. Such unexpected changings triggered by COVID-19 have further led to an imbalance between demand and supply, which results in fierce conflicts in urban green space management. This study presents a spatial pattern analysis of how people perceive RESs in a megacity-scale case study of Beijing using geo-tagged camping notes posted on Little Red Book (LRB). We employed these camping notes in the context of a megacity to (i) map public camping behaviors patterns in urban green spaces, (ii) evaluate spatial clusters of high/low RESs, and (iii) investigate the relationship between RESs, local landscape features, and gender through correspondence analysis. Our results show that considerable spatial clustering of camping behaviors was observed in both suburban and urban green spaces. However, suburbs revealed a substantially higher RES value than central urban areas. In addition, water bodies were discovered to have remarkably low RES, while grassland and urban forests were found to have a close link with higher RES. In addition, significant gender preferences have been discovered, where female visitors prefer to camp in grassland, and male visitors favor bare ground and urbanized regions. Our findings would assist decision-makers in optimizing urban green space planning and management, adapting to fast-changing public camping demands in the context of the post-COVID-19 era. Findings also contribute to the literature by applying spatial analysis of social media data to understand public outdoor recreation activities and perceived value for megacities’ green space management.
Forests, Volume 14; https://doi.org/10.3390/f14061150
Interactions between the introduced gray squirrel (Sciurus carolinensis) and the native red squirrel (S. vulgaris) play an important role in the ecological equilibrium of European forest ecosystems. However, the range dynamics of the grey squirrel and red squirrel under future climate change scenarios remain unknown. The present study examined the range dynamics of grey squirrels and red squirrels in Europe and their range overlap now and in the future based on climate change. Under the most optimistic climate change scenario (SSP126), expansion of the grey squirrel’s range was mainly predicted in Germany, France, Croatia, Serbia, and Bulgaria. Under the most pessimistic climate change scenario (SSP585), expansion of the grey squirrel’s range was predicted in vast and scattered regions. Additionally, France, Italy, and Germany were overlapping ranges for the grey squirrel and red squirrel in the future under the SSP126 scenario but not under the current conditions, suggesting that there will be new regions where grey squirrels may threaten red squirrels in the future under SSP126. The range overlaps under the SSP585 scenario but not under the current conditions were vast and scattered, suggesting that there will be new regions in the future where grey squirrel may displace red squirrels under SSP585. Despite considerable variation, we detected expansions in the grey squirrel and red squirrel ranges and an increase in overlapping ranges between grey squirrels and red squirrels in the future. Therefore, our prediction suggests increasing threats of grey squirrels toward red squirrels in Europe in the future under climate change, which may impact the ecological equilibrium of European forest ecosystems.
Forests, Volume 14; https://doi.org/10.3390/f14061149
The oblique corner joints (OCJ) of wood-frame furniture doors crack easily during common usage due to external loads or changes in temperature and humidity. Aiming to solve this technology issue, the effects of the selected factors, i.e., material type (MT), diameter of dowel hole (DDH), moisture content of dowel (MCD), and distance between two dowels (DTD), on the diagonal tensile strength of the oblique corner joint (OCJ), were investigated experimentally and optimized based on the response surface method. The results showed that there were two typical mechanical behaviors of OCJs when subjected to diagonal tensile loads, according to load and displacement curves and failure modes. The critical crack strength, Fc, and ultimate strength, Fu, of samples made of heat-treated alder were smaller than those of samples made of control alder. DDH had a significant effect on Fc but not on Fu, while the effect of DTD on both Fc and Fu was significant. The Fc defined in this study was a better indicator for evaluating the crack load resistance of OCJs than Fu. The OCJs constructed by double dowels were significantly greater than those of single dowels. The optimal parameters for constructing the OCJs were obtained: MT was the control wood material, DDH was 7.8 mm, double dowels with a DTD of 27 mm, and the MCD should be higher than that of the base material.
Forests, Volume 14; https://doi.org/10.3390/f14061148
The effects of wood knots of Chinese weeping cypress (Cupressus funebris Endl.) wood on selected physical and color properties were investigated. Thirty samples of live knots, dead knots, and clear wood groups were selected for experiments to determine the physical properties of wood density, wood shrinkage, wood swelling, and wood color. The experimental analysis results showed that the wood density values are in the order: dead knots > live knots > clear wood, with a significant difference in wood density between different groups (p < 0.01). In addition, the values of the air-dry volumetric wood shrinkage, air-dry volumetric wood swelling, oven-dry volumetric wood shrinkage, and oven-dry volumetric wood swelling ratios are in the order: dead knots > live knots > clear wood, being consistent with a variation in wood density. Three groups of wood colors were provided: the color of clear wood is light, the color of live knots is reddish, and the color of live knots is blackish, in relative terms. The chromatic aberration between the three groups can be identified, and the wood color difference resulted from the discrepancy in the lightness index.
Forests, Volume 14; https://doi.org/10.3390/f14061145
A majority of mangroves are located in the coastal intertidal zone and are subject to tidal periodic inundation. However, the previous vegetation indices used for extracting the spatial distribution of mangroves were not able to effectively extract submerged mangroves, and the applicability of the vegetation indices used on different spatial resolution images obtained from different sensors was not verified. In this study, a new vegetation index, namely the intertidal mangrove identification indices (IMIIs), was proposed, based on GF-2 images of high and low tide levels. Meanwhile, other commonly used vegetation indices were also extracted. All the vegetation indices were used to extract the spatial distribution of mangroves under tidal inundation, and applicability tests of the vegetation indices were conducted on Sentinel-2 images in three different regions. It was found that the IMIIs proposed based on GF-2 images of high and low tide levels can extract submerged mangroves relatively well, and the spatial distribution extraction results of mangroves are better than those of other vegetation indices, with IMII2 outperforming IMII1. At the same time, IMIIs have good applicability in medium resolution Sentinel-2 images, and there are relatively large differences in the extraction results of mangrove spatial distribution among different vegetation indices in areas with significant impact of tidal inundation. Among all vegetation indices, the extraction results of IMIIs are relatively superior. In most cases, multi variables collaborative application can improve the accuracy of mangrove spatial distribution extraction results. Based on the results of this study, it was concluded that the IMIIs proposed in this study can accurately extract the spatial distribution of mangroves inundated by tides from both medium- and high-resolution images, providing accurate basic data for effective management and scientific protection of mangrove resources.
Forests, Volume 14; https://doi.org/10.3390/f14061147
Insect outbreaks are major drivers of natural disturbances in forest ecosystems. Outbreaks can have both direct and indirect effects on the composition of soil arthropod communities through canopy opening, nutrient addition and predator-prey interactions. In this study, we aimed to understand the effects of forest tent caterpillar (Malacosoma disstria; FTC) outbreaks through cascading effects on ant communities in both temperate and boreal forests in Canada. Pitfall traps and Berlese funnels were used to compare the ant communities, as well as the surrounding arthropod communities, between control and outbreak sites in boreal and temperate forests (in Quebec, Canada). Using the Sørensen dissimilarity index, we determined the alpha and beta diversity of the ant community. Other arthropods collected in the traps were counted to evaluate the richness and abundance of potential prey for the ants and other potential predators of the FTC. We used an indicator species analysis to examine the species associated with sites defoliated by the outbreak. In the boreal forest, we found that FTC outbreaks caused decreases in species richness and increases in the evenness of ant communities in defoliated sites. In the boreal forest sites, species composition varied significantly between control and outbreak sites. This pattern was driven in part by the presence of other predators. A similar, but weaker pattern was observed in the temperate forest. We saw no changes in the beta diversity in the boreal forest, but did see a significant decrease in the temperate forest between the outbreak sites and the control sites. Ant species in the boreal forest tended to exhibit a more marked preference for either control or previously defoliated sites than species in the temperate forest. Our study showed that disturbances such as insect outbreaks can drive changes in the ant community. While we saw small effects of outbreaks, manipulation experiments using resource addition could help us validate the mechanisms behind these relationships.
Forests, Volume 14; https://doi.org/10.3390/f14061146
Wildfires are one of the most hazardous natural disasters in Australia in terms of fatalities, property damage and financial losses. Events of catastrophic wildfires are recorded across the world including in the United States and Canada. Failures along power distribution infrastructure and network faults have been identified as some of the causes for the initiation of wildfires. Thus, it is critical to better understand the mechanisms and the potential prevention strategies for wildfires caused by power distribution system faults. In this light, this paper presents how the power distribution network faults cause wildfires highlighting the main mechanisms. Further, this paper reviewed studies on recent advancements for the prediction, detection and prevention of wildfires. Condition assessment of power distribution infrastructure including poles, crossarms, overhead cables and other attachments are paramount to detect potential defects and to carry out timely replacements which can subsequently mitigate the possibility of wildfire initiation. Therefore, this paper summarized the studies on condition monitoring and surveillance techniques for power distribution infrastructure. Altogether, this paper aimed to enhance the awareness about the prevention strategies for wildfires caused by power distribution system faults.