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ArticleInfluence of snow cover change and temperature anomalies on the transformation of boreal forests and fires in north Asia
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.In the last three decades, the number and area of fires in the North Asian taiga, forest-tundra and tundra is increasing. Analysis of spatial data on fires against the information on local climate anomalies indicates significant correlation. The estimates are generally based on average seasonal temperatures and the duration of the vegetation period; however, while these parameters are useful for global bioclimatic regularities, they are not sufficient for local forest change influenced by small-scale climate effects. Comparison of satellite images at the beginning and the end of the snow period with patterns of fire activities shows that the frequency and scale of temperature and snow anomalies are also key factors. Field studies that aimed to verify the snow properties as identified through satellite imagery were carried out on more than 200 plots in the Urals and the Russian Far East. It was found out that tree crowns of dark-coniferous and mixed forests intercept up to a quarter of total snow reducing accumulation and decreasing snowmelt logging. This leads to the desiccation of the soil layer in spring and increases the risk of fires in forests, where this risk used to be low. Another important effect is the increased frequency of dry and hot autumns in taiga and forest-tundra, which dramatically aggravate the risk of litter ignition. Field observations and analysis of satellite images for 30 years give information on the spatial differentiation of the effects. The higher risk of fires associated with the redistribution of snow by tree crowns is typical of the south and central taiga. Soil desiccation in autumn is the important factor for fires in the north taiga and forest-tundra. These effects are additional to the seasonal temperature anomalies, which are the key risk factor. Taking account of these effects in context of the global warming provides better estimation of fires, including the risk of fires in unique forests on protected areas in North Asia. Keywords: Climate change, Adaptive and integrated management, Biodiversity conservation, Sustainable forest management, Research ID: 3485018 -
DocumentManaging taxonomic and functional diversity is the key to sustain aboveground biomass and soil microbial diversity: A synthesis from long-term forest restoration of southern China
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Exploring the biodiversity-ecosystem functioning relationship is one of the central goals of ecological research. Restoration is essential for supporting key ecosystem functions such as aboveground biomass production and managing soil microbial diversity. However, the relative importance of functional versus taxonomic diversity in explaining aboveground biomass and soil microbial diversity during restoration is poorly understood. Here, we used a trait-based approach to test for the importance of multiple plant diversity attributes in regulating aboveground biomass and soil microbial diversity in four 30- years-old restored subtropical forests in southern China. High-throughput Illumina sequencing was applied for detecting fungal and bacterial diversity. We show that both taxonomic and functional diversities are significant and positive regulators of aboveground biomass; however, functional diversity (FD) was more important than taxonomic diversity (TD) in controlling aboveground biomass. FD had the strongest direct effect on aboveground biomass compared with TD, soil properties, and community weighted mean (CWM) traits. Our results further indicate that leaf and root morphological traits and traits related to the nutrient content in plant tissues showed acquisitive resource use strategy which influenced aboveground biomass. In contrast to aboveground biomass, taxonomic diversity explained more of the soil microbial diversity than the FD and soil properties. Prediction of fungal richness was better than that of bacterial richness. In addition, root traits explained more variation of soil microbes than the leaf traits. Our results suggest that both TD and FD play a role in shaping aboveground biomass and soil microbial diversity; but FD is more important in supporting aboveground biomass while TD for belowground microbial diversity. These results imply that enhancing TD and FD is important to restoring and managing degraded forest landscapes. Key words: Biodiversity-Ecosystem functions; soil microbial diversity, taxonomic diversity, functional diversity, forest restoration ID: 3486373 -
ArticleNear-infrared analysis and model optimization about main Chemical Components of pulpwood in Hainan Province
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.In order to improve the utilization of pulpwood in Hainan Province, alleviate the shortage of pulping materials, reduce pollution and overall costs in Chinese pulping and papermaking industry, this study aimed to use near- infrared spectroscopy to realize the rapid analysis of holocellulose and Klason lignin content in pulpwood. A holographic grating near-infrared pectrometer, with a simple structure and easy modification, was used to collect the near-infrared spectrum of 205 samples of pulpwood common in Hainan (E.urophlla× E.tereticornis, Eucalyptus urophylla×grandis, Eucalyptus urophylla, Acacia mangium, Acacia crassicarpa Benth.), and the content of holocellulose and Klason lignin were measured ccording to the traditional laboratory methods. Suitable pretreatment methods were selected in combination with partial least squares (PLS) to establish analysis models of holocellulose and Klason lignin. Then genetic algorithm was used to eliminate the irrelevant variables and clarify the feature absorption of holocellulose and Klason lignin in order to optimize the models. The holocellulose model was established by pretreatment methods of smoothing, vector normalization, first derivative of the original spectrum, with 1150.3~2362.0nm bands participated in modeling. The RMSEP value of the model was 0.55% and the absolute deviation range was -0.91~0.87%. The Klason lignin model was established by pretreatment methods of smoothing, multiplicative scatter correction(MSC), second derivative of the original spectrum, with 1137.6~1872.5nm and 2131.0~2424.1nm bands participated in modeling. The RMSEP value of the model was 0.45% and the absolute deviation range was -0.76~0.79%. The RPD values of the two models were 4.71 and 3.47, respectively, which can meet the industrial needs of online rapid analysis. At the same time, this study provides a theoretical basis for the establishment of a near-infrared characterization system for pulpwood. Keywords: near-infrared; Genetic Algorithm; characteristic wavelengths; holocellulose; Klason lignin ID: 3486598
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