Evaluation of two round baling systems for harvesting understory biomass

The objective of this study was to evaluate the performance and to estimate costs of two round baling systems for harvesting understory biomass. One system was a cutter-shredder-baler prototype (Bio-baler). The other system required two successive operations. The first operation was cutting and shredding with a Supertrak tractor equipped with a Fecon mulcher head. The second operation was baling with a Claas baler. The machines were evaluated in three different pine stands on the Osceola National Forest in Florida, United States. Data collection included time study, fuel consumption and bale measurements. Material was collected from a sample of bales for heat and moisture content determination. On the most representative site (Site 2), the Bio-baler recovered 8.05 green t ha⁻¹ while the mulcher and the Claas baler recovered 9.75 green t ha⁻¹ (43 and 52 percent of original understory biomass, respectively). Productivity was 0.30 ha h⁻¹ for the Bio-baler and 0.51 ha h⁻¹ for the Claas baler. Density of the bales was 321 green kg m⁻³ for the Bio-baler and 373 green kg m⁻³ for the Claas baler. Average net heat content was 6263 MJ bale⁻¹ for the Bio-baler and 6695 MJ bale⁻¹ for the Claas baler with biomass containing 38 percent of moisture content on a wet basis. Cost per unit area was less with the Bio-baler (US$320.91 ha⁻¹) than with the mulcher-baler system (US$336.62-US$596.77 ha⁻¹).     

Economic analysis on small-scale forest biomass gasification considering geographical resources distribution and technical characteristics

Biomass is getting the great interest in Japan, and the cabinet approved “Biomass Nippon Strategy” in 2002 to promote the utilization of biomass. Although various projects utilizing wood biomass for energy uses have started already, many of them utilize mainly waste wood. Forest biomass remains unutilized because of the high logistic cost and the small scale of resource generation at a site. Small-scale gasification is considered as a suitable technology for forest biomass, and more than 10 demonstration plants have started to be operated recently. This study analyzes the economic feasibility of the small-scale forest biomass CHP system with gasification technology in Japan.The authors have developed the BiRReT tool, which takes input data such as geographical resource distribution and scale merit information of the target technology, and analyzes the economics of bioenergy system in target region by finding the optimal conditions; namely plant size, plant location, the number of plants, and lower generation costs. A case study in Miyagi prefecture revealed the conclusion that the system with logging residue fuel has the economic feasibility if the capital cost and the resource price will decrease from the BAU case by technological learning in the future. On the other hand, thinned wood will not be utilized as a fuel for power plants due to high fuel production cost. It is also found by the tool analysis that the technology’s scale merit has stronger impact on power generation cost in the trade-off between scale merit and the transportation cost.     

On the relationship of canopy LAI and photon recollision probability in boreal forests

The theory of spectral invariants, or ‘p-theory’, states that the canopy scattering coefficient at any wavelength can be related to the leaf scattering coefficient at the same wavelength through a spectrally invariant canopy structural parameter — the photon recollision probability p. The p-theory has recently gained interest in the vegetation reflectance modeling community as an efficient tool for characterizing scattering in clumped foliage structures. In this short communication paper, we report empirical data of the relationship of canopy leaf area index (LAI), diffuse non-interceptance and photon recollision probability for 1032 coniferous and broadleaved forest plots measured in Finland. Our results indicate that the relationship of canopy LAI and diffuse non-interceptance is near-universal in boreal stands i.e. it does not depend on stand age, tree species or growth conditions. This allows improving parameterizations used by canopy reflectance models which utilize the photon recollision probability concept. Our results also suggest that establishing species-specific p-LAI functions for northern European forests requires more research on the influence of micro- and macroscale foliage grouping on photon recollision probability.     

Landscape-scale modeling of water quality in Lake Superior and Lake Michigan watersheds: How useful are forest-based indicators?

The Great Lakes watersheds have an important influence on the water quality of the nearshore environment, therefore, watershed characteristics can be used to predict what will be observed in the streams. We used novel landscape information describing the forest cover change, along with forest census data and established land cover data to predict total phosphorus and turbidity in Great Lakes streams. In Lake Superior, we modeled increased phosphorus as a function of the increase in the proportion of persisting forest, forest disturbed during 2000–2009, and agricultural land, and we modeled increased turbidity as a function of the increase in the proportion of persisting forest, forest disturbed during 2000–2009, agricultural land, and urban land. In Lake Michigan, we modeled increased phosphorus as a function of ecoregion, decrease in the proportion of forest disturbed during 1984–1999 and watershed storage, and increase in the proportion of urban land, and we modeled increased turbidity as a function of ecoregion, increase in the proportion of forest disturbed during 2000–2009, and decrease in the proportion softwood forest. We used these relationships to identify priority areas for restoration in the Lake Superior basin in the southwestern watersheds, and in west central and southwest watersheds of the Lake Michigan basin. We then used the models to estimate water quality in watersheds without observed instream data to prioritize those areas for management. Prioritizing watersheds will aid effective management of the Great Lakes watershed and result in efficient use of restoration funds, which will lead to improved nearshore water quality.     

Assessing terrestrial wildlife populations in the Toronto and Region Area of Concern

Beneficial use impairments (BUIs) under the Great Lakes Water Quality Agreement identify environmental issues requiring remedial action within the Great Lakes Areas of Concern (AOCs). We conducted this study to support the assessment of the wildlife component of BUI 3: degradation of fish and wildlife populations. We compared bird and amphibian (frogs and toads) data from the Toronto and Region Conservation Authority’s Terrestrial Long-term Monitoring Program in the Toronto and Region AOC to an adjacent, but otherwise similar, reference watershed, Duffins Creek. Twelve of 13 targets were met within the AOC for forest bird, wetland bird, meadow bird and amphibian populations based on averages of mean annual values at sites within the AOC that were within two standard deviations of averages at sites in the Duffins Creek reference watershed between 2008 and 2017. Even though wildlife populations within the AOC were within the normal range of variability expected from a reference watershed, they were often at lower levels than within the Duffins Creek reference watershed. In addition, forest bird and amphibian populations were negatively affected by urbanization within the AOC and meadow bird indices declined. We conclude that while wildlife populations within the AOC currently meet targets for BUI 3, they continue to be negatively impacted by numerous stressors that are primarily related to past and ongoing urbanization. Thus, continued restoration of wildlife habitat and protection of existing habitat within the AOC is highly recommended.     

超轻型直升飞机与固定翼飞机在森林病虫害防治应用中的比较研究

对超轻型直升飞机与固定翼飞机在森林病虫害防治应用中的性能、喷洒效果、作业效率、使用费用、安全性等方面进行了比较,结果表明,在山区森林病虫害防治中,超轻型直升飞机优于固定翼飞机,能有效地提高防治效果.     

基于改进遗传算法和SVM的森林火灾视频目标鉴别

计算机视觉是目前计算机技术研究的热门课题之一,目标对象特征的选择和提取是计算机视觉的核心问题。在分析和研究火焰图像中火焰预判方法的基础上,提出了从纹理、动态、几何3个方面筛取火焰图像的组合特征,并且重点介绍了动态特征的提取方法。在火焰识别的特征选择方面做了较深入的研究,综合利用了火焰的内容特征,基于遗传算法提出了新的适应度函数,使得特征选择更加科学,而基于结构风险最小化理论的SVM在识别过程中可充分发挥优势,因此在实验中取得了理想的效果。     

基于 Aquatox 的北京奥林匹克森林公园主湖生态净化模拟

景观水体是风景园林的重要组成部分,在水资源短缺和水污染的现状条件以及公众节约意识增强的情况下,如何既能节约成本,又能维持景观水体的水质就成为重要的问题。本研究采用Aquatox模型对北京奥林匹克森林公园主湖的水生态系统进行模拟,评估水生态系统现状情况的效果以及现有湿地系统水质净化措施的有效性。之后从生态净化的角度,提出丰富主湖水生植物类型和增加底栖动物、完善生物链两个调整方案并分别对两个改进方案进行模拟,再与有、无湿地系统净水措施的情形进行对比研究。模拟结果表明,现有湿地系统净水措施和两个调整方案都具有稳定性,其中增加底栖动物、完善食物链的措施具有最高的鱼类承载力,而无湿地系统循环净水时水质缺乏稳定性。通过模拟得出的净化水质的能力排序为：增加底栖动物、完善食物链>现有湿地循环净化系统>在主湖增加植物类型>无湿地循环净化系统。