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The Environment Today
Published in Anco S. Blazev, Power Generation and the Environment, 2021
Nine tenths of the forest’s energy is stored in the leaves and tissues of the trees themselves. The forest floor is a porous mass that prevents minerals and nutrients from being washed away and lost. As soon as a tree falls, or a creature dies, decomposers begin to turn it into a food source and mulch. The vegetation to renew the cycle quickly absorbs the nutrients that are released. Forest fires help the renewal process by accelerating the normal aging processes, whereby a tree can be burned in minutes, instead of slowly decomposing for years. This way its nutrients are delivered to the soil quickly and efficiently.
Basic Hydraulics and Accessories
Published in Frank R. Spellman, The Science of Wind Power, 2022
In cities, in summer, rain strikes hot cement and asphalt and swiftly evaporate, or run into storm drains, swiftly rejoining the cycle. In fields, rain brings essential moisture to crops, and sinking deeper into the earth, ends as groundwater. If water strikes a forested area, the forest canopy breaks the force of the falling drops. The forest floor, carpeted in twigs, leaves, moss, dead, and decaying vegetation, keeps the soil from splashing away in erosion as the water returns to the depths of the earth, or runs over the land to join a stream.
Land Application of Liquid Sludge
Published in Alice B. Outwater, Reuse of Sludge and Minor Wastewater Residuals, 2020
Increased tree growth is a nearly universal effect of sludge application in the forest. For years following a sludge application, major portions of the supplemental nutrients and trace elements are retained as unavailable, undecomposed forms in the humus of the forest floor. Nutrients in available forms moving from the forest floor are readily taken up by plants, with no significant fertility changes in the surface or subsurface soils. This means that a single sludge application can provide a slow, steady supply of nutrients that lasts for many years.
Mercury fluxes, budgets, and pools in forest ecosystems of China: A review
Published in Critical Reviews in Environmental Science and Technology, 2020
Jun Zhou, Buyun Du, Lihai Shang, Zhangwei Wang, Hongbiao Cui, Xingjun Fan, Jing Zhou
Figure 4 shows the seasonal variations of soil–atmosphere Hg exchange fluxes at forest areas in China. The variations can be classified into two distinct types: evergreen forest and deciduous forest. At evergreen forests, the mean exchange fluxes in warm seasons (summer and spring) were relative higher than in cold seasons (winter and autumn, t test: p < .05 for all). Solar radiation over the forest canopy was much higher in the warm seasons, but the branches and leaves were also luxuriant, so soils received similar sunlight with other seasons at the subtropical evergreen forests (Ma, Wang, Sun, Shen, & Huang, 2013). Therefore, elevated soil–atmosphere Hg exchange fluxes in warm seasons under the evergreen canopy were mainly caused by the increasing soil/air temperature. In contrast, in the deciduous forests, such as larch, mixed broadleaf forest, and wetland in Mt. Dongling, the means of soil–atmosphere Hg exchange fluxes were significantly higher in cold seasons (leaf-off period) than that in the other seasons (t test: p < .01). Solar radiation was the maximum amount reaching the forest floor during leaf-off periods in winter, which was ∼300 W m−2 and promoted Hg0 production. Whereas during leaf-on periods in summer, the maximum solar radiation at the forest floor was only about 116 W m−2.
Novel extracting methods for conifer stumps
Published in International Journal of Forest Engineering, 2019
Juha Laitila, Asko Poikela, Heikki Ovaskainen, Kari Väätäinen
The main functions of stump and root systems are the acquisition of soil-based resources, resource storage and anchoring the tree against wind and snow damage (Peltola et al. 2000; Lundström et al. 2007; Kalliokoski et al. 2008). Root architecture differs greatly between species, which entails different solutions for the various species (Kalliokoski et al. 2008). Because tree stumps and roots have evolved to resist breaking forces in all directions, extracting stump-root systems requires considerable force (Peltola et al. 2000; Lundström et al. 2007; Lindroos et al. 2010). Stump extraction also causes physical disturbance to the soil and the forest floor thorough mixing and redistribution of the soil material (Helmisaari et al. 2014). Such disturbance is likely to be dependent on stump size, extraction method, soil type and timing of stump harvesting (Berg 2014; Berg et al. 2015). From an environmental standpoint, this ground disturbance and rising concerns about erosion, rutting and soil compaction are the main drawbacks of stump extraction as binding lateral roots are removed (Walmsley and Godbold 2010; Berg 2014; Helmisaari et al. 2014; Berg et al. 2015; Olsson et al. 2017; Persson 2017; Kaarakka et al. 2018).
Assessing occupational erionite and respirable crystalline silica exposure among outdoor workers in Wyoming, South Dakota, and Montana
Published in Journal of Occupational and Environmental Hygiene, 2018
Catherine Beaucham, Bradley King, Karl Feldmann, Martin Harper, Alan Dozier
Tree thinning is a process of removing slower growing or defective trees to create more space between trees which reduces forest fire risk and the ability of a fire to spread rapidly. Felling is the process of downing individual trees, while bucking is the process of cutting a felled and de-limbed tree into logs. Excessive vegetative growth is also cleared using a masticator attached to a Bobcat. The masticator grinds woody vegetation into wood chips that are deposited onto the forest floor. The masticator cuts down and grinds up whole standing trees in a single, continuous process. During mastication activities, the operator remained inside of the closed vehicle cab of the Bobcat.