Sitka Spruce


Book Description




Guide to Biomass comminution: material properties, machinery, principles of the process and fundamentals of process modelling


Book Description

This study aims to derive a qualitative model for energy requirements of the wood chipping process. A relationship is shown between energy requirements and properties of biomass, which is a quite variable material.The relationship between comminution machinery and energy which is necessary for the process is highlighted. The derivation of the model is focused on chipping, but it is generally possible to make it available for both different types of biomass (f. ex. agricultural residues)and different types of comminution machinery (f. ex. hammermills) by using different material properties adjusted to the machinery mechanics. The properties which are used in the derivation are meant to be easy to measure. Furthermore, the model is meant to be used as a base for a quantitative model that, thanks to measurements taken from real comminution machinery and thanks to using wood with known properties, could answer two important questions: - Would hypothetical changes in the desired size of output material increase the total system efficiency, taking into consideration the lowest efficiency of the combustion process (e.g., higher amounts of unburned fuel)? - Considering the energy used for the process, how can comminution as an operation in the biofuel supply chain be optimised? Answers for the above questions could highlight new possibilities in terms of further energy savings and a maximising of the energy efficiency of the bioenergy sector. Furthermore, the results could motivate optimized choices of comminution machinery for the biofuel supply chain as well as for other applications. Another important feature of this study is its unique holistic point of view that takes into consideration aspects from the fields of mechanics, material sciences and natural sciences to deliver the full picture to the reader.




Shades of Green


Book Description

This book takes a fresh look at the most disliked tree in Britain and Ireland, explaining the reasons it was introduced and why it became ubiquitous in the archipelagos of northwest Europe. Sitka spruce has contributed to the Pacific Coast landscapes of North America for over ten millennia. For the Tlingit First Nation it is the most important tree in terms of spiritual relationships, art, and products in daily use such as canoes, containers, fish-traps and sweet cakes. Since the late nineteenth century it has also been the most important tree to the timber industry of west coast North America. The historical background to the modern use of Sitka spruce is explored. The lack of cultural reference may explain negative public response when treeless uplands in the UK and Ireland were afforested with introduced conifer species, particularly Sitka spruce, following two World Wars. The multipurpose forestry of today recognizes that Sitka spruce is the most important tree to the timber industry and to a public which uses its many products but fails to recognize the link between growing trees and bought goods. The apparently featureless and wildlife-less Sitka spruce plantations in UK uplands are gradually developing recognizable ecological features. Sitka spruce has the potential to form temperate rain forests this century as well as to produce much-needed goods for society. The major contribution of Sitka spruce to landscapes and livelihoods in western North America is, by contrast, widely accepted. But conserving natural, old-growth forests, sustaining the needs of First Nations, and producing materials for the modern timber industry will be an intricate task.




Trees, Woods and Forests


Book Description

Forests—and the trees within them—have always been a central resource for the development of technology, culture, and the expansion of humans as a species. Examining and challenging our historical and modern attitudes toward wooded environments, this engaging book explores how our understanding of forests has transformed in recent years and how it fits in our continuing anxiety about our impact on the natural world. Drawing on the most recent work of historians, ecologist geographers, botanists, and forestry professionals, Charles Watkins reveals how established ideas about trees—such as the spread of continuous dense forests across the whole of Europe after the Ice Age—have been questioned and even overturned by archaeological and historical research. He shows how concern over woodland loss in Europe is not well founded—especially while tropical forests elsewhere continue to be cleared—and he unpicks the variety of values and meanings different societies have ascribed to the arboreal. Altogether, he provides a comprehensive, interdisciplinary overview of humankind’s interaction with this abused but valuable resource.




Sitka Spruce


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The Practical Lumberman


Book Description




The Silviculture of Trees Used in British Forestry, 3rd Edition


Book Description

British woodlands and forests are often located on sites and in regions that are marginal for agriculture; many are at high elevations and exposed, with short growing seasons. Wherever forests are located, site and climatic conditions must dictate species choice in forest management. This book provides a detailed guide to the biological suitability of different sites and soils for all important native trees and the most extensively used exotics. Apart from physical difficulties such as steepness and stoniness, forest soils also frequently have problems associated with them. They can be waterlogged or drought-prone, suffer from extremes of acidity or alkalinity, or have compacted layers. The book provides information on species' suitability for different purposes. It includes details of species' origin and introduction (where applicable), as well as their climatic and soil requirements and other silvicultural characteristics. Information about provenance, yield and timber is also provided. Fully updated throughout, this 3rd edition puts more emphasis on species suitable for changing climatic conditions, with accounts of several species that may become more prominent in British forests: including several silver firs, hickories, eucalypts, spruces, poplars and wingnuts. The book concludes with simple keys for identifying the trees most likely to be encountered in British forests. It is an essential resource for students, researchers and forestry professionals.







Boreal and Temperate Trees in a Changing Climate


Book Description

This book provides an overview of how boreal and temperate tree species have adapted their annual development cycle to the seasonally varying climatic conditions. Therefore, the frost hardy dormant phase, and the susceptible growth phase, are synchronized with the seasonality of the climate. The volume discusses the annual cycle, including various attributes such as timing of bud burst and other phenological events, seasonality of photosynthetic capacity or the frost hardiness of the trees. During the last few decades dynamic ecophysiological models have been used increasingly in studies of the annual cycle, particularly when projecting the ecological effects of climate change. The main emphasis of this volume is on combining modelling with experimental studies, and on the importance of the biological realism of the models.