Larch Status A

LARCH is a model that is used by the Netherlands Environmental Assessment Agency (PBL) for ex-ante and ex-post evaluations of Dutch nature policies. LARCH generates the potential habitat networks of a species. LARCH will not predict the actual distribution of a specie

Effect of Aspect-Slope on the Growth of Conifers in a Harsh Boreal Climate of Northwest Sweden

Tree development is affected by different factors including topographic features. The effect could be even more complex in harsh environments such as in the northwest of Sweden. In this study, we analyzed the effect of aspect-slope on the development up to the age of 34 years of five species: black spruce, lodgepole pine, Norway spruce, Siberian larch and Scots pine. The species were planted in a field experiment on the southwest slope, mountaintop, and northeast slope in a randomized complete block design in the northwest of Sweden (latitude 67 degrees) with 2 m x 2 m spacing. No re-measurement data were available and, as such, retrospective diameters and heights were derived from sample discs and measurement of length to every branch whorl, respectively. Variations in tree survival rate, height and diameter were analyzed using a linear mixed-effect model. The results showed that there were significant (p < 0.05) differences between species in survival rate, diameter and height growth; in some cases, differences were found between contrasting aspect-slope. Black spruce and Siberian larch had the best survival rate under this harsh boreal climate. However, Siberian larch had the best growth and developed well on the mountaintop and northeast slope. Lodgepole pine developed well on the southwest slope. Scots pine also grew well on the southwest slope and mountaintop. Norway spruce had the slowest growth. Based on this study, Siberian larch and lodgepole pine can serve as alternatives to the two traditional conifer species, Norway spruce and Scots pine, used in Sweden. Siberian larch is particularly suitable because it is able to withstand the harshness of the boreal environment

Techniques for Modelling Structured Operational and Denotational Semantics Definitions with Term Rewriting Systems

A fundamental requirement for the application of automatic proof support for program verification is that the semantics of programs be appropriately formalized using the object language underlying the proof tool. This means that the semantics definition must not only be stated as syntactically correct input for the proof tool to be used, but also in such a way that the desired proofs can be performed without too many artificial complications. And it must be clear, of course, that the translation from mathematical metalanguage into the object language is correct. The objective of this work is to present methods for the formalization of structured operational and denotational semantics definitions that meet these requirements. It combines techniques known from implementation of the $\lambda$-calculus with a new way to control term rewriting on object level, thus reaching a conceptually simple representation based on unconditional rewriting. This deduction formalism is available within many of the existent proof tools, and therefore application of the representation methods is not restricted to a particular tool. Correctness of the representations is achieved by proving that the non-trivial formalizations yield results that are equivalent to the meta-level definitions in a strong sense. Since the representation algorithms have been implemented in form of executable programs, there is no need to carry out tedious coding schemes by hand. Semantics definitions can be stated in a format very close to the usual meta language format, and they can be transformed automatically into an object-level representation that is accessible to proof tools. The formalizations of the two semantics definition styles are designed in a consistent way, both making use of the same modelling of the underlying mathematical basis. Therefore, they can be used simultaneously in proofs. This is demonstrated in a larger example, where an operational and a denotational semantics definition for a programming language are proved to be equivalent using the Larch Prover. This proof has been carried out by hand before, and so the characteristics of the automated proof can be made quite clear

Incorporating specialized theories into a general purpose theorem prover

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1995.Includes bibliographical references (p. 77-79).by Anna Pogosyants.M.S

Biomolecules extraction from forest biomass

295 p

Biomolecules extraction from forest biomass

295 p

Northern Eurasia Future Initiative (NEFI): facing the challenges and pathways of global change in the twenty-first century

During the past several decades, the Earth system has changed significantly, especially across Northern Eurasia. Changes in the socio-economic conditions of the larger countries in the region have also resulted in a variety of regional environmental changes that can have global consequences. The Northern Eurasia Future Initiative (NEFI) has been designed as an essential continuation of the Northern Eurasia Earth Science Partnership Initiative (NEESPI), which was launched in 2004. NEESPI sought to elucidate all aspects of ongoing environmental change, to inform societies and, thus, to better prepare societies for future developments. A key principle of NEFI is that these developments must now be secured through science-based strategies co-designed with regional decision-makers to lead their societies to prosperity in the face of environmental and institutional challenges. NEESPI scientific research, data, and models have created a solid knowledge base to support the NEFI program. This paper presents the NEFI research vision consensus based on that knowledge. It provides the reader with samples of recent accomplishments in regional studies and formulates new NEFI science questions. To address these questions, nine research foci are identified and their selections are briefly justified. These foci include warming of the Arctic; changing frequency, pattern, and intensity of extreme and inclement environmental conditions; retreat of the cryosphere; changes in terrestrial water cycles; changes in the biosphere; pressures on land use; changes in infrastructure; societal actions in response to environmental change; and quantification of Northern Eurasia’s role in the global Earth system. Powerful feedbacks between the Earth and human systems in Northern Eurasia (e.g., mega-fires, droughts, depletion of the cryosphere essential for water supply, retreat of sea ice) result from past and current human activities (e.g., large-scale water withdrawals, land use, and governance change) and potentially restrict or provide new opportunities for future human activities. Therefore, we propose that integrated assessment models are needed as the final stage of global change assessment. The overarching goal of this NEFI modeling effort will enable evaluation of economic decisions in response to changing environmental conditions and justification of mitigation and adaptation efforts