Aspects of hybrid larch (Larix X eurolepis Henry) as a potential tree species in southern Swedish forestry

The interest in growing hybrid larch (Larix × eurolepis Henry) in southern Sweden has increased in recent decades, one of its assumed advantages being high volume growth. The work underlying this thesis was designed to contribute to our understanding of hybrid larch and its use in commercial forestry as a complement to Norway spruce (Picea abies (L.) Karst.) in southern Sweden. A literature review supported the hypotheses that young hybrid larch stands have high growth and yield potential. In addition, it highlighted the difficulties involved in morphologically distinguishing the hybrid from its parental species and stressed the susceptibility of hybrid larch to root rot (mainly caused by Heterobasidion annosum (Fr.) Bref.). A survey conducted through interviews in 1993 of the opinions of forest managers with practical experience of growing hybrid larch showed that the species was considered to offer an interesting complement to other conifer tree species in southern Sweden. In addition, a growth simulator was developed, based on data from 28 sample plots established in stands on fertile sites managed with practical forestry programs. It included regression functions for basal area increment, stand form-height and initial basal area. Top height growth curves from a Norwegian study were also included in the simulator. A yield table was calculated for the age span 15 to 45 years. The calculations showed that the yield of hybrid larch stands on fertile sites in southern Sweden was slightly higher compared to Norway spruce, and its growth rate was markedly higher in young stands. On fertile sites the mean annual volume increment peaked at an age of 35 years, at a level of 13 m³/ha. However, the bark volume, as a proportion of total volume, was ca. 5% lower for Norway spruce than for hybrid larch. Economic calculations using current prices and costs (year 2002) showed that cash flow for hybrid larch was slightly higher and the soil expectation value was more than double the corresponding values for Norway spruce. Hybrid larch stands can be damaged by root and butt rot, but there was no clear evidence that the species was markedly worse than Norway spruce in this respect. The general opinion was that well managed older larch stands were less susceptible to wind throw than old Norway spruce stands. A general conclusion was that hybrid larch could be an attractive complement to Norway spruce on relatively rich sites in southern Sweden

Matthew Burt: idea to object

A monograph outlining the career and the practice of the Wiltshire-based furniture designer-maker Matthew Burt. The book was published for the exhibition held at the Crafts Study Centre in November 2008 and then touring

A History of the Eastern Larch Beetle, \u3ci\u3eDendroctonus Simplex\u3c/i\u3e (Coleoptera: Scolytidae), in North America

The eastern larch beetle, Dendroctonus simplex, is reputedly a secondary pest but may attack and kill tamarack and ornamental larches throughout Canada, the northeastern United Stales, and Alaska. Isolated infestations of this pest have been reported for over 100 years. The first recorded widespread outbreaks of D. simplex started in eastern Canada and the northeastern United States as well as in Alaska in the mid-1970s. During the outbreak in the Atlantic provinces, in excess of 1.4 million m3 of tamarack was killed. No damage estimates are available for Quebec and the United States. Insect defoliators were the most common factors predisposing tamarack to beetle attack

On the trails of Josias Braun-Blanquet : changes in the grasslands of the inneralpine dry valleys during the last 70 years. First results from the 11th EDGG Field Workshop in Austria

The 11th EDGG Field Workshop was held from 6 to 13 July 2018 in Austria. Its aim was to revisit dry grasslands in the inneralpine dry valleys of Austria that were investigated in the late 1950s by Braun-Blanquet and to collect high-quality biodiversity data from these. Sampling was carried out in the Styrian Mur Valley, the Virgen Valley in East Tyrol, the Upper Inn Valley in the Austrian Eastern Alps, and Griffen in Carinthia. In total, we sampled 15 EDGG biodiversity plots and 37 additional 10 m2 plots. Butterfly data were record-ed in four biodiversity plots and two additional plots. We found maximum richness values of 49, 68 and 95 vascular plant species on 1, 10 and 100 m², while the corresponding values for the complete terrestrial vegetation were 56, 73 and 106 species. Maximum butterfly richness was 19, but it was in general quite low, and generalists dominated. Some of the areas originally studied by Braun-Blanquet were no longer dry grasslands and only a few sites remained largely unchanged. Detrended Correspondence Analysis (DCA) showed profound changes between the old (1950s and 1980s) and our current plots. Without grazing or other human land management activities, only very small cores of rocky dry grassland could survive in the comparatively humid Austrian inneralpine valleys. Finally, the sampled data raise questions about the syntaxonomic position of some of the grasslands, which needs to be addressed in a more comprehensive study, which is planned as the next step

Software process modelling as relationships between tasks

Systematic formulation of software process models is currently a challenging problem in software engineering. We present an approach to define models covering the phases of specification, design, implementation and testing of software systems in the component programming framework, taking into account non-functional aspects of software (efficiency, etc.), automatic reusability of implementations in systems and also prototyping techniques involving both specifications and implementations. Our proposal relies on the identification of a catalogue of tasks that appear during these phases which satisfy some relationships concerning their order of execution. A software process model can be defined as the addition of more relationships over these tasks using a simple, modular process language. We have developed also a formal definition of correctness of a software development with respect to a software process model, based on the formulation of models as graphs.Peer ReviewedPostprint (published version

Testing the stability of the benefit transfer function for discrete choice contingent valuation data

We examine the stability of the benefit transfer function across 42 recreational forests in the British Isles. A working definition of reliable function transfer is put forward, and a suitable statistical test is provided. The test is based on the sensitivity of the model log-likelihood to removal of individual forest recreation sites. We apply the proposed methodology on discrete choice contingent valuation data and find that a stable function improves our measure of transfer reliability, but not by much. We conclude that, in empirical studies on transferability, function stability considerations are secondary to the availability and quality of site attribute data. Modellers’ can study the advantages of transfer function stability vis-à-vis the value of additional information on recreation site attributes

Economics of Managing Invasive Species in Tropical and Sub-Tropical Areas of the U.S.A.: Case Study Development

Resource /Energy Economics and Policy,