This paper documents the existence and character of a little known fire-maintained anthropogenic ecosystem in the southeastern Olympic Peninsula of Washington State, U.S.A. Due to cessation of anthropogenic burning, there is no longer an intact example of this ecosystem. We present evidence from Skokomish oral tradition, historical documents, floral composition, tree-ring analysis, stand struct...

Water Howellia (Howellia aquatilis) is a rare and endangered wetland plant listed as a threatened species under the Federal Endangered Species Act. 70% of the world population is found in the 1:7 £ 10 ha Swan Valley, Montana, USA in wetlands of usually less than 1-ha. Survival of this aquatic species requires emergence during mid-summer, the drying out of occupied portions of the wetlands, a sl...

Results from a long-term planted mixture of cherrybark oak (Quercus pagoda Raf.) and sweetgum (Liquidambar styraciflua L.) showed sweetgum taller in height and larger in diameter than cherrybark oak early in plantation development. By age 17 years, cherrybark oak was similar in height and diameter with sweetgum and by age 21 years was taller in height and larger in diameter than sweetgum depend...

Reactive oxygen species (ROS) and reactive nitrogen (RNS) incessantly produced as by-products of metabolism play significant roles in seed physiology. ROS (hydroxyl, superoxide radical hydrogen peroxide) RNS (nitric oxide, nitric dioxide, nitrous acid dinitrogen tetroxide) content changes all phases life cycle that influence germination, dormancy longevity. Recent studies illustrate are perform...

Article history: Received 30 September 2008 Received in revised form 6 December 2008 Accepted 11 December 2008 Available online 5 February 2009 The paper presents a combined simulation–optimization approach to model forest conversion planning taking the values of timber, carbon and biodiversity into account. The development of a virtual age-class forest was predicted by adopting a single tree f...

BAKER, P. J. & SCOWCROFT, P. G. 2005. Stocking guidelines for the endemic Hawaiian hardwood, Acacia koa. Stocking relationships are an important tool for foresters because they provide a means for evaluating how effectively the trees in a stand use available growing space. While stocking guidelines are not available for many tropical tree species, readily obtained measurements of stem and crown...

Jonsson. B. 2001. Volume yield to mid-rotation in pure and mixed sown stands of Pirl~ls sylcestris and Pice& uhies in Sweden. Stztrliu Forestulir~ Suecicu 211. 19 pp. ISSN 0039-3150. ISBN 91-576-6137-5. Volume yield to mid-rotation in pure and mixed sown stands of Scots pine and Norway spruce was investigated in an experiment in central Sweden. The 43-year-old stands were situated on a 7-ha sit...

Post-Conservation Reserve Program (CRP) land may provide an excellent opportunity to satisfy certified organic crop production requirements. However, conversion of CRP or long-term pastureland to certified organic production will require tillage because the use of herbicides is prohibited in organic production. Our objectives were to evaluate stand establishment, weed competition, yield, and gr...

Wind disturbance profoundly shapes temperate forests but few studies have evaluated patterns and mechanisms of long-term forest dynamics following major windthrows. In 1990, we initiated a large hurricane simulation experiment in a 0.8-ha manipulation (pulldown) and 0.6-ha control area of a maturing Quercus rubra--Acer rubrum forest in New England. We toppled 276 trees in the pulldown, using a ...

poor wheat stand establishment is a major cause of yield loss, particularly in rainfed and poorly irrigated environments. seeds of eight wheat cultivars (triticum aestivum l.) including irrigated and rainfed varieties, belonging to three different climates of iran (hamedan as cold, karaj as temperate and sarpolzohab as warm climates) were primed using osmoprimig treatments through use of urea ,...