Wetlands and forest with a flora and fauna of international importance in Northeastern Greece

Due to Mediterranean, continental and oceanic influences we find in Northeastern Greece an exceptionally rich flora and fauna. Distributed over a distance of only 60–70 km from sea level northward to the Rhodopi mountains (with very cold and snowy winters at a height of 1000 m to 1600 m near the Bulgarian border) emerges a complex sequence of biozones unparalleled in a comparably small area in Europe. The low population density and the poor development of industry has allowed some natural landscapes to remain relatively undisturbed. The wetlands, including lake Kerkini and lake Vistonis as well as the deltas of the rivers Nestos and Evros, are a home or hibernating place for a large avifauna that includes vanishing bird species. In the oak‐ and beech‐forests of Rhodopi mountains, unusually rich in flowers, e.g. orchids, most of the large European mammals, including bear, wolf and wild boar, as well as birds of prey still find a basis for living. Pollution and damming of waters, erosion, cutting of riparian forests and overgrazing by domesticated animals are among other serious threats to the whole area. Problems, tasks and possibilities for protecting these zones of extraordinary quality are to be discussed along with an ecodevelopment concept for the whole region.     

Influence of fur trade,famine, and forest fires on moose and woodland caribou populations in northwestern Ontario from 1786 to 1911

Hudson’s Bay Company records were used to estimate the 1786–1911 annual number of moose (Alces alces andersonii) and caribou (Rangifer tarandus caribou) involved in trade by northern Ojibwa natives to the company post at Osnaburgh House (51°10′N 90°15′W) in northwest Ontario, Canada. The human population for the early 19th century, and the number and severity of human starvations from 1786 to 1911 were estimated. The extent of forest fires in the region around Osnaburgh was documented using a “fire-day” index computed from Hudson’s Bay Company journals and using qualitative archival information. It is argued that the human population was too small to have caused the observed early 19th century moose and caribou population decline solely through predation. Likewise, severe early 19th century famines were caused by climatic factors rather than by declines in moose and caribou numbers. Habitat change caused by increased forest fires correlates with the observed decline of caribou, while moose increased and subsequently collapsed as winter shelter was destroyed. A burgeoning human population, sustained during winter food shortages on potatoes donated by the Hudson’s Bay Company, then kept ungulate populations to low levels until the late 19th century. Only then did maturing forests and a new outbreak of fires provide renewed habitat for resurgences of, respectively, caribou and moose.     

Safeguarding Crushing Points by Limitation of Forces

Limitation of forces can be a simple measure to safeguard crushing points at doors, machines, and vehicles. In this connection different standards define a threshold force value of 150 N. This widely accepted value refers to static forces only. The dynamic forces that arise from impact on a person are frequently ignored, although they are generally higher than the static forces.

The article describes an instrument for the measurement of static and dynamic crushing forces. This instrument has a stiffness that approximates the average stiffness of human fingers as one of the most at-risk parts of the human body with regard to crushing injuries. Sensory tests were carried out to define dynamic forces considered admissible at crushing points.     

Recycling in the USA : Vision and reality

In 1978 the US Environmental Protection Agency contracted Mathtech Incorporated to identify the impediments to recycling and evaluate their economic effects. The facilities studied represented a cross-section of recycling technologies, ownership types, geographical locations, and recovered products. It was discovered that none of the facilities was economical in the sense of providing the least-cost mode of disposal for municipal solid waste, and all of them suffered net losses in recent operations. Indications were that financial performance would improve slightly. A major deterrent to economical operations was the availability of lower-cost disposal by landfill.