The distribution, extent and causes of peat loss in central and northwest Ireland

Selected abstracts in the Pacific Northwest. One study estimates the cost of preserving old-growth forests as habitat for the spotted owl at $26 billion over the next 50 yr. But such analyses have considered only losses from lower timber harvests. They have failed to take into account the benefits society would receive from preserving old-growth forests and wildlife habitat and the resulting biological diversity these features make possible. -from Authors 92Z/10579 Manatees and tourism in southern Florida: opportunity o r t h r e a t ? M. Shackley, Journal of Environmental Management, 34(4), 1992, pp 257-265. The dwindling Trichechus manatus population of S Florida is under stress from many directions, but the greatest threat comes from water-based tourism. Mortality and injury rates, chiefly from boat propellers, are rising by 25% per year and 10% of the total manatee population was killed in 1989. A highly successful public education and awareness campaign has resulted in increased interest in manatees, with the consequent emergence of new forms of tourism. Manatees now also face disturbance by divers, helicopters and canoeists. A powerful commercial lobby is emerging which makes the imposition of tougher legislation or the extension of manatee sanctuary areas unlikely. -from Author 92Z/10582 Responses by oribi to different range m a n a g e m e n t practices in Natal P. S. Everett, M. R. Perrin & D. T. Rowe-Rowe, South African Journal of Wildlife Research, 21(4), 1991, pp 114-118. Ourebia ourebi selected areas that had been recently mowed or burnt, where the herbage had a higher protein and energy content, and a lower fibre content. Short grass was used for feeding, longer grass for cover and concealment of young. Autunm-bumt areas supported higher oribi densities but the management system needed to maintain both high oribi numbers and veld in good condition was biennial spring buming, combined with the provision of mowed areas and wide firebreaks during autumn and winter. -from Authors

Back from the brink: the road to muskox conservation in the Northwest Territories 92Z/10583

W. Barr, (Arctic Institute of North America, University of Calgary; Komatik Series, 3), ISBN (paperback) 0 919034 67 5, price C$20.00, 1991, 127 pp, index. Brings together data on Ovibos moschatus populations, based on the historical record, with attention focusing on indications of naturally-controlled population fluctuations. The study begins with a survey of sightings and records of exploitation of muskoxen on the mainland from the time of the first sighting by Europeans in 1689 to the start of the major commercial trade in hides around 1860. The details of the Hudson's Bay Company's trade in hides are presented, followed by a review of complementary reports during the same period. The next section deals with observations of muskox populations on the mainland (by area) since the time of adoption of protective legislation in 1917. Thereafter reports of exploitation and observations on populations on the arctic islands are surveyed by island and on a chronological basis. The study ends with consideration of the role that muskoxen (or concerns about them) have played in the establishment and maintenance of Canada's sovereignty in the Arctic. -from Author

Regional 92Z/10584 The Conservation Reserve - yesterday, today a n d tomorrow. Symposium proceedings, Washington, DC, January 1991 ed L. A. Joyce, J. E. Mitchell & M. D. Skold, General

Technical Report - US Department of Agriculture, Forest Service, RM-203, 1991, 65 pp. The question of what will happen when the US Conservation Reserve Program (CRP) contracts begin to expire in 1996 is the focus of this symposium. The problem is addressed from the perspective of effects on people and resources, beginning with an introduction to the CRP and

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its future prospects, tracing the history of land use in the Great Plains. The following ten, mostly short, papers concentrate on: an overview of the AgrlculturalResources Conservation Program; economics of livestock and crop ucrion on post-CRP lands; landowner options when ends; CRP's effects on soil, water and environmental quality; CRP's effects on wildlife and recreation; future costs and benefits of Conservation Reserve lands; impacts of CRP in the central Great Plains; research questions related to CRP; some sociological and ecological effects of CRP in the N Great Plains; and CRP in the Columbia Basin, Oregon. -J.W.Cooper 92Z/10585 The causes of tropical deforestation in E c u a d o r : a statistical analysis D. Southgate, R. Sierra & L. Brown, World Development, 19(9), 1991, pp 1145-1151. Statistical analysis of the causes of agricultural colonization and land clearing in E Ecuador bolsters many of the ¢~vUments that have been made about the social forces ing tropical deforestation. Institutional reform is needed to encourage conservation of tropical forests. -from Authors 92Z/10586 The distribution, extent and causes of peat loss in central and northwest I r e l a n d A. R. G. Large & A. C. Hamilton, Applied Geography, 11(4), 1991, pp 309-326. Four land classes and seven vegetation tYl~S were identified, and peat modification and loss described with reference to them. Of the area examined, 33% was peatcovered, twice the average for either Northern Ireland or the Republic of Ireland. Of this cover, 47% of that in Leitrim and Cavan and 29% of that in Fermanagh had suffered loss of peat by volume in the past. The main factor in this loss was seen to be variation in intensity of land use, whilst site,specific variations in slope and climate also had an effect. A c o m m o n feature m areas where loss had occurred was the healing of the surface through re-establishment of the vegetation cover. Active removal of peat is associated with peat extraction, burning and grazing. -from Authors 92Z/10589 Principles and conditions of functioning of the system Zielonka Primeval F o r e s t (protected forestland) - u r b a n i z e d a r e a s D. Solowiej & M. Mielcarek, Ecology (CSFR), 10(3), 1991, pp 283-304. Examined possible means of restricting the negative effect of urban functions developing in the neighbourhood of protected forestland, including the Zielonka Primeval Forest, on the natural functions of these areas. -from Authors 92Z/10590 The gift of a n o - m a n ' s - l a n d C. Pooie, BBC Wildlife, 9(9), 1991, pp 636-639. The demilitarised zone between North and South Korea has become an important nature reserve, encompassing a variety of the countries' habitats from the rocky east coast, through pine and oak forest, to the central mountains. It includes the marshy interior basin of the Imjin river and estuarine and intertidal flats. It is a sanctuary for a great diversity of species, some of which are very rare outside this zone. -G.M.Sheall 92Z/10591 A study of logging damage in upland rainforest in north Queensland F. H. J. Crome, L. A. Moore & G. C. Richards, Forest Ecology & Management, 49(1-2), 1992, pp 1-29. Logged trees were concentrated along ridges and mean removals were 6.6 stems, 4.9 m 2 basal area and 37 m 3 logs ha l. Losses from the whole stand were highest in the smalest and largest size classes and averaged 146.7 stems ha "l and 12 m2ha -I. No tree species were eliminated by logging. Some 22% of the canopy was lost and amount o f light reaching the ground was even altered on areas that received no overhead canopy loss. Changes in canopy profiles were not just a simple reduction o f the upper layers. Logging tracks occupied-5% of the area. The Queensland system appears to cause less incidental damage than those reported from SE Asia. Recommended improvements to