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891.
Replacing monocultures with mixed-species stands: Ecosystem service implications of two production forest alternatives in Sweden 总被引:2,自引:0,他引:2
Adam Felton Urban Nilsson Johan Sonesson Annika M. Felton Jean-Michel Roberge Thomas Ranius Martin Ahlström Johan Bergh Christer Björkman Johanna Boberg Lars Drössler Nils Fahlvik Peichen Gong Emma Holmström E. Carina H. Keskitalo Maartje J. Klapwijk Hjalmar Laudon Tomas Lundmark Mats Niklasson Annika Nordin Maria Pettersson Jan Stenlid Anna Sténs Kristina Wallertz 《Ambio》2016,45(2):124-139
Whereas there is evidence that mixed-species approaches to production forestry in general can provide positive outcomes relative to monocultures, it is less clear to what extent multiple benefits can be derived from specific mixed-species alternatives. To provide such insights requires evaluations of an encompassing suite of ecosystem services, biodiversity, and forest management considerations provided by specific mixtures and monocultures within a region. Here, we conduct such an assessment in Sweden by contrasting even-aged Norway spruce (Picea abies)-dominated stands, with mixed-species stands of spruce and birch (Betula pendula or B. pubescens), or spruce and Scots pine (Pinus sylvestris). By synthesizing the available evidence, we identify positive outcomes from mixtures including increased biodiversity, water quality, esthetic and recreational values, as well as reduced stand vulnerability to pest and pathogen damage. However, some uncertainties and risks were projected to increase, highlighting the importance of conducting comprehensive interdisciplinary evaluations when assessing the pros and cons of mixtures. 相似文献
892.
Dr. Etel Kemény 《Journal of the Air & Waste Management Association (1995)》2013,63(6):278-281
This report, published as Informative Report No. 1 of the Air Pollution Control Association’s TA-8 Meteorological Committee, began to move through the fourteen step approval procedure in March 1964. Comments made by members of the Technical Council were used in the preparation of the final report. It is now being published as representing the "best thinking of the Association." It is an extremely timely and informative report. 相似文献
893.
Dr. Waldo Sepulveda Konstantinos D. Stagiannis Phillip M. Cox Jonathan S. Wigglesworth Nicholas M. Fisk 《黑龙江环境通报》1995,15(7):660-664
Amyoplasia is a rare, sporadic condition characterized by different degrees of maldevelopment of the skeletal muscles, which are replaced by fibrous and fatty tissue. In this report, we present a case of generalized amyoplasia presenting at 19 weeks' gestation. The most striking finding was the absence of fetal movements, resulting in severe multiple congenital contractures, hydrops, and polyhydramnios. At autopsy, histological examination of the skeletal muscle showed small groups of poorly developed fibres within areas of fat. This report suggests that generalized amyoplasia could be a common cause of severe forms of multiple congenital contractures, but is probably underdiagnosed at post-mortem because of inadequate examination of muscles. Definitive diagnosis is important in determining the risks of recurrence in these cases. 相似文献
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A pregnant woman has two children affected by moderately severe Hb H disease due to compound heterozygosity of South-east Asian deletion and Constant Spring mutation. In her third pregnancy, transabdominal chorionic villus sampling was performed at the tenth gestational week to obtain fetal DNA. The polymerase chain reaction was used for detection of both the South-east Asian deletion and the Constant Spring mutation. Hb H disease was diagnosed in the fetus. After genetic counselling, the couple elected to have the pregnancy terminated. 相似文献
897.
Dr A. Y. Sangodoyin 《The Environmentalist》1993,13(4):255-261
Summary There has been a paucity of reliable data on the contribution of Nigerian women in rural development, particularly with respect to water projects. From a detailed survey of many rural settings, and an evaluation of the availability of sources of water and the existing methods of purification, it was discovered that rural women, especially those of younger years, were heavily involved in water collection. The time and energy involved in water fetching and purification could sometimes be so high that other economic and domestic activities were adversely affected. The participation of Nigerian women in water development and quality improvement is hindered by problems, such as their standard of education, low level of awareness of the benefits of a good water source, lack of funds and organisational constraints. In general, this study has recognised an urgent need for more imaginative, better funded and better co-ordinated water development projects for the enhancement of the quality of life, especially for women in rural settings. 相似文献
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