Mixing degree, stand density, and water supply can increase the overyielding of mixed versus monospecific stands in Central Europe

Abstract Key message We applied a modified forest gap model (ForClim) to depict changes in stand water transpiration via density reduction as a forest adaptation strategy. This approach is the key to analyzing the ecological resilience to drought, stress-induced mortality, and economic efficiency of managed mixed forest stands in Central Europe. The results show that specific geographic conditions and forest composition define the optimal stand density of drought-resilient forests. Context Reducing stand density has been recognized as a valid strategy to increase forest resilience to drought. Moreover, to develop adaptive management strategies (AMS) under climate change, it is crucial to consider not only drought resilience but also the economic efficiency of alternative AMS proposed to alleviate drought effects. Aims To analyze how decreased inter-tree competition among overstorey trees affects stand vulnerability to drought and its expected yield. Methods We integrated experimental thinning data and historical responses to drought years in a climate-sensitive forest gap model, ForClim. We tested a business as usual (BAU) and three alternative AMS (“do-nothing,” low- and high-intensity overstorey removal) in mixed stands of Norway spruce (Picea abies), silver fir (Abies alba), and European beech (Fagus sylvatica) along an elevational gradient of 520–1020 m a.s.l. in Central Europe. Results High-intensity overstorey removal in mixed stands of all three species considerably increased forest volume growth resilience to drought and decreased stress-induced mortality by two-thirds vis à vis a “do-nothing” strategy. In sites including only conifer species, forest resilience was equally improved by high- and low-intensity overstorey removal compared to that in the BAU strategy. Regarding the timber economy, high-intensity overstorey removal resulted in a higher economic revenue of mixed stands (~ 22% higher net present value than other strategies) on the high-elevation sites (> 1000 m a.s.l.). Conclusion Modifying forest density and structure by overstorey removal is principally suitable to increase forest resilience to drought and improve its economic efficiency. The magnitude of the effect however depends on the geographical setting and forest composition.

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Enumeration and Identification of Asbestos Fibres in Water

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010005264x ◽

1974 ◽

Vol 32 ◽

pp. 526-527 ◽

Cited By ~ 1

Author(s):

O. Mudroch ◽

J. R. Kramer

Keyword(s):

Water Supply ◽

Water Samples ◽

Drainage Basin ◽

Lake Superior ◽

Research Work ◽

List Type ◽

The West ◽

Asbestos Fibre ◽

Amphibole Asbestos

Approximately 60,000 tons per day of waste from taconite mining, tailing, are added to the west arm of Lake Superior at Silver Bay. Tailings contain nearly the same amount of quartz and amphibole asbestos, cummingtonite and actinolite in fibrous form. Cummingtonite fibres from 0.01μm in length have been found in the water supply for Minnesota municipalities.The purpose of the research work was to develop a method for asbestos fibre counts and identification in water and apply it for the enumeration of fibres in water samples collected(a) at various stations in Lake Superior at two depth: lm and at the bottom.(b) from various rivers in Lake Superior Drainage Basin.

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Bacterial biofilm behavior in water-supply lines of dental units

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100124811 ◽

1992 ◽

Vol 50 (1) ◽

pp. 882-883

Author(s):

B.D. Tall ◽

K.S. George ◽

R. T. Gray ◽

H.N. Williams

Keyword(s):

Water Supply ◽

Medical Devices ◽

Biofilm Formation ◽

Bacterial Biofilm

Studies of bacterial behavior in many environments have shown that most organisms attach to surfaces, forming communities of microcolonies called biofilms. In contaminated medical devices, biofilms may serve both as reservoirs and as inocula for the initiation of infections. Recently, there has been much concern about the potential of dental units to transmit infections. Because the mechanisms of biofilm formation are ill-defined, we investigated the behavior and formation of a biofilm associated with tubing leading to the water syringe of a dental unit over a period of 1 month.

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