Agrobiodiversity and Shade Coffee Smallholder Livelihoods: A Review and Synthesis of Ten Years of Research in Central America

We used households as the primary unit of analysis to synthesize agrobiodiversity research in small-scale coffee farms and cooperatives of Nicaragua and El Salvador. Surveys, focus groups, and plant inventories were used to analyze agrobiodiversity and its contribution to livelihoods. Households managed high levels of agrobiodiversity, including 100 shade tree and epiphyte species, food crops, and medicinals. Small farms contained higher levels of agrobiodiversity than larger, collectively managed cooperatives. Households benefited from agrobiodiversity through consumption and sales. To better support agrobiodiversity conservation, our analysis calls for a hybrid approach integrating bottom-up initiatives with the resources from top-down projects.     

White mica K-Ar ages of blueschist-facies rocks from the Piemonte 'calc-schists' of the western Italian Alps

Abstract Fifty calc-schists have been systematically collected from the Piemonte zone of the western Italian Alps and examined in terms of petrology, X-ray powder diffractometer (XRD) analysis of carbonaceous materials, and K-Ar ages of white mica separates. The petrological study and XRD analysis of carbonaceous materials have shown that calc-schists have suffered blueschist-facies metamorphism in the subduction zone of the convergent margin between the Apulian (African) continental and Tethyan oceanic plates. The metamorphic sequence is divided into three mineral zones based on increasing metamorphic temperature: chlorite (lower than 300°C), chloritoid, and rutile (higher than 450°C). The chlorite zone has dispersed ages of white mica separates, ranging from 115 to 44 Ma, whereas the rutile zone has a comparatively uniform age distribution from 60 to 40 Ma. The chloritoid zone has an intermediate age variation. The large variation in the chlorite zone is attributed to mixing of variable amounts of detrital mica derived from older high temperature metamorphic rocks in the separates, which have not been completely reset during Alpine metamorphism. The uniform age (average ca 50 Ma) in the rutile zone is the cooling age of blueschist-facies calc-schists, which have been episodically exhumed at the collision event of the European and Apulian continents in the Paleocene-Eocene.     

The significance of rainsplash in the surficial debris cascade of the colorado front range foothills

The surficial characteristics and precipitation regime of sparsely vegetated hillslopes in the montane zone of the Colorado Front Range suggest that rainsplash may be an important component of the surficial debris cascade. Site sediment flux data from two study periods reveal marked spatial and temporal variability. Comparison of these date with sediment movement data from splashcups suggests the following conclusions: (1) Detachment rates of the rainsplash process appear great enough to account for the sediment flux in the open Gerlach-type traps; (2) Areal extrapolation of rainsplash transport suggest that 88 per cent of the fine sediment flux in 1982 can be attributed to rainsplash; (3) Estimates of rainfall energy and changes in the potential energy of hillslopes by mass transport suggests a process efficiency of 0.05 per cent for rainsplash. If this procedure is applied to sediment flux values from open traps, the low precipitation-energy cascade of 1982 appears to be largely rainsplash-transported sediment. Extrapolation with the 1981 data suggests more aggressive overland flow erosion and transport.     

Rediversion salinity change in the Cooper River,South Carolina: Ecological implications

A 70% reduction in freshwater discharge through the Cooper River Basin, South Carolina, has provided a unique opportunity to study changes in estuarine plant communities in response to a system-wide increase in salinity. A one-dimensional tidal prism mixing model was used to simulate the changes in the longitudinal salinity distribution which have occurred in the Cooper River since a diversion in 1985 reduced the mean flow from 442 to 130 m³ s^?1. Model simulations indicate that a salinity increase of 10–14‰ has occurred in the region of the river where the marsh plant community shifts from a virtual monoculture ofSpartina alterniflora to a more diverse brackish community. The flow reduction and associated salinity increase are expected to result in an increased dominance of the halophyte,S. alterniflora, and a progressive exclusion of the less halotolerant species which currently inhabit this region.     

Detoxification of chlorinated sewage effluent by dechlorination in estuarine waters

Secondary treated sewage was chlorinated to a residual level of 2–10 mg/l in a continuous flow system in the laboratory and diluted to various levels with estuarine water. A portion of the chlorinated sewage effluent was dechlorinated with sodium thiosulfate and the dechlorinated waste was diluted with estuarine water in the same proportions as the chlorinated waste.Menidia menidia, Palaemonetes pugio andCrassostrea virginica were exposed to chlorinated and dechlorinated treatments. High concentrations of chlorinated effluent caused mortalities inM. menidia andP. pugio, whereas similar concentrations of dechlorinated wastes did not cause mortalities. Mortalities in the chlorinated waste are correlated with chlorine residuals. Similarly, the chlorinated wastes depressed the shell deposition rate ofC. virginica below 50% of controls at all doses. Dechlorinated waste allowed shell deposition greater than 50% of controls. However, the occurrence of some growth inhibition inC. virginica exposed to dechlorinated waste suggests the presence of toxic material in the waste other than chlorine.     

Carbonaceous material in pelitic schists of the Sanbagawa metamorphic belt in central Shikoku,Japan

Carbonaceous material in pelitic schists of the Sanbagawa metamorphic belt in central Shikoku, Japan, was separated from the host rocks and its X-ray diffraction and chemical composition were studied. Its crystal structure and chemistry change continously with increasing metamorphic grade and approach those of well-ordered graphite near the biotite isograd. As graphitization is a rate process, the temperature of complete graphitization differs from one metamorphic terrain to another as a function of the duration of metamorphism. In an individual metamorphic terraan, however, the degree of graphitization is a useful indicator of relative metamorphic temperature in lower-grade rocks.     

Measurement of the effects of temperature and partial pressure of oxygen on the oxidation states of europium in silicate glasses

The techniques of electron paramagnetic resonance (EPR) were used to measure the concentration ratio of Eu²⁺ to Eu³⁺ in quenched CaMgSi₂O₆, Ca₃Si₃O₁₂, and CaAl₂Si₂O₈ liquids as functions of partial pressure of oxygen and temperature. The redox equilibrium of the Eu ions was described by the reaction 4Eu³⁺ + 20^2? = 4Eu²⁺ + O₂. The reduction of Eu³⁺ to Eu²⁺ was endothermic, and for CaMgSi₂O₆ and Ca₃Al₂Si₃O₁₂ liquids the mean value of ΔH⁰ and the standard deviation from that mean were 25 ± 7 kcal/mole.The magnitude of the Eu anomaly in the distribution coefficients is discussed in terms of the compositions of the solid and liquid phases.     

Magnetic crustal character in Central Ireland

The simplest magnetic model for the upper 20 km of crust in central Ireland is of two layers. A thin, weakly magnetic upper layer carrying a number of magnetic bodies that can be related to surface geology overlies a magnetic crustal zone whose gross magnetization increases towards the north. The deeper trace of the lapetus Suture in central Ireland forms the boundary between a more magnetic northern crustal area and a less magnetic southern area. A pre-Carboniferous major dextral offset of this suture boundary occurs in the Limerick area. The suture is traced beneath the Dingle peninsula in the far south-west of Ireland. In east-central Ireland, between the Iapetus Suture and Southern Upland Line, the crust contains a large, south-dipping magnetic body with no surface expression, which produces the Virginia magnetic anomaly. The development of magnetic bodies — in particular, volcanic rocks of Carboniferous age — has been controlled by regional stress patterns. The major volcanic centre at Limerick lies at the intersection of two major Caledonian block fault systems just to the north of the surface trace of the Hercynian Front.