The Effect of Form, Rate, and Position of Phosphatic Fertilizers on Growth and Nutrient Uptake of Sitka Spruce on Deep Peat

The effects of superphosphate, ground rock phosphate, and basicslag, each applied in three positions, on the growth of Sitkaspruce (Picea sitchensis Carr.) were compared up to the eighthyear after planting on deep oligotrophic blanket peat in NorthernIreland. Broadcast application was initially the most effective,but after eight years there was no significant difference inmean tree height between this method and placement on top ofthe planting ribbon. Application of fertilizer below the ribbongave consistently poorer results but with the previously usedmethod of placement in the planting hole growth was almost 40per cent less even than this. At equivalent rates, superphosphateand ground rock phosphate were equally effective and both weresignificantly better than basic slag. Fertilizer position had little effect on foliar nutrient concentrationin either the fifth or eighth growing seasons. In both seasons,foliar N concentration increased with amount of slag appliedbut N levels were higher with superphosphate and G.R.P. in boththe fifth and eighth seasons. At the lower rates of appliedslag, foliar N concentrations were below the accepted optimumin the eighth season. Foliar P concentration also decreasedsignificantly with time and, except where 100 Kg P per ha hadbeen applied as slag, the P nutrition of the trees after 8 yearswas becoming critical. Fertilizer treatment had no significanteffect on foliar K concentration in the fifth season but bythe eighth season foliar K levels were inversely related togrowth rate. This suggests an imminent K deficiency. It is concluded that the broadcast application of ground rockphosphate at not less than 50 Kg P per ha is an effective fertilizerregime for the establishment of Sitka spruce on deep blanketpeat, but that supplementary fertilizing with K, and possiblyP, may be necessary about 8 years after planting.     

FORESTRY IN NORTH SCOTLAND

History, climate, geology, and soils are dealt with in generalterms and the history of land use from the seventeenth centuryin the seven crofting counties is discussed, while the problemsof integration of forestry and agriculture are considered. TheForestry Commission forests in the North Conservancy are described.The forests are grouped into six different groups, the forestsin each having certain common characteristics. Problems of physiography,geology, soils, species selection, silviculture, management,and utilization are dealt with for each group.     

Nonemployment Income and the Economic Base of Michigan Counties: 1959–1986

ABSTRACT Despite the fact that nonemployment income makes up approximately one-third of all personal income, its impact on local area economies has not been closely examined. This study uses Michigan county data to examine the impact of nonemployment income on nonbasic income over a twenty-seven-year period. This impact is compared to the impact of basic income by employing regression analysis to estimate comparative multiplier effects for both types of income. Nonemployment income is found to have a significant impact on nonbasic income, particularly in metropolitan and nonmetropolitan urban counties, where its impact appears to be stronger than that of basic income.     

Direct observations of structural phase transitions in planar crystallized ion plasmas

Laser-cooled 9Be+ ions confined in two-dimensionally extended lattice planes were directly observed, and the images were used to characterize the structural phases of the ions. Five different stable crystalline phases were observed, and the energetically favored structure could be sensitively tuned by changing the areal density of the confined ions. The experimental results are in good agreement with theoretical predictions for the planar (infinite in two dimensions) one-component plasma. Qualitatively similar structural phase transitions occur, or are predicted to occur, in other experimentally realizable planar systems.     

The 1882 tilefish kill — a cold event in shelf waters off the north-eastern United States?

A mass mortality of `warm-water' tilefish in the Middle Atlantic Bight between April and August of 1882 suggests an episode of extreme cold in the shelf waters off the north-eastern United States. This cooling is hypothesized to be a consequence of enhanced equatorwards transport of cold water in the Labrador Current, coincident with a minimum in the North Atlantic Oscillation (NAO) index during the early 1880s.
Although there is little direct evidence for this historical event, an analogue for the 1880s cooling is found in the 1960s, at the most recent NAO-index minimum. Post-1945 observations in the Middle Atlantic Bight / Gulf of Maine region reveal changes in winter baroclinic circulation between cool and warm decades, with greater equatorward penetration of south-westwards flow along the shelf-edge during the cool 1960s. Over the period 1934–77, the NAO is found to account for 17% of the interannual variance in Labrador Current transport around the Grand Banks.
Proxy evidence for the cold episode of the early 1880s is sought. Records of bottom temperature in the Middle Atlantic Bight region are reconstructed using stable oxygen isotopic analysis on the annual bands of shells of a bivalve mollusc ( Arctica islandica ) and an empirical model of covariability with local air temperature. The result is confirmation of the presence of anomalously cold water during the early 1880s.