Laboratory study of phosphorus forms and test procedures on soils under aerobic and anaerobic conditions

The inorganic forms of phosphorus in nine samples of surface soils from the Nainital Tarai of India were determined by a series of extractions with different reagents after incubation for 45 days under aerobic or anaerobic conditions. The forms of phosphorus in samples incubated under aerobic conditions and the pH range of 7.2–8.5 indicated that the soils had been subject to slight chemical weathering. Anaerobic incubation to simulate conditions in lowland rice paddies converted part of the inorganic phosphorus into more labile forms, based on changes in amounts of isotopically exchangeable phosphorus. Amounts of the element converted to more labile forms differed among the nine soil samples.A better correlation was found between amounts of phosphorus extracted by 0.5M NaHCO³ (Olsen's method) than by 0.03N NH₄F in 0.25N HCl (Bray's method) and the isotopically exchangeable phosphorus. The better correlation suggests that the bicarbonate extraction would be the better method for estimating “availablelrd phosphorus in soils of lowland rice paddies. Recalibration of the test prior to such use seems desirable to allow for increases in amounts of phosphorus in labile forms after soils have been shifted from aerobic to anaerobic conditions.     

Phenolic esters in peat

The p-hydroxypropiophenone ester of stearic acid has been isolated sedge peat. This appears to be the first report of the ester as a natural product.     

Cherry leaf roll virus causing a disease of Betula spp. in the United Kingdom

A virus, serologically related to isolates of cherry leaf rollvirus (CLRV) from Prunus avium (L.) L. and Sambucus nigra L.was transmitted to a range of herbaceous plants from leavesor roots of thirty-one of forty-seven trees of Betula spp. growingat two heathland sites in Berkshire. Ageing leaves of virus-infectedindividuals which had mild chiorotic blotches or ring and linepatterns in July showed bright yellow ring and line patternsin October. In the season after B. verrucosa seedlings wereinoculated with CLRV isolates, leaves developed chlorotic ringand blotch patterns; the symptoms being similar whether theinocula were originally isolated from S. nigra, P. avium orB. verrucosa. Palisade and mesophyll cells of naturally infectedleaves of B. verrucosa contained chloroplasts in which granalorganization was appreciably less distinct than that of chloroplastsfrom virus-free leaves. In many instances, virus-infected leafcells had spherical virus-like particles about 30 mn in diametercontained within tubular structures in cell wall projections;these structures were not seen in virus-free material. An isolate of CLRV from B. verrucosa, purified from systemicallyinfected leaves of Nicotiana clevelandii Gray by ammonium sulphateprecipitation and differential centrifugation, contained twomajor components having sedimentation coefficients of 118s and130s. Each component was composed of spherical particles withdiameters in the range 26–30 nm and having buoyant densitiesin caesium chloride of 1·460 and 1·493 gm/cm³.Polyacrylamide gel electrophoresis of preparations from bothbuoyant components indicated that they each contained a singlespecies of protein whose molecular weight was in the range 53,000–54,000daltons.     

An Experiment to Control Fomes annosus in Second Rotation Pine Crops

Stump removal was found to singnificantly reduce killing byFomes annosus in second rotation crops of pine. Poisoning andgirdling of trees prior to felling and also stump poisoningfailed to control the disease. In this experiment no significantdifferences were detected in the susceptibility of Scots andCorsican pine to attack. Increasing periods of delay beforereplanting resulted in less mortality. An equation is presented,based on factors of the first rotation crop which may be usedto predict losses likely to occur when a site is replanted.Root attack by F. annosus results in reduced growth and yieldas well as mortality. The results from the experiment are discussed in trems of themangement of pine crops attacted by F. annosus in Theford Chase.     

Preliminary observations on the effects of burning on the hemiptera (Heteroptera and Auchenorhyncha) of limestone grassland

Samples of Hemiptera were taken in September 1972, from areas of carboniferous limestone grassland which were burnt in April and May 1972, and from adjacent unburnt areas. Significantly larger numbers of species, of both Heteroptera and Auchenorhyncha, were recorded from the unburnt areas, and the species-diversity of the samples was significantly greater. The effects of burning on individual species are considered in relation to their biology and the effects of other kinds of management. The results are discussed in relation to the management of grassland for the conservation of wildlife, and a short review of the effects of burning on populations of invertebrate animals is made.     

The exploitation of helix pomatia L.

The evidence at present available, although incomplete, gives rise to fears for the future of the edible snail Helix pomatia L. The scale of exploitation is increasing, particularly in Eastern Europe, to meet growing demand, mainly from the West. The growth of legislation to control collecting supports the evidence of declining numbers, but the legislation does not appear to be backed by sufficiently detailed population ecology studies. The need for co-ordinated international action on farming, legislation and ecological study is urged.     

Some genetic characteristics of the freely drained soils of the ettrick association in East Scotland

This paper describes the interrelated characteristics of the freely drained soil series of the Ettrick Association. These soils are extensively developed in the Southern Uplands of Scotland on glacial drift derived from greywacke.At the present day the soils of the Linhope series are acid brown soils whereas the Minchmoor and Dod series include podzols and peaty podzols. Subalpine podzols and alpine soils are included within the Merrick series. It is concluded that the soils of the Linhope, Minchmoor and Dod series were all formerly brown forest soils under deciduous woodland. They have evolved to their present status after forest clearance which gathered momentum after the widespread establishment of monastic institutions in Scotland in the twelfth and thirteenth centuries A.D. The evolutionary outline of profile development is described and discussed.