A multiple coring system for use with scuba

A diver-operated coring system which takes undisturbed contiguous samples has been developed. A perspex space-frame localises a number of contiguous thin-walled tubes which can be driven into the sediment and from which core samples can be extracted. The corer consists of transparent tubing and low-pressure gate valve. The system is useful for describing small-scale spatial dispersion and for sampling patchy habitats. It is light, simple, inexpensive and is flexible with respect to the size and number of contiguous cores.     

A comparison of lead and zinc sediment profiles from cores taken by diver and a gravity corer

The zinc and lead concentrations were compared in several pairs of sediment cores obtained with a modified K-B corer and by Scuba diver from Coon Lake, Canada. A slow approach to and penetration of the sediments (ca. 0.1 m s^-1) was employed for both coring devices. The modified K-B corer gave similar lead and zinc profiles to the diver cores. The divers observed that the K-B corer caused no disturbance of the surface sediment layers as it approached and entered the sediments. These results suggest that the K-B corer is suitable for use in lake studies requiring short, undisturbed cores from fine-grained sediments.     

Comparison of two gravity coring devices for sedimentation rate measurement by 210Pb dating techniques

Marine sediment cores were collected in Puget Sound using a 7.6 cm diameter corer and a 15 × 15 cm square cross-section corer. The cores were dated by the ²¹⁰Pb method and sedimentation rates and depth of sediment mixed layers were compared. The results show that both the sedimentation rates and the depth of sediment mixed layers obtained from small diameter corer are 2–3 times smaller than the corresponding values obtained from large cross-section corer. A cross-calibration of coring techniques seems necessary to correlate the sedimentation rates obtained using different devices.     

A handy impact corer for sampling lake surface sediment

A handy impact corer for sampling of surface sediment (< 50 cm) in lakes is described. The coring apparatus consists of a sample tube, tube holder, stopper, stopper holder, shaft with wing, shaft holder, hammer, and pushing rod. The total weights are 3.8 kg (Type I: 2.3 cm inside diameter of the tube) and 6.7 kg (Type II: 5.5 cm inside diameter of the tube). The system enables confirmation of the vertical landing of the corer onto the lake bottom and effective entering of sediment into the sample tube using hammer, and prevention of falling out of the core using stopper and pushing rod.     

The tom-tom corer: a new design of the Kajak corer for use in meiofauna sampling

A new corer, the tom-tom, is a modification of the basic Kajak design. New modifications increase the efficiency of the corer in soft muds and increase the stability of the corer during ascent and descent. A stepped release trigger mechanism allows the corer to trip easily in even the softest muds, and a Phleger “bomb’ weight adds stability to the device. The corer can be deployed in a slow, controlled descent from small as well as large boats to reduce bow-wave. Four cores (4.50 cm inner diameter) are taken simultaneously in a fixed spatial pattern. Limited comparative sampling revealed that the tom-tom collected more meiofauna than a Van Veen grab and attained numbers statistically indistinguishable from diver-collected cores (only small sample sizes were available however). The corer will be most efficient in sediments without an extremely well-developed, suspendable layer, and most practical for smaller vessels in environments where diver collected cores are precluded by depth, strong currents or poor visibility. Although used in meiofauna collection, the corer should be appropriate for any sampling needs requiring a relatively undisturbed core.     

Shortening of surface sediment cores during sampling

Coring in recent lake sediments is most easily performed using lightweight open barrel gravity corers. The cores will in most cases have the fine lamination intact and they may thus be interpreted as representative of the sediment in situ.Parallel cores taken by means of other techniques have shown that cores taken with open barrel gravity corers become shorter than the distance of penetration in the sediment. This investigation shows that the shortening depends both on the corer diameter and on its velocity during the penetration. Experiments also show that soft layers become more reduced in thickness than stiffer ones. This may lead to misinterpretation of sedimentation rate during special periods. Seasonally occurring sediment fractions may be diluted or concentrated during the coring.     

Activity traps and the corer: complementary methods for sampling aquatic invertebrates

We compared the picture of aquatic invertebrate fauna given by three types of sampling methods: the corer as well as bottom and mid-water activity traps. The corer mainly caught benthic animals (89%), the most numerous groups of which were chironomids and sphaerids. Nekton was more abundant in activity traps (77% in bottom and 63% in mid-water), the most numerous groups were Cladocera and water mites. The size distributions in catch of the corer and the activity traps differed but there was no difference between the two types of activity traps. In activity traps, individuals of the smallest size class were most abundant, wheras animals of the second smallest size class were most numerous in the corer. We suggest that activity traps and the corer could be used as complementary methods to sample aquatic invertebrate communities.     

A comparison of a corer and a shovel for sampling populations of wheat bulb fly Delia coarctata eggs

The most commonly used tool for sampling soil for eggs of the wheat bulb fly Delia coarctata Fall.) is a corer, but in Scotland samples are taken with a modified shovel. The sampling properties of a corer and shovel were compared in two exercises in which soil samples were taken from the ridge, sides and furrow of drills of maincrop potatoes at several sites in east Scotland. Although each tool sampled approximately the same surface area of soil, the corer sampled three times as much soil as the shovel. The numbers of wheat bulb fly eggs estimated by the corer and shovel were similar in both sampling exercises and there were no indications that the comparison of the two tools was affected by the sampling position on the potato ridge. The results of the two exercises gave no reason to believe that in similar conditions the shovel is an inferior sampling tool or that population estimates obtained with a shovel in Scotland are not comparable with those obtained with a corer. Evidence from some sites suggested that wheat bulb flies lay more eggs on the potato ridge than in the furrow.     

Meiofauna of silty sediments in the coastal area of the North Adriatic,with special reference to sampling methods

At five coastal silty sediment stations ranging in depth from 8 to 30 m, the abundance and composition of meiofauna were investigated. Three methods of sampling were used, i.e. Pfleger corer, Van Veen grab and SCUBA divers. Four samples per station were taken. The mean density of total meiofauna was 660 ± 109 ind. 10 cm². The main meiofauna group was Nematoda, the second abundant was Copepoda, and third was Kinorhyncha. Statistical tests showed significant differences in meiofaunal abundance between corer and grab samples, and between corer and divers samples.Differences in meiofauna abundance between stations were found.     

A simple semi-continuous piston corer for organic sediments

A simple semi-continuous piston corer for stratigraphic sampling up to 15 m of organic lake sediments has been developed. The design is flexible so that components can be assembled to suit the depth of core required. For cores up to 6 m, the apparatus is easily deployed from a small boat with the minimum of difficulty. With increasingly long cores, the operational complexity increases. For the designed maximum core depth, two workers on the surface and one SCUBA diver are required to operate the corer. A small stable inflatable boat or raft is required as a platform.The corer is simple to construct, assemble and operate. The total cost of the corer is under $200(US). The individual components of the corer are long (up to 10 m), but moderate weight (up to 86 kg) allows transportation to the lake site by truck, or in remote areas by helicopter.     

Evaluation of a standpipe corer for sampling aquatic interstitial biotopes

The relative efficiencies of two sizes of a standpipe corer were evaluated. The size composition of the gravel sampled by the corer was very similar to that (below the opening size of the core chamber) of the streambed. The small corer (25 cm³ sample size) produced a mean overestimate of total numbers of only 19% even in highly heterogeneous gravels. Most of the taxa commonly in the substrates sampled did not escape from the corer. A few rare taxa were consistently over- or under-estimated and possible reasons for this are discussed.     

A pedal corer for the quantitative sampling of sediments and benthic organisms in submerged areas accessible on foot

This paper presents a new device to collect quantitative samples of sediment and benthic organisms. The device is specially designed for sampling with the advantages of box-corer or Eckman dredges in submerged areas that are accessible on foot. The pedal corer is a simple, lightweight, user-friendly device that does not disturb the sediment structure and provides easy access to the sample contained inside the core. With this device, sampling in shallow water zones that are constantly submerged is made easy and sampling time is extended in intertidal zones. Handling editor: J. Saros     

Long‐term dynamics in a planted conifer forest with spontaneous ingrowth of broad‐leaved trees

Question: What are the age structure and growth trends in a 160‐year old not‐managed Pinus sylvestris plantation with spontaneous development of Quercus robur and can recruitment of Q. robur be related to the radial growth pattern of the P. sylvestris overstorey? Location: Mattemburgh forest reserve, The Netherlands. Methods: Throughout the forest, we sampled 103 oaks and 102 pines with an increment corer. Tree ring widths were measured and cross‐dated to produce mean ring width series. With these data we determined tree ages, investigated growth trends and identified growth releases and suppressions. Results: Q. robur is uneven‐aged: some individuals recruited around 1925, but most reached coring height in the 1940s. The latter recruitment period related to a transition from stressed to released growth of the overstorey pines, growth releases of the oldest Q. robur and occurrence of P. sylvestris regeneration. No further recruitment has taken place since 1950. Conclusions: This study demonstrates that an old pine plantation can develop spontaneously into well‐structured pine forest with an understorey of oak and pine. However, understorey recruitment in these forest types is not a continuous process and in this case a single allogenic canopy disturbance triggered its establishment.     

A study of root distribution and growth in a Pinus sylvestris L. (Scots pine) plantation in east anglia

Summary The root systems of Scots pine in a plantation were studied by three methods; soil coring, soil monoliths, and a root trench with observation windows were used to estimate root length, root diameters and the initiatio of new root tips. The vertical and horizontal distribution of roots is described and root distribution has been related to distance from the tree and soil heterogeneity. It was found that the initiation of new root tips was not readily relatable to the soil environment and the usefulness of the root window technique for observing new root tips is questioned.     

Minimally Invasive Mitral Valve Replacement Using the Valve-in-valve Technique

A 90-year-old woman with two previous mitral valve replacements, presented with pulmonary edema due to mitral regurgitation from degeneration of her bioprosthetic mitral valve. A minimally invasive approach was used to replace the bioprosthetic mitral valve. During surgery, the bioprosthetic valve was noted to be too adherent to the endocardium of the left atrium, making removal of the prosthesis not only difficult, but also potentially harmful. The new bioprosthetic valve was instead placed using a valve-in-valve approach.     

A corer for taking undisturbed peat samples

Summary A corer is described for sampling peats to a depth of 1 m with minimum disturbance of the sample. The instrument is simple and inexpensive to construct and is suitable for routine sampling operations.     

Effects of disturbance scale on soil microbial communities in the Western Cascades of Oregon

Aims

To gain a better understanding of how rapidly microbial communities respond to different magnitudes of perturbation that mimic minor or catastrophic disturbances.

Methods

Two montane sites in the western Cascade Mountains of Oregon with adjacent areas of forest and meadow vegetation were studied. A reciprocal transplant experiment evaluated both minor (soil cores remaining in the same vegetation type) or more severe disturbance (soil cores transferred to a different vegetation type). The biomass and composition of the bacterial and fungal communities were measured for 2 years following the establishment of the experiment.

Results

Minor disturbance (coring) had little impact on microbial biomass but transferring between vegetation type showed greater fungal biomass in soil incubated in the forest environment. The composition of bacterial communities was not influenced by coring but responded strongly to transfers between vegetation sites, changing to reflect their new environment after 2 years. Fungal community composition responded somewhat to coring, probably from disrupting mycorrhizal fungal hyphae, but more strongly to being transferred to a new environment.

Conclusions

The response of the microbial community to major disturbance was rapid, showing shifts reflective of their new environment within 2 years, suggesting that microbial communities have the capacity to quickly adjust to catastrophic disturbances.     

Lightweight remotely actuated switching valve for rebreathing exercise studies

A new type of switching valve used in rebreathing studies for estimating cardiac output is described. This valve employs a unique deformable elastic element, actuated by low-pressure compressed air, to effect switching. The capability for remote operation (via a compressed air line) and the light weight of the valve (110 g) make the valve especially well suited to exercise stress testing studies. Two valves of this type have been satisfactorily used in graded exercise stress tests in a clinical setting for over 2 yr.     

To core,or not to core: the impact of coring on tree health and a best‐practice framework for collecting dendrochronological information from living trees

Trees are natural repositories of valuable environmental information that is preserved in the growth and structure of their stems, branches and roots. Dendrochronological analyses, based on the counting, crossdating and characterisation of incrementally formed wood rings, offer powerful insights for diverse fields including ecology, climatology and archaeology. The application of this toolset is likely to increase in popularity over coming decades due to advances in the field and a reduction in the cost of analyses. In research settings where the continued value of living trees subject to dendrochronological investigation is important, the use of an increment bore corer to extract trunk tissue is considered the best option to minimise negative impacts on tree health (e.g. stress and fitness). A small and fragmented body of literature, however, reports significant after‐effects, and in some cases fatal outcomes, from this sampling technique. As it stands, the literature documenting increment bore coring (IBC) impacts lacks experimental consistency and is poorly replicated, making it difficult for prospective users of the method to assess likely tree responses to coring. This paucity of information has the potential to lead to destructive misuse of the method and also limits its safe implementation in circumstances where the risk of impacts may be appropriate. If IBC is to fulfil its potential as a method of choice across research fields, then we must first address our limited understanding of IBC impacts and provide a framework for its appropriate future use. Firstly, we review the historical context of studies examining the impacts of IBC on trees to identify known patterns, focal issues and biases in existing knowledge. IBC wound responses, particularly those that impact on lumber quality, have been the primary focus of prior studies. No universal treatment was identified that conclusively improved wound healing and few studies have linked wound responses to tree health impacts. Secondly, we build on literature insights using a theoretical approach to identify the most important factors to guide future research involving implementation of IBC, including innate tree characteristics and environmental factors. Thirdly, we synthesise and interrogate the quantitative data available through meta‐analysis to identify risk factors for wound reactions. Although poor reporting standards, restricted scopes and a bias towards temperate ecosystems limited quantitative insight, we found that complete cambial wound closure could still harbour high rates of internal trunk decay, and that conditions favouring faster growth generally correlated with reduced indices of internal and external damage in broadleaved taxa. Finally, we propose a framework for guiding best‐practice application of IBC to address knowledge gaps and maximise the utility of this method, including standardised reporting indices for identifying and minimising negative impacts on tree health. While IBC is an underutilised tool of ecological enquiry with broad applicability, the method will always incur some risk of negative impacts on the cored tree. We caution that the decision to core, or not to core, must be given careful consideration on a case‐by‐case basis. In time, we are confident that this choice will be better informed by evidence‐based insight.     

A disposable corer for sampling organic soils

A disposable and inexpensive corer is described that offers a versatile method for sampling soft soils with a large organic content. The cans are suitable for the immediate collection of soil and for field incubations. Fine roots are sliced easily during insertion of corers by the sharp bottom edge, and the thin walls and the high thermal conductivity of steel aid transfer of heat energy between the bulk soil and the sample. If desired the cylinders may be perforated, have the upper cap removed and also can be used as an indicator of anaerobic soil conditions. This revised version was published online in June 2006 with corrections to the Cover Date.