Community Structure and Zonation of Antarctic Benthic Invertebrates: Using a Remotely Operated Vehicle under Ice to Define Biological Patterns

The Ross Sea, Antarctica is a deep bay of the Southern Ocean that exhibits seasonal sea ice and is adjacent to a permanent ice shelf overlying seawater. In 2008 and 2009, imagery of the seafloor under the McMurdo Ice Shelf and under the seasonal ice in the Ross Sea was collected via remotely operated vehicle (ROV) at depths to 300 m. Distinct differences in Antarctic benthic communities were observed over multiple environmental gradients. Species abundance typically exhibited a unimodal distribution with depth with mid-depth peaks, reflecting a food limitation at the deep end and potentially ice disturbance on the shallow end. Diversity and depth had a unimodal relationship at two of three sites encompassing a depth gradient. In terms of functional groups, the proportion of suspension feeders decreased with depth at one site, and no pattern was found at other sites. The group of sessile predators, comprised of several species of anemones, increased with depth proportionally, suggesting that they use a range of feeding strategies to adapt to life at depth. Benthic communities under seasonal ice were different than those under permanent ice shelves, with higher overall species diversity, a greater proportion of suspension feeders, and a degree of magnitude higher abundance

The influence of post-production materials on lightweight wood fiberboard parameters

The aim of this study was to produce a very low-density insulation wood fibreboard, in dry technology, with the use of post-production fibres. During the tests, different amounts of post-production fibres, coming from various stages of processing such as grinding, edges cutting, cutting to the required board size, milling and disqualification of faulty boards, were added to lightweight fibreboard. The amount of possible added post-production wood fibres strongly depends on the characteristic of the fibres and particles size distribution. The parameters of the lightweight board, the most influenced by the dimensions of the fibres used, are mainly thermal conductivity and compressive strength