What can physical, biotic and chemical features of a tree hollow tell us about their associated diversity?

Tree hollows are keystone structures for saproxylic fauna and host numerous endangered species. However, not all tree hollows are equal. Many variables including physical, biotic and chemical ones, can characterise a tree hollow, however, the information that these could provide about the saproxylic diversity they harbour has been poorly explored. We studied the beetle assemblages of 111 Quercus species tree hollows in four protected areas of the Iberian Peninsula. Three physical variables related to tree hollow structure, and two biotic ones (presence of Cetoniidae and Cerambyx species recognised as ecosystem engineers) were measured in each hollow to explore their relative effect on beetle assemblages. Moreover, we analysed the chemical composition of the wood mould in 34 of the hollows, in order to relate beetle diversity with hollow quality. All the environmental variables analysed (physical and biological) showed a significant influence on saproxylic beetle assemblages that varied depending on the species. Furthermore, the presence of ecosystem engineers affected both physical and chemical features. Although wood mould volume, and both biotic variables could act as beetle diversity surrogate, we enhance the presence of Cetoniidae and Cerambyx activity (both easily observable in the field) as indicator variables, even more if both co-occur as each affect to different assemblages. Finally, assimilable carbon and phosphorous contents could act as indicator for past and present beetle activity inside the cavity that could become a useful tool in functional diversity studies. However, an extension of this work to other taxonomic groups would be desirable.

Subsidence damage assessment of a Gothic church using differential interferometry and field data

The Santas Justa and Rufina Gothic church (fourteenth century) has suffered several physical, mechanical, chemical, and biochemical types of pathologies along its history: rock alveolization, efflorescence, biological activity, and capillary ascent of groundwater. However, during the last two decades, a new phenomenon has seriously affected the church: ground subsidence caused by aquifer overexploitation. Subsidence is a process that affects the whole Vega Baja of the Segura River basin and consists of gradual sinking in the ground surface caused by soil consolidation due to a pore pressure decrease. This phenomenon has been studied by differential synthetic aperture radar interferometry techniques, which illustrate settlements up to 100 mm for the 1993–2009 period for the whole Orihuela city. Although no differential synthetic aperture radar interferometry information is available for the church due to the loss of interferometric coherence, the spatial analysis of nearby deformation combined with fieldwork has advanced the current understanding on the mechanisms that affect the Santas Justa and Rufina church. These results show the potential interest and the limitations of using this remote sensing technique as a complementary tool for the forensic analysis of building structures.

Physical and acoustic sediment properties of sediment cores from the eastern equatorial Atlantic

To reconstruct the deep-water circulation for the last 3.5 Ma from deep-sea sediments of the eastern equatorial Atlantic, sea floor morphology, sub-bottom reflectors and the echo character have been mapped on the basis of 3.5 kHz records and sediment cores. Physical properties of sediments and synthetic seismograms derived from them enable us to decipher reflector sequences in environments of pelagic, current-resuspended and turbidity sedimentation. The individual reflectors originate from carbonate dissolution, hiatus, coarse sand layers and interferences. Those which are related to carbonate dissolution and hiatus provide evidence of water-mass boundaries by their distribution. Five phases of different deep-water circulation can be seen in the record of th elast 3.5 Ma, and these are related to climate history: 1. Between 3.7 Ma and 2.2 Ma a strong deep-water circulation indicates a northward flow of bottom water below 4200 m (AABW = Antarctic-Bottom Water) and a southward flow of deep-water above 4200 m (NADW = North-Atlantic Deep Water). 2. Between 1.6 and 1.4 Ma a southward flow of bottom water below 4500 m and a diminished southward flow above 4500 m can be detected. This water-mass geometry can be interpreted by an expansion of the NADW-masses and a displacement of the AABW-masses during the same time. 3. Since 1.4 Ma a northward flow of a bottom-water current developed again. This current flow created a leeside sediment ridge in the southern part of the Kane Gap and furrows in the northern part of it. 4. Between 400,000 and 200,000 yrs B. P. the oceanic and atmospheric circulation increased. The strengthened oceanic circulation caused and increase in carbonate dissolution, which is documented by a traceable reflector from 2800 m to 4500 m water depth. At the same time an increase of the atmospheric circulation caused a drastic rise in the pelagic sediment accumulation (> 100 %) through an intensification of upwelling. This runs parallel with a higher oceanic productivity in the northern equatorial divergence zone and an enhanced supply of fluvial and probably eolian sediments from the Senegal and Guinea. 5. Before 10,000 yrs B. P. an erosive northward flowing bottom-water current prevailed below 4500 m water depth. After 10,000 yrs B.P. the bottom-water flow was sluggish and non erosive.

Initial soil properties and biomass after experimental grazing and warming in mesic and wet sites, Adventdalen valley, Spitzbergen

High-latitude ecosystems store large amounts of carbon (C); however, the C storage of these ecosystems is under threat from both climate warming and increased levels of herbivory. In this study we examined the combined role of herbivores and climate warming as. drivers of CO2 fluxes in two typical high-latitude habitats (mesic heath and wet meadow). We hypothesized that both herbivory and climate warming would reduce the C sink strength of Arctic tundra through their combined effects on plant biomass and gross ecosystem photosynthesis and on decomposition rates and the abiotic environment. To test this hypothesis we employed experimental warming (via International Tundra Experiment [ITEX] chambers) and grazing (via captive Barnacle Geese) in a three-year factorial field experiment. Ecosystem CO2 fluxes (net ecosystem exchange of CO2, ecosystem respiration, and gross ecosystem photosynthesis) were measured in all treatments at varying intensity over the three growing seasons to capture the impact of the treatments on a range of temporal scales (diurnal, seasonal, and interannual). Grazing and warming treatments had markedly different effects on CO2 fluxes in the two tundra habitats. Grazing caused a strong reduction in CO2 assimilation in the wet meadow, while warming reduced CO2 efflux from the mesic heath. Treatment effects on net ecosystem exchange largely derived from the modification of gross ecosystem photosynthesis rather than ecosystem respiration. In this study we have demonstrated that on the habitat scale, grazing by geese is a strong driver of net ecosystem exchange of CO2, with the potential to reduce the CO2 sink strength of Arctic ecosystems. Our results highlight that the large reduction in plant biomass due to goose grazing in the Arctic noted in several studies can alter the C balance of wet tundra ecosystems. We conclude that herbivory will modulate direct climate warming responses of Arctic tundra with implications for the ecosystem C balance; however, the magnitude and direction of the response will be habitat-specific.

The chemical and physical examination of Portland cement,

Mode of access: Internet.

The methods of glass blowing and of working silica in the oxy-gas flame, for the use of chemical and physical students /

Mode of access: Internet.

Developing countries--soil properties and behavior (Jan 72 - May 81) : citations from the NTIS data base.

Includes index.

[Translation] of the new London pharmacopoeia, including also the new Dublin and Edinburgh pharmacopoeias, with a full account of the chemical and medicinal properties of their contents, forming a complete materia medica.

Mode of access: Internet.

Chemical and toxicological properties of coal fly ash /

Bibliography: p. 62-70.

Chemical and physical data for disposal wells, Eastern Snake River Plain, Idaho /

Bibliography: leaves 30-31.

Studies on the chemical and biological properties of coumestrol and related compounds

Bibliography: p. 83-95.