Biodiversidade e dinâmica estrutural de assembleias de esponjas marinhas (Filo Porifera) da Ilha Grande e cercanias, Rio de Janeiro, Brasil

Estudos de comunidades de esponjas marinhas são escassos no Brasil, sendo este trabalho pioneiro nessa abordagem para a Ilha Grande - RJ, um local de alta diversidade biológica. A estrutura das assembleias de esponjas marinhas e da comunidade bentônica marinha séssil foi avaliada, a partir de índices descritores de diversidade, em seis pontos da Ilha Grande e ilhas próximas, sendo três do lado continental e três do lado oceânico. As assembleias foram comparadas entre os diferentes lado e profundidade, através da contagem do número de indivíduos e área de cobertura por foto-quadrados. Paralelamente, as esponjas foram coletadas, fixadas e posteriormente identificadas através de metodologia e literatura especializada. Foi encontrado um total de 5.457 indivíduos, representando as Classes Demospongiae e Calcarea, distribuídos em 41 espécies e nove morfotipos, indicando maior diversidade para Lagoa Azul e menor para Parnaióca, sendo o local com maior riqueza a Ilha do Abraão. Dentre as espécies identificadas, quatro dominaram mais de 50% do total e 26 não alcançaram nem 5% da abundância absoluta. Análises de variância por GLM só evidenciaram diferença significativa para profundidade com substratos diferentes (F= 2,79; p<0,04), enquanto o fator lado (F= 2,23; p>0,16) e a interação entre os fatores (F= 1,17; p>0,38) não tiveram diferença estatística. As análises multivariadas de ordenação Cluster e MDS indicaram a formação de quatro assembleias de esponjas: 1) quatro locais com substrato não consolidado; 2) Lagoa Azul com substrato não consolidado; 3) locais oceânicos de substrato rochoso; e 4) locais continentais de substrato consolidado. Já para a comunidade geral, 49 espécies foram encontradas, sendo o Filo Porifera o de maior representatividade específica, apesar das macroalgas terem formado o grupo mais abundante. A comunidade bentônica foi dominada por quatro espécies, que juntas alcançaram média de 50% da cobertura bentônica: alga calcária incrustante, algas formadoras de tapete de turf, a esponja Iotrochota arenosa e o zoantídeo Palythoacaribaeorum. Estatisticamente, o lado continental se mostrou diferente do oceânico, o qual possui maior riqueza, diversidade e uniformidade de espécies, muito provavelmente pelo menor número de espécies dominantes e aliado a isso maior heterogeneidade de habitats, o que promove o aumento da diversidade. Quinze novas espécies estão sendo registradas para a Baía da Ilha Grande, sendo três novas espécies, as quais estão sendo descritas por especialistas, e 12 são novos registros de espécies ou gêneros para a região, evidenciando que a diversidade de esponjas marinhas na BIG é alta e ainda pouco conhecida e que a formação de assembleias pode ser devida a singularidade de cada local, implicando na necessidade de conservação dos costões rochosos da Ilha Grande e cercanias, a qual pode ser manejada através da realização de rápidos levantamentos sobre a riqueza e o número de indivíduos da espécie na região

中国褐腐真菌泊氏孔菌等三属的分类和生态研究

木材腐朽真菌在森林生态系统中起着关键的降解还原作用，是森林生态系统物质循环中不可缺少的重要组成部分。黄孔菌属Auriporia、褐腐干酪属Oligoporus和泊氏孔菌属Postia的种类具有降解木材中的纤维素和半纤维素、造成木材褐色腐朽的功能，而混合于针叶林土壤中的褐腐残余物是针叶林生态系统更新所必不可少的。但以往国内对三属种类的研究并不深入，仅报道了其中约50%的种类，尚有大量新物种和国内新记录种有待于进一步发现；且有关褐腐真菌的生态学研究尚属空白。本论文对中国地区的黄孔菌属、褐腐干酪属和泊氏孔菌属进行分类学和生态学研究，明确这三属在中国的确切种类，发现新种和中国新记录种，并对这三属种类在寄主树木上的演替进行初步探讨。 研究结果表明： 1、中国目前发现黄孔菌属有2个物种，褐腐干酪属有5个物种，泊氏孔菌属有22种，其中包括本次研究发现的3个新种，分别是Postia calcarea、 P. gloeocystidiata和P. subundosa；2个中国新记录种，分别是Postia lateritia和P. persinica。 2、对每个属的种类给出了的检索表。 3、生态演替的结果表明，黄孔菌属、褐腐干酪属和泊氏孔菌属在树木腐烂程度为无皮倒木且没有完全腐朽时生长发生频次和种类数量均为最多，说明这三属大多数种类均为喜阴、腐生。 4、在对寄主树木选择性的研究结果表明，黄孔菌属、褐腐干酪属、泊氏孔菌属的种类主要生长在针叶树木上，有27种，占总数的93%。在29个物种中能生长在云杉属树木上的种类最多，为18种；而阔叶树中最适宜这三属物种生长的树种是桦属，有8种生长在该类寄主树木上。

Distribution of molluscan remains in the sediment of the Chukchi Sea and its vicinity, the Arctic

The result of an analysis of mollusca remains collected from the Chukchi Sea, Beaufort Sea and Bering Sea in the First Chinese National Arctic Research Expedition, from July to September, 1999 is presented. Seventeen species of mollusca have been identified, which belong to two classes: Bivalvia and Gastropoda. The compositions of the mollusca are very simple. According to the distribution pattern two groups may be distinguished among molluscan species. The Pan-Arctic and circumboreal group comprises Nuculana pernula, N.radiata, Nucula bellotii, Astarte montagui, Seripes groenlandicus, Macoma calcarea, M. moesta alaskana, Liocyrna fluctuosa, Mya pseudoarenaria and Turritella polaris. Three species, Cyclocardia crebricostata, Trichotrois coronata and Argobuccinum oregonense are components of the Pan-Arctic and Pacific boreal group. With regard to feeding habits, detritus feeders dominate. There are 7 species of detritus feeders, i.e., Nuculana pernula, N. radiata, Nucula bellotii, Macoma calcarea, M. moesta alaskana, Macoma sp. and Trichotropis coronata. Detritus feeders are dominant with regard to the numbers of species as well as to the frequency of occurrence. Macoma calcarea is the most abundant species.

A randomized controlled trial of homeopathic treatment of weaned piglets in a commercial swine herd

Aim: To evaluate the zootechnic performance and occurrence of diarrhea in piglets in the week post-weaning comparing supplementation with sucrose saline which contained or did not contain added homeopathic medicine.Method. Animals were randomly divided into three groups of 24 piglets each. The control group did not receive any treatment. Another group received sucrose saline, and the third group received sucrose saline with homeopathic medicine added, in the period of zero to seven days post-weaning. The homeopathic treatment consisted of Echinacea angustifolia, Avena sativa, Ignatia amara, Calcarea carbonica, all 6cH. Piglets were weighed daily for weight gain or loss, and observed for diarrhea and feed intake.Results: Animals receiving sucrose saline alone and sucrose saline with homeopathy had less weight loss than control (p = 0.017, p = 0.0001 respectively). There was no statistical difference in relation to overall incidence of diarrhea or food consumption. These data suggest that the supplementation with sucrose saline with added homeopathic medicine in the first seven days post-weaning may be an useful option to reduce weight loss in weaned piglets. Homeopathy (2008) 97, 202-205.

Modifizierungen des Enzyms Silicatein alpha zur direkten Immobilisierung auf verschiedenen Oberflächen : neuartige Herstellung von Kompositmaterialien unter physiologischen Bedingungen

Das Silicatein α ist ein 24 kDa großes Enzym, welches im Schwamm Suberites domuncula für die Synthese von Biosilikat verantwortlich ist. Vorhergehende Studien haben gezeigt, dass Silicatein auch die Synthese anderer Metalloxide wie Titandioxid, Galliumoxid und Zirkoniumdioxid katalysieren kann. Diese Fähigkeiten machen das Silicatein α für biomedizinische und biotechnologische Anwendungen interessant, da die Synthese unter nahezu physiologischen Bedingungen ablaufen kann, was die Herstellung neuartiger Kompositmaterialien mit einzigartigen Eigenschaften erleichtern würde. Zur Immobilisierung des Silicatein α auf verschiedenen Oberflächen wurde bislang ein Nickel-NTA-Kopolymer eingesetzt. Diese Art der Immobilisierung bietet eine Reihe von Möglichkeiten in der Nanobiotechnologie, stößt aber in der Biomedizin an ihre Grenzen, da sich nicht alle Oberflächen für ein solches Coating eignen. Zudem können die zur Aktivierung des Polymers nötigen Lösungsmittel und die über die Zeit freigesetzten Monomere aus dem Polymergerüst toxische oder mutagene Wirkung auf das umliegende Gewebe haben. Deshalb wurde das Silicatein α in dieser Arbeit mit zwei Affinitäts-Tags so modifiziert, dass es an verschiedene Oberflächen immobilisiert werden kann und dabei seine Aktivität beibehält. Zuerst wurde das Silicatein mit einem Glu-tag am N-terminalen Ende modifiziert. Dadurch gelang die direkte Immobilisierung an Hydroxyapatit und die folgende, enzymkatalysierte Synthese von Biosilikat-Beschichtungen auf diesem Träger. Die Eigenschaften eines solchen HA-Kompositmaterials können zum Beispiel zu einem verbesserten, schnelleren und stabileren Einwachsen von Knochenimplantaten führen, da Biosilikat die Reifung und Differenzierung von Osteoblasten beschleunigt. rnMit dem an Hydroxyapatit-Plättchen immobilisierten Glu-tag-Silicatein wurde ein modifizierter Pull-down Assay etabliert, wodurch bekannte, aber auch bis dahin noch unbekannte Protein-Interaktionspartner identifiziert werden konnten. rnUm zu zeigen, dass der entwickelte Glu-tag an präformierte, calciumhaltige Oberflächen binden kann, wurden die Nadeln des Kalkschwammes Paraleucilla magna als Modellorganismus verwendet. Die Nadeln konnten durch das immobilisierte Silicatein mit einer Titandioxid-Schicht überzogen werden und unter Verwendung des Interaktionspartners Silintaphin-1 konnte diese Beschichtung noch verstärkt werden. Solche CaCO3-Kompositmaterialien könnten sowohl in der Biomedizin als auch in der Biotechnologie zum Einsatz kommen. Neben den erwähnten calciumhaltigen Materialien finden auch andere Stoffe wie TiO2-Nanodrähte Verwendung in der Forschung. In weiterführenden Experimenten konnte gezeigt werden, dass der entwickelte Glu-tag auch Affinität zu Titandioxid-Oberflächen vermittelt. Auch hier konnte durch das oberflächenimmobilisierte Enzym eine Biosilikatbeschichtung synthetisiert werden. rnMit der zweiten Modifikation - einem Cys-tag - konnte Silicatein direkt auf Goldoberflächen immobilisiert werden. Durch die Verwendung eines Polydimethylsiloxan (PDMS)-Stempels wurde das Cys-getaggte Silicatein in einem linienförmigen Muster auf das Gold übertragen und die Synthese von Titandioxid dort nachgewiesen.rnDie Experimente und Ergebnisse dieser Arbeit haben gezeigt, dass Silicatein α durch einfache Modifikationen an verschiedene Oberflächen immobilisiert werden kann und dabei immer noch seine Aktivität behält. rnHierdurch ergibt sich die Möglichkeit, unter Normalbedingungen verschiedenste Kompositmaterialien herzustellen.rn

Megabenthic communities in the waters around Svalbard during POLARSTERN cruise ARK-VIII/2 (EPOS II)

Composition and distribution of megabenthic communities around Svalbard were investigated in June/July 1991 with 20 Agassiz trawl and 5 bottom trawl hauls in depths between 100 and 2100 m. About 370 species, ranging from sponges to fish, were identified in the catches. Species numbers per station ranged from 21 to 86. Brittle stars, such as Ophiacantha bidentata, Ophiura sarsi and Ophiocten sericeum, were most important in terms of constancy and relative abundance in the catches. Other prominent faunal elements were eunephthyid alcyonarians, bivalves, shrimps, sea stars and fish (Gadidae, Zoarcidae, Cottidae). Multivariate analyses of the species and environmental data sets showed that the spatial distribution of the megabenthos was characterized by a pronounced depth zonation: abyssal, bathyal, off-shore shelf and fjordic communities were discriminated. However, a gradient in sediment properties, especially the organic carbon content, seemed to superimpose on the bathymetric pattern. Both main factors are interpreted as proxies of the average food availability, which is, hence, suggested to have the strongest influence in structuring megabenthic communities off Svalbard.

Planktonic assemblages during sapropel S5 deposits in the Urania Basin

A micropaleontological study of planktonic assemblages on the partially laminated sapropel S5 (late Pleistocene, marine isotope stage (MIS) 5e) was performed in two piston cores from Urania Basin area (eastern Mediterranean, west of Crete): UM94PC16 and UM94PC31 recovered during a PALEOFLUX Project Cruise. The abundance of Florisphaera profunda indicates the development of a deep chlorophyll maximum (DCM) before the anoxic condition at bottom were established, whereas patterns of upper photic zone coccoliths suggest extreme oligotrophy in surface water. The short appearance of Globorotalia scitula and the presence of Globigerinoides ruber in the lower part of sapropel testify to a thermal stratification, also recorded by changes in primary producers. During G. scitula occurrence, diatoms, mainly represented by Pseudosolenia calcar-avis, appear and bloom because of their capability in using nutrients from DCM. Scanning electron microscope analyses performed on selected intervals from UM94PC16 show that the sapropel is organized in microlaminae mostly composed by siliceous microfossils. In particular, sapropel S5 could be related to an enhanced nutrient availability in the lower-middle part of the photic zone, stratified conditions, and a higher continental input.

Neogene diatoms of the Japan Sea

A series of excellent upper Miocene through Quaternary diatomaceous sequences recovered at four sites during Leg 127 was examined for diatoms. The diagenetic transition from opal-A to opal-CT is a diachronic horizon from the uppermost part of the Denticulopsis katayamae Zone (8.5 Ma) at Hole 797B to the uppermost part of the Neodenticula kamtschatica Zone (5.73 Ma) at Hole 795A. The diatom zonation of Koizumi (1985) best divides the upper Miocene to Quaternary sequences above the opal-A/opal-CT boundary and also is useful to date carbonate concretions including diatoms below the boundary. Forty diatom datum levels were evaluated biostratigraphically based on the sediment accumulation rate curve, and several isochronous datum levels are newly proposed for the Japan Sea area. A warm-water current did not penetrated into the Japan Sea through the Tsushima strait during the late Miocene and Pliocene time, because subtropical warm-water diatoms are essentially not present in such sediment samples. The occurrences of diatom are cyclic throughout the Quaternary sediments and are affected by eustatic sea level changes.

Diatom deposits in the ostpreußischen Haffe

Als man nach dem ersten Weltkrieg im verkleinerten Deutschland nach der Möglichkeit von Neulandgewinnung suchte, dachte man auch an eineTrockenlegung der ostpreußischen Haffe. Aus diesem Anlaß wurden umfangreiche Bohrungen ausgeführt, um ein möglichst genaues Bild vom Untergrunde der Haffe zu bekommen. Auf Veranlassung der Preußischen Geologischen Landesanstalt wurde ich mit der Untersuchung der Diatomeen in den Bohrproben beauftragt. Die Arbeit wurde 1934 begonnen und Ende 1937 wurde der letzte Arbeitsbericht abgeliefert. Die beabsichtigte Veröffentlichung ist bisher unterblieben, weil die Druckvorlagen später verloren gegangen sind. Seitdem sind über die Haffuntersuchungen mehrere Teilergebnisse veröffentlicht worden, von denen hier schon wegen der Terminologie die pollenanalytischen Arbeiten von L. HEIN (1941) und HUGO GROSS (1941) erwähnt seien, auf die im Abschnitt Il 2e näher eingegangen wird. Bei der geologischen Auswertung war Zurückhaltung geboten; denn es wäre gewagt, allein aus der Perspektive der Diatomeenforschung endgültige Aussagen machen zu wollen. Darum habe ich mich bemüht, das Material so weit aufzuschließen, daß es Geologen später auch bei veränderter Fragestellung auswerten können. "Die Theorien wechseln, aber die Tatsachen bleiben." Der Initiative des Herrn Prof. Dr. K. GRIPP und der finanziellen Hilfe der Deutschen Forschungsgemeinschaft ist es zu verdanken, daß die vorliegende Arbeit im Druck erscheinen kann. Zusammenfassung 1. Nur in den alluvialen Schichten des Kurischen Haffs wurden Diatomeen gefunden. 2. Die Diatomeenflora des Kurischen Haffs besteht zur Hauptsache aus Süßwasserformen. 3. Salzwasserformen finden sich in allen Schichten verstreut unter der Süßwasserflora. Wenn sie auch nach Zahl der Arten in manchen Proben einen erheblichen Prozentsatz der Flora ausmachen, so ist doch die Zahl der Individuen stets so gering, daß man nirgends von einer Brackwasserflora sprechen kann. 4. Die Süßwasserflora besteht in den unteren Schichten vorwiegend aus Grundformen; und zwar machen die epiphytischen Bewohner flacher Sumpfgewässer einen großen Teil der Flora aus. 5. In einzelnen Bohrungen kommt in den untersten alluvialen Schichten eine Grundflora mit zahlreichen Mastogloien vor. Dies sind die ältesten diatomeenführenden Schichten, entstanden in isolierten Sumpfgewässern. 6. Die übrigen Schichten mit überwiegender Grundflora sind vermutlich Ablagerungen der Ancyluszeit. 7. Die oberen Schichten, in denen die Planktondiatomeen überwiegen, dürften größtenteils der Litorina-Transgressionszeit angehören, jedoch ist der Transgressions-Kontakt nicht klar zu erkennen. 8. Das Ende der Litorinazeit ist noch weniger erkennbar, da eine grundsätzliche Veränderung der Flora nach oben nicht zu beobachten ist. 9. Die ostbaltischen Charakterformen sind in allen Schichten vertreten.

Stable isotope ratios measured on carbonate tests from the Kara Sea

River discharge of Ob and Yenisei to the Kara Sea is highly variable on seasonal and interannual time scales. River water dominates the shallow bottom water near the river mouths, making it warmer and less saline but seasonally and interannually more changeable than bottom water on the deeper shelf. This hydrographic pattern shows up in measurements and modelling, and in stable isotope records (delta18O, delta13C) along the growth axis of bivalve shells and in multiple analyses of single benthic foraminiferal shells. Average isotope ratios increase, but sample-internal variability decreases with water depth and distance from river mouths. However, isotope records of bivalves and foraminifera of a sediment core from a former submarine channel of Yenisei River reveal a different pattern. The retreat of the river mouth from this site due to early Holocene sea level rise led to increasing average isotope values up core, but not to the expected decrease of the in-sample isotope variability. Southward advection of cold saline water along the palaeo-river channel probably obscured the hydrographic variability during the early Holocene. Later, when sediment filled the channel, the hydrographic variability at the core location remained low, because the shallowing proceeded synchronously with the retreat of the river mouth.

Siliceous microfossil assemblage and accumulation rate variations across the Middle Eocene Climatic Optimum at ODP Site 171-1051

The Middle Eocene Climatic Optimum (MECO; ~ 40 million years ago [Ma]) is one of the most prominent transient global warming events in the Paleogene. Although the event is well documented in geochemical and isotopic proxy records at many locations, the marine biotic response to the MECO remains poorly constrained. We present new high-resolution, quantitative records of siliceous microplankton assemblages from the MECO interval of Ocean Drilling Program (ODP) Site 1051 in the subtropical western North Atlantic Ocean, which are interpreted in the context of published foraminiferal and bulk carbonate stable isotope (d18O and d13C) records. High diatom, radiolarian and silicoflagellate accumulation rates between 40.5 and 40.0 Ma are interpreted to reflect an ~ 500 thousand year (kyr) interval of increased nutrient supply and resultant surface-water eutrophication that was associated with elevated sea-surface temperatures during the prolonged onset of the MECO. Relatively low pelagic siliceous phytoplankton sedimentation accompanied the peak MECO warming interval and the termination of the MECO during an ~ 70 kyr interval centered at ~ 40.0 Ma. Following the termination of the MECO, an ~ 200-kyr episode of increased siliceous plankton abundance indicates enhanced nutrient levels between ~ 39.9 and 39.7 Ma. Throughout the Site 1051 record, abundance and accumulation rate fluctuations in neritic diatom taxa are similar to the trends observed in pelagic taxa, implying either similar controls on diatom production in the neritic and pelagic zones of the western North Atlantic or fluctuations in sea level and/or shelf accommodation on the North American continental margin to the west of Site 1051. These results, combined with published records based on multiple proxies, indicate a geographically diverse pattern of surface ocean primary production changes across the MECO. Notably, however, increased biosiliceous accumulation is recorded at both ODP Sites 1051 and 748 (Southern Ocean) in response to MECO warming. This may suggest that increased biosiliceous sediment accumulation, if indeed a widespread phenomenon, resulted from higher continental silicate weathering rates and an increase in silicic acid supply to the oceans over several 100 kyr during the MECO.

The Global Plankton Database: an inventory and data from the Former Soviet Union expeditions

At present time, there is a lack of knowledge on the interannual climate-related variability of zooplankton communities of the tropical Atlantic, central Mediterranean Sea, Caspian Sea, and Aral Sea, due to the absence of appropriate databases. In the mid latitudes, the North Atlantic Oscillation (NAO) is the dominant mode of atmospheric fluctuations over eastern North America, the northern Atlantic Ocean and Europe. Therefore, one of the issues that need to be addressed through data synthesis is the evaluation of interannual patterns in species abundance and species diversity over these regions in regard to the NAO. The database has been used to investigate the ecological role of the NAO in interannual variations of mesozooplankton abundance and biomass along the zonal array of the NAO influence. Basic approach to the proposed research involved: (1) development of co-operation between experts and data holders in Ukraine, Russia, Kazakhstan, Azerbaijan, UK, and USA to rescue and compile the oceanographic data sets and release them on CD-ROM, (2) organization and compilation of a database based on FSU cruises to the above regions, (3) analysis of the basin-scale interannual variability of the zooplankton species abundance, biomass, and species diversity.

Siliceous microplankton in surface sediments and the water column of the Red Sea

We studied the siliceous microplankton assemblages (mainly diatoms) from plankton tows (mesh size 20 µm) and surface sediment samples collected along a N-S transect in the northern Red Sea (28-21°N). In addition, we analyzed differences/similarities between plankton and sediment assemblages within a brine-filled basin (the southern basin) of the Shaban Deep and compared these assemblages with those from outside the brine. Plankton samples revealed the overwhelming dominance of diatoms over other siliceous groups. Diatoms accounted for ca. 97% of all biosiliceous particles at 120-20 m (vs. 2.9% silicoflagellates and 0.4% radiolarians), and ca. 94% at 200-120 m (vs. 4.5% silicoflagellates and 1.6% radiolarians). In general, a marine, warm-water (tropical/subtropical) diatom assemblage characterizes the plankton samples. Representatives of the Nitzschia bicapitata group are by far the most abundant contributors at both depth intervals (average=43%), ranging from ca. 30% in the North to ca. 60% in the South. Biogenic opal content in non-brine surface sediments is very low, (below 0.2 wt.% SiO2); and concentration of siliceous microorganisms is also low and of the order of 5*10**3-10**4 microorganisms/g dry sediment. Diatoms are the main contributors to the opal signal in the 20-40 µm fraction, while they share dominance with radiolarians in the >40 µm fraction. Total diatom concentrations average 1.2*10**4 valves/g in the 20-40 µm fraction and 4*10**3 valves/g in the >40 µm fraction. Robust taxa of warm water affinity (Alveus marinus, Azpeitia neocrenulata, Azpeitia nodulifera and Roperia tesselata) characterize the surface sediments. In contrast, biogenic opal content in brine surface sediment samples is much higher than in the non-brine samples, ranging from 2.8 to 3.8 wt.% SiO2, and concentration of siliceous microorganisms is 3-4 orders of magnitude higher. In addition here, diatoms dominate the opal signal. The taxa found in these samples are a mixture of non-brine and plankton samples, and fragile forms (e.g., N. bicapitata group, Neodelphineis indica) are well preserved in these sediments. Thus, brine sediments in this region seem to offer a great potential for palaeoenvironmental studies.

Biostratigraphical investigations of Lago d'Averno, near Naples

Remains of diatoms, molluscs, ostracods, foraminifera and pollen exines preserved in the sediments of Lago d'Averno, a volcanic lake in the Phlegrean Fields west of Naples, allowed us to reconstruct the changes in the ecological conditions of the lake and of the vegetation around it for the period from 800 BC to 800 AD. Lago d'Averno was at first a freshwater lake, temporarily influenced by volcanic springs. Salinity increased slowly during Greek times as a result of subsidence of the surrounding land. Saline conditions developed only after the lake was connected with the sea by a canal, when Portus Julius was built in 37 BC. The first post-Roman period of uplift ended with a short freshwater phase during the 7th century after Christ. Deciduous oakwoods around the lake was transformed into a forest of evergreen oaks in Greek times and thrived there - apparently almost uninfluenced by man - until it was felled, when the Avernus was incorporated into the new Roman harbour in 37 BC, to construct a shipyard and other military buildings there. Land-use was never more intense than during Roman times and weakest in Greek and Early Roman times, when the Avernus was considered a holy place, the entrance to the underworld.