The time of arrival of people in Australia is an unresolved question. It is relevant to debates about when modern humans first dispersed out of Africa and when their descendants incorporated genetic material from Neanderthals, Denisovans and possibly other hominins. Humans have also been implicated in the extinction of Australia’s megafauna. Here we report the results of new excavations conducted at Madjedbebe, a rock shelter in northern Australia. Artefacts in primary depositional context are concentrated in three dense bands, with the stratigraphic integrity of the deposit demonstrated by artefact refits and by optical dating and other analyses of the sediments. Human occupation began around 65,000 years ago, with a distinctive stone tool assemblage including grinding stones, ground ochres, reflective additives and ground-edge hatchet heads. This evidence sets a new minimum age for the arrival of humans in Australia, the dispersal of modern humans out of Africa, and the subsequent interactions of modern humans with Neanderthals and Denisovans. Optical dating of sediments containing stone artefacts newly excavated at Madjedbebe, Australia, indicate that human occupation began around 65,000 years ago, thereby setting a new minimum age for the arrival of people in Australia. When did humans first colonize Australia? The date of the initial landing on the continent that is now associated with cold lager and 'Waltzing Matilda' has been highly controversial. Dates from a site called Madjedbebe in northern Australia had put the presence of modern humans in Australia at between 60,000 and 50,000 years ago, but these results have since been hotly contested. Here, the results from a comprehensive program of dating of new excavations at the site confirm that people first arrived there around 65,000 years ago. The results show that humans reached Australia well before the extinction of the Australian megafauna and the disappearance of Homo floresiensis in neighbouring Indonesia.

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Human occupation of northern Australia by 65,000 years ago

The step in cladistic analysis that has received least attention is delimitation of char- acter states, there usually being little justification for their delimitation. It is generally assumed that states of cladistic characters are discrete, even when variation is quantitative. I show here that a majority of the character states of obviously quantitative characters used in lower-level cladistic studies in botany over the last generation are ambiguous even when ingroup variation alone is analyzed. Consideration of variation in the outgroup may compromize either the states recognized in the ingroup and/or the polarity that they are subsequently assigned. Furthermore, many so- called qualitative characters are based on a quantitative phenomenological base filtered through the reified semantic discontinuities of botanical terminology; such characters face the problems of their more obviously quantitative relatives. Methods for delimiting states within quantitative char- acters are examined. Some produce gaps in the variation by redefining the character, scoring the intermediates in a distinctive fashion, performing phylogenetic analyses within the terminal taxa, or changing the hierarchical level at which the variation is evaluated. Others produce states by manipulation of the statistical properties of the variation of the ensemble of taxa being studied. These latter methods often allow greater resolution of the phylogeny, but at the cost of lowering the significance of the most parsimonious tree. The underlying assumptions of the two sets of methods are briefly analyzed. Problems manifest in the division of continuous variation into char- acter states suggest a reappraisal of the early steps of cladistic analysis; in practice, character states often seem to be delimited in conjunction with developing ideas of the phylogeny, rather than in a step prior to a phylogenetic analysis. It is recommended that character states be delimited by carefully analyzed discontinuities (not necessarily absolute gaps) in the variation, attention having been paid to variation in the outgroup, and that "morphological" characters in general are assumed to be quantitative unless demonstrated otherwise. Explicit justification for the delimitation of char- acter states should be given as a matter of course in all phylogenetic studies.

Character States, Morphological Variation, and Phylogenetic Analysis: A Review

A monophyletic pantropical group of papilionoid legumes, here referred to as the ‘‘dalbergioid’’ legumes, is circumscribed to include all genera previously referred to the tribes Aeschynomeneae and Adesmieae, the subtribe Bryinae of the Desmodieae, and tribe Dalbergieae except Andira, Hymenolobium, Vatairea,and Vataireopsis. This previously undetected group was discovered with phylogenetic analysis of DNA sequences from the chloroplast trnK (including matK) and trnL introns, and the nuclear ribosomal 5.8S and flanking internal transcribed spacers 1 and 2. All dalbergioids belong to one of three well-supported subclades, the Adesmia, Dalbergia, and Pterocarpus clades. The dalbergioid clade and its three main subclades are cryptic in the sense that they are genetically distinct but poorly, if at all, distinguished by nonmolecular data. Traditionally important taxonomic characters, such as arborescent habit, free stamens, and lomented pods, do not provide support for the major clades identified by the molecular analysis. Short shoots, glandular-based trichomes, bilabiate calyces, and aeschynomenoid root nodules, in contrast, are better indicators of relationship at this hierarchical level. The discovery of the dalbergioid clade prompted a re-analysis of root nodule structure and the subsequent finding that the aeschynomenoid root nodule is synapomorphic for the dalbergioids.

The dalbergioid legumes (Fabaceae): delimitation of a pantropical monophyletic clade

Bamboo plays an essential role in the daily life of millions of people in subtropical and tropical regions. Increased research during the recent years has contributed considerably to the understanding of these important arborescent grasses as well as to an improved processing for wider uses. The treatise gives an overview on aspects of biology, properties and utilization of bamboos with emphasis on further research directions.

Research on bamboo.

Aluminum phytotoxicity and genetically based aluminum resistance has been studied intensively during recent decades because aluminum toxicity is often the primary factor limiting crop productivity on acid soils. Plants that grow on soils with high aluminum concentrations employ three basic strategies to deal with aluminum stress. While excluders effectively prevent aluminum from entering their aerial parts over a broad range of aluminum concentration in the soil, hyperaccumulators take up aluminum in their aboveground tissues in quantities above 1000 ppm; that is, far exceeding those present in the soil or in the nonaccumulating species growing nearby. In between these two extremes are indicator species, representing intermediate responses. A list of aluminum hyperaccumulators in angiosperms is compiled on the basis of data in the literature. Aluminum hyperaccumulators include mainly woody, perennial taxa from tropical regions. Recent molecular phylogenies are used to evaluate the systematic and ...

Aluminum Hyperaccumulation in Angiosperms: A Review of Its Phylogenetic Significance

Pieter Baas – Leiden, The Netherlands Nadezhda Blokhina – Vladivostok, Russia Tomoyuki Fujii – Ibaraki, Japan Peter Gasson – Kew, UK Dietger Grosser – Munich, Germany Immo Heinz – Munich, Germany Jugo Ilic – South Clayton, Australia Jiang Xiaomei – Beijing, China Regis Miller – Madison, WI, USA Lee Ann Newsom – University Park, PA, USA Shuichi Noshiro – Ibaraki, Japan Hans Georg Richter – Hamburg, Germany Mitsuo Suzuki – Sendai, Japan Teresa Terrazas – Montecillo, Mexico Elisabeth Wheeler – Raleigh, NC, USA Alex Wiedenhoeft – Madison, WI, USA

IAWA list of microscopic features for softwood identification

Comprehensive investigations on trabeculae in softwoods have shown that they occur much more frequently than has hitherto generally been assumed. A systematic study oflarge series of microtome sections, i.e., transverse sections and particularly radial sections of extended annual ring sequences will, as a rule, give sufficient evidence for the occurrence of trabeculae and related structures. Apart from this phenomenon an increased occurrence of trabeculae was often found in the annual rings of healthy and diseased trees from forest decline areas from the middle of the 1970's onwards. Moreover, trabeculae occur with particularly great frequency and in significantly larger numbers than in nonnal wood in association with wound tissue fonnation as a consequence of injuries, in spruce with hazel growth, or in cedars with traumatic resin ducts. Also, in compression wood trabeculae are fonned much more often than in normal wood. A detailed survey of trabeculae structure and possible patterns of trabeculae arrangement is also given.

On the Occurrence of Trabeculae With Special Consideration of Diseased Trees

An insgesamt 76 kunstlich angelegten Stammverletzungen in Form von Flachwunden von 7 einheimischen Laubholzarten wurde der Schutzholzbereich markroskopisch und mikroskopisch untersucht. Es werden die histologischen Veranderungen, die infolge einer Kambiumverletzung im bereits vor der Verletzung gebildeten Holzgewebe stattfinden, sowie artspezifische Unterschiede der Schutzholzbildung in den untersuchten Laubbaumen beschrieben. Unabhangig von artspezifischen Unterschieden scheinen Wirksamkeit und Ausdehnung der Abschottung stark von der Art der Verletzung (Flachwunden bzw. Bohrkernentnahmen) beeinflust zu sein. Der durch das CODIT-Modell verdrangte Begriff “Schutzholz” im Sinne Franks (1884) wird diskutiert und als berechtigt gehalten zur Beschreibung von Wundreaktionen im bereits gebildeten Holzkorper. Innerhalb des Schutzholzes lassen sich mit Austrocknungszone, eigentlicher Verfarbungszone und umgebender Grenzschicht drei Bereiche voneinander unterscheiden.

Histologische Untersuchungen über das Schutzholz einheimischer Laubbäume

Die Verteilung der Leitbundel und der Zellarten innerhalb einer Sprosachse wurde an den BambusartenCephalostachyum pergracile Munro,Phyllostachys edulis Riv.,Phyllostachys makinoi Hay.,Schizostachyum brachycladum Kurz,Teinostachyum dullooa Gamble undThyrsostackys oliveri Gamble untersucht. Von den Leitbundeln liegen 50 ... 80% in der auseren Rohrwandzone, 10 ... 35% in der mittleren und nur 10 ... 20% in der inneren: zwischen verschiedenen Arten sowie auch vertikal innerhalb einer Sprosachse bestehen hierin signifikante Unterschiede. Mit der Hohe im Halm verringert sich die absolute Leitbundelmenge stetig, wahrend die Leitbundeldichte kontinuierlich zunimmt. Die Beziehungen zwischen Leitbundelmenge und Leitbundeldichte werden diskutiert. Die Sprosachsen der untersuchten Bambusarten bestehen aus rd. 53% Parenchymzellen, 39% Sklerenchymfasern und 8% Leitgewebezellen (Gefase und Siebrohren). Die Verteilung der Zellarten innerhalb der Rohrwand in horizontaler und vertikaler Richtung zeigt gesetzmasige Tendenzen. Im inneren Wanddrittel ist in jeder Halmhohe der Anteil an Parenchymzellen (41 ... 46%) und an Leitgewebe (36 ... 46%) hoher als im auseren, wahrend der Faseranteil in der auseren Zone (44 ... 52%) groser ist als in der inneren (15 ... 22%). In vertikaler Richtung nimmt der Faser- und Leitgewebeanteil in der Sprosachse standig zu, wahrend der Parenchymanteil entsprechend abnimmt. Die Zellartenverteilung wird wesentlich von der Anordnung der Leitbundel bestimmt.

Verteilung der Leitbündel und Zellarten in Sproßachsen verschiedener Bambusarten

Untersucht wurden kranke und gesunde Fichten und Kiefern aus drei bayerischen Forstamtern. Als Arbeitshypothese wurden quantitative und qualitative Veranderungen des nach bzw. vor der Erkrankung gebildeten Holzes angenommen und entsprechend gepruft. Erkrankte Baume weisen teils gravierende Zuwachsdepressionen, teils nur wenig verringerte, teils gesunden Baumen vergleichbare Jahrringbreiten duf. Die Zell- und Gewebeelemente des Nadelholzes bleiben in erkrankten Baumen unverandert, so das in dieser Hinsicht keine signifikanten Unterschiede zwischen erkrankten und gesunden Baumen bestehen. Im Stammholz erkrankter Baume wurden jedoch in groser Anzahl Trabeculae (intrazellulare Stabe) beobachtet. Da auch in erkrankten Buchen Trabeculae nachzuweisen waren, wird auf einen Zusammenhang zwischen Erkrankung und Trabeculae geschlossen. Als Ursache der vermehrten Stabbildungen wird eine verminderte Frostharte erkrankter Baume fur moglich gehalten, nicht jedoch ein Einflus von Viren oder Pilzen.

D. Grosser

Papers

IAWA list of microscopic features for softwood identification

On the Occurrence of Trabeculae With Special Consideration of Diseased Trees

Histologische Untersuchungen über das Schutzholz einheimischer Laubbäume

Verteilung der Leitbündel und Zellarten in Sproßachsen verschiedener Bambusarten

Mögliche anatomische Veränderungen in erkrankten Nadelbäumen