bluuebunny/crossref_metadata_2025 huggingface dataset:
The Dolaucothi Drainage Wheel
Authors: Boon George C. , Williams Colin
Published: May 2006

The discovery of an oak board from the box-rim of a de-watering device at the Dolaucothi mine is reported by O. Davies in Arch. Camb. XCI (1936), 51–7. An examination of the specimen, which is in the National Museum of Wales, in the light of parallels from the Iberian peninsula and elsewhere led to the accompanying attempt at a reconstruction of the original design. The Dolaucothi wheel is the only British representative of its type, and, curiously enough, the surviving board is the only definitely Roman object ever recorded from within the workings at Dolaucothi, as opposed to the general neighbourhood of the mine.
Animalizing the Slave: the Truth of Fiction
Authors: Bradley Keith
Published: May 2006

In his discussion of natural slavery in the first book of thePolitics(1254a17–1254b39), Aristotle notoriously assimilates human slaves to non-human animals. Natural slaves, Aristotle maintains (1254b16–20), are those who differ from others in the way that the body differs from the soul, or in the way that an animal differs from a human being; and into this category fall ‘all whose function is bodily service, and who produce their best when they supply such service’. The point is made more explicit in the argument (1254b20–4) that the capacity to be owned as property and the inability fully to participate in reason are defining characteristics of the natural slave: ‘Other animals do not apprehend reason but obey their instincts. Even so there is little divergence in the way they are used; both of them (slaves and tame animals) provide bodily assistance in satisfying essential needs’ (1254b24–6). Slaves and animals are not actually equated in Aristotle's views, but the inclination of the slave-owner in classical antiquity, or at least a representative of the slave-owning classes, to associate the slave with the animal is made evident enough. It appears again in Aristotle's later statement (1256b22–6) that the slave was as appropriate a target of hunting as the wild animal.
Rhetoric and Intention in Cicero's Pro Marcello
Authors: Dyer R. R.
Published: May 2006

Caesar returned to Rome from his African campaign on 25 July 46 b.c. (by the old calendar). Cicero felt comparatively secure at Rome at this time, both because of the assurances of safety he had received from Caesar and because of his intimacy with those who expected to play a role in the new administration: A. Hirtius, L. Cornelius Balbus, and the pardoned C. Cassius Longinus, M. Iunius Brutus, and P. Cornelius Dolabella. At Brutus's request he had composed a treatise on the role of oratory in the practice of republican politics (Brutus, published earlier in the year) and was at this very moment composing a panegyric on Cato. Cassius, Dolabella and Hirtius had been guests at his Tusculan villa engaged with the master in long-interrupted oratorical exercises (‘intermissis exercitationibus’, Fam. 9. 18. 3) for some time during the month, whence he ‘sent’ them to greet Caesar and put in a word for him with their familiaris.
Vindolanda 1985: the New Writing-Tablets
Authors: Bowman Alan K. , Thomas J. David
Published: May 2006

Excavations were resumed at Vindolanda in the pre-Hadrianic section of the site in the summer of 1985. The prediction that the area was likely to contain further deposits of writing-tablets was strikingly confirmed and it can now be confidently stated that the publication, by the present authors, of the tablets discovered in 1973-5 was only the first instalment. It is as yet unclear when the full publication of the new finds can be expected or what precise form it will take. This is the justification, if any is needed, for presenting this summary account of the 1985 material. The inventory numbers under which the new tablets are catalogued run to almost 340; many contain several fragments; most, but not all, have at least traces of writing. It is at present envisaged that three more seasons of excavation will be undertaken in 1986, 1987 and 1988, investigating an area which extends some 15–20 metres to the north of the present terminus. There is some reason to think that the writing-tablet deposit may cover the whole or a substantial part of this area and it is therefore possible that the subsequent seasons may yield as many tablets as that of 1985.
The Lex Irnitana: a New Copy of the Flavian Municipal Law
Authors: González Julián
Published: May 2006

In the spring of 1981, on a hill called Molino del Postero, in undulating territory 5 km south-west of El Saucejo and 3 km north-east of Algámitas, in the province of Seville, a group of men looking for ancient coins and armed with metal-detectors discovered six bronze tablets and some small fragments of other tablets, containing part of the municipal law of a hitherto unknown town, the Municipium Flavium Irnitanum. Although the name of the town was probably Irni, since ancient place-names in Spain ending with -i are very common, such as Astigi, Ucubi, Tucci, Iptuci etc, a name such as Irnium remains possible.
Shaping the Rural Environment: Surveyors in Ancient Rome
Authors: Campbell Brian
Published: May 2006

Horace, reflecting on his relationship with Maecenas and the top men or ‘gods’ in Rome, complained that passers-by asked him questions about affairs of state, expecting him to be privy to the deliberations of the great. One question was: ‘What about the land allocations (praedia) that the emperor promised to the soldiers? Will they be on the three-cornered island (Sicily) or on Italian soil? When I swear that I know nothing about it they are amazed at me as the only mortal who knows how to keep a vital unfathomable secret’ (Serm. 11.6.51–8).

The poet strikingly illustrates how land distribution was a familiar and important aspect of Roman life and of great interest not only to soldiers but also to many citizens, perhaps partly because of their apprehension about expropriations, which had created great anguish during the civil wars. We see too how the whole business was viewed as under the personal direction of the emperor and his entourage, and incidentally how difficult it was for people to find out about decisions taken behind the scenes.
The Amount of Wages Paid to the Quarry-Workers at Mons Claudianus
Authors: Cuvigny Hélène
Published: May 2006

O.Claud, inv. 4751; 14.5 × 10.5 cm; A.D. 136–146.

Instructions from Pachoumis for the month of Thoth. Wages: 47 drachmae. Deductions: advance 20 drachmae (you get a receipt); 3 cotylae of oil; I mation of lentils; I mation of onions; I amphora of wine; symbole: 3 drachmae. My wheat to the desert. Dapane: 4 obols. The rest to the desert.

Pachoumis worked in the imperial quarries at Mons Claudianus. He was either a quarryman, a stone-mason, or a smith. He belonged to the group of workers called pagani.
A Military Strength Report from Vindolanda
Authors: Bowman Alan K. , Thomas J. David
Published: May 2006

The text here published has a claim to be the most important military document ever discovered in Britain. It was found during the 1988 season of excavation of the pre-Hadrianic area at Vindolanda. The archaeological context in which it was found is the earliest level in which tablets are present; it was located in the ditch by the west wall of the earliest phase of the fort, beneath four successive buildings of the later periods. The ditch appears to have been filled by A.D. 90/92 and the tablet is therefore most probably to be dated c. A.D. 90 (unless it was part of a deposit of rubbish put into the Period I ditch by the builders of the Period II structures). It would thus reflect the situation at Vindolanda only a few years after Agricola's departure from Britain, presumably just before the enlargement of the fort which made this area the site of the praetorium in the southern sector of the central range of buildings. The small amount of relevant evidence from other writing-tablets confuses rather than clarifies the picture. The commanding officer named in the strength report is Iulius Verecundus and there are five or six other texts associated with a man named Verecundus who may or may not be the same person (in only one case is the gentilicium (Iulius) preserved).
The Purpose of the Lex Calpurnia de repetundis
Authors: Richardson J. S.
Published: May 2006

In 149 B.C. the tribune L. Calpurnius Piso proposed a law which was to have momentous consequences for the legal, political and administrative history of the Roman republic. It was his lex de rebus repetundis which first established the practice of trial before a quaestio perpetua, a jury, drawn from a panel of jurors who had always to be available, which became the standard procedure for criminal cases in the late republic. For over fifty years, from the first tribunate of C. Gracchus in 123 to the passing of the Lex Aurelia in 70, such courts were to provide a political storm-centre as various political figures attempted for their own ends to alter the criteria for the selection of the iudices who manned the juries. Moreover, from the late second century B.C. down to at least the second century A.D., the process de repetundis formed the most important means that was available to Rome's provincial subjects of bringing an action against a provincial governor for maladministration.
The Present State of the Corpus Signorum Imperii Romani
Authors: Harrison R. M.
Published: May 2006

The scheme for an international Corpus of Sculpture of the Roman World (Corpus Signorum Imperii Romani) was launched in Paris in 1963. It was from the outset accepted by an encouragingly large number of countries, each of which is to contribute comprehensive and fully illustrated catalogues of Roman sculpture. These are to be in the form of regional fascicules, and each country is responsible for its own publication. A central committee, under the auspices of the International Association for Classical Archaeology, has laid down general rules governing the scope, format, and arrangement. Its present chairman is Prof. F. Braemer. All stone sculpture is included and large bronzes, but not figurines, whether of bronze or clay; unfigured architectural elements are omitted. The principle of some flexibility for each country in its interpretation of the rules is recognized.
Paternal Power in Late Antiquity
Authors: Arjava Antti
Published: May 2006

One of the most peculiar features of Roman law was the father's dominant position. In theory, he exercised an almost absolute authority,patria potestas, over his descendants until his own death. The uniqueness of their family system did not escape the Romans themselves. In his mid-second-century legal textbook Gaius explained:

Item in potestate nostra sunt liberi nostri quos iustis nuptiis procreavimus. Quod ius proprium civium Romanorum est; fere enim nulli alii sunt homines, qui talem in filios suos habent potestatem, qualem nos habemus. Idque divus Hadrianus edicto, quod proposuit de his, qui sibi liberisque suis ab eo civitatem Romanam petebant, significavit. Nec me praeterit Galatarum gentem credere in potestate parentum liberos esse. (Inst.1.55)

Again, we have in our power our children, the offspring of a Roman law marriage. This right is one which only Roman citizens have; there are virtually no other peoples who have such power over their sons as we have over ours. This was made known by the emperor Hadrian in an edict which he issued concerning those who applied to him for Roman citizenship for themselves and their children. I have not forgotten that the Galatians believe that children are in the power of their parents. (Translated by W. M. Gordon and O. F. Robinson, The Institutes of Gaius (1988))

This account immediately raises at least one fundamental question: Ifpatria potestaswas a distinctive feature of Roman society, how did the other peoples of the Empire react to it after the universal grant of the Roman citizenship in A.D. 212?
Roman Military Pay from Caesar to Diocletian
Authors: Alston R.
Published: May 2006

In a recent issue of this Journal, M. Alexander Speidel published a new document concerning Roman military pay, a receipt from Vindonissa dating to A.D. 38. This document, he claims, provides the missing link, which allows him to present a table of pay rates for legionaries and auxiliaries from Caesar to Diocletian and prove finally the proposition resurrected by M. P. Speidel that soldiers of the auxiliary cohorts were paid five sixths of the annual pay of legionaries. From a re-examination of the texts and documents traditionally used as evidence for the pay rates of the Roman military, I conclude that, although we can establish the rates of legionary infantry pay from the date of the increase under Caesar until A.D. 197, we have little evidence for legionary pay rates in the third century and, since most of the documents provide us with figures which are unknown proportions of the annual pay of the soldiers concerned, the evidence for auxiliary pay is not sufficient to allow the calculation of exact pay rates for any period. There are, therefore, no grounds for believing either the five-sixths theory as elaborated by M. Alexander Speidel or, indeed, any of the many other theories that have been proposed. Nevertheless, the documentation can be interpreted to establish likely minimum figures for auxiliary pay rates in the first century A.D. This interpretation of the documents suggests that there was, in fact, no difference between the rates of pay of auxiliary and legionary infantry and the cavalry of the legions and alae, a controversial conclusion that has previously been avoided for reasons central to much of Roman imperial military historiography.
Archisynagogoi: Office, Title and Social Status in the Greco-Jewish Synagogue
Authors: Rajak Tessa , Noy David
Published: May 2006

The cities of the Roman Empire were, on the whole, plural societies, which had in them significant sub-groups, ethnic, religious, or, indeed, both together — for the two categories were still only sometimes distinguishable. Such an environment carries many resonances for us and it is surprising to realize its neglect as a subject for study. The classical Greek polis had been a theoretically homogeneous institution of look-alike citizens, with outsiders excluded or enslaved. The notional Roman approach was, in the early days, to deal with outsiders by assimilating them. When we look at the cities of the Hellenistic kingdoms, we observe that they often did consist of several racial elements, though how these were accommodated has been for some time an issue for debate, and this remains an open question. But beyond that, our concern seems to stop.
The Anatomy of Rome from Capitol to Cloaca
Authors: Gowers Emily
Published: May 2006

‘Can I fix Rome for you on this poor sheet of paper?’ Something like Petrarch's lament must precede any attempt to sum up Rome in words; only an Atlas could do justice to the vast weight of such a city. But there is at least one compensation: we are describing a city that we all know, or think we know. For Montaigne, it was the first city that entered his consciousness: ‘I have had knowledge of the affairs of Rome long time before I had knowledge of those of my own house. I knew the Capitol and its platform before I knew Louvre, the palace of our kings in Paris; the river Tiber before Seine’. And for him it remained the ultimate city: ‘And therefore can I not look so often into the situation of their streets and houses, and those wondrous-strange ruins, that may be said to reach down to the Antipodes, but so often must I amuse myself on them. Is it nature or by the error of fantasy, that the seeing of places we know to have been frequented or inhabited by men whose memory is esteemed or mentioned in stories doth in some sort move and stir us up as much or more than the hearing of their noble deeds or reading of their compositions?’ For Freud, the city provided the best analogy for the human consciousness itself, an overlayering of past and present events, all capable of being experienced simultaneously. He asks us, in a flight of fancy, to ‘suppose that Rome is not a human habitation but a psychical entity with a similarly long and copious past — an entity, that is to say, in which nothing that has once come into being will have passed away and all the earlier phases of development continue to exist alongside the latest one’.
Cult and Personality in Horace
Authors: Griffin Jasper
Published: May 2006

It was the main contention of a book published a few years ago that the material and the attitudes which we find in the works of the Augustan poets are intimately connected with the realities of Roman life. The poems are not to be amputated, as too often happens, from the society in which they were produced and enjoyed. Literature is not a balloon floating in the air, but a plant with its roots firmly fixed in the earth. It was argued there that ‘the same material can be observed at different levels of stylisation in different poetical contexts’, and that we can learn a great deal about the poems and their authors by following the ways in which they employ and vary the same subject matter. That was illustrated in connection with such elements of the life of pleasure as drinking and singing, bathing and nakedness; and also with the topic of death. Those ideas are carried further in this paper, which extends that approach to another area: that of religious cult. It concentrates on the poet Horace and aims to show how he uses and varies the theme of religious festivals and ceremonies, and what contrasts are offered by the work of Propertius and Ovid.
Apamea in Syria in the Second and Third Centuries A.D.
Authors: Balty Jean Ch.
Published: May 2006

‘While Trajan was tarrying in Antioch’—it was in the winter of A.D. 115, after the conquest of Armenia and the annexation of Mesopotamia, before setting out for the Tigris, Ctesiphon and the Persian Gulf—‘a terrible earthquake occurred; many cities suffered injury, but Antioch was the most unfortunate of all’.
Caesar and the Mutiny of 47 B.C.
Authors: Chrissanthos Stefan G.
Published: May 2006

In 47 B.C., despite victory at the Battle of Pharsalus and the subsequent death of Cn. Pompeius Magnus, the Civil War continued for C. Julius Caesar. He faced hostile Roman armies in Spain and North Africa. Rumours circulated that the African army was preparing to invade Italy. Order was kept in Rome only through the force employed by Caesar's lieutenant M. Antonius. Contemporaries certainly did not believe Caesar's victory was a foregone conclusion. In the midst of these crises, Caesar faced a mutiny amongst his veteran Gallic legions billeted in Campania. These troops refused his orders to move from Italy to Africa to fight the Pompeian army that had gathered there. Instead they marched to Rome to demand back pay, discharge, and promised bonuses of money and land. Caesar's power, and his very survival, were hanging in the balance.
Dionysius, Lucian, and the Prejudice against Rhetoric in History
Authors: Fox Matthew
Published: May 2006

This article will explore the familiar polarity between history and rhetoric by comparing two rather different accounts from the early Empire. The treatment of history in the rhetorical theory of Dionysius of Halicarnassus and the curious work of historical theory by Lucian will be contrasted to open up some new areas of debate. Although the relationship between rhetoric and history has been the subject of numerous studies, none have given much weight to one central aspect of the juxtaposition: the dialectic between rhetoric and aesthetics, and the place of that dialectic in ancient historical theory. Since scholars generally agree that ancient historiography exists, like all other forms of ancient writing, within a culture where rhetoric provides all educational resources, and thus acts as a substitute for aesthetic theory, this is not in itself surprising. A close reading of these particular texts, however, produces a more differentiated view of what rhetoric might mean to those seeking to define historiography. Dionysius and Lucian are both concerned with the relationship between rhetoric and wider issues of moral and social education. But because rhetoric is not philosophy, but rather a system concerned above all with the formal qualities of spoken utterance, these moral issues become closely implicated with aesthetic concerns. More startlingly, they do so in each author in a significantly different way. The interweaving of moral and aesthetic may at first sight seem strange; we are accustomed to think of the aesthetic and the moral as operating in rather different spheres, at least when it comes to literary production.
Association between cacti and nurse perennials in a heterogeneous tropical dry forest in northwestern Mexico
Authors: Arriaga Laura , Maya Yolanda , Diaz Sara , Cancino Jorge
Published: May 2006

Abstract. The Sierra de La Laguna, Baja California Sur harbors the only tropical dry forest of the Peninsula. An inventory of the perennial plants was carried out at the eastern part of this mountain range. Plant spatial distribution was analyzed considering the species composition and vertical stratification of plant clusters in a study plot of 2 500 m2. A plant cluster was defined as a group of at least three individuals with a maximum distance between plants of 1 m. Soil physical‐chemical characteristics and soil surface temperatures were compared between shade and sun conditions.

The tropical dry forest of Baja California Sur presents a highly aggregated pattern of species distribution. Most of the perennial plants grow clumped, yet not all of the six cactus species recorded were significantly associated with them. Pattern analysis revealed that only Stenocereus thurberii and Ferocactus peninsulae were aggregated and associated to perennial plants. There is no replacement pattern between cacti and perennial plants. Nutrient content, including soil fertility, between shade and sun conditions does not seem to explain the patchy distribution of perennial plants, while the differences in solar radiation between these conditions appear to be restrictive and determinant of this spatial pattern of distribution.
Heat budget and fire behaviour associated with the opening of serotinous cones in two Pinus species
Authors: Johnson E. A. , Gutsell S. L.
Published: May 2006

Abstract. We have constructed a heat budget for the transient heating of cones showing that there is a logarithmic relationship between the time (sec) to serotinous cone opening, releasing viable seeds, or cone ignition and temperature (°K) in the convective column above a fire. The rate of opening at a given temperature is controlled by a thermal time constant which is the ratio of the thermal resistance of a cone to convection, to the heating capacity of a cone by conduction. The observed times to cone opening and ignition fit the logarithmic relationship as predicted by the heat budget model. In order to understand the fire behaviour that results in cone opening and ignition, we changed the variables of temperature and time to the fire behaviour variables of fire intensity (kW/m) and fire rate of spread (m/min). Cones borne high in the canopy open in fires with low rates of spread and high fuel consumption, where intensity = rate of spread × fuel consumption × heat of ignition, but not when the rate of spread is high and fuel consumption low.
Phytosociology and ecology of a humid Afromontane forest on the Central Plateau of Ethiopia
Authors: Bekele Tamrat
Published: May 2006

Abstract. This paper describes an analysis of the floristic composition and ecological relationships of the Jibat forest, a large remnant humid forest in western Shewa, Ethiopia. The description was based on cover‐abundance data for both woody and understorey species. The environmental analysis included altitude, slope, aspect, and physical and chemical soil properties. The application of classification and ordination methods resulted in the recognition of eight community types, which could be arranged along an altitudinal gradient. Organic matter, cation exchange capacity, phosphorus, and silt are positively correlated, while clay, electrical conductance and magnesium are negatively correlated with altitude. A clearer result was obtained when Canonical Correspondence Analysis was applied only to the woody species composition.
BOOK REVIEWS
Authors: Liebman Matt
Published: May 2006

Book reviewed in this issue.

Vandermeer, J. 1989. The Ecology of Intercropping. 237 pp. Cambridge University Press, Cambridge, U. K. ISBN 0–521–34592–8. Price: USD 59.50.
The robustness of Correspondence, Detrended Correspondence, and TWINSPAN Analysis
Authors: van Groenewoud H.
Published: May 2006

Abstract. Simulated vegetation data of known structure and varying complexity were analyzed with Correspondence Analysis (CA), Detrended Correspondence Analysis (DCA), and a polythetic divisive method of classification as incorporated in the computer program TWINSPAN. The CA and DCA axes were statistically compared with the original gradients. In the case of TWINSPAN, the results were visually evaluated. The analyses showed that both CA and DCA will recover the first vegetation gradient in an acceptable manner only if the variation in the vegetation due to second or higher order gradients is small. Second gradients were never recovered in a meaningful manner. The sample points along these axes were so far displaced from their original positions along the gradients that the axes could not be used to represent the gradients. In particular, when the two gradients have the same length, CA and DCA gave very poor results for both the first and the second axes. This is thought to be one of the main reasons why TWINSPAN does not perform well, especially after the first division.
A morphological classification of plants, with special reference to the New Zealand alpine flora
Authors: Halloy S.
Published: May 2006

Abstract. A plant is a complex of integrated systems (leaves, leaf groups, stems, roots, inflorescences), coexisting side by side or superimposed on each other to produce the life form (orphysiognomy) of the individual. The classic Raunkiaer classification based fundamentally on one character (apex position) is insufficient for the purpose of a functional classification.

Five keys are given to determine the categories of:

the plant silhouette or general shape resulting from a combination of other systems, with 11 categories proposed;

the leaf group, with 14 categories;

the stem, with 27 categories;

the root, with 5 categories; and

the inflorescence, with 3 categories.

Each plant can be named according to the category or model of each of the five different systems that they most resemble, or by using only the name(s) of systems which are more conspicuous than others. Characters are selected primarily for their influence on form and secondarily on size.

This scheme allows for detailed studies of a flora in terms of morphological characteristics (alone or in systems), expressed as frequency of occurrence of each character in the flora. Characters can be analysed separately (e.g. entire margined leaves), as a combination of characters (e.g. leaf groups) or as a combination of systems (e.g. rosettes without stems). Thus correlations between environmental variables and plants canbe made with more precision than in previous classification schemes.

The classification also serves as the framework for including additional morphological data and incorporating new models.

The New Zealand alpine flora is used as a test case and to exemplify the classification.
Distribution of submerged macrophytes in the Camargue in relation to environmental factors
Authors: Grillas Patrick
Published: May 2006

Abstract. The species composition of stands of submerged macrophytes was studied in relation to the main environmental factors in oligohaline wetlands of the Camargue, southern France. Correlations were sought between the environmental factors and the abundance of the different species using canonical analysis. 24 species of submerged macrophytes, including 10 species of Charophyta, were recorded in the 60 sites studied. The hydrological regime and the salinity appeared to be the main factors controlling the abundance of the different species. This is related to the management of the marshes in the Camargue, which is carried out using these two controlling factors, particularly the hydrological regime, and also includes the destruction of emergent vegetation, mechanically or by grazing.

The bivariate ecological amplitude of the individual species was calculated from field data along the gradients of flooding duration and conductivity of the water. My‐riophyllum spicatum, Potamogetón pectinatus and Ruppia cirrhosa dominate permanent marshes along the conductivity gradient. In temporary marshes, all having a low conductivity, Zannichellia pedunculata, Ranunculus baudotii, Chara áspera and Callitriche truncata dominate.
Influence of colonizing shrubs on species‐area relationships in alvar plant communities
Authors: Rejmének Marcel , Rosén Ejvind
Published: May 2006

Abstract. In herbaceous plant communities of Stora Alvaret (the Great Alvar), Öland, Sweden, we studied the dependence of species‐area relationships on the canopy cover of the colonizing shrubs Juniperus communis and Potentilla fruticosa. A series of plots 0.25 ‐ 256 m2 in area were sampled in communities with varying canopy cover of Juniperus or Potentilla. Species number ‐ log (area) regressions always fitted data better than log (species number) ‐ log (area) regressions. The number of species declines more dramatically with increasing Potentilla cover than with increasing Juniperus cover. The total species number in large Juniperus plots follows a unimodal curve with a peak at about 75% shrub cover. The alvar (limestone grassland) species number in plots of all sizes declines monotonically with Juniperus cover following the regression equation S = 31.09 + 10.75 log A ‐ 0.0025 P2, where A is area and P is percentage Juniperus cover. There is a monotonic decline of species number with increasing shrub cover in Potentilla plots of all sizes. The species richness in plots with Potentilla was fitted by the regression equation S = 16.48+ 14.91 log A‐0.131 P‐0.00104 P2 log A, where P is% Potentilla cover. A faster initial decline of species number with Potentilla colonization is apparently caused by its preferential establisment in species‐rich, elevated microsites.
Root length/leaf area ratios of chalk grassland perennials and their importance for competitive interactions
Authors: Mortimer Simon R.
Published: May 2006

Abstract. The use of root / shoot ratios to describe allocation of dry weight to structures for capturing soil resources and light is limited due to other functions of the root and shoot such as support and storage. The ratio of fine‐root length to leaf area (RLA) provides a better expression of the relative sizes of above‐and below‐ground exchange surfaces. Dry matter partitioning, leaf area and root lengths were determined for five species of chalk grassland perennial (Carex flacca, Cirsium acaule, Festuca ovina, Leontodon hispidus and Scabiosa columbaria) by extraction of soil cores from an intact sward. The forb species had a greater proportion of their dry matter below‐ground. Interspecific variation in values of RLA was considerable, mean values ranging from 137 m/m2 in Cirsium acaule to ca. 27 000 m/m2 for Festuca ovina. The implications of this interspecific variation in RLA for the competitive interactions in infertile calcareous grasslands are discussed in relation to phenology and internal nutrient cycling.
Patterns of growth, mortality and biomass change in a coastal Picea sitchensis ‐ Tsuga heterophylla forest
Authors: Greene S. E. , Harcombe P. A. , Harmon M. E. , Spycher G.
Published: May 2006

Abstract. Ten years (1979‐1989) of growth and mortality were determined in a 130‐yr old stand on the Oregon coast based on periodic remeasurements in 441000 m2 plots. Western hemlock (Tsuga heterophylla) constituted 90 % of the individuals and 57 % of the biomass. Wind is a major form of disturbance in this area, creating both small discrete and large diffuse disturbance patches; wind therefore has a direct effect on the location and extent of regeneration. Rates of tree mortality were high for this coastal stand (2.8 %/yr), especially compared to similar‐aged stands in the western and eastern Cascade Ranges. Though low in absolute density, Sitka spruce (Picea sitchensis) persisted in competition with the more tolerant western hemlock. Net production of bole biomass (4.9 Mg ha‐1 yr‐1) did not equal mortality (8.7 Mg ha‐1 yr‐1), and total biomass declined over the 10‐yr measurement period from 499 to 460 Mg/ha; this trend may have begun as early as the mid‐1950's at a peak biomass of about 600 Mg/ha. The decline may have been due to a positive feedback in which new gaps and enlarging gap perimeters exposed more and more trees to potential wind damage.
Patterns of reproductive effort with time since last fire in Florida scrub plants
Authors: Ostertag Rebecca , Menges Eric S.
Published: May 2006

Abstract. In periodically burned ecosystems, fire frequency may be an important selective pressure for the evolution of plant reproductive allocation patterns. We evaluated this hypothesis for Florida (USA) scrub plants by developing three models of reproductive effort with time since last fire given assumptions concerning seed dormancy and seedling establishment. We then examined reproductive effort of five woody, resprouting shrubs at sites representing nine times since last fire (ranging from 0–64 yr). All species showed significant patterns with time since fire in percentage of stems reproductive and fruit production. Stems of all species needed to attain a minimum size before flowering. Four species had the greatest level of reproductive effort (fruit biomass/above‐ground biomass) within 5 yr post‐fire and best fit the Early Peak Model of reproductive effort (i.e. between‐fire seedling recruitment or seed dormancy). A fifth species best fit the Broad Peak Model (i.e. immediate post‐fire seedling establishment), peaking in reproductive effort at 7 yr post‐fire. Both of these models are based on somewhat variable fire‐return intervals, suggesting that the frequency of scrub fires may have been too unpredictable to select for reproductive allocation patterns precisely reflecting particular fire‐return intervals. Early peaks in post‐fire reproductive effort may be a bet‐hedging strategy to allow for greater chances of seedling establishment and survival.
How environmental and disturbance factors influence species composition in temperate Australian grasslands
Authors: McIntyre S. , Lavorel S.
Published: May 2006

Abstract. A distinctive feature of Australian vegetational history is the abruptness of change since European settlement, involving the influx of exotic species and the imposition of exogenous disturbances which are novel in both intensity and character. This can produce two sources of habitat variability: the natural patterns arising from environmental variation, as well as an overlying effect of disturbance. The relative importance of these two types of variables were compared in temperate herbaceous vegetation. Canonical Correspondence Analysis showed that environment and disturbance had similar contributions to floristic variability. Individually, lithology, altitude and soil disturbance were the strongest variables while slope position, grazing and water enrichment were slightly less important.

Despite generally low levels of site specificity, groups of species associated with lithology, slope position, altitude and different disturbance regimes were identified. Exotic species were associated with higher levels of disturbance, but showed levels of environmental specialization similar to the native component.

Through combination of this analysis with a previous analysis of species richness for the same data set, it became evident that environmental variation mostly resulted in species substitutions while disturbances led to losses of species, with partial replacement by exotics.

Synthesizing these results, we identified three broad groups in relation to tolerance of levels of exogenous disturbance: (1) intolerant species ‐ native taxa intolerant of severe disturbances and constituting the species ‐ rich component of the vegetation; (2) tolerant species ‐ exotic and native taxa occurring at both disturbed and undisturbed habitats and (3) disturbance specialists ‐ predominantly exotic species, correlated with high levels of disturbance.
Revegetation of harvested peat surfaces in relation to substrate quality
Authors: Salonen V.
Published: May 2006

Abstract. The relationship between substrate quality and pattern of revegetation of harvested peat surfaces was studied by means of a survey and a field experiment examining influences of modest NPK‐fertilization on plant colonization of an initially bare peat surface. The harvested peat surfaces varied a great deal in their chemical and physical characteristics and the sites differed in revegetation pattern. Early successional vegetation was dominated by perennial species native to nutrient‐poor habitats on all sites. Soluble phosphorus and ash content, mean particle size of surface peat, and thickness of peat layer had the strongest influence in a CCA‐ordination of species. The species composition depended on the amount and form of soluble nitrogen in the surface peat. Sites with a high content of phosphorus and ammonium nitrogen, and with a thick peat layer were usually densely revegetated by Eriophorum vaginatum alone, while sites characterized by thin peat layers associated with a high ash content, large particle size and a high content of nitrate nitrogen were mainly dominated by different grass and weed species. Deschampsia cespitosa clearly favoured sites with a high potassium content and small particle sizes of the peat.

The importance of nutrient availability for the rate and pattern of colonization was also demonstrated by the field experiment. Application of 20 g/m2 of NPK‐fertilizer resulted in a significant increase in the number of established plant individuals and marked differences in species composition compared to unfertilized plots.
Effects of removal of organic matter on the productivity of heathlands
Authors: Diemont W.H.
Published: May 2006

Abstract. Effects of milling, mowing and sod cutting on productivity in a Deschampsia grass heath and a Molinia‐Deschampsia grass heath were studied from 1977 to 1986. The sum of above‐ground biomass, litter and accumulated humified matter (TOM) in both types was ca. 70 ton/ha and the primary productivity 3–5 ton ha‐1yr‐1. Mulching did not affect the annual production. Sod cutting reduced the productivity to 1–2 ton ha‐1yr‐1; on the Molinia‐Deschampsia site this reduction lasted for at least a decade, while the Deschampsia heath started to recover from sod cutting soon and increased in productivity again. Annual mowing both with and without removal of hay reduced the production as well, particularly on the Molinia‐Deschampsia heath. Lower production was either the result of phosphorus depletion ‐ Molinia‐Deschampsia site ‐ or nitrogen depletion ‐ Deschampsia site. In the mowing treatments there was also a depletion of carbohydrate reserves.
BOOK REVIEWS
Authors: Keating Philip L.
Published: May 2006

Abstract. Barota, J. 1991. Tropical Forests: Some African and Asian Case Studies of Composition and Structure. xii + 274 pp. Elsevier Science Publishing, New York. ISBN 0‐444‐98768‐1. Price: USD 120.‐.
BOOK REVIEWS
Authors: Goldblum David
Published: May 2006

Abstract. Caldwell, M.M. & Pearcy, P.W. (eds.) 1994. Exploitation of environmental heterogeneity by plants: ecophysiological processes above‐and belowground. xvii + 429 pp. Academic Press, New York. ISBN 0‐12‐155070‐2. Price: USD 89.‐.
Regression Tree Analysis of satellite and terrain data to guide vegetation sampling and surveys
Authors: Michaelsen Joel , Schimel David S. , Friedl Mark A. , Davis Frank W. , Dubayah Ralph C.
Published: May 2006

Abstract. Monitoring of regional vegetation and surface biophysical properties is tightly constrained by both the quantity and quality of ground data. Stratified sampling is often used to increase sampling efficiency, but its effectiveness hinges on appropriate classification of the land surface. A good classification must be sufficiently detailed to include the important sources of spatial variability, but at the same time it should be as parsimonious as possible to conserve scarce and expensive degrees of freedom in ground data. As part of the First ISLSCP (International Satellite Land Surface Climatology Program) Field Experiment (FIFE), we used Regression Tree Analysis to derive an ecological classification of a tall grass prairie landscape. The classification is derived from digital terrain, land use, and land cover data and is based on their association with spectral vegetation indices calculated from single‐date and multi‐temporal satellite imagery. The regression tree analysis produced a site stratification that is similar to the a priori scheme actually used in FIFE, but is simpler and considerably more effective in reducing sample variance in surface measurements of variables such as biomass, soil moisture and Bowen Ratio. More generally, regression tree analysis is a useful technique for identifying and estimating complex hierarchical relationships in multivariate data sets.
Influence of grazing and soil conditions on secondary savanna vegetation in India
Authors: Pandey C. B. , Singh J. S.
Published: May 2006

Abstract. Savanna vegetation and pertinent soil features were studied on 43 sites in a dry tropical forest region of India. Grazing intensity ranged from 0.68 to 0.98. Soil moisture was positively related to the proportion of fine soil particles (< 0.1 mm), and the latter decreased while the proportion of coarse particles (2.0‐0.5 mm) increased with increasing grazing intensity. Canopy biomass ranged from 28 to 104 g/m2 in grazed communities and from 230 to 337 g /m2 in ungrazed communities and was positively related to vegetation cover which ranged between 30–72 % in grazed and 68 ‐ 91 % in ungrazed communities. Vegetation cover was negatively related to grazing intensity. Species richness and diversity were highest at low grazing intensity. Using community coefficients and Detrended Correspondence Analysis, the grazed stands were clustered into six and the ungrazed ones into three communities.

The grazed communities were recognised as degradation stages and the ungrazed ones as recovery stages. Only five grass species, in various combinations were able to dominate in one of the different stages. Evidently the harsh climatic conditions (high temperatures, high variability in rainfall and a long dry period) in the region permit only a few species already adapted to these conditions to participate in the succession.
Secondary succession in disturbed Pinus‐Quercus forests in the highlands of Chiapas, Mexico
Authors: González‐Espinosa Mario , Quintana‐Ascencio Pedro F. , Ramírez‐Marcial Neptalí , Gaytán‐Guzmán Patricia
Published: May 2006

We present floristic and structural data on serai plant communities (Old‐Field, Grassland, Shrubland, and Early Successional, Mid‐Successional, and Mature Forest) resulting from the current land use pattern in the Pinus‐Quercus forests in the highlands of Chiapas, Mexico. The number of species ranged from 24 in the Old‐Field stage up to 100 in the Mature Forest, and the shrub layer was richest in all the forested stands. An almost complete floristic replacement exists between the open and the forested communities. Quercus and Pinus dominate the canopy of old‐growth stands, but their recruitment does not occur or is very low in the shade. Vigorous seedlings and saplings of these species are found only in the open serai stages or in forest gaps. Demographic and phytosociological data are used to indicate the successional role of dominant species in the forested stages. Some implications of the regional land use patterns for conservation and succession are discussed.
Patterns of species richness among North Carolina hardwood forests: tests of two hypotheses
Authors: Palmer Michael W.
Published: May 2006

The number of species (species richness) and 13 soil variables were determined in 30 0.1 ha plots in the Duke Forest, Durham and Orange Counties, North Carolina, in order to test whether variability in species richness can be accounted for by the environmental variability hypothesis, or the sampling effect hypothesis. The environmental variability hypothesis predicts a positive correlation between the variance in factors which are ecologically important and species richness. However, the variabilities of environmental factors are unrelated to richness. The sampling effect hypothesis predicts that more rare species will be found in species‐rich sites. However, as richness increases, the number of species in all abundance classes increases. Both the environmental variability hypothesis and the sampling effect hypothesis are therefore unlikely to account for the substantial variability in species richness which exists in the Duke Forest.
The structure and dynamics of Abies magnifica forests in the southern Cascade Range, USA
Authors: Taylor Alan H. , Halpern Charles B.
Published: May 2006

Abies magnifica (Red fir) forests in the Cascade Range and Sierra Nevada of California are composed of groups, or patches, of even‐sized individuals that form structurally complex stands. Patches may be even‐aged, resulting from synchronous post‐disturbance establishment, or multi‐aged, reflecting continuous recruitment of seedlings moderately tolerant of shade. We analyze the population structure (i.e. age, size, and spatial patterning) of A magnifica, and associated A concolor, White fir, and reconstruct the disturbance history of two mature to old‐growth A. magnifica forests in order to determine the relationship between disturbance and forest structure.

Within both stands examined, the distributions of A. magnifica seedlings, saplings, and small understory trees were clumped, with clump sizes corresponding to the area of canopy gaps. Gaps were created by frequent wildfire (mean fire return interval of 41 yr) and by windstorms. Severe fire initiated mass establishment of Abies magnifica, whereas gaps created by windthrowreleasedalreadyestablishedindividuals. Lowinten‐sity fire stimulated little recruitment, but Red fir established continuously during fire‐free intervals. Thus, the complex age and structures of Red fir forests reflect both episodic and continuous recruitment, as determined by the type and severity of natural disturbance.
Recruitment pattern of Rhus integrifolia populations in periods between fire in chaparral
Authors: Lloret Francisco , Zedler Paul H.
Published: May 2006

Population structure, fruit production and dispersal, and recruitment of Rhus integrifolia, a gynodioecious sclerophy llous shrub living in coastal chaparral, were studied in two localities in southern California last burned 60 and 90 years ago. Though hermaphroditic plants produce some fruits, only the male‐sterile plants bore significant numbers. Among the sample plants, one individual accounted for 50% of the crop measured. Terrestrial animals, through the loss of some seeds taken for consumption, play a decisive role in the seed dispersal, promoting the establishment of seedlings outside the parent's canopy. Birds have not been demonstrated to contribute to long distance dispersal, but they are responsible for dropping 25% of the fruits collected below the R. integrifolia canopies, 36%) of which were completely destroyed. Allelopathic effects were not observed in laboratory assays, and germination is probably not influenced by the species beneath which seeds have been deposited. This pattern can explain the non‐aggregated distribution of individuals observed in the studied populations. We conclude that establishment of new individuals has been continuous at both localities and that the populations of R. integrifolia are increasing in these long unburned stands. This may be indicative of a successional trend in unburned chaparral and coastal scrub toward a sclerophy llous woodland.