bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vegetation patterns in heterogeneous landscapes: The importance of history and environment
Authors: Motzkin Glenn , Wilson Paul , Foster David R. , Allen Arthur 
Published: May 2006

Abstract. Throughout the eastern United States, plant species distributions and community patterns have developed in response to heterogeneous environmental conditions and a wide range of historical factors, including complex histories of natural and anthropogenic disturbance. Despite increased recognition of the importance of disturbance in determining forest composition and structure, few studies have assessed the relative influence of current environment and historical factors on modern vegetation, in part because detailed knowledge of prior disturbance is often lacking. In the present study, we investigate modern and historical factors that control vegetation patterns at Harvard Forest in central Massachusetts, USA. Similar to the forested uplands throughout the northeastern United States, the site is physiographically heterogeneous and has a long and complex history of natural and anthropogenic disturbance. However, data on forest composition and disturbance history collected over the past > 90 years allow us to evaluate the importance of historical factors rigorously, which is rarely possible on other sites.Soil analyses and historical sources document four categories of historical land use on areas that are all forested today: cultivated fields, improved pastures/mowings, unimproved pastures, and continuously forested woodlots. Ordination and logistic regressions indicate that although species have responded individualistically to a wide range of environmental and disturbance factors, many species are influenced by three factors: soil drainage, land use history, and C:N ratios. Few species vary in accordance with ionic gradients, damage from the 1938 hurricane, or a 1957 fire. Contrary to our expectation that the effects of disturbance will diminish over time, historical land use predicts 1992 vegetation composition better than 1937 composition, perhaps because historical woodlots have become increasingly differentiated from post‐agricultural stands through the 20th century.Interpretations of modern vegetation must consider the importance of historical factors in addition to current environmental conditions. However, because disturbances such as land use practices and wind damage are complex, it is often difficult to detect disturbance effects using multivariate approaches, even when the broad history of disturbance is known.
A fragmented landscape in northern Spain analyzed at different spatial scales: Implications for management
Authors: Rescia A.J. , Schmitz M.F. , Martin de Agar P. , de Pablo C.L. , Pineda F.D. 
Published: May 2006

Abstract. Changes in landscape pattern are analyzed through sampling plots of different size taken along a time series of aerial photographs at three scales of observation. The results indicate that variation in the landscape pattern shows a less pronounced change at the local scale than at larger scales and that appreciation of the structure of this landscape and description of its temporal variation are scale‐dependent.Analysis of the spatial complexity on different scales, measured by the C(s) index (Rescia et al. 1994), shows that the number of types of boundary between patches is the most important landscape component on all scales. Spatial complexity and the number of boundary types are related to woody plant diversity at a local scale.In the studied landscape, human activities on a local scale strongly influence the spatial configuration on a regional scale. This concerns territorial planning, the main problem of which is not found in selecting a correct observation scale, but in recognizing that the change under study occurs at various scales at the same time. This underlines the importance of analysing the landscape pattern at different scales with the design of plans and conservation programs in mind.
History of aPinus strobus‐dominated stand in northern New York
Authors: Kearsley Jennifer B. , Jackson Stephen T. 
Published: May 2006

Abstract.Pollen, plant macrofossils and charcoal from a small forest hollow were analyzed to determine the formation and dynamics of aPinus strobus‐dominatedforest stand on outwash soil in northern New York.P. strobus, Betula papyriferaandAbies balsameacolonized the upland surrounding the hollow following a major disturbance that occurred ca. 360 yr ago. Pre‐disturbance vegetation consisted of shade‐tolerantTsuga canadensis, Fagus grandifoliaandPicea ruhens. The size‐class distribution of modern vegetation suggests continuing recruitment ofA. balsameaandAcer rubrumat the site. The status ofP. strobusandB. papyriferain the stand is uncertain, but there is no evidence for recolonization ofT. canadensis, F. grandifoliaorP. rubens. Frequent windthrow has probably played a role in stand dynamics since ca. 310 yr BP due to the high wind‐susceptibility of overstory and understory tree taxa in the modern forest patch.Vegetation change that occurred following fire(s) ca. 310 yr BP was recorded by plant macrofossils but not by pollen, indicating that the pollen assemblage was insensitive to vegetation change within at least 30 m (and potentially 60 m) of the hollow. The apparent insensitivity of this small‐hollow pollen assemblage to local vegetation change may be related to the relatively large size of the hollow (75 m2) and/or to its close proximity to a 0.24 ha kettle pond.
Fine‐scale spatial population patterns and mobility of winter‐annual herbs in a dry grassland
Authors: Geißelbrecht‐Taferner Leonore , Geißelbrecht Jürgen , Mucina Ladislav 
Published: May 2006

Abstract. Winter annuals were mapped in a series of permanent plots located in gaps in an Austrian dry grassland over a period of 3 yr. Great differences in abundance were found among nine winter annuals — Arabis auriculata, Arenaria leptoclados, Cerastium glutinosum, Erophila spathulata, Holosteum umbellatum, Hornungia petraea, Saxifraga tridactylites, Thlaspi perfoliatum and Veronica praecox –‐ occurring in the gaps. The absolute frequency of species varied considerably from year to year, while their relative proportions remained nearly constant in the plots over the study period.High spatial dissociation (low level of spatial coincidence) between populations was observed; this was ascribed to boleochory, known to generate monospecific patches. No trend in self‐replacement of a species was found. This means that occupying a place in one year does not necessarily mean the same place will be occupied in following years. The probability of a species replacing another was found to be low. The space could be inhabited by any species or remain unoccupied. We suggest that the distribution patterns of species are controlled by dispersal and preference for microhabitats, at least at the scale of 20 cm × 20 cm. It was shown by a permutation method based on cumulative frequencies, that at smaller scales the habitat differentiation vanishes. We suggest that, up to a typical dispersal range of the winter annuals, the Carousel model can be applied due to the lack of coincidence (and presumably also interactions) of individuals. Nevertheless, time may eliminate the habitat differentiation at any scale. A design of an improved data‐sampling and a handling procedure was developed.
Herodotus and an Egyptian mirage: the genealogies of the Theban priests
Authors: Moyer Ian S. 
Published: May 2006

AbstractThis article re-evaluates the significance attributed to Hecataeus' encounter with the Theban priests described by Herodotus (2.143) by setting it against the evidence of Late Period Egyptian representations of the past. In the first part a critique is offered of various approaches Classicists have taken to this episode and its impact on Greek historiography. Classicists have generally imagined this as an encounter in which the young, dynamic and creative Greeks construct an image of the static, ossified and incredibly old culture of the Egyptians, a move which reveals deeper assumptions in the scholarly discourse on Greeks and ‘other’ cultures in the Mediterranean world. But the civilization that Herodotus confronted in his long excursus on Egypt was not an abstract, eternal Egypt. Rather, it was the Egypt of his own day, at a specific historical moment – a culture with a particular understanding of its own long history. The second part presents evidence of lengthy Late Period priestly genealogies, and more general archaizing tendencies. Remarkable examples survive of the sort of visual genealogy which would have impressed upon the travelling Greek historians the long continuum of the Egyptian past. These include statues with genealogical inscriptions and relief sculptures representing generations of priests succeeding to their fathers' office. These priestly evocations of a present firmly anchored in the Egyptian past are part of a wider pattern of cultivating links with the historical past in the Late Period of Egyptian history. Thus, it is not simply the marvel of a massive expanse of time which Herodotus encountered in Egypt, but a mediated cultural awareness of that time. The third part of the essay argues that Herodotus used this long human past presented by the Egyptian priests in order to criticize genealogical and mythical representations of the past and develop the notion of an historical past. On the basis of this example, the article concludes by urging a reconsideration of the scholarly paradigm for imagining the encounter between Greeks and ‘others’ in ethnographic discourse in order to recognize the agency of the Egyptian priests, and other non-Greek ‘informants’.
‘Eumelos’: a Corinthian epic cycle?
Authors: West M.L. 
Published: May 2006

AbstractThe author surveys the evidence for the three antiquarian epics commonly ascribed to Eumelos: theTitanomachy, KorinthiakaandEuropia. He elucidates and restores details, and endeavours to grasp their poets' objectives. He argues that they were products of the Corinthian-Sikyonian sphere, and to a degree mutually complementary; that they were composed between the late seventh and the late sixth century, considerably after the supposed lifetime of Eumelos; and that they were perhaps attributed to him for lack of other claimants, he being famous as the Corinthian poet of the Messenians' treasured Prosodion.
Wild and Cultivated Plants: a Note on the Peasant Economy of Roman Italy
Authors: Frayn Joan M. 
Published: May 2006

It has long been surmised that the Italian peasant in the Roman period could not have subsisted entirely upon his heredium, even when it was considerably more than two iugera. Juvenal was speaking for many of those before him, as well as for his own contemporaries, when he said of the traditional allocation:‘Nunc modus hic agri nostro non sufficit horto’.(Satires XIV, 172)Yet amid much speculation upon this point one aspect of the countryman's livelihood seems to have attracted little attention. In addition to any other resources he had the use of the wild plants of the extensive forests, the mountains, pastures and fallow fields. In general, food obtained from wild plants did not in Roman times, any more than it does in Italy today, take the place of grain, the staple article of diet. This may account for Pliny's statement in the Natural History XXI, 50 (86) where, after mentioning the large number of ‘herbae sponte nascentes’ used for food by other peoples, he writes: ‘In Italia paucissimas novimus, fraga, tamnum (wild vine), ruscum (butcher's broom), batim marinam (samphire), batim hortensiam, quam aliqui asparagum Gallicum vocant. …’ Such a remark seems astonishing in view of the numerous other examples Pliny himself has previously given, but its interpretation depends on the meaning to be assigned to the word cibus, as well as on the limiting effect of the phrase ‘herbae sponte nascentes’, which may not include all the plants we call ‘wild’. It is clear from the conclusion of the paragraph cited above, where ‘oblectamenta’ are compared with ‘cibos’, that cibi is being used here to mean ‘staple foods’.
Construction of Truth Predicates: Approximation Versus Revision
Authors: Barba Juan 
Published: May 2006

§1. Introduction. The problem raised by the liar paradox has long been an intriguing challenge for all those interested in the concept of truth. Many “solutions” have been proposed to solve or avoid the paradox, either prescribing some linguistical restriction, or giving up the classical true-false bivalence or assuming some kind of contextual dependence of truth, among other possibilities. We shall not discuss these different approaches to the subject in this paper, but we shall concentrate on a kind of formal construction which was originated by Kripke's paper “Outline of a theory of truth” [11] and which, in different forms, reappears in later papers by various authors.The main idea can be presented as follows: assume a first order language ℒ containing, among other unspecified symbols, a predicate symbolTintended to represent the truth predicate for ℒ. Assume, also, a fixed modelM= 〈D, I〉 (thebase model)whereDcontains all sentences of ℒ andIinterprets all non-logical symbols of ℒ exceptTin the usual way. In general,Dmight contain many objects other than sentences of ℒ but as that would raise the problem of the meaning of sentences in whichTis applied to one of these objects, we shall assume that this is not the case.
Step by Recursive Step: Church's Analysis of Effective Calculability
Authors: Sieg Wilfried 
Published: May 2006

AbstractAlonzo Church's mathematical work on computability and undecidability is well-known indeed, and we seem to have an excellent understanding of the context in which it arose. The approach Church took to the underlying conceptual issues, by contrast, is less well understood. Why, for example, was “Church's Thesis” put forward publicly only in April 1935, when it had been formulated already in February/March 1934? Why did Church choose to formulate it then in terms of Gödel's general recursiveness, not his own λ-definability as he had done in 1934? A number of letters were exchanged between Church and Paul Bernays during the period from December 1934 to August 1937; they throw light on critical developments in Princeton during that period and reveal novel aspects of Church's distinctive contribution to the analysis of the informal notion ofeffective calculability. In particular, they allow me to give informed, though still tentative answers to the questions I raised; the character of my answers is reflected by an alternative title for this paper,Why Church needed Gödel's recursiveness for his Thesis. In Section 5, I contrast Church's analysis with that of Alan Turing and explore, in the very last section, an analogy with Dedekind's investigation of continuity.
The Complexity of Propositional
Proofs
Authors: Urquhart Alasdair 
Published: May 2006

§1. Introduction.
The classical propositional calculus has an
undeserved reputation among logicians as being
essentially trivial. I hope to convince the reader
that it presents some of the most challenging and
intriguing problems in modern logic.
Although the problem of the complexity of
propositional proofs is very natural, it has been
investigated systematically only since the late
1960s. Interest in the problem arose from two
fields connected with computers, automated theorem
proving and computational complexity theory. The
earliest paper in the subject is a ground-breaking
article by Tseitin [62], the published version of
a talk given in 1966 at a Leningrad seminar. In
the three decades since that talk, substantial
progress has been made in determining the relative
complexity of proof systems, and in proving strong
lower bounds for some restricted proof systems.
However, major problems remain to challenge
researchers.
The present paper provides a survey of the
field, and of some of the techniques that have
proved successful in deriving lower bounds on the
complexity of proofs. A major area only touched
upon here is the proof theory of bounded
arithmetic and its relation to the complexity of
propositional proofs. The reader is referred to
the book by Buss [10] for background in bounded
arithmetic. The forthcoming book by Krajíček [40]
also gives a good introduction to bounded
arithmetic, as well as covering most of the basic
results in complexity of propositional
proofs.
Frege's Theorem and the Peano Postulates
Authors: Boolos George 
Published: May 2006

Two thoughts about the concept of number are incompatible: that any zero or more things have a (cardinal) number, and that any zero or more things have a number (if and) only if they are the members of some one set. It is Russell's paradox that shows the thoughts incompatible: the sets that are not members of themselves cannot be the members of any one set. The thought that any (zero or more) things have a number is Frege's; the thought that things have a number only if they are the members of a set may be Cantor's and is in any case a commonplace of the usual contemporary presentations of the set theory that originated with Cantor and has become ZFC.In recent years a number of authors have examined Frege's accounts of arithmetic with a view to extracting an interesting subtheory from Frege's formal system, whose inconsistency, as is well known, was demonstrated by Russell. These accounts are contained in Frege's formal treatise Grundgesetze der Arithmetik and his earlier exoteric book Die Grundlagen der Arithmetik. We may describe the two central results of the recent re-evaluation of his work in the following way: Let Frege arithmetic be the result of adjoining to full axiomatic second-order logic a suitable formalization of the statement that the Fs and the Gs have the same number if and only if the F sand the Gs are equinumerous.
Definability in the Recursively Enumerable Degrees
Authors: Nies André , Shore Richard A. , Slaman Theodore A. 
Published: May 2006

§1. Introduction. Natural sets that can be enumerated by a computable function (the recursively enumerable or r.e. sets) always seem to be either actually computable (recursive) or of the same complexity (with respect to Turing computability) as the Halting Problem, the complete r.e. set K. The obvious question, first posed in Post [1944] and since then called Post's Problem is then just whether there are r.e. sets which are neither computable nor complete, i.e., neither recursive nor of the same Turing degree as K?Let be the r.e. degrees, i.e., the r.e. sets modulo the equivalence relation of equicomputable with the partial order induced by Turing computability. This structure is a partial order (indeed, an uppersemilattice or usl)with least element 0, the degree (equivalence class) of the computable sets, and greatest element 1 or 0′, the degree of K. Post's problem then asks if there are any other elements of .The (positive) solution of Post's problem by Friedberg [1957] and Muchnik [1956] was followed by various algebraic or order theoretic results that were interpreted as saying that the structure was in some way well behaved:Theorem 1.1 (Embedding theorem; Muchnik [1958], Sacks [1963]). Every countable partial ordering or even uppersemilattice can be embedded into .Theorem 1.2 (Sacks Splitting Theorem [1963b]). For every nonrecursive r.e. degreeathere are r.e. degreesb, c < asuch thatb ∨ c = a.Theorem 1.3 (Sacks Density Theorem [1964]). For every pair of nonrecursive r.e. degreesa < bthere is an r.e. degreecsuch thata < c < b.
Monuments Relating to the Odyssey
Authors: Harrison Jane E. 
Published: May 2006

The object of this paper is to bring before the notice of the Society two unpublished vases relating to the escape of Odysseus and his comrades from the cave of Polyphemus. I shall endeavour to show:1st. The place that these two vases take in the history of vase painting, and certain special points of interest that attach to each of them.2nd. The relation of the designs on each of these vases to what I must call the ‘typography’ of the myth they represent.The two questions can in fact, as it is now well understood, scarcely be considered apart. To analyse a vase satisfactorily it is as necessary to consider its ‘typography,’ i.e. the exact form in which the legend is embodied, and the relation of that form to other forms preceding and following, as it is to discuss the actual technique of the design.
Judith and Holofernes
Authors: Hicks E. L. 
Published: May 2006

Among the books of the Apocrypha two portions stand out in strong relief as bearing the marks of genius. One is the Book of Wisdom, with its sustained moral fervour and luxuriant yet devout fancy; the other, the noble tragedy of the Book of Judith. The latter work has the further interest of presenting a curious literary problem. Is ‘Judith’ in any sense history, or even based on history, or is it mere romance ? Certainly the writer takes great liberties with facts. Time and place have to yield to the requirements of the narrative. Famous names are mingled together in extraordinary combinations. Nebuchadnezzar reigns over the Assyrians at Nineveh; and he reigns soon after the Jewish return from Captivity. An Arphaxad rules at Ecbatane as king of the Medes. An unknown high priest Joachim is supreme at Jerusalem. The book opens moreover with a catalogue of nations brought under this Nebuchadnezzar's sway; and the list teems with contradictions of history and even of probability.Learned opinion since the time of Grotius has been almost unanimous in pronouncing the book to be an historical romance, of the time of the Maccabees or later, wherein the writer sets forth in parable the hopes and fears of his nation, and stirs up his countrymen to heroic resistance to the oppressor.
An Inscription from Boeae
Authors: Gardner E. A. 
Published: May 2006

By the kindness of the Rev. H. J. Bidder, we are enabled to publish the following inscription, obtained by him from Βοιαὶ, the modern Neápolis, in Laconia. On a slab of white marble: size 11 in. x 7½ in. x ½ in., height of letters ⅜ in. The slab is broken away at the top and right side; more lines may be lost above; it is also broken across.The forms of the letters are somewhat inconsistent: thus we find l. 6, l. 11, Ρ twice, l. 15, beside the more characteristic forms. In l. 14, the fifth letter was first inscribed as Ν, by a mere inadvertence, and then corrected.Before the inscription was cut, faintly scratched lines were ruled to keep the letters in even rows.The date, from the forms of the letters, seems the second or third century of our era.