Search Results
You are looking at 11 - 19 of 19 items for
- Author or Editor: J. Podani x
- Refine by Access: All Content x
Cushing, J. M., R. F. Costantino, B. Dennis, R. A. Desharnais and S. H. Henson 2003. Chaos in Ecology. Experimental Nonlinear Dynamics (Theoretical Ecology Series). Academic Press, San Diego, xiv+225 pp. ISBN: 0-12-198876-7, hard cover, price: EUR 70.95, GBP 46.95, USD 68.95; E. van der Maarel (ed.) 2005. Vegetation Ecology. Blackwell, Oxford, x+395 pp. ISBN: 0-632-05761-0, paperback, price: USD 79.95, GBP 34.99; S. Mazzoleni, G. di Pasquale, M. Mulligan, P. di Martino and F. Rego (eds.) 2004. Recent Dynamics of the Mediterranean Vegetation and Landscape. Wiley, Chichester, xiv+306 pp. ISBN: 0-470-09369-2, hard cover, price: EUR 165; Forget, P. M., J. E. Lambert, P. E. Hulme and S. B. Vander Wall (eds) 2005. Seed Fate: Predation, Dispersal and Seedling Establishment. CABI Publishing, Wallingford, xv+410 pp. ISBN: 0-85199-806-2, hard cover, price: GBP 75.00, USD 140.00;
D. R. Nielsen and O. Wendroth. 2003. Spatial and Temporal Statistics. sampling Field Soil and their Vegetation. Castena Verlag, Reiskirchen, Germany. 416 pages, many illustrations. Paperback. ISBN 3-923381-46-6. Price: 50 EUR. Y. Gutterman. 2002. Survival Strategies of Annual Desert Plants (Adaptations of Desert Organisms). xx + 348 pages. Springer-Verlag, Belin, Heidelberg, New York. Hardcover. ISBN: 3-540-43172-1. Price: 159 EUR. P. S. Johnson, S. R. Shifley and R. Rogers. 2002. The Ecology and Silviculture of Oak. CABI Publishing, Wallingford, UK. 503 pages. Hardback. ISBN 0 85199 570 5. Price: 85 GBP, 149 USD. J. Belnap and O.L. Lange (eds.). 2003. Biological Soil Crusts: Structure, Function and Management (Ecological Studies, Vol. 150). 1st edition, revised 2nd printing. xviii + 503 pages. Springer-Verlag, Berlin, Heidelberg, New York. Softcover. ISBN: 3-540-43757-6. Price: 49.95 EUR.
Link distribution is an important architectural feature of ecological networks, since it is thought to influence community dynamics. Several attempts have been made in order to characterize the typical link distribution of food webs, but the number of webs studied thus far is low and their quality is unbalanced. Comparability is a rarely asked methodological question, and as far as we see only two data bases are available which allow reliable comparison of food webs: one for terrestrial, high resolution, host-parasitoid webs and another for highly aggregated, marine trophic networks. We present an analysis of a set of food webs belonging to the latter type, since the host-parasitoid networks are only subgraphs and therefore uninformative on the structure of the entire community. We address the following three questions: (1) how to characterize the link distribution of these small networks which cannot always be fitted statistically to well-known distributions (such as the exponential or the Poisson, etc.), (2) are these distributions of more or less similar shape or they belong to different „architectural classes”, and (3) if there are different classes, then what are their distinctive topological and biological properties. We suggest that link distribution of such small networks can be compared to each other by principal coordinates ordination and clustering. We conclude that (1) the webs can be categorized into two different classes, and (2) one of the classes contains significantly larger and topologically more heterogeneous webs for which net output of material is also of higher variance. We emphasize that link distribution is an interesting and important property not only in case of complex, speciose food webs, but also in highly aggregated, low-resolution webs.
A new approach to the measurement of functional diversity based on two-state nominal traits is developed from the florula diversity concept of P. Juhász-Nagy. For evaluating functional diversity of an assemblage, first a traits by species matrix is compiled. Various information theory functions are used to examine structural properties in this matrix, including the frequency distribution of trait combinations. The method is illustrated by actual examples, the first from plant communities prone to fire in Spain, and the second from running water invertebrate assemblages in Hungary. The results suggest that of the various functions used the standardized joint entropy, termed combinatorial functional evenness supplies most meaningful results. In plant communities, high fire recurrence decreased combinatorial functional evenness, while this measure for freshwater assemblages was uncorrelated with stream width and negatively correlated with the degree of human impact. Stream width is negatively correlated with the number of manifested functional combinations. In both case studies, combinatorial functional evenness has an inverse relationship to species richness — i.e., fewer species have a larger chance to produce equiprobable functional combinations.
K. J. Gaston and J. I. Spicer (eds.) 2004. Biodiversity: An Introduction (Second Edition). Blackwell Science Ltd, a Blackwell Publishing Company, Padstow, Cornwall, 191 pp. ISBN 1-4051-1857-1, paperback, price: USD 49.95, GBP 19.99; U. Sommer and B. Worm (eds.) 2002. Competition and Coexistence. Ecological Studies, Vol. 161. Springer Verlag, Berlin, 221 pp. (with 69 figures, 5 in color, and 2 tables). ISBN 3-540-43311-2, hardback, price: EUR 69.95; J. Kolbek, M. Šrùtek and E. O. Box. (eds.) 2003. Forest Vegetation of Northeast Asia. Geobotany 28. Kluwer Academic Publishers, Dordrecht, xii+462 pp. ISBN 1-4020-1370-1, hardback, price: EUR 200.00;
A discrete mathematical method, based on the Jakó Iterative Canonical Forms (ICF) of Boolean functions is proposed for the analysis of species combinations and the detection of characteristic areas in plant communities. Information on species combinations (or florulas) appearing in a sample is expressed in compact form to reveal fundamental properties of community pattern. The new method provides a complementary tool for the florula diversity approach: whereas florula diversity is indicative of the frequency distribution of species combinations regardless their interrelationships, the new procedure detects complexity in the abstract structure of species combinations. Graph-theoretical representations of the ICF promote understanding the new method and visualizing its results. A cellular automata model and field data provide illustrative examples.
The increasing availability of phylogenetic information facilitates the use of evolutionary methods in community ecology to reveal the importance of evolution in the species assembly process. However, while several methods have been applied to a wide range of communities across different spatial scales with the purpose of detecting non-random phylogenetic patterns, the spatial aspects of phylogenetic community structure have received far less attention. Accordingly, the question for this study is: can point pattern analysis be used for revealing the phylogenetic structure of multi-species assemblages? We introduce a new individual-centered procedure for analyzing the scale-dependent phylogenetic structure of multi-species point patterns based on digitized field data. The method uses nested circular plots with increasing radii drawn around each individual plant and calculates the mean phylogenetic distance between the focal individual and all individuals located in the circular ring delimited by two successive radii. This scale-dependent value is then averaged over all individuals of the same species and the observed mean is compared to a null expectation with permutation procedures. The method detects particular radius values at which the point pattern of a single species exhibits maximum deviation from the expectation towards either phylogenetic aggregation or segregation. Its performance is illustrated using data from a grassland community in Hungary and simulated point patterns. The proposed method can be extended to virtually any distance function for species pairs, such as functional distances.
