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Competition between weeds and groundnuts was studied in two field experiments in the inland Zanderij area of Suriname. The crop was kept weed-free or without weed control for increasing periods of time after planting. Observations made at the end of each period with or without weed control provided an analysis of the growth of a crop with weed control and of a crop without weed control. Uncontrolled weed growth was concentrated between the rows. Competition with weeds reduced ground cover and LAI of the crop. DM accumulation was affected, resulting in lower yields. Plant density and number of branches per plant were not influenced. Weed competition increased stem length and reduced the number of leaves and pods per plant. Timing of flowering was not influenced. Competition for nutrients was absent, but there was competition for light and water. About 15 weed-free days after planting were sufficient to prevent yield losses. Yield losses were due to a reduction in number of pods per plant. Competition should especially be prevented in the period when the number of pods per plant is established, i.e. around 35-60 days after planting. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Two field experiments were carried out in the inland Zanderij area of Suriname to study competition between soyabeans and weeds. The crop was kept weed-free or without weed control for increasing periods of time after sowing. An analysis of the growth and development of a crop with weed control and of a crop without weed control was obtained by making observations at the end of each period of time with or without weed control. Uncontrolled weed growth concentrated mainly between the rows. Competition with weeds reduced ground cover and LAI of the crop, leading to a lower weight and yield. Plant density was not affected, but weed competition reduced the number of branches, inflorescences, and pods per plant. Timing of flowering was not influenced. Competition for water was inferred and competition for light seemed likely. Competition for nutrients was weak. Weeding in the period of pod initiation, i.e. around 45-70 days after sowing, appeared to be essential to avoid competition with weeds. A period of around 4 weed-free weeks after sowing was necessary to avoid yield reduction or too much weed growth at harvest. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Summary: Resume: Zusammenfassung The effect of broadcast or band-placed application of fertilizer on the growth of weeds was studied at two locations on low-fertility acid soils in Suriname. Band placement of fertilizers considerably reduced weed growth compared to fertilizer-applied broadcast. With band-placed fertilizer the increased weed growth due to fertilizer application was concentrated on the fertilized bands. Weed growth was also stimulated in planter wheel-tracks. The spatial distribution of the weed growth is discussed in relation to the crops groundnut, sorghum and soybean, grown at the same location. Reponse des adventices au mode d'application des engrais sur des sols acides de faible fertilite au Surinam L'effet d'application d'engrais sur le rang ou en plein sur la croissance des mauvaises herbes a eteetudiee en deux lieux du Surinam sur sols acides pauvres. Le traitement sur le rang des engrais a considerablement reduit la croissance des adventices comparea l'application en plein. Avec l'application de l'engrais en ligne l'augmentation de croissance due a la fertilisation etait concentree sur les bandes fertilisees. La croissance des adventices etaient egalement stimulee dans les traces de roues de tracteurs. La distribution spatiale de la croissance des adventices est discutee en relations avec la distribution spatiale de la croissance des adventices trouve chez le sorgho, le soja, l'arachide cultives dans les memes lieux. Wirkung der Dungungsmethode auf die Verunkrautung ertragarmer, saurer Boden in Surinam An 2 Ortem mit ertragarmen, sauren Boden in Surinam wurde die Wirkung der Dungungs-methode auf das Wachstum von Unkrautern untersucht. Banddungung reduzierte das Unkrautwachstum im Vergleich zur breitwurfigen Dungung erheblich. Ein gefordertes Unkrautwachstum zeigte sich nur auf dem Dongungsband und auch auf den Fahrspuren. Die unterschiedliche Verunkrautung in Erdnus, Sorghum und Sojabohne wird diskutiert.

The Journal of Vegetation Science was launched by the International Association for Vegetation Science (IAVS) in 1990, specifically to be a journal owned and governed by the Association. Now, in its 20th year of publication, it is the reference journal for plant community ecology. Eddy van der Maarel concluded in his editorial of the first issue: ‘‘Vegetation science is rapidly developing towards a general science of plant communities with its own body of theory and an enormous potential for application in the fields of nature conservation and environmental management. . . . Let the Journal of Vegetation Science be a journal for all vegetation scientists’’ (van der Maarel 1990). The world has changed much in those 19 years. So has vegetation science, with the Journal of Vegetation Science drawing together vegetation scientists from almost all the countries of the world and with every approach to the subject. Peter White had been with the Journal of Vegetation Science since it started. He had been an Associate Editor since they existed, and a Chief Editor since they did. He is now taking a break1 from the Journal, primarily because he is overseeing developments in the North Carolina Botanic Garden. This is a good time to thank him for all his work and all his wisdom since 1990. Fil: Wilson, J. Bastow. University of Otago. Botany Department; Nueva Zelanda Fil: Chiarucci, Alessandro. University of Siena. Department of Environmental Science “G. Sarfatti”; Italia Fil: Diaz, Sandra Myrna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Pärtel, Meelis. University Of Tartu.; Estonia

Summary: To assess the potential contribution of growing highly competitive crops to control Cyperus esculentus in the Netherlands, the influence of silage maize, hemp, winter barley and silage winter rye on emergence, growth and reproduction of this weed was studied in two field experiments. Growth and reproduction of C. esculentus (determined both as tuber production per plant and density of the weed in the subseuent crop maize) was reduced by each crop, compared to plots in which no crop was grown. In hemp, hardly any tuber production was observed. By growing a green manure crop after harvest of the winter barley the tuber production of the weed was reduced to about 40% of that in winter barley followed by fallow. Decreasing the light regime in a greenhouse experiment in the same order as was observed in the crops winter barley, maize and hemp, caused a similar reduction of tuber production to that found in the field. Therefore, it is suggested that competition for light is the main factor explaining the observed crop effects on the population dynamics of the weed. It is concluded that growing competitive crops as hemp in rotation may effectively complement chemical control of C. esculentus. Resume: Pour mesurer la contribution potentielle de cultures fortement competitives pour lutter centre Cyperus esculentus aux Pays-Bas, l'influence du mais ensilage, du chanvre, de l'orge d'hiver, du seigle d'hiver sur la levee, la croissance et la reproduction de cette adventice a eteetudiee dans deux experimentations au champ. La croissance et la reproduction de C. esculentus (determinees a la fois par la production de tubercules par plante et la densite d'adventice dans la culture suivante de mais) ont ete reduites par chaque culture comparativement aux parcclles laissees sans culture. Dans le chauvre, une assez forte production de tubercules a ete observed. En semant un engrais vert apres la moisson de l'orge de l'hiver, on a reduit la production de tubercules de l'adventice de 40% par rapport a celle observee en orge d'hiver suivi par une jachere. Dans une experimentation de serre en regime de lumiere decroissante de la meme nature que celle qui est observee sous les couverts d'orge d'hiver, de mais et de chanvre a entraine une reduction de la production de tubercules similaire de celle observee en plein champ. De cela, on deduit que la competition pour la lumiere est le principal facteur expliquant les effets observes des cultures sur la dynamique des populations de l'adventice. On en conclut que l'introduction d'une culture competitive comme le chanvre dans la rotation peut completer efficacement la lutte chimique contre C. esculentus. Zusammenfassung: Um den moglichen Beitrag konkurrenzstarker Kulturen zur Bekampfung von Cyperus esculentus L. in den Niederlanden zu erfassen, wurde der Einflus von Mais, Hanf, Wintergerste und Roggen auf den Austrieb, den Wuchs und die Reproduktion dieses Unkrauts in 2 Feldver-suchen untersucht. Wuchs und Reproduktion, beide in Mais als Folgekultur mit der KnoUen-zahl pro Pflanze und der Wuchsdichte bestimmt, wurden— im Vergleich zu Parzellen ohne Einsaaten— durch alle Kulturen herabgesetzt; in Hanf wurde kaum eine Bildung neuer Knollen beobachtet. Bei Anbau von Grundungungspflanzen nach der Ernte der Wintergerste wurden nur etwa 40% so viele Knollen gebildet wie bei folgender Brache. In einem Gewachshausversuch mit zunehmender Beschattung bis zu der in Wintergerste, Mais und Hanf beobachteten ergab sich eine ahnliche Abnahme der Knollenbildung wie im Freiland. Deshalb wird angenommen, das die Konkur-renz um Licht der wichtigste Faktor fur die festgestellten Einflusse der Kulturen auf die Populationsdynamik dieser Unkrautart ist. Der Anbau konkurrenzstarker Kulturen wie z. B. Hanf in einer Fruchtfolge kann die chemische Bekampfung von Cyperus esculentus wirkungs-voll erganzen.

Fil: Wilson, J. Bastow. University of Otago. Botany Department; Nueva Zelanda Fil: Chiarucci, Alessandro. University of Siena. Department of Environmental Science G. Sarfatti; Italia Fil: Diaz, Sandra Myrna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: White, Peter S.. University of North Carolina. Department of Biology; Estados Unidos

The paper chosen for the award by the Chief Editors of Applied Vegetation Science, from among those published in 2007 is that by Hartman & McCarthy (2007). Exotic (alien, non-indigenous) species are a concern for their impact on native communities, as well as fascinating probes into community structure: natural experiments. Recent research has tried to measure their impact by examining invaded and non-invaded sites. This approach has the flaw that the non-invaded sites may not have been invaded because they were different in the first place. Examining sites before and after an invasion is difficult because invasions are not normally noticed until after they have happened, and anyway there might have been an allogenic environmental change, or one caused by the reaction of the other species. The ideal would be to go backwards in time in both invaded and non-invaded sites. Impossible? But Hartman & McCarthy (2007) did this by dendrochronology. Working in deciduous hardwood forest in Ohio, USA, they shewed that the exotic understorey shrub Lonicera maackii (Rupr.) Herder reduced the growth of native trees in the overstorey.

Grenzen in beweging bevat onder meer hoofdstukken over Europese en mondiale verspreiding van vaatplanten, plantengeografie van Nederland, halfnatuurlijke graslanden, hotspots van plantendiversiteit en effecten van klimaatverandering. Het boek geeft een boeiend overzicht van de historische en recente ontwikkelingen in de vegetatiegeografie. De vele kaartjes, tekeningen, tabellen en grafieken vormen een heldere aanvulling op de tekst. Het is het eerste deel van een reeks Vegetatiekundige Monografieën

Grenzen in beweging bevat onder meer hoofdstukken over Europese en mondiale verspreiding van vaatplanten, plantengeografie van Nederland, halfnatuurlijke graslanden, hotspots van plantendiversiteit en effecten van klimaatverandering. Het boek geeft een boeiend overzicht van de historische en recente ontwikkelingen in de vegetatiegeografie. De vele kaartjes, tekeningen, tabellen en grafieken vormen een heldere aanvulling op de tekst. Het is het eerste deel van een reeks Vegetatiekundige Monografieën

The effects of incorporating mustard as a non-crop plant within a broccoli planting was tested for pest regulation. By varying sowing dates of the mustard, a critical period for crop-weed competition was determined, after which time, crop competition was insignificant. Mustard sowed one week after broccoli transplanting showed no reduction of broccoli yield and tended to reduce numbers of the cabbage aphid, Brevicoryne brassicae L., while increasing effective predation by syrphid larvae. Mechanisms explaining this effect are discussed in relation to diversity. The data also suggest that mustard serves as a trap crop for pest insects that normally feed on brassica crops.

The vegetation of the embankments of the Zak van Zuid-Beveland were surveyed phytosociologically, the vegetation being assigned to the Lolio-Cynosuretum plantaginetosum mediae, Arrhenatheretum elatioris picridetosum, Arrhenatheretum elatioris alopecuretosum and Ulmo-Rubetum ulmifolii . In total, including the subordinate fragmentary communities and variants, 12 communities are described, together with an indication of their synecology. The composition of the vegetation in 1986 is compared to that in 1972 and the influence of different management practices, i.e. grazing, mowing, burning and no management, on the vegetation changes is illustrated. The changes in vegetation composition and structure are clearly related to management practices. This even applies to the low level of syntaxonomic hierarchy, i.e. subassociations and variants. In general the highest intensities of grazing by the flock, i.e. between 8 and more than 15 h a month by 200 sheep per 500 m of embankment, were best suited for the improvement or maintenance of the conservation value. Under the same conditions, light grazing (less than 8 hours) proved to be insufficient.

Disturbance ecology has become an integral part of vegetation science over the past 25 years. Understanding human disturbances and human effects on natural disturbance regimes is a key to establishing restoration goals and initiating restoration projects. However, as this literature has developed, the picture has become both more interesting and more complex: Disturbances interact; each disturbance leaves behind a patch work of effects; and particular disturbances have different effects in different seasons and from one year to another. In addition, different species respond differently to the same disturbance. We are left with questions such as: Can we predict vegetation response to fire in restoration projects? Clearly, we must understand the mechanisms of species response to disturbance in order to answer these questions and achieve a predictive science. The Editor’s Award for 2005 goes to a paper that treats interactions of fire and mowing in a long-term experiment: “Long-term composition responses of a South African mesic grassland to burning and mowing” by Fynn, Morris & Edwards (2005). The authors report on the 50+ year Ukulinga burning and mowing experiment at the research farm of the University of KwaZuluNatal in South Africa. This experiment, initiated in 1950, is remarkable: three replicates in a randomized split-plot, full-factorial design with four whole-plot and 11 subplot treatments. Mowing treatments included none to early season, late season, and early-plus-late season. Fire treatments were none, annual, biennial, and triannual in winter, spring or autumn. In sum, plot disturbance ranged from protection over 50 years to twice summer mowing plus mowing or fire in the dormant season each year. The authors found that grasses responded to type of disturbance and fire frequency, but forbs were less sensitive to disturbance type. The disturbance combinations controlled vegetation structure and composition, with some combinations producing a short-grass Disturbance, seeds, restoration, and the importance of experiments and long-term observations: the Editors’ Award for 2005 White, Peter S.1*; Chiarucci, Alessandro2; Collins, Beverly3 & Díaz, Sandra4 1Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280, USA; 2Dipartimento di Scienze Ambientali ‘G. Sarfatti’, University of Siena, Via P.A. Mattioli 4, 53100 Siena, Italy; 3Savannah River Ecology Lab, P.O. Drawer E, Aiken, SC 29802, USA; 4Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, Casilla de Correo, RA-5000 Córdoba, Argentina; *Corresponding author; E-mail peter.white@unc.edu community and others a tall-grass community. Tillering strategy (below or above ground) for grasses and habit (erect or creeping) for forbs explained many responses and are a means to predict differing responses of grasses and herbs and different responses of species within each group to disturbance combinations. The conclusion of the study suggests that the highest diversity and greatest number of species (as well as benefits for wildlife species) can be achieved by applying results at the landscape scale to create patches of diverse structures from simple combinations of disturbance type and season. The authors also found transient responses and compensatory changes among species, thus demonstrating the importance of long-term and experimental research. Fil: White, Peter S.. University of North Carolina; Estados Unidos Fil: Chiarucci, Alessandro. Universita Degli Studi Di Siena; Italia Fil: Collins, Beverly. University of Georgia. Savannah River Ecology Laboratory; Estados Unidos Fil: Díaz, Sandra Myrna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Phytosociological bibliography of Poland, Pflanzensoziologische Bibliographie von Polen

The definition of vegetation types at different hierarchical levels, both to study the vegetation processes and for practical cartography representation, is still considered a critical issue in many circles of plant ecologists. The problems are mainly related to the misleading idea that classification of the vegetation system, as developed by European phytosociologist during the last century within the discipline called syntaxonomy, would imply the assumption of the organismic concept of the plant community. After a short discussion on the role of Braun- Blanquet approach in plant ecology and in landscape ecology, the methods to detect multispecies responses along environmental gradients are briefly reviewed. In the main part of this article, we intend to stress that concepts considered critical, such as plant association and its ecological niche, are just operational tools that have nothing to do with the individualistic or organismic interpretation of plant communities in vegetation studies. Important to our views on vegetation, we believe that plant associations as well as the higher sintaxa can be regarded as fuzzy sets in an operational context for describing vegetation along ecological gradients in synthetic ways and can further the understanding of vegetation variation.

The population biology of Galium aparine L. needs to be better understood, in order to be able to rationalize decisions about the short- and long-term control of this weed species for different cropping practices.A population dynamics model was developed to simulate the basic processes of the life cycle of G. aparine as influenced by environmental conditions. The effect of temperature, light, moisture, nitrate supply and soil structure on germination and emergence and on growth and seed production were investigated. Data were integrated in a model simulating field emergence and an ecophysiological model on crop-weed competition. The information was used to evaluate the effects of crop rotations, control levels, cultural measures and timing and choice of soil cultivation practices on the population dynamics of G.aparine. The ecophysiological model of competition between G. aparine and sugar beet was extended to predict reductions in crop yield reduction and increases or decreases in the weed population on the basis of the actual situation in the field. The variation caused by weather conditions appeared to be small.The results of simulations demonstrate the possibilities of reducing herbicide use to control G.aparine in both the short and long term, by adapting crop rotation and cropping practice, increasing mechanical control in cereals and not controlling lateemerging G. aparine plants in sugar beet.