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Different Grass Species (different + grass_species)
Selected AbstractsRe-evaluation of the liming-fertilization interaction in grasslands on poor and acid soilsGRASS & FORAGE SCIENCE, Issue 2 2010V. Poozesh Abstract The effect of surface liming on herbage production in permanent grasslands is rather uncertain. To better understand the effect of liming on the grassland, a study was made with a field experiment and a pot experiment with soil from the same field. In the field, the effects of liming and NPK fertilization on the production and composition of the vegetation were studied. In pots, the effects of liming and phosphate fertilization on different grass species were analysed. The effect of NPK fertilization (+3·96 t ha,1) on the production of the original grassland was greater than that of liming (+0·68 t ha,1), which was only observed (P < 0·05) on the unfertilized plots. Liming increased the total number of species and the proportion of dicotyledons. After replacing the semi-natural community with Dactylis glomerata L., the effects of liming (+2·37 t ha,1) and fertilization (+6·52 t ha,1) were increased. These results, together with those of the pot trial, show the important role of phosphorus in the fertilization effect, and are interpreted as a protective effect of P against aluminium toxicity. [source] The Identification of a Limited Number of Vegetative Compatibility Groups within Isolates of Sclerotinia homoeocarpa Infecting Poa spp. and Agrostis palustris from Temperate ClimatesJOURNAL OF PHYTOPATHOLOGY, Issue 7-8 2006N. A. Mitkowski Abstract Sclerotinia homoeocarpa is responsible for causing significant damage on a wide variety of different grass species. Because it is an asexual fungus, the study of its population structure can be difficult. Previous research has determined that S. homoeocapra has anywhere from three to 20 vegetative compatibility groups (VCGs) within localized geographic ranges in the United States. However, a survey of a large geographic area has yet to be undertaken. The present study examined 25 isolates of S. homoeocarpa from the United Kingdom, Rhode Island, Massachusetts, Connecticut, Ohio, Illinois and Oregon. Among the 25 isolates, eight VCGs were identified. Other researchers have reported that there are seven VCGs in temperate North America on amenity turfgrasses. It is still unclear how this relates to the pathogen's VCG diversity in subtropical and tropical climates. [source] Co-existing grass species have distinctive arbuscular mycorrhizal communitiesMOLECULAR ECOLOGY, Issue 11 2003P. Vandenkoornhuyse Abstract Arbuscular mycorrhizal (AM) fungi are biotrophic symbionts colonizing the majority of land plants, and are of major importance in plant nutrient supply. Their diversity is suggested to be an important determinant of plant community structure, but the influence of host-plant and environmental factors on AM fungal community in plant roots is poorly documented. Using the terminal restriction fragment length polymorphism (T-RFLP) strategy, the diversity of AM fungi was assessed in 89 roots of three grass species (Agrostis capillaris, Festuca rubra, Poa pratensis) that co-occurred in the same plots of a field experiment. The impact of different soil amendments (nitrogen, lime, nitrogen and lime) and insecticide application on AM fungal community was also studied. The level of diversity found in AM fungal communities using the T-RFLP strategy was consistent with previous studies based on clone libraries. Our results clearly confirm that an AM fungal host-plant preference exists, even between different grass species. AM communities colonizing A. capillaris were statistically different from the others (P < 0.05). Although grass species evenness changed in amended soils, AM fungal community composition in roots of a given grass species remained stable. Conversely, in plots where insecticide was applied, we found higher AM fungal diversity and, in F. rubra roots, a statistically different AM fungal community. [source] Savanna dynamics in central Texas: just succession?APPLIED VEGETATION SCIENCE, Issue 1 2009Norma L. Fowler Abstract Question: What is the best way to model savanna dynamics? Specifically, under what conditions is a traditional succession model, i.e., a model of ordered, uni-directional change in the plant community, better than a state-and-transition model? Location: Central Texas savannas. Methods: We describe three examples of successional processes in central Texas savannas: (a) woody plant encroachment, (b) invasion by a non-native grass, and (c) establishment of different grass species in highly disturbed sites. Results and Conclusions: Savanna dynamics are now commonly conceptualized with state-and-transition models. However, in some situations a traditional succession model may be more appropriate or more useful. Succession models may better fit current ecological reality, as found in central Texas. Succession models emphasize transient dynamics rather than an (often unknown) endpoint, and direct us towards relevant literature from non-savanna ecosystems. Succession models may be particularly useful for land management and restoration, and where woody plant encroachment and/or invasions by non-native species control vegetation dynamics. [source] Exposure to grass pollen in EuropeCLINICAL & EXPERIMENTAL ALLERGY REVIEWS, Issue 1 2008S. JaegerArticle first published online: 7 APR 200 Summary Pooideae encompass both common wild and cultivated grasses, which are responsible for grass pollen exposure and sensitization in Europe. Across Europe, the pollination period of different members of this subfamily overlap and hayfever sufferers are therefore naturally exposed to a mixture of pollens from different grass species. Because of their morphological homology, Pooideae pollens are evaluated together in pollen counts and cannot be distinguished. Neither patients themselves, nor physicians can link the onset of hayfever symptoms to a specific grass species. [source] | |||||||||||||