In order to understand the temporal changes of botanical composition in grassland ecosystem, and to clarify the relation between these changes and environmental impacts, such as climatic factors and artificial disturb...In order to understand the temporal changes of botanical composition in grassland ecosystem, and to clarify the relation between these changes and environmental impacts, such as climatic factors and artificial disturbance, a grazing trail was carried out during a 21-year period from 1974 at a sown grassland of the National Grassland Research Institute, located in Nishinasuno, the central area of Japan. The data sets of biomass for each mouth(from April to November)of the 21 year period were analyzed in this paper. The botanical composition of aboveground biomass varied greatly with both season and year. The biomass ratio of improved herbage species to invaded native plants gradually decreased each year. This may have been owing to meteorological factors, such as low air-temperature in winter, dry and hot summers, grassland management(including grazing intensity and fertilizer application), and inter-specific competition between native and introduced herbage plants.展开更多
Background Recently,there has been increasing interest in the use of multispecies(MS)swards in dairy grazing systems.Methods A plot grazing study was established to investigate the potential contribution of different ...Background Recently,there has been increasing interest in the use of multispecies(MS)swards in dairy grazing systems.Methods A plot grazing study was established to investigate the potential contribution of different sward species(perennial ryegrass,legumes and herbs)sown in grazing pastures.Ten sward mixtures were sown,ranging in complexity from a perennial ryegrass(PRG)monoculture to binary mixtures including either forage legumes or herbs to a five-species mixture;four different nitrogen(N)application rates of 0,100,150 and 200 kg N ha−1 were applied to each sward.Results Species abundance for all sward species components was associated with the interaction of time point and sward mixture;species abundance for all sward components,except PRG,was associated with the interaction of N application and sward mixture.The interactions of time point and sward mixture,and time point and N application rate,were associated with all analysed sward chemical components,except for sward digestibility.Conclusions Increased N application rates reduced the level of clover in all sward mixtures.Increased levels of white clover led to increased sward crude protein levels;the inclusion of ribwort plantain led to some seasonal variation in the nutritive value of swards.展开更多
Continuing climate changes are strongly associated with status of water, threatening the majority of ecosystems, including the grass ecosystem. The climate changes primarily affect the botanical composition of grassla...Continuing climate changes are strongly associated with status of water, threatening the majority of ecosystems, including the grass ecosystem. The climate changes primarily affect the botanical composition of grassland that is subsequently determined by production of above-ground phytomass which is used like feed for the ruminants. In our field experiment we assessed the impact of climate changes on grass ecosystem during the long-term period （23 years）. We obtained a picture of the preceding development of botanical composition in this stand, due to the assumption that expected climate changes are going to disturb the botanical composition of grassland especially in the grass biome. From the obtained results follows the significant change in botanical composition in grass-herbaceous vegetation with the low share of legumes. It is not possible to confirm strict relation between precipitation during vegetation season and the share of individual botanical group. Analysis of long-term development of the botanical composition of monitored grassland influenced by different pratotechnical interventions demonstrated the significant flexibility this plant community in the times of changing climatic conditions.展开更多
文摘In order to understand the temporal changes of botanical composition in grassland ecosystem, and to clarify the relation between these changes and environmental impacts, such as climatic factors and artificial disturbance, a grazing trail was carried out during a 21-year period from 1974 at a sown grassland of the National Grassland Research Institute, located in Nishinasuno, the central area of Japan. The data sets of biomass for each mouth(from April to November)of the 21 year period were analyzed in this paper. The botanical composition of aboveground biomass varied greatly with both season and year. The biomass ratio of improved herbage species to invaded native plants gradually decreased each year. This may have been owing to meteorological factors, such as low air-temperature in winter, dry and hot summers, grassland management(including grazing intensity and fertilizer application), and inter-specific competition between native and introduced herbage plants.
基金The authors would like to thank the Moorepark farm and grassland laboratory staff,in particular,Andy McGrath,Pat O'Connor,David Flynn and Michelle Liddane,for their help with data collection and processing.The authors would also like to acknowledge the support of the Teagasc Walsh Scholarship scheme and University College Dublin,along with the financial support of VistaMilk(16/RC/3835),which facilitated the current study.
文摘Background Recently,there has been increasing interest in the use of multispecies(MS)swards in dairy grazing systems.Methods A plot grazing study was established to investigate the potential contribution of different sward species(perennial ryegrass,legumes and herbs)sown in grazing pastures.Ten sward mixtures were sown,ranging in complexity from a perennial ryegrass(PRG)monoculture to binary mixtures including either forage legumes or herbs to a five-species mixture;four different nitrogen(N)application rates of 0,100,150 and 200 kg N ha−1 were applied to each sward.Results Species abundance for all sward species components was associated with the interaction of time point and sward mixture;species abundance for all sward components,except PRG,was associated with the interaction of N application and sward mixture.The interactions of time point and sward mixture,and time point and N application rate,were associated with all analysed sward chemical components,except for sward digestibility.Conclusions Increased N application rates reduced the level of clover in all sward mixtures.Increased levels of white clover led to increased sward crude protein levels;the inclusion of ribwort plantain led to some seasonal variation in the nutritive value of swards.
文摘Continuing climate changes are strongly associated with status of water, threatening the majority of ecosystems, including the grass ecosystem. The climate changes primarily affect the botanical composition of grassland that is subsequently determined by production of above-ground phytomass which is used like feed for the ruminants. In our field experiment we assessed the impact of climate changes on grass ecosystem during the long-term period （23 years）. We obtained a picture of the preceding development of botanical composition in this stand, due to the assumption that expected climate changes are going to disturb the botanical composition of grassland especially in the grass biome. From the obtained results follows the significant change in botanical composition in grass-herbaceous vegetation with the low share of legumes. It is not possible to confirm strict relation between precipitation during vegetation season and the share of individual botanical group. Analysis of long-term development of the botanical composition of monitored grassland influenced by different pratotechnical interventions demonstrated the significant flexibility this plant community in the times of changing climatic conditions.
