The floristic composition of the established vegetation and the soil seed bank in seven herbaceous communities under different traditional management regimes were compared in the Valdeón valley (Picos de Europa, Spain), a valley chosen for study because of its high diversity and non-dominance of any single species which have become increasingly rare in Western Europe as a result of changes in agriculture practices. Although the biological richness in this valley is well know, few studies have been made of the effects of different traditional management regimes on the floristic soil seed bank composition of these grasslands. The aim of this study was to examine the influence of traditional management regimes on the floristic composition of the established vegetation and soil seed bank determining which species groups are most represented in each case to increase scientific information about these communities that every day are more scarce in Western Europe because of intensive management (generally due to fertiliser application to increase production) and abandonment of the traditional methods of management with a profound modification of the agrarian structure. An indirect germination method was used to study the seed bank. Soil samples were put into a germination chamber. 119 species of the vegetation and 104 of the seed bank were identified, 54 species being common to both. Results were analysed using Correspondence Analysis (CA), samples and species on the above-ground flora being ordered in the first two axes in well-defined groups: limestone and siliceous pastures, formerly-cultivated land and hay meadow. In the case of the below-ground seed bank, the manure used as fertiliser in some communities affected principally the concentration of therophytes in the soil and defined the different groups. Sampling time, management and differences between the persistence of seeds of different species in the soil seed bank were responsible for the large differences between the composition of the vegetation and seed bank. Ruderal species, species with persistent seeds and therophytes, which were better represented in the seed bank were responsible for the low correlation between seed bank and vegetation established.
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Over the last decades, global changes have altered the structure and properties of natural and semi-natural mountain grasslands. Those changes have contributed to grassland loss mainly through colonization by woody species at low elevations, and increases in biomass and greenness at high elevations. Nevertheless, the interactions between agropastoral components; i.e., ecological (grassland, environmental, and geolocation properties), social, and economic components, and their effects on the grasslands are still poorly understood. We estimated the vulnerability of dense grasslands in the Central Pyrenees, Spain, based on the connectivity loss (CL) among grassland patches that has occurred between the 1980s and the 2000s, as a result of i) an increase in biomass and greenness (CL-IBG), ii) woody encroachment (CL-WE), or iii) a decrease in biomass and greenness (CL-DBG). The environmental and grassland components of the agropastoral system were associated with the three processes, especially CL-IBG and CL-WE, in relation with the succession of vegetation toward climax communities, fostered by land abandonment and exacerbated by climate warming. CL-IBG occurred in pasture units that had a high proportion of dense grasslands and low current livestock pressure. CL-WE was most strongly associated with pasture units that had a high proportion of woody habitat and a large reduction in sheep and goat pressure between the 1930s and the 2000s. The economic component was correlated with the CL-WE and the CL-DBG; specifically, expensive pastures were the most productive and could maintain the highest rates of livestock grazing, which slowed down woody encroachment, but caused grassland degradation and DBG. In addition, CL-DBG was associated with geolocation of grasslands, mainly because livestock tend to graze closer to passable roads and buildings, where they cause grassland degradation. To properly manage the grasslands, an integrated management plan must be developed that includes an understanding of all components of the agropastoral system and takes into account all changes that have occurred in dense mountain grasslands. Addressing the problems individually risks the improvement of some grasslands and the deterioration of others.
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