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A comparative study of floristic richness of 125 permanent peat grasslands was made in 1983-84 across Zuid-Holland and Utrecht provinces. Three different parameters of floristic richness were used: the number of species, the number of those species that contribute to the conservational value (quality indicating species) and a 'nature value' index that combines species richness with rarity of species. N supply (0-600 kg N/ha per year) was the most important factor determining number of quality-indicating species. Additional factors were peat mud dressing and soil type. Utilization of grassland (whether frequently cut or continuously grazed), ground water table level, pH, P and K contents of the topsoil and type of animal manure had no effect on floristic richness. At levels below 200 kg N/ha per year, a considerable number of species of conservational value (e.g. Lychnis flos-cuculi and Carex nigra) became abundant. The significance of the results for nature conservation with regard to current agricultural practice is discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)

On sand dunes at Meijendel (the Netherlands) the thistle Carlina vulgaris grows almost exclusively near shrubs of willow (Salix repens) and more rarely near shrubs of sea buckthorn (Hippophaë rhamnoides), although both scrubs occur in similar frequency The critical stage in the life cycle is the phase of establishment of seedlings, which is better in Salix than in Hippophae Once established, the performance of plants IS better under buckthom than willow Watering greatly improved seedling establishment and subsequent growth, especially under sea buckthom As a result, after watering the total biomass of C vulgaris became even higher in buckthom scrub than in willow Because of its higher humus content, the water content of the top 10 cm of the soil was consistently higher (c 55%) under willow than buckthom Apparently low water availability prevents C vulgaris from establishing outside willow scrub but once this limitation has been overcome, other habitats are entirely suitable for growth Roots of C vulgaris plants in unwatered plots in willow were less colonized by mycorrhiza than in buckthom plots Our results do not indicate that mycorrhiza helps seedling establishment