Population structure and establishment of the threatened long‐lived perennial Scorzonera humilis in relation to environment

摘要: Summary 1 The intensification of agriculture has resulted in the decline many plant species nutrient-poor wet grasslands. At some sites local populations long-lived characteristic have persisted and might benefit from recent extensification schemes. However, little is known about population biology these plants, prospects for are uncertain. 2 We studied structure establishment Scorzonera humilis 23 Luxembourg neighbouring Belgium. Two types could be distinguished according to their structure: regenerating populations, with a high proportion plants only one or few rosettes, aged low small, young but individuals rosettes. The total density was higher than populations. 3 Within sites, S. restricted more open patches. composition vegetation plots where present significantly different that without species, indicating particular microhabitats. 4 In multiple regression analyses, environmental variables explained large part variation genets, genets size main influence were site productivity soil moisture. With increasing decreasing moisture small decreased increased. Increased had contrasting effects at genet ramet (rosette) levels. While decreased, increased, if fertilized, recruitment new survival reduced, growth surviving increased. 5 The results sowing experiment indicated an due lack recruitment. number seeds germinated seedlings survived until next summer positively correlated negatively productivity. Germination rate success Molinion grassland Calthion grasslands. 6 The suggest may not good indicators status species. In (> 1000 genets) still exist, all type. order preserve existing humilis, management should aim reduce increase