Species-richness correlations of six different taxa in Swedish seminatural grasslands

An important question in conservation biology, is whether the biodiversity of different taxa is correlated. We studied the extent to which the number of species of six different taxa-plants. birds, butterflies, bumblebees, ground beetles, and dung beetles-in 31 Swedish seminatural grasslands covary,, and whether species diversity, can be related to habitat variables, During 1990 and 1997 we surveyed plants and animals with appropriate techniques for each taxa and mapped the grassland habitat. fit general. correlations between taxa were few. Grassland plant diversity (currently used as an indicator for conservation value) was Bumblebee diversity was significantly only, significantly positively correlated to total bird diversity related to both total and grassland butterflies, whereas there was a significant negative relationship between grassland birds and dung beetles. Plants, birds, bumblebees, rind butterflies showed significant similarities in patterns of species composition, as did birds, butterflies, grassland butterflies, and ground beetles. The total number of plants and both subsets of birds (total and grassland) were significantly positively related to area, whereas there was a significant negative association between area and dung-beetle, diversity. The diversity of both butterflies and bumblebees was significantly, negatively related to The proportion of short-grazed field layer. Bumblebees showed a positive relationship with junipers, whereas ground beetles and grassland birds were negatively associated with trees. The total number of bird species was Positively influenced 17). the occurrence of shrubs. Our results suggest that neither the species richness of grassland plants nor that other of the surveyed taxa can be used as an indicator for total biodiversity, The lack of similar patterns of species composition among taxa also makes it difficult to define functional groups with similar habitat demands. Until we have more detailed knowledge of the demands; of species and taxa. it is important that we direct management efforts so that we provide a wide spectrum of grassland characteristics.