Gradients of Taxonomic Diversity among Local Floras in the Russian Arctic

Latitudinal and longitudinal changes in taxonomic variables were analyzed in 319 local floras in the Russian Arctic. Within the studied segment of latitudinal gradient, most changes can be described in terms of linear regression with negative coefficients (a number of species, genera and families), or positive coefficients (a proportion of the leading families and genera). However, the mean number of species in a family or genus almost does not change with increasing latitude, although it slightly increases as one moves eastward. The proportion of monocots does not correlate with latitude, but slightly decreases as one moves eastward. Proportions of various families change asynchronously. Although correlation with longitude was less pronounced, mean species richness was specific to many subprovinces, even within a certain subzone. These differences reflect both the diversity of landscapes and the history of flora formation. Keywords: the Arctic, local floras, latitudinal and longitudinal gradient, floristic subprovince

GRADIENTS IN TAXONOMIC DIVERSITY OF LOCAL FLORAS IN RUSSIAN ARCTIC

Latitudinal and longitudinal changes in taxonomical parameters and their correlation with climate characteristics were analyzed at 319 local floras in Russian Arctic and Subarctic. Species, genera and families numbers decrease to the north can be described as linear regression. The proportion of the leading genera and families increase to the north, that is stronger expressed in the northernmost subzones. Mean number of species in a family and in a genus slightly increases eastwards. Proportions of different leading families exhibit various latitudinal trends. There is no common longitudinal trend of taxonomical richness, but species numbers often differ significantly between various subprovinces on the whole and within certain subzones.Работа выполнена в рамках плановой темы Лаборатории растительности Крайнего Севера БИН РАН