Essential mineral nutrients of the high-latitude steppe vegetation and the herbivores of mammoth fauna

摘要

The geographical distribution of mammoth fauna was based not only on the optimal climatic range and suitable grass-rich ecosystems, but also on stable and sufficient pool of mineral nutrition in the seasonal cycle. Widespread high-latitude steppes or tundra-steppes were the landscape basis for the Beringia herbivores. Now patches of the relict steppes persist only on steep slopes with southern aspects. Numerous palynological, carpological, isotopic, and DNA data from the Pleistocene plant remains show that relict steppes are similar to mammoth steppe in many ways. A six-year study of ash and plant mineral contents of two types of steppes and grass-herb ecosystems at the Kolyma Lowland, Arctic Siberia has been carried out. The comparative content of essential mineral nutrients (Ca, P, K, Mg, Mn, Na, Fe, S) and the important element ratios in different vegetation types were analyzed. Results indicated that the ash and Ca, Mg contents are higher for the steppe vegetation. High Ca : P ratio and optimal K (Ca+Mg) or tetanic ratio in steppe plants are within the recommended range for large herbivores. Mineral nutrient contents are higher for herbs vs grasses for steppe taxa. Generally accumulation of essential mineral elements of the Siberian Arctic steppes is comparable to those in the Asian temperate steppes. The research results can be used for better understanding of such an important issues of paleoecology of large grazers as availability, sufficiency and equilibration of mineral nutrient elements of grass-rich ecosystems - one of the significant factors of megafauna existence. (C) 2019 Elsevier Ltd. All rights reserved.