Bioenergetics and Total Impact of Vole Populations

in the year of outbreak for wheat and alfalfa fields, respectively. The highest consumption was observed in mid-summer, the lowest in early spring. Total impact on alfalfa fields was determined for a period of 42 d in late summer. The maximum daily consumption of alfalfa was 27.2 kg ha-1, while the total impact as much as 365.2 kg ha-1 d-1. In wheat fields the impact was estimated for a period of 80 d (April-July) in terms of influence on grain quantity and quality. In the year of outbreak, consumption of the population reduced the grain crop by 0.5 kg ha- 1 d- 1, and total impact by 2.25 kg ha-1 d-l. The total impact on both crops studied was 4 to 13 times greater than the consumption as computed from energy requirements. Thus, extraenergetic effects of