高寒草甸金露梅灌丛根田鼠种群生产力的研究 Ⅲ.种群生物能学

PRODUCTIVITY INVESTIGATION OF THE ROOT VOLE(MICROTUS OECONOMUS)POPULATION IN HAIBEI ALPINE BUSHLAND(POTENTILLA FRUTICOSA): Ⅲ.POPULATION ENERGETICS

本文在根田鼠(Microtus oeconomus)种群动态及种群生产量研究的基础上,探讨了根田鼠对天然食物选择、食物的摄入、消化率和同化水平、每日能量收支、年能量收支、并在种群生产量(P=Pg+Pr)和呼吸量(R)的基础上,按照A=P+R的途径,估计了通过根田鼠种群的能流。

The root vole(Microtus oeconomus)is the dominant rodent species in Haibei alpine bushland(Potentilla fruticosa),and various aspects of its bioenergetics have been extensively studied. In order to come to a better understanding of the vole's bioenergetics and a more reasonable evaluation of its role in the alpine meadow ecosystem, we conducted a comprehensive investigation of its energetics including net primary production, population density,population production, average metabolic rate (ADMR), reproductive cost,daily activity rhythm, energy intake, digestion,assimilation, daily energy budget, yearly energy budget, and energy flow through the vole population. The daily energy budget(DEB)model was constructed on the basis of ADMR (Table 3) and by concurrent consideration of huddling effect,surface activity time,and reproductive effort(Table5). DEB is the highest during the green up period, and this can be illustrated by the fact that in this period almost all voles comprise the population are overwintered adults, they are heavier and more involved in reproductive and surface activities (thus meet higher thermoregulatory demand).Yearly energy intake of the vole population(Table 6) ranges from 568.175×103 to 1541.692×103KJ/ha. yr, and we concluded that the vole's food resource is relatively abundant compared with the net primary production (Pn)of the bushland (Table 1)and the food availabe (Fa) for the vole (70.12% Pn of the herb layer).Population assimilation is 398.576×103tol081.230 ×103KJ/ha.yr, of which 1.22% -2.23% is transformed into population production, and no significant difference was found between the production due to growth(Pg)and production due to reproduction(Pr) (Table6).Finally,the potential errors of the two ways,namely A = C-F-U and A = P + R, traditionally used to estimate energy flow were discussed,and we suggest that for more precise estimation of respiration and energy flow,the doubly labelled water(DLW)me-thod be employed in future studies.