Data on the productivity of plant cover of the main types of soils of the North-Western precaspian in connection with the dynamics of ecological factors.

The data of the researches describes the were to establish the species composition of pasture cenoses and the productivity potential of light-chestnut and meadow-chestnut soils under different climatic conditions and in different periods of the year in the Terek-Kuma lowland of the North-Western Precaspian. Two peaks of productivity of phytocoenosis have been observed: the first is - ephemeral synusia in the middle of May- early June; second - motley grass and saltworts in the second half of September. The data on receipt of photosynthetically active radiation (PAR) on the soil surface and the coefficient of its use over the years and periods of the year depending on the hydrothermal conditions and dynamics of harmful salts in the soil are given.

Changes in activity of neutral proteases in tissues of ground squirrels in the dynamics of hibernation.

Total activities of neutral proteases in the cerebral, hepatic, and myocardial tissues of ground squirrel vary during hibernation: in autumn (before hibernation) activities of the enzymes in the brain and myocardium start increasing, while in the liver they do not change. A common feature for all tissues is minimum activity of active neutral proteases in the middle of hibernation month 1 bout, while the maximum activity is recorded before awakening.

[Temperature compensation in homeothermic animals].

Low temperature optimum of the glutaminase activity in synaptosomal fraction of the brain occurs in deep hypothermia, similar phenomenon occurring in hibernation. The optimum depends on the animal body temperature. The data obtained suggest a manifestation of the temperature compensation.