From 1974 to 1997 the effect of unusual climatic conditions on plant and animals was monitored. In some years, this revealed significant variations in plant development and animal activity. In autumn 1996, it was so warm (5-8§C) and rainy that fresh growth was stimulated in some plant species. Catkins opened out (about 30-40% on hazel, 20-25% on silver birch, and 15-20% on common alder). Most soil invertebrates (Nematoda, Lumbricidae, Enchytraeidae), and amphibians and reptiles (Oniscus, Julius, Chilopoda, Bibio) remained continuously active, and provided a source of food for moles. From December 16 the weather abruptly got colder with no snow, resulting in death of many of these animals and of 70-80% of the moles. Dead moles were found on the ground near burrow entrances. In early March of the following year, warm weather (8-12§C) resulted in the opening of buds. There followed a fall in temperature to between -8 and -12§C from March 13 for about 20 days with occasional small rises of temperature. That warm, rainy autumn, with a sudden fluctuation of temperature in winter and particularly in spring resulted in death of some plants and changes in the phenology of others. On the plot in Vyshen'ky village (Kiev Oblast, Boryspil district) 67 out of 95 rose-bushes coated in soil of 20 cm thick were destroyed by frost, while some rose-bushes and cuttings coated by soil 5-10 cm thick survived. Some southern varieties of grape (Doina, Cardinal), mint, melissa and chrysanthemum were slightly frosted, and bark on apricot trees cracked. Even some wild cold-resistant bushes, like violet willow (Salix acutifolia Willd.) also suffered from frost. The death of geobionts and herpetobionts was not, however, observed. Flowering of early spring plants (snowdrop, lungwort and sweet violet) was prolonged markedly by up to 30-40 days. The rest of the catkins on hazel opened out in early March, and the last of them fell in early May (they usually hang for 20-30 days). Fruit-trees like cultivated apple, common pear, cherry, apricot and plum, as well as white and black poplar, box-elder and common ash were in blossom in early May as usual. No deviations in their phenology were observed. Thus abrupt changes of climatic conditions in autumn and particularly in spring with big fluctuations from plus to minus temperature result in death or frost damage to some plants and animals. Because of global warming, these effects must be looked at in other European countries.