Starting from the mid-80s botanists, particularly plant morphology specialists started to notice new forms of branches on the Moscow trees: an accumulation of small sprouts and knots. They originate from a single point somewhere in the middle of a thick branch and stretch out in various directions like spider's legs. This peculiarity has been observed by the specialists long ago and became obvious for non-specialists about three years ago - the 'spiders' have extensively spread out on the trees along the busy streets of the city. The young sprouts are disappearing and that is the reason why such strangely shaped tree crowns occur.
"A Russian botanist Vysotsky has described the mechanism of similar shapes formation", Professor M. T. Mazurenko said. "At the beginning of the 20th century he investigated how the plants adapt themselves to the semi-desert conditions and found out that in these unfavourable conditions the tree crowns periphery was drying out every year."
In spring a bush or a tree shoots out a strong sprout with a lot of leaves which are feeding the plant through photosynthesis. In summer, the major part of such sprout dries up. Some cells remain alive to provide for the next year sprouts. The bush dries up to such an extent that only a short stump rises above the ground. Later on it gives rise to a thick brush of sprouts.
'Spider'-branches are typical not only for Moscow. They are quite frequent on the roadside trees along the busy highways, especially where the automobiles often stuck in jams and heavy haulers rev up violently.
The 'spiders' formation on the Moscow trees signify solely that the plants 'believe' that their environment has become similar to a semi-desert and the plants need to rely upon their reserves for survival. Salt, air pollution by automobile exhaust, hazardous emissions of thermoelectric power stations and industrial enterprises, harmful asphalt exhalations are the main factors which cause premature death of the sprouts. However, the abundance of 'spider'-branches along the intercity highways proves that the air pollution prime factor is automobile exhaust.
For the scientists such a catastrophe is an opportunity to investigate living beings' behaviour in hard conditions and observe the reactions - some species perish, while the others undergo modifications and adapt themselves to a new environment. On the other hand, human beings are equally affected by the same factors that threaten the trees survival and cause death to many plant species unable to adapt themselves to the changes. Crippled trees serve an excellent bio indicator of unfavourable living conditions. To efficiently purify the city air the plant biomass should quickly increase by dozens of times. Only the plants' leaves are capable to utilise harmful substances, discharged by vehicles, asphalt and chimney-stalks.
The space in the city is very expensive. Therefore, plants should be cultivated on the buildings roofs and walls. Various undemanding and fast growing lianas, as well as bushes and grass growing on the rocks are serving this purpose best. It is not worth keeping defective and dying trees in squares and boulevards. They should be replaced by the young ones - strong, vital and capable to actively fight for survival. Such trees should be cultivated from the 'parents' adapted to the Moscow environment, the vegetation being an easy and quick way of multiplying the best plants.
To avoid a waste of money by planting beautiful but, unfortunately, frail saplings, it is necessary to investigate how the polluted city air components get into the plants and how the plants make them harmless. The scientists should carry out a thorough chemical research of interaction between the plants and city environment and determine the critical points of the process. It will enable the scientists to concentrate their efforts on finding or creating (with the help of genetic engineering methods) the organisms