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Green Isle Survives In The Urban Environment

May 07, 2002

Fortunately, green spots still remain on the map of Moscow tending to be located in the suburbs of the city, in the valleys of the rivers, away from the densely populated communities. Among them there are several little spots which are surrounded by the city being isolated like isles in the ocean. One of them is the forest park of the Timiryazev Agricultural Academy, which makes part to the Petrovsko-Razumovskoye natural preserve. Long ago the forest was planted especially for the professional training of forestry specialists Russia is famous for. For this purpose the forest was regularly checked up - from time to time the biologists used to count all the plant and animal species in the forest. Actually, the counts happened at rather long intervals: the count results being published once in about half a century. Nevertheless, when the Moscow biologists under the guidance of K.V. Avilova, Senior Research Assistant, Faculty of Biology, Moscow State University, carried out the 2000 `population census` of the plant and animal species at the Experimental Wood Plot, the Timiryazev Agricultural Academy, the biologists had at their disposal the publications to compare the current results with the available counts of 1915 and 1958.
        
The forest has changed within a century: the soil has improved, the microclimate has formed, the upper crown of the trees has become dense and the underbrush has grown thick, the major change affecting the tree species diversity. Initially, the pine-tree was the main tree species in the Timiryazev forest park. Although the number of pine-trees has decreased, this tree species is still prevailing. The fir-tree has become extremely rare - this species can hardly survive in big cities. Instead, the biologists have planted the larch trees to replace the fir-trees, the larch tree has become the dominating species in some locations and has occupied the `ecological niche` of the fir-tree. The territory covered by the oak forest has reduced, but the area occupied by the birch-trees has grown up: the birch-tree is known for high tenacity for life in the urban environment.
        
The bird population of the forest has also been affected. The bird species variety has decreased by the middle of the 20th century as compared to that of the beginning of the last century. This change has particularly affected those species which are not only visiting the forest, but also build the nests and hatch the nestlings there. However, the situation has improved by 2000 - the number of nesting birds has increased. The scientists compared the processes taking place in the bird populations in the first and the second half of the 20th century. Strange as it may seem, the outcome of the research proved the following fact: some bird species disappeared from the Timirayzev forest and some occasionally resettled again. Nevertheless, in the first half of the 20th century the ecosystem was enriched only by one species - starling, while in the second half of the last century there appeared more than 20 species (long-eared owl, mallard duck, goldeneye (Bucephala), grosbeak (Coccothraustes coccothraustes) and some others). A number of species reappeared after a long period (goshawk, lesser-spotted woodpecker, raven , jay (Garrulus), wren and some others). At the beginning of the 20th century more species were recorded to have decreased their populations, later they apparently adapted themselves to the forest in the urban environment. They were the tawny owl (Strix aluco), kestrel (Falco tinnunculus), spotted flycatcher (Muscicapa striata) and red-breasted flycatcher (Muscicapa parva), redwing (Turdus iliacus) and some others. Recently the number of species rather stable in terms of population size (chaffinch (Fringilla coelebs), icterine warbler (Hippolais icterina), bullfinch (Pyrrhula pyrrhula) has risen, this being a good sign.

        The biologists focused on several species living in coniferous forests, particularly in fir-woods. Within the 20th century the Timirayzev forest park witnessed the size of these species populations undergoing different fluctuations. By the middle of the last century the populations of the great spotted woodpecker (Dendrocopos major), robin (Erithacus rubecula), greenfinch (Chloris chloris) and wood warbler (Phylloscopus sibilatrix) have decreased as compared to those of the beginning of the century, but by the end of the 20th century the bird populations have recovered their original size. The bullfinch has always been a rare bird in the forest park, but this species has not disappeared completely from this habitat in spite of the assumptions the scientists could have made. The red-breasted flycatcher (Muscicapa parva), blackcap capinera (Sylvia atricapilla) and song thrush (Turdus philomelos) are the `stars` among the song-birds, their songs being the charm of coniferous forests. By the middle of the last century their populations have decreased, the population size remaining at the same level up to now. In the middle of the 20th century the kinglet (Regulus), siskin (Spinus spinus), pika (Ochotona) and chiffchaff (Phylloscopus collybitus) completely disappeared from the Timirayzev forest park, however, currently they have resettled there again.

        The above resettlement makes the biologists particularly happy, since it signifies that even in a big city a `forest isle` is not necessarily doomed. The forest is able to live, develop and even get enriched with new species, should people help such forest areas to survive. If all the city forests become civilised parks with food stalls and attractions, people may not be able to admire the sight of woodpeckers and robins, to enjoy the songs of the blackcaps and to hear mysterious cries of the tawny owls.

Informnauka (Informscience) Agency