General characteristic of the Codrii Natural Reserve (Moldova)
Written by Ilya Trombitsky
The “Codrii” Natural Reserve (hereafter – Reserve) was founded according to the Decision of the Council of Ministers of the Moldavian SSR nr. 310 from September 27, 1971 with the aim to conserve the most representative areas of forests, specific for Moldova’s Central Plateau. It is the oldest scientific nature reserve in the country.The Reserve is subordinated to Moldova's Forestry Agency “Moldsilva” and operates in accordance with the special Regulations adopted by the Government. Reserve is located 47 km to the South-East from the country capital (Chisinau) (Fig. 1). Its head office is situated near the village Lozova, Straseni raion.
Figure 1 Maps of the Codrii Reserve location (above) and its topography (below). Red line – the reserve borders
The general area of the Reserve is 51.77 sq. km (with the adjacent territory it amounts to 350 sq. km) and is divided into three functional zones (Fig. 2):
Figure 2 Division of the Codrii Reserve into functional zones, Magenta - the strictly protected zone; green the buffer zone
· Strictly protected zone (720 ha), or the core area, which forms the Reserve’s nucleus and comprises sectors with habitats of rare animal and plant species of exceptional value from their scientific and conservation viewpoint. Within this zone any kind of human activity, except scientific and protection research, is forbidden, and here people are just observers.
· Buffer zone (4457 ha) surrounds the strictly protected zone to limit the human impacts. This zone represents forest types similar to those, which are surrounded, and requires an ecological reconstruction through scientifically based interventions within ecological limits of forest ecosystemsnatural development.
· Transition zone (12,300 ha)comprises 2-km area around the buffer zone; it includes mainly private or public agriculture lands. Within this zone all kinds of economic activities, which don’t break the protective limits of natural systems, are allowed.
The natural conditions of the Reserve are typical for the Codrii Central Plateau that was formed by tectonic processes in the Carpathian mountain range resulted in the formation of a hilly forested area; at first sight it create an impression of mountainous area (Fig. 1). The relief is a consequence of tectonic processes, erosion and landslides that caused the development of narrow watersheds with diverse aspects and slopes up to 40°. The highest elevation is in the Cogãlnic Bic River’s watershed and basin, reaching 382.5 m above sea level; the lowest elevation (130 m) is in the valley and watershed of Botna – one of the River Bic tributary’s – that divides the Reserve into two almost equal parts. Large water bodies within the Reserve are missing, but there are many creeks and springs that sometimes create small wetlands.
Climate of the Reserve is temperate continental with short mild winter and long hot summer. In last two decades (1993-2012) the mean annual air temperature was 9.5°C, with mean winter temperature -1.3°C and mean summer temperatures – 20.2°C; mean temperature of transition seasons (spring and autumn) were 9.7°C and 9.6°C, respectively. Absolutely minimal temperatures are observed in January-February (on the average about -13°C), with the record value (-25.9°C) observed in January 2006. Absolutely maximum temperature are observed in July and August (above 31°C), with the record value 39.7°C observed in July 2007. Spring daily temperatures exceeding 5°C (the beginning of plant vegetation) are recorded between 20 and 30 March; late frosts in the air and on the ground are observed between 12 and 19 April, and 27 April and 2 May, respectively. The first autumn frosts occur in the second decade of October. Annual average wind speed is low (about 1.3 m/sec). Mean annual sum of precipitation in the last two decades was 580 mm, varying from 400 mm (2009 yr) to 760 mm (2010 yr). Maximal precipitation are observe in summer (above 200 mm), minimal precipitation – in winter (about 100 mm). 70% of total precipitations fall during the warm season (April to October); only about 10% of precipitation falls as snow. Such climatic conditions favor the growth and developments of all species. The negative aspects of climate, especially in a warm season, are water deficit and dry spells that sometimes can last from 10 days to 2.5 months. Water scarcity limits the spread and normal growth of many plant species.
Soils in the Reserve are of two types: brown and gray. Typical brown soils that occupy the highest hills were formed under beech and oak forests at altitudes of 350-380 m. Grey soils occupy predominant heights of the Reserve at altitudes of 140-300 m. They were formed in different sedimentary rocks, mainly on the Sarmatian bare slopes. The physical properties of soils are satisfactory for normal development of trees. Accumulation of organic matter in the form of humus is the essence of soils, playing a key role in processes of forest growth. As a bioaccumulation peculiarity can be considered the accumulation of organic debris, especially from deciduous leaves. In the upper soil the accumulation of large amount of organic debris from the earth’s surface leads to formation of a bioaccumulative horizon (A) consisting from organic substances.
Climate and geological conditions of the Reserve have resulted in forming a rich and varied flora, and everybody is impressed by nature’s plentiful forms and species, some of which are close to extinction. On the whole here almost 1000 species of plants are protected, that is half of the flora specific to Moldova, including 67 species of lichen, 334 species of fungus, 69 species of moss, and other. The mosaic of ecological environment favors the development of wide-range flora and phytocenosis. Vegetation in the reserve zone is represented by deciduous forests like those in Central Europe. The main types of identified forest vegetation are characterized by the highest floristic complexity and ubiquitous presence of basic species such as oak. Other species can be main or secondary mixtures, depending on the flora dominant position - ash, linden, maple, hornbeam, apple and pear tree, strainer, etc. Although beech occupies not very big area, being on the eastern limit of its natural range, there are reported some types of its forest tree species. Inter zone vegetation was formed in hollows and is represented by narrow strips and patches of poplar, Salcete and mesophilic meadows. Characteristic of this vegetation type is riverside coppice willow in the floodplains of inland waters in the state of marsh vegetation, reeds, rushes, depressions basic slopes gley soils and peat.
The average age of forest is 80 years (from 35 to 95 years). Forests’ distribution by their species is shown in Fig. 3.
Figure 3 Distribution of Codrii forests by their species
The fauna of the Reserve is almost the same as in the forests of Central and Western Europe. It includes about 52 species of mammals, 151 species of birds, 8 species of reptiles, 10 species of amphibians and more than 8,000 species of insects. 10 species of birds are included in the Red Book of Moldova. Codrii is the only reserve in Moldova with a regular study of invertebrates.