2.5.2. Fauna
Presently, there are no more ecosystems in Moldova that have kept their natural state. The country’s territoryhas been heavily modifiedso that the present ecosystemsare in fact compositesystems consisting of natural and technogenic elements. Due to the impact of human activities, especiallyintensive agriculture, the habitatsof most terrestrial animal species, with a few exceptions, suffereda significantreduction and fragmentation. The enlargement of arable landcaused the retreat of many species to the protected areas (forests, meadows, protection belts). Habitats’ shrinkingis also causedby thetroubling factors: woodcutting, development of the network of settlements and roads, destruction of reproduction sites, poaching, etc.
The fauna is negatively affectedby both local and general factors;animal species can be brought to the brink of extinction through direct elimination or indirectly (climate changes, disappearance of suitable habitats, elimination by other species as result of disbalances induced in the state of natural communities, etc).At any rate, the anthropic factor is by far the main cause of extinction.
The impact of agricultureand industry
The changes in natural landscapes (enlargement of agriculture fields, increased application of agrochemicals, intensivetillage) leaded to shrinking or complete disappearance of some naturalbiotopes. The replacement of the natural communities with new ones leaded to the reduction of the trophic resources for many predators. A lot of species of birds, mammals and lizards are on the brink of extinction. Similarly, many species of big insects whichmake up a significant part of the diet of insectivorous birds, reduced their number.
Manywild animalsneedmosaichabitats, they can not survive in monoculture agriculture landscapes. Despite the parcellation of land as a result of the recent land reform, the damagesthat have been brought to the wild fauna by intensive agriculture practices in the past, have not been compensated [35].
Hydrotechnical works
The hydrotechnical works have a major negative impact onaquatic and paludous ecosystemsthroughthe destruction of natural habitats andintroduction of environmental disbalances. Draining the wetlands in the downstream areas of the rivers Dniester and Prutcausedthe destructionof natural nestingsites for water birds. The construction of barrages on these rivershad a major impact on the migrationand reproductionof manyfish species. It affected the current velocity and water temperaturein the rivers and, consequently, thewhole river ecosystems. As a result, the fish populationsfrom the downstream reaches of the riversDniester and Prut drasticallydecreased. Other major causes affecting the fish populations are water pollution and over-fishing.
Big-scale irrigation also had a negative impacton water ecosystems. Large-scaleirrigation pumps were absorbinga large number of frythat affectedthe reproduction of fish populations. However, the quasi-disappearance of large-scale irrigation schemes, together with the defunct collective farms they served, has removed this factor from the range of major anthropic factors affecting the water ecosystems.
All small (50-200 km length) rivers in Moldova have been regulated during the last 40-50 years. The riverbeds where streamlined and large wetland areas in the floodplain where drained. Presently, in most places the water protection zones are not respected, the floodplainsare intensively used for animal grazing. All meadow ecosystems are degraded.The above factors contributed to the eutrophication of lakes,soilsalinisation, etc. [29]
Inadequate use of pesticidesandmineral fertilizers
The excessive use of pesticidesand mineral fertilizers in the pastcaused the contamination of the environment and the poisoning ofanimals from several species. Persistent pesticidesand their by-products remain in the soil for long time and have capacity for biomagnification through progressive accumulation in the food chain. It is very important to reduce as far as possible the use of pesticides for crop protection and/or to introduce readily biodegradable pesticides.
Pollution ofnatural ecosystems
The pollution of air, watersand soilshave a major impact on the diversityof fauna. Waste water discharges from big animal farms,heavily polluted with organic matters, had disastrous effects on river ecosystems. The high input of nutrients into the water bodies (eutrophication) caused dramatic lossesin aquatic communities (plants, fish, birds). The bioaccumulation of persistenttoxic substances in fish and bird eggs affected the reproduction capacity of animal species.
During the last years,the industrial and agriculture pollutiondecreased due tothedrop in economic activity [13, 24].
Direct impact of anthropicactivities. Hunting, fishingandpoaching
The main factors ofdecreaseof the economically valuable species (fallow-deer, wild boar) are hunting and poaching. The number ofthe mentioned specieshas significantly reducedwhileother wild species almost disappeared (ermine, otter, deer, etc.). Moldavian law allows hunting only on selected areas within an agreed time frame. However, poaching is widespread and cannot be effectively stopped due to the poor capacity of the authorities.
Selective fishing, destructionof reproduction places, introductionof new fish speciesaffectedthe local fish populations.
(Dis)Replacementoflocal species
Several attempts tointroduce new species for hunting purposes did not bring the expected results (racoonlike dog Nyctereutes proceonoides, sika deer Cervus nippon, etc). In a primary stage, the introduced speciesincreased their number spectacularly but due to uncontrolled hunting it,then, rapidly and significantly decreased. The introductionof the sika deer createdthe problem of new hybrids withthered deer (Cervus elaphus). The moufflon andspoon bill (Platalea leucorodia), also introduced in the past, havenever reached a significantnumber.
The stray dogs areanothernegative factor, of anthropic origin, affectingthe stability of local ecosystems. Their number increased quickly over the last years and they took over the niche of the wolf. However, the stray dogs do not play the role of regulator of wild hoofed animals, as wolfs do. [34].
The disturbance factor
The impact of a denseroad network has a number of aspects. The most important is the fragmentation of habitats. The roadscreate barriersfor the movement of animals and act as a major disturbancefactor. Intensive traffic causesthe death of animalsbeing hit by cars. The pollution with exhaust gases and acoustic pollution are alsosignificant.
Lack of public awareness
The scientific information about local animal species, collected over the years, isquite extensive. Nowadays, aneven bigger challenge is to bring this information to the local authorities and the population in the form that would encourage the local communities toprotect the biodiversity.
Natural factors
Natural disasters
The fauna is influencedby droughts, floods, cold winters. These primarily affectthe number ofinvertebrate and small vertebrate speciesandthe animalsthat use them for food [20].
Climate changes
In the recent past, several species (the European bison, aurocchs Bos primigenius, tarpanEquus gmelini, bustard, saiga, etc) disappeared from this territory mainly due to long-term climate changes. Presumably, due to the global climate change induced by man’s activity (raise ofglobal temperature, desertification),several animal species could decrease (wild boar, fallow deer, mice, partridge, quail, snakes, lizards, etc) while other species, with higher temperature preferendum, could appear or increase in number (saiga, marmot, beaver, etc.) [32].
In the Republic ofMoldova, the decreaseof animal diversityis a continuous process (fig. 2.22). The rare speciesand the species on the brink of extinctionare includedin the Red Book of the Republic ofMoldovathat containsdata on animals’ ecology, abundance, area, protection measures. The first Red Book of Moldovawas published in 1979, listing 29 animal species.In 1995,the list of endangered specieswas revised, to include 109 species. In 2001,the second RedBook of the Republic of Moldova was issued, including 116 animal species [8].
Fig. 2.22. Number ofanimal species includedin the Red Book oftheRepublic ofMoldova [8]