Ecological and biological factors of the geographical distribution of dragonflies of the Mediterranean faunal subregion

The article presents the results of the study of ecological and biological factors of geographical distribution of Mediterranean dragonflies faunal subdomain. Based on the study of climatic, topographical and biological features of the regularities of the distribution of dragonflies dragonflies Distribution depends primarily on the temperature, which, along with humidity, is the main climatic factor. The dependence of dragonfly distribution on temperature is evident in their latitudinal-zonal and vertical-belt distribution. Seasonal conditions of the Northern part of the species range are very similar to those in the mountains. Under such conditions, the vertical variability of the summer duration is largely similar to latitudinal and depends on the average annual air temperatures. By its duration, the water preimaginal phases occupy the main part of the time in the life cycles of dragonflies. Therefore, the characteristics of the aquatic environment, along with the climate, are one of the decisive environmental factors determining the spread of dragonflies. The shortage of suitable water bodies is the most important limiting factor in the spread of dragonflies. Choosing in different parts of the area different degrees of warming standing or flowing water, different populations of the same species are able to gain the necessary amount of ontogenesis effective temperatures, allowing them to exist within a wide gradient of thermal and other factors. This gives many of their species the ability to form and maintain vast three-dimensional habitats. Of the many biotic relationships, interspecies interactions are the most important. Simpatichnuyu the totality of different species of dragonflies has become accepted to call “odontogenic”. Another important biotic factor, which largely determines distribution, is food. However, dragonflies are predators with a very wide food spectrum and there is a point of view that food for them is not a significant biotic factor that can affect their distribution. Compared with natural, anthropogenic factors act very quickly and powerfully. With all the diversity and ambiguity of these factors on the impact on dragonflies, they are divided into two opposite groups: negative factors, primarily the destruction of habitats and positive - the creation of artificial reservoirs.