Distribution and diversity of genera Merodon Meigen and Cheilosia Meigen in Southeast Europe: landscape ecological analysis

Abstract

<p>Istraživanje je urađeno u cilju utvrđivanja obrazaca distribucije rodova <em>Merodon</em><br />Meigen, 1802 i <em>Cheilosia</em> Meigen, 1822 na području jugoistočne Evrope. Rodovi<br /><em>Cheilosia</em> i<em> Merodon </em>su najbrojniji fitofagni rodovi osolikih muva, a jugoistočna<br />Evropa je izabrana kao posebno interesantno područje analiziranja distribucije vrsta<br />zbog specifične kombinacije istorijskih, abiotičkih i biotičkih faktora koji određuju<br />distribuciju. Na području jugoistočne Evrope registrovano je ukupno 202 vrste<br />istraživanih rodova; 121 vrsta pripada rodu <em>Merodon</em>, a 81 vrsta pripada rodu<br /><em>Cheilosia</em>. Broj od preko 200 vrsta pokazuje da je jugoistočna Evropa područje od<br />izuzetnog bogatstva vrsta rodova <em>Merodon</em> i <em>Cheilosia</em>. Ovakav zaključak dopunjen je<br />postojanjem čak 79 (39%) endemskih vrsta za područje jugoistočne Evrope. Prema<br />gradijentu geografske &scaron;irine, rodovi <em>Merodon</em> i <em>Cheilosia</em> pokazuju različit distributivni<br />obrazac; uočava se da broj vrsta roda <em>Merodon</em> opada od juga ka severu, dok je<br />distributivni obrazac obrnut za rod <em>Cheilosia</em>.<br />U cilju analiziranja uticaja koje predeona struktura i promene u načinu kori&scaron;ćenja<br />zemlji&scaron;ta imaju na vrste rodova <em>Merodon </em>i <em>Cheilosia</em>, sprovedena je predeono -<br />ekolo&scaron;ka analiza, uz pomoć GIS i odgovarajućih ekolo&scaron;kih softvera. Istraživanje<br />pokazuje da postoji specifičan odnos između predeonih parametara i kompozicije vrsta<br />istraživanih rodova - sa različitom osetljivo&scaron;ću rodova <em>Merodon</em> i <em>Cheilosia</em> na<br />povezanost stani&scaron;ta i promene u načinu kori&scaron;ćenja zemlji&scaron;ta. Vrste roda <em>Cheilosia</em> su<br />pozitivno korelisane sa povezno&scaron;ću stani&scaron;ta a negativno korelisane sa svim ostalim<br />predeonim parametrima, dok najveći broj vrsta roda <em>Merodon</em> pokazuje veću otpornost<br />pri antropogenim promenama u ekosistemima. Ovakvi rezultati upućuju na<br />diferenciraniji pristup pri upravljanju područjima, fokusiran na intenzitet kori&scaron;ćenja<br />zemlji&scaron;ta (ispa&scaron;e) i povezanost stani&scaron;ta.<br />Istraživanje je obuhvatilo i evaluaciju stani&scaron;ta u okviru predela različitih karakteristika<br />(prostorno i vremenski), primenom analize SyrphTheNet bazom podataka, koja<br />uključuje vrste rodova <em>Merodon </em>i <em>Cheilosia</em> kao bioindikatore. Vrste rodova <em>Merodon</em> i<br /><em>Cheilosia</em> su se pokazale kao veoma dobri indikatori koji mogu da ukažu na trenutni<br />kvalitet istraživanog područja, kao i promene tokom dužeg vremenskog perioda.<br />Analizom korelacije utvrđeno je da postoji povezanost između promena predeonih<br />parametra u periodu od 25 godina i gubitka vrsta i kvaliteta makrostani&scaron;ta na 17<br />istraživanih lokaliteta.</p>

<p>The research has been carried out with the main aim to determine distributional patterns of two genera, <em>Merodon</em> Meigen 1802, and <em>Cheilosia</em> Meigen, 1822, in Southeast Europe region. <em>Cheilosia</em> and <em>Merodon</em> are the most numerous phytophagous hoverflies genera.</p><p>Southeast Europe has been chosen as the specific region of interest to analyze species distribution due to its specific combinations of historical, abiotic and biotic factors that determine the species distribution.</p><p>In the area of Southeast Europe, a total of 202 species of <em>Merodon</em> and <em>Cheilosia</em> have been recorded; 121 species belonging to the genus <em>Merodon</em>, and 81 species belonging to the genus <em>Cheilosia</em>, being a region exceptionally rich in species of the two genera. This conclusion has been supported by the fact that 79 (39%) endemic species has been found in the region. With regard to the gradient latitude, species of <em>Merodon </em>and <em>Cheilosia</em> genera show a different distribution pattern. More precisely, it has been shown that the number of <em>Merodon</em> species decreases from the south to the north, while the opposite pattern is true for the species of <em>Cheilosia</em> genus.</p><p>In order to analyze the responses of hoverfly species to landscape structure, land cover analyses were performed using GIS tools and related ecological software. <em>Merodon </em>and <em>Cheilosia </em>species differ in their responses to land-use change and connectivity, with the latter genus being positively correlated with connectivity and negatively correlated with all other variables. Connectivity is the primary factor affecting <em>Cheilosia</em>, while most <em>Merodon</em> species demonstrated greater resistance to changes in human-modified ecosystems. These results suggest that different management efforts, focused on land-use intensity (grazing) or connectivity, seem to be appropriate when trying to conserve these taxa.</p><p>In addition, the study examined the quality of habitats in landscapes of different characteristics (spatial and temporal), using SyrphTheNet database, in which species of the <em>Merodon</em> and <em>Cheilosia</em> genera were&nbsp;&nbsp; used as bioindicators. Species of the two genera proved to be very good indicators of the current quality of the study area, as well as changes over a longer period of time. Correlation analysis has found a significant relationship between the changes of landscape parameters for a period of 25 years and the loss of species and quality macrohabitats on 17 investigated study sites.</p>