اهميت رابطه متقابل مورچه و آهو براي ساختار و تركيب پوشش گياهي در پارك ملي كلاه قاضي اصفهان

چكيده انگليسي :

The importance of ant gazelle interaction for vegetation structure and composition in Kolah Qazi National Park Isfahan Razieh Mirzajani Darestani Department of Natural Resources Isfahan University of Technology Isfahan 84156 8311 Iran Degree M Sc Language PersianSupervisors Majid Iravani majid iravani@cc iut ac ir Donat Agosti Mahmoodreza HemamiAbstractThe structure and species composition of vegetation in grazing ecosystems have been formed as aresult of the evolutionary and mutual relationship of different animal groups with each other and thevegetation within a long period of time Herbivores with a variety of body sizes including both vertebrates and invertebrates have interactive effects on each other through the vegetation in theircommon habitat The impact of such relationships on the vegetation is still one of the subjects ofinterest by the ecologists In this study the importance of seed harvesting ants Messor species andPersian gazelle Gazelle subgutturosa on the vegetation and soil seed bank in rangeland habitats ofKolah Ghazi National Park were investigated 15 active ant nest sites established besides the gazelledroppings accumulation sites gazelle presence ant presence sites were chosen and then in theclosest distance to each location one ant nest site without gazelle droppings accumulation site in thesurrounding ant presence gazelle absence sites and a gazelle droppings accumulation site withoutany ant nest site around it gazelle presence ant absence sites were selected totally 15 sites for eachcombination of gazelle and ant presences Vegetation was studied inside and outside of each siteusing a 25 25cm plots A pooled soil sample was taken from each site to investigate the soil seedbank composition in the greenhouse Totally 61 plant species belonged to 19 different families and 60different genera were recorded in the vegetation plots of sites and the relevant surrounding areas Thetotal vegetation cover and the relative frequency of annual and also forb species at the gazellepresence ant presence sites were significantly higher than those of the droppings accumulation sites Specie richness and the relative frequency of graminoid species at the droppings accumulation siteswere significantly higher than those of gazelle presence ant presence sites Meanwhile the results ofDCA analysis indicated that vegetation species composition in droppings accumulation sites isdifferent from those of gazelle presence ant presence sites In germination experiments at thegreenhouse for 6 months 4 625 seeds from 120 cultivated soil samples germinated which belonged to69 plant species from 24 families and 59 genera The relative frequency of forb species in gazellepresence ant presence sites was significantly bigger than the same for the mere droppingsaccumulation sites or mere ant nest sites this is while the total density specie richness and therelative frequency of graminoid species in soil seed bank of mere droppings accumulation sites werehigher On the other hand the results of DCA analysis showed the different species composition ofsoil seed bank in different sites of presence of the two animal groups one or both In conclusion theeffect of activities of both animal groups e g ant nest and or gazelle droppings accumulation sites onthe vegetation and soil seed bank are obvious while such effect is different Meanwhile the jointeffect of both animal groups on the vegetation and soil seed bank is different from their independenteffects Considering the dry climate of the studied ecosystem both animal groups therefore play amajor role in the structure and composition of vegetation and specially the seed storage of plantspecies in the soil which is essential for their cycle of life The result of this study presents theecological importance of different animal groups in dry regions ecosystems especially relating to thesoil seed bank and vegetation dynamics which may be applied in the management of protectedecosystems and rangeland habitats

ميرزاجاني، راضيه

اهميت رابطه متقابل مورچه و آهو براي ساختار و تركيب پوشش گياهي در پارك ملي كلاه قاضي اصفهان

اكوسيستم هاي چرايي , علفخواران , پويايي پوشش گياهي و بانك بذر خاك , تركيب گونه اي , آزمايشات جوانه زني