انتقال بذر توسط علفخواران با جثه متفاوت و ارتباط آن با پوشش گياهي در پارك ملي كلاه قاضي

چكيده انگليسي :

Seed Dispersal by Different sized Herbivores and its relationship with established vegetation in Kolah Ghazi National Park Reza Kavandi Habib R kavandihabib@na iut ac ir Department of Natural Resources Isfahan University of Technology Isfahan 84156 8311 IranDegree M Sc Language PersianSupervisors Majid Iravani Majid Iravani@wsl ch Josef Senn Mohammad Taghi FeiziAbstractSeed dispersal via dung endozoochorous seed dispersal is one of the vital impacts of herbivores onrangeland habitats which plays key role in vegetation dynamics of such ecosystems This is trulyimportant for arid and semiarid ecosystems in which most of plant species regenerate by seeds To assessthe potential seed dispersal of plant species by different sized herbivores in rangeland habitats of CentralIran three wild herbivore species of cape or brown hare Lepus capensis Persian gazelle Gazellesubguttrosa and wild goat Capra aegagrus in Kolah Ghazi National Park were considered 10 habitatsites including 5 independent replicates for wild goat and 5 ones for another two herbivore species wereselected During spring and autumn growing seasons April to June and October to November inflorescences production and grazing pattern of all plant species were studied using five 15m2 belttransects 30 x 0 5m In each sampling period 10 freshly pellet groups dung sample of herbivorespecies were randomly collected in each of selected habitat sites 5 sampling period 5 habitat sites foreach herbivore in total 750 dung samples Dung samples were dried in a dark room by exposing to openair and then from each a 50 g sample was taken and kept in refrigerator for two months at 3 c for coldstratification treatment Seed content of dung samples were determined in greenhouse germinationexperiments over a period of 8 months In total 3766 seedlings from 60 plant species 19 43 and 45 seedspecies in dung samples of cape hare Persian gazelle and wild goat respectively 31 families and 54genera were recorded in dung samples of the three herbivore species Dung seed content was mainlycomposed by annual herbaceous species with attractive inflorescences which have no dispersalmechanism except production of many small seeds The highest and least dung seed density for allherbivore species were observed in April and November samples respectively Seed species compositionof dung samples significantly differed between different sized herbivores Also the number of seedspecies dispersed via dung of three herbivore species was directly related to their body sizes However the observed differences in dung seed density of herbivore species was not related to their sizes so thatthe highest and the least number of seeds were recorded in dung samples of wild goat and Persian gazelle respectively Comparison between the species composition of dung samples and of the inflorescenceproduction transects where they had been dropped showed that dung seed content of larger herbivores wild goat and Persian gazelle might be more as a result of both forage selection pattern and number ofinflorescences seeds produced whereas in case of hare it might be mainly associated with forageselection pattern Given that most of plant species recorded in the Park regenerate by seeds and that seedsof different plant species dispersed by herbivore species seed dispersal via dung of different sizedherbivores may play an important role in vegetation conservation and dynamics of these rangelandshabitats only if necessary environmental factors met While increasing knowledge of plant seed dispersal results of the present research can be specially applied in managing country s protected ecosystems andrangeland habitats Keywords Seed germination experiments foliage selection pattern vegetation dynamics seed andinflorescences production rangelands habitats dung seed content

كاوندي حبيب، رضا

انتقال بذر توسط علفخواران با جثه متفاوت و ارتباط آن با پوشش گياهي در پارك ملي كلاه قاضي

آزمايش هاي جوانه زني بذر , الگوي انتخاب علوفه , پويايي پوشش گياهي , توليد گل آذين و بذر , زيستگاه هاي مرتعي