Limitations to Reproductive Success in the Dioecious Tree Rhamnus davurica
نویسندگان
چکیده
The reproductive success of a female plant in a dioecious species may be affected by pollen limitation and resource limitation. This study presents evidence that the reproductive success of the dioecious understorey tree species, Rhamnus davurica, is affected by the distance to the nearest male. The sex ratios were female-biased, although showing fluctuations in the three years of conducting the study. The mortality rate of females was higher than that of males indicating a trade-off between reproduction and survival. Altogether 49 females, designated as "focal females", were randomly selected for monitoring their reproductive status between April and October in 2010. But successful reproduction (meaning that the flowering female trees had fruit in the fruiting season) was observed only in 28 females in 2011 and 16 females in 2012. The method of path analysis was applied to determine the effect of topography, local competition and proximity to the nearest male on the fruit set of the females. In the three years of the study, elevation, competition and female size had no significant effect on the fruit set. The distance to the nearest male, however, had a significant effect on fruit set. Number of fruits and fruit set were decreased with increasing distance to the nearest male. It was possible to estimate maximum fruit set, based on the comparatively large dataset. The number of fruits and the fruit set are exponentially related to the distance to the nearest male and the relationships are described by an exponential model. The results of this study support the importance of pollen limitation on the reproductive success in Rhamnus davurica.
منابع مشابه
Analysis of Flavonoids in Rhamnus davurica and Its Antiproliferative Activities.
Rhamnus davurica Pall. (R. davurica) has been used as a traditional medicinal herb for many years in China and abroad. It has been well documented as a rich source of flavonoids with diversified structures, which in turn results in far-ranging biological activities, such as anti-inflammation, anticancer, antibacterial and antioxidant activities. In order to further correlate their anticancer po...
متن کاملRhamnus davurica leaf extract inhibits Fyn activation by antigen in mast cells for anti-allergic activity
BACKGROUND Complementary and alternative herbal medicines are recently considered as a promising approach for treating various diseases. We screened approximately 100 plant extracts for anti-allergic activity. Rhamnus davurica leaf extract showed the most potent inhibitory effect on the activation of RBL-2H3 mast cells. Although Rhamnus davurica extract has been used to treat pruritus, dysuresi...
متن کاملOak forest decline and effects of two invasive shrubs in the Midwest Driftless Area: current status and implications for the future
Oak forests throughout the world are in a state of decline due to lack of oak seedling recruitment to larger size classes. Much of this recruitment decline has been attributed to changes in ecosystem disturbance regimes that have led to increased competition from other species. The Midwest Driftless Area forests in the United States are currently dominated by large oak trees of three species: Q...
متن کاملNovel natural products from marketed plants of eastern and southern Africa*
Marketed plants are an important but a vulnerable group of plants whose investigations as well as conservation should be considered with priority. The chemistry, and in some cases biological activities of novel iso ̄avonoids, nor-lignans, anthracene and naphthalene derivatives and poly prenylated ̄avonoids isolated and characterized from Hagenia abyssinica, Salsola somalensis, Hypoxis spp., Tave...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 8 شماره
صفحات -
تاریخ انتشار 2013