Pollinator shift and reproductive performance of the qinghai-tibetan plateau endemic and endangered Swertia przewalskii (Gentianaceae)

NWIPB OpenIR

	Pollinator shift and reproductive performance of the qinghai-tibetan plateau endemic and endangered Swertia przewalskii (Gentianaceae)
	Duan, Yuan-Wen ; Liu, Jian-Quan
	2007-06-01
发表期刊	BIODIVERSITY AND CONSERVATION ; Duan YuanWen,Liu JianQuan.Pollinator shift and reproductive performance of the qinghai-tibetan plateau endemic and endangered Swertia przewalskii (Gentianaceae).BIODIVERSITY AND CONSERVATION,2007,16(6):1839-1850
摘要	Reproductive failure results in many plant species becoming endangered. However, little is known of how and to what extent pollinator shifts affect reproductive performance of endangered species as a result of the artificial introduction of alien insects. In this study we examined breeding systems, visitor species, visiting frequency and seed set coefficients of Swertia przewalskii in two years that had different dominant pollinator species (native vs. alien). Flowers of this species were protandrous and herkogamous and insects were needed for the production of seeds. The stigmatic receptivity of this species was shorter than for other gentians. No significant difference in seed set coefficient was found for hand-pollinated plants between the two years, indicating that pollinator shift only had a minor effect on this plant's breeding system. The commonest pollinators in 2002 were native bumblebees, alien honeybees and occasional solitary bees, however, only alien honeybees were observed in 2004. The flower visitation rate in both years was relatively high, although the total visit frequency decreased significantly in 2004. The control flowers without any treatment produced significantly fewer seed sets in 2004 than in 2002. In the past decade the seed production of this species may have partly decreased due to pollination by alien honeybees, however, we suggest that they might have acted as alternative pollinators ensuring seed production of S. przewalskii when native pollinators were unavailable. The main reason that this plant is endangered is probably the result of habitat destruction, but changes in land use, namely intensified agricultural practice and unfavorable animal husbandry have also contributed to its decline. We recommend that in-situ conservation, including the establishment of a protected area, is the best way to preserve this species effectively.; Reproductive failure results in many plant species becoming endangered. However, little is known of how and to what extent pollinator shifts affect reproductive performance of endangered species as a result of the artificial introduction of alien insects. In this study we examined breeding systems, visitor species, visiting frequency and seed set coefficients of Swertia przewalskii in two years that had different dominant pollinator species (native vs. alien). Flowers of this species were protandrous and herkogamous and insects were needed for the production of seeds. The stigmatic receptivity of this species was shorter than for other gentians. No significant difference in seed set coefficient was found for hand-pollinated plants between the two years, indicating that pollinator shift only had a minor effect on this plant's breeding system. The commonest pollinators in 2002 were native bumblebees, alien honeybees and occasional solitary bees, however, only alien honeybees were observed in 2004. The flower visitation rate in both years was relatively high, although the total visit frequency decreased significantly in 2004. The control flowers without any treatment produced significantly fewer seed sets in 2004 than in 2002. In the past decade the seed production of this species may have partly decreased due to pollination by alien honeybees, however, we suggest that they might have acted as alternative pollinators ensuring seed production of S. przewalskii when native pollinators were unavailable. The main reason that this plant is endangered is probably the result of habitat destruction, but changes in land use, namely intensified agricultural practice and unfavorable animal husbandry have also contributed to its decline. We recommend that in-situ conservation, including the establishment of a protected area, is the best way to preserve this species effectively.
文献类型	期刊论文
条目标识符	http://210.75.249.4/handle/363003/45664
专题	中国科学院西北高原生物研究所
推荐引用方式 GB/T 7714	Duan, Yuan-Wen,Liu, Jian-Quan. Pollinator shift and reproductive performance of the qinghai-tibetan plateau endemic and endangered Swertia przewalskii (Gentianaceae)[J]. BIODIVERSITY AND CONSERVATION, Duan YuanWen,Liu JianQuan.Pollinator shift and reproductive performance of the qinghai-tibetan plateau endemic and endangered Swertia przewalskii (Gentianaceae).BIODIVERSITY AND CONSERVATION,2007,16(6):1839-1850,2007.
APA	Duan, Yuan-Wen,&Liu, Jian-Quan.(2007).Pollinator shift and reproductive performance of the qinghai-tibetan plateau endemic and endangered Swertia przewalskii (Gentianaceae).BIODIVERSITY AND CONSERVATION.
MLA	Duan, Yuan-Wen,et al."Pollinator shift and reproductive performance of the qinghai-tibetan plateau endemic and endangered Swertia przewalskii (Gentianaceae)".BIODIVERSITY AND CONSERVATION (2007).