关键词: 国际生物多样性观察年

Abstract: Salix psammophila is an excellent sand-fixation plant that can not only thrive in arid desert environment, but also can fix sand and promote desert management by maintaining the balance and stability of desert ecosystems. To understand the species diversity and ecological distribution of AM fungi associated with S. psammophila, we collected soil samples (0–50 cm deep) from the rhizosphere of S. psammophila at three different sites (Heichengzi, Zhenglanqi and Yuanshangdu) in Inner Mongolia in May, August and October 2009. A total of 37 AM fungal species belonging to four genera were isolated. Of these, 23 species belong to Glomus, 10 to Acaulospora, 3 to Scutellospora, and 1 to Gigaspora. Glomus reticulatum was the dominant species at all three sites, Scutellospora was found only in Heichengzi and Zhenglanqi, and Gigaspora decipiens only in Zhenglanqi. Generally, species richness, evenness, Shannon diversity and Simpson diversity indices showed the following trend across sites: Zhenglanqi > Heichengzi > Yuanshangdu. Species diversity of AM fungi in Yuanshangdu was significantly lower than that at the other sites. Species richness and Shannon diversity index of AM fungi were higher in August and October than in May. Species richness, evenness, and diversity indices first increased and then decreased with increasing levels of soil available N. Our results suggest that the subtle complexities present in the symbiotic relationship between S. psammophila and AM fungi in desert ecosystems.

Key words: The International Biodiversity Observation Year