title: Contribution of arbuscular mycorrhizal fungi of sedges to soil aggregation along an altitudinal alpine grassland gradient on the Tibetan Plateau.
abstract: The diversity of arbuscular mycorrhizal fungi (AMF) in sedges on the Tibetan Plateau remains largely unexplored, and their contribution to soil aggregation can be important in understanding the ecological function of AMF in alpine ecosystems. Roots of Kobresia pygmaea C.B. Clarke and Carex pseudofoetida Kük. in alpine Kobresia pastures along an elevational transect (4149-5033 m) on Mount Mila were analysed for AMF diversity. A structural equation model was built to explore the contribution of biotic factors to soil aggregation. Sedges harboured abundant AMF communities covering seven families and some operational taxonomic units are habitat specific. The two plant species hosted similar AMF communities at most altitudes. The relative abundance of the two sedges contributed largely to soil macroaggregates, followed by extraradical mycorrhizal hyphae (EMH) and total glomalin-related soil protein (T-GRSP). The influence of plant richness was mainly due to its indirect influence on T-GRSP and EMH. There was a strong positive correlation between GRSP and soil total carbon and nitrogen. Our results indicate that mycorrhization might not be a major trait leading to niche differentiation of the two co-occurring sedge species. However, AMF contribute to soil aggregation and thus may have the potential to greatly influence C and N cycling in alpine grasslands.
authors: College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China.
authors: Xiaoliang
authors: X
authors: Li
authors: College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China.
authors: Junling
authors: J
authors: Zhang
authors: College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China.
authors: Jingping
authors: J
authors: Gai
authors: Tibet Agricultural and Animal Husbandry College, Tibet University, Linzhi, 860000, China.
authors: Xiaobu
authors: X
authors: Cai
authors: College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China.
authors: Peter
authors: P
authors: Christie
authors: College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China.
authors: Xiaolin
authors: X
authors: Li
mesh_terms: D000531:Altitude; D044822:Biodiversity; D002244:Carbon / Q000378:metabolism; D031255:Carex Plant / Q000382:microbiology*; D029785:Cyperaceae / Q000382:microbiology*; D005656:Fungal Proteins / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D065948:Grassland; D025301:Hyphae / Q000145:classification / Q000235:genetics; D038821:Mycorrhizae; D009584:Nitrogen / Q000378:metabolism; D018517:Plant Roots / Q000382:microbiology*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D018609:Tibet
chemical_list: D005656:Fungal Proteins; D006023:Glycoproteins; D012987:Soil; C573268:glomalin; D002244:Carbon; D009584:Nitrogen