title: Plant Functional Diversity Can Be Independent of Species Diversity: Observations Based on the Impact of 4-Yrs of Nitrogen and Phosphorus Additions in an Alpine Meadow.
abstract: Past studies have widely documented the decrease in species diversity in response to addition of nutrients, however functional diversity is often independent from species diversity. In this study, we conducted a field experiment to examine the effect of nitrogen and phosphorus fertilization ((NH4)2 HPO4) at 0, 15, 30 and 60 g m-2 yr-1 (F0, F15, F30 and F60) after 4 years of continuous fertilization on functional diversity and species diversity, and its relationship with productivity in an alpine meadow community on the Tibetan Plateau. To this purpose, three community-weighted mean trait values (specific leaf area, SLA; mature plant height, MPH; and seed size, SS) for 30 common species in each fertilization level were determined; three components of functional diversity (functional richness, FRic; functional evenness, FEve; and Rao's index of quadratic entropy, FRao) were quantified. Our results showed that: (i) species diversity sharply decreased, but functional diversity remained stable with fertilization; (ii) community-weighted mean traits (SLA and MPH) had a significant increase along the fertilization level; (iii) aboveground biomass was not correlated with functional diversity, but it was significantly correlated with species diversity and MPH. Our results suggest that decreases in species diversity due to fertilization do not result in corresponding changes in functional diversity. Functional identity of species may be more important than functional diversity in influencing aboveground productivity in this alpine meadow community, and our results also support the mass ratio hypothesis; that is, the traits of the dominant species influenced the community biomass production.
authors: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, 712100, China; Institute of Soil and Water Conservation of Chinese Academy of Sciences & Ministry of Water Resource, Yangling, 712100, China.
authors: Wei
authors: W
authors: Li
authors: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, 712100, China; Institute of Soil and Water Conservation of Chinese Academy of Sciences & Ministry of Water Resource, Yangling, 712100, China.
authors: Ji-Min
authors: JM
authors: Cheng
authors: Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia, 22904-4123, United States of America.
authors: Kai-Liang
authors: KL
authors: Yu
authors: Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia, 22904-4123, United States of America.
authors: Howard E
authors: HE
authors: Epstein
authors: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, 712100, China; Institute of Soil and Water Conservation of Chinese Academy of Sciences & Ministry of Water Resource, Yangling, 712100, China.
authors: Liang
authors: L
authors: Guo
authors: Institute of Soil and Water Conservation of Chinese Academy of Sciences & Ministry of Water Resource, Yangling, 712100, China.
authors: Guang-Hua
authors: GH
authors: Jing
authors: College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China.
authors: Jie
authors: J
authors: Zhao
authors: School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
authors: Guo-Zhen
authors: GZ
authors: Du
mesh_terms: D044822:Biodiversity; D018533:Biomass; D029785:Cyperaceae / Q000145:classification / Q000187:drug effects* / Q000254:growth & development; D005308:Fertilizers; D065948:Grassland; D006801:Humans; D009584:Nitrogen / Q000494:pharmacology*; D010758:Phosphorus / Q000494:pharmacology*; D010802:Phylogeny; D018515:Plant Leaves / Q000187:drug effects* / Q000254:growth & development; D006109:Poaceae / Q000145:classification / Q000187:drug effects* / Q000254:growth & development; D029626:Ranunculaceae / Q000145:classification / Q000187:drug effects* / Q000254:growth & development; D018609:Tibet
chemical_list: D005308:Fertilizers; D010758:Phosphorus; D009584:Nitrogen