J Plant Ecol ›› 2016, Vol. 9 ›› Issue (2): 144-152.DOI: 10.1093/jpe/rtv043

• Research Articles • Previous Articles     Next Articles

The effects of fertilization on the trait-abundance relationships in a Tibetan alpine meadow community

Xiaolong Zhou1, Youshi Wang2, Pengfei Zhang1, Zhi Guo1, Chengjin Chu1,3 and Guozhen Du1,*   

  1. 1 State Key Laboratory of Grassland and Agro-ecosystems, School of Life Sciences, Lanzhou University, 222 Tianshui Road, Lanzhou 730000, Gansu, People's Republic of China; 2 Ministry of Education Key Laboratory of Western China's Environmental Systems, Research School of Arid Environment and Climate Change, Lanzhou University, 222 Tianshui Road, Lanzhou 730000, Gansu, People' Republic of China; 3 SYSU-Alberta Joint Lab for Biodiversity Conservation, State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University, 135 Xingang Road, Guangzhou 510275, Guangdong, People' Republic of China
  • Received:2014-12-20 Accepted:2015-04-26 Published:2016-03-24
  • Contact: Du, Guo-zhen

Abstract: Aims Comparisons of the trait–abundance relationships from various habitat types are critical for community ecology, which can offer us insights about the mechanisms underlying the local community assembly, such as the relative role of neutral vs. niche processes in shaping community structure. Here, we explored the responses of trait–abundance relationships to nitrogen (N), phosphorus (P) and potassium (K) fertilization in an alpine meadow.
Methods Five fertilization treatments (an unfertilized control and additions of N, P, K and NPK respectively) were implemented using randomized block design in an alpine Tibetan meadow. Species relative abundance (SRA), plant above-ground biomass and species richness were measured in each plot. For 24 common species, we measured species functional traits: saturated height, specific leaf area (SLA) and leaf dry matter content (LDMC) in each treatment but seed size only in the unfertilized control. Standard major axis (SMA) regression and phylogenetically independent contrasts (PICs) analysis were used to analyse species trait–abundance relationships in response to different fertilization treatments.
Important findings Positive correlations between SRA and saturated height were raised following N, P and NPK fertilizations, which indicated an increase in light competition in these plots. In P fertilized plots, SRA was also positively correlated with LDMC because tall grasses with a nutrients conservation strategy often have a relative competitive advantage in capturing limited light and soil nutrients. In K fertilized plots, neither the trait–abundance relationships nor above-ground biomass or species richness significantly differed from that in the control, which suggests that K was not a limiting resource in our study site. These significant correlations between species traits and relative abundance in fertilized treatment suggest that trait-based selection plays an important role in determining species abundance within local communities in alpine meadows.

Key words: community structure, community assembly, functional trait, non-neutral process, species relative abundance

摘要:
Aims Comparisons of the trait–abundance relationships from various habitat types are critical for community ecology, which can offer us insights about the mechanisms underlying the local community assembly, such as the relative role of neutral vs. niche processes in shaping community structure. Here, we explored the responses of trait–abundance relationships to nitrogen (N), phosphorus (P) and potassium (K) fertilization in an alpine meadow.
Methods Five fertilization treatments (an unfertilized control and additions of N, P, K and NPK respectively) were implemented using randomized block design in an alpine Tibetan meadow. Species relative abundance (SRA), plant above-ground biomass and species richness were measured in each plot. For 24 common species, we measured species functional traits: saturated height, specific leaf area (SLA) and leaf dry matter content (LDMC) in each treatment but seed size only in the unfertilized control. Standard major axis (SMA) regression and phylogenetically independent contrasts (PICs) analysis were used to analyse species trait–abundance relationships in response to different fertilization treatments.
Important findings Positive correlations between SRA and saturated height were raised following N, P and NPK fertilizations, which indicated an increase in light competition in these plots. In P fertilized plots, SRA was also positively correlated with LDMC because tall grasses with a nutrients conservation strategy often have a relative competitive advantage in capturing limited light and soil nutrients. In K fertilized plots, neither the trait–abundance relationships nor above-ground biomass or species richness significantly differed from that in the control, which suggests that K was not a limiting resource in our study site. These significant correlations between species traits and relative abundance in fertilized treatment suggest that trait-based selection plays an important role in determining species abundance within local communities in alpine meadows.