DOI: 10.5061/dryad.n8pk0p37d
title: Nitrogen and phosphorus enrichment differentially affect grassland ecosystem functioning via multi-trophic pathways

description: The enrichment of nutrients (e.g., N and P) is crucial in shaping the
 links between diversity and ecosystem functions. Previous research has
 mainly focused on how nutrient enrichment affects community diversity and
 composition within a single trophic level, such as plants or soil
 microbial communities. However, how nutrient enrichment affects community
 composition and diversity across multiple trophic levels and ecosystem
 functions has not been extensively explored. By conducting two long-term
 N- and P-enrichment experiments in temperate steppes, we explored the
 response of diversity and composition at both the community and functional
 group level across the soil food webs to nutrient enrichment, as well as
 their relationship with ecosystem functions. We found that the responses
 of soil biota and plants to nutrient enrichment varied depending on the
 community and functional group. N-enrichment resulted in a decrease in
 plant and bacterial richness at both the community and functional group
 levels, while P-enrichment decreased fungal and nematode richness at both
 levels. In addition, N-enrichment changed the community composition of
 plants and all soil biota, while P-enrichment only affected the community
 composition of fungi and nematodes. Our findings also showed that
 community composition across multiple trophic levels played a crucial role
 in regulating ecosystem functions (e.g., plant biomass, soil biota
 biomass, and soil organic matter (SOM) decomposition) when considering
 both community composition and diversity simultaneously. For example,
 N-enrichment induced changes in the community composition of plants,
 bacteria, and nematodes, which altered plant biomass, while P-enrichment
 induced changes in the community composition of nematodes that altered
 soil biota biomass and SOM decomposition. Overall, our study suggests that
 long-term nutrient enrichment may have a greater impact on community
 composition than diversity across multiple trophic levels, and these
 changes in community composition can have broad implications for ecosystem
 functions. Therefore, more effort should be made not only on community
 diversity but also on composition to clarify the relationship between
 diversity and ecosystem functions in future studies under climate change.
description: # Nitrogen and phosphorus enrichment differentially affect grassland
 ecosystem functioning via multi-trophic pathways The dataset consists of
 an NP_Data.xlsx and an R code file (R_code.txt). Sheet 1 was the dataset
 for all raw data. The dataset contains 113 variables for Sheet 1. NA in
 the dataset indicates missing data for the relevant variable. **Column
 name -- Units, Description** SampleID -- Unique ID for each sample Treat
 -- unitless Different treatments Block -- Unique ID for each block Lev --
 unitless Level of nutrient enrichment ZLev1 -- unitless Level of nutrient
 enrichment ZLev -- unitless Level of nutrient enrichment PH -- Soil pH SM
 -- % Soil moisture TIN -- mg kg-1 Total inorganic nitrogen SOC -- g kg-1
 Soil organic carbon TSN -- g kg-1 Total soil nitrogen TSP -- g kg-1 Total
 soil phosphorus CTN -- ratio of SOC and TSN CTP -- ratio of SOC and TSP
 NTP -- ratio of TSN and TSP Plant_Rich -- Plant richness AB_Rich --
 Annuals and biennials richness PB_Rich -- Perennial bunchgrass richness
 PF_Rich -- Perennial forbs richness PR_Rich -- Perennial rhizome grasses
 richness Ba_Rich -- Bacterial richness BC_Rich -- C-cycle bacteria
 richness BN_Rich -- N-cycle bacteria richness Fu_Rich -- Fungal richness
 ECM_Rich -- Mycorrhizal fungi richness Path_Rich -- Plant pathogen fungi
 richness Sap_Rich -- Soil saprotrophic fungi composition Nema_Rich -- Soil
 nematode richness BF_Rich -- Bacteria-feeders nematode richness FF_Rich --
 Fungal-feeders nematode richness HF_Rich -- Plant-feeders nematode
 richness OC_Rich -- Omnivores+carnivores nematode richness Plant_PCo1 --
 Plant composition, first axis of the PCoA Plant_PCo2 -- Plant composition,
 second axis of the PCoA AB_PCo1 -- Annuals and biennials composition,
 first axis of the PCoA AB_PCo2 -- Annuals and biennials composition,
 second axis of the PCoA PB_PCo1 -- Perennial bunchgrass composition, first
 axis of the PCoA PB_PCo2 -- Perennial bunchgrass composition, second axis
 of the PCoA PF_PCo1 -- Perennial forbs composition, first axis of the PCoA
 PF_PCo2 -- Perennial forbs composition, second axis of the PCoA PR_PCo1 --
 Perennial rhizome grasses composition, first axis of the PCoA PR_PCo2 --
 Perennial rhizome grasses composition, second axis of the PCoA Ba_PCo1 --
 Bacterial composition, first axis of the PCoA Ba_PCo2 -- Bacterial
 composition, second axis of the PCoA BC_PCo1 -- C-cycle bacteria
 composition, first axis of the PCoA BC_PCo2 -- C-cycle bacteria
 composition, second axis of the PCoA BN_PCo1 -- N-cycle bacteria
 composition, first axis of the PCoA BN_PCo2 -- N-cycle bacteria
 composition, second axis of the PCoA Fu_PCo1 -- Fungal composition, first
 axis of the PCoA Fu_PCo2 -- Fungal composition, second axis of the PCoA
 ECM_PCo1 -- Mycorrhizal fungi composition, first axis of the PCoA ECM_PCo2
 -- Mycorrhizal fungi composition, second axis of the PCoA Path_PCo1 --
 Plant pathogen fungi composition, first axis of the PCoA Path_PCo2 --
 Plant pathogen fungi composition, second axis of the PCoA Sap_PCo1 -- Soil
 saprotroph fungi composition, first axis of the PCoA Sap_PCo2 -- Soil
 saprotroph fungi composition, second axis of the PCoA Nema_PCo1 --
 Nematode taxon composition, first axis of the PCoA Nema_PCo2 -- Nematode
 taxon composition, second axis of the PCoA BF_PCo1 -- Bacterial feeders
 composition, first axis of the PCoA BF_PCo2 -- Bacterial feeders
 composition, second axis of the PCoA FF_PCo1 -- Fungal feeders
 composition, first axis of the PCoA FF_PCo2 -- Fungal feeders composition,
 second axis of the PCoA HF_PCo1 -- Plant feeders composition, first axis
 of the PCoA HF_PCo2 -- Plant feeders composition, second axis of the PCoA
 OC_PCo1 -- Omnivores+carnivores composition, first axis of the PCoA
 OC_PCo2 -- Omnivores+carnivores composition, second axis of the PCoA
 ZPlant_Rich -- Standardized plant richness ZPlant_PCoA1 -- Standardized
 plant composition ZAB_Rich -- Standardized annuals and biennials richness
 ZAB_PCoA1 -- Standardized annuals and biennials composition ZPB_Rich --
 Standardized perennial bunchgrass richness ZPB_PCoA1 -- Standardized
 perennial bunchgrass composition ZPF_Rich -- Standardized perennial forbs
 richness ZPF_PCoA1 -- Standardized perennial forbs composition ZPR_Rich --
 Standardized perennial rhizome grasses richness ZPR_PCoA1 -- Standardized
 perennial rhizome grasses composition ZBa_Rich -- Standardized bacterial
 richness ZBa_PCoA1 -- Standardized bacterial composition ZBC_Rich --
 Standardized C-cycle bacteria richness ZBC_PCoA1 -- Standardized C-cycle
 bacteria composition ZBN_Rich -- Standardized N-cycle bacteria richness
 ZBN_PCoA1 -- Standardized N-cycle bacteria composition ZFu_Rich --
 Standardized fungal richness ZFu_PCoA1 -- Standardized fungal composition
 ZECM_Rich -- Standardized mycorrhizal fungi richness ZECM_PCoA1 --
 Standardized mycorrhizal fungi composition ZPath_Rich -- Standardized
 plant pathogen fungi richness ZPath_PCoA1 -- Standardized plant pathogen
 fungi composition ZSap_Rich -- Standardized soil saprotroph fungi richness
 ZSap_PCoA1 -- Standardized soil saprotroph fungi composition ZNema_Rich --
 Standardized soil nematode richness ZNema_PCoA1 -- Standardized nematode
 taxon composition ZBF_Rich -- Standardized bacteria-feeders nematode
 richness ZBF_PCoA1 -- Standardized bacterial feeders composition ZFF_Rich
 -- Standardized fungal-feeders nematode richness ZFF_PCoA1 -- Standardized
 fungal feeders composition ZHF_Rich -- Standardized plant-feeders nematode
 richness ZHF_PCoA1 -- Standardized plant feeders composition ZOC_Rich --
 Standardized omnivores+carnivores nematode richness ZOC_PCoA1 --
 Standardized omnivores+carnivores composition AFun -- the functions of
 plant biomass BFun -- the functions of soil biota biomass SFun -- the
 functions of SOM decomposition Litter -- Soil decomposition ANPP -- g m-1
 Aboveground net primary production BB -- g m-1 Belowground biomass Cmin --
 mg kg-1 day-1 Soil C mineralization rate Nmin -- mg kg-1 day-1 Soil N
 mineralization rate TMB -- nmol g-1 Total microbial biomass TNA -- ind g-1
 Soil nematode abundance ZAFun -- Standardized the functions of plant
 biomass ZBFun -- Standardized the functions of soil biota biomass ZSFun --
 Standardized the functions of SOM decomposition ## Code/Software The file
 R_code includes all the code required for the manuscript. Any scripts,
 code,or packages can be run using R version 4.0.5 (R Core Team, 2021).