DOI: 10.5061/dryad.d2547d87j
title: Dataset for: Asymmetric response of aboveground and belowground temporal stability to nitrogen and phosphorus addition in a Tibetan alpine grassland

description: Anthropogenic eutrophication is known to impair the stability of
 aboveground net primary productivity (ANPP), but its effects on the
 stability of belowground (BNPP) and total (TNPP) net primary productivity
 remain poorly understood. Based on a nitrogen and phosphorus addition
 experiment in a Tibetan alpine grassland, we show that nitrogen addition
 had little impact on the temporal stability of ANPP, BNPP and TNPP,
 whereas phosphorus addition reduced the temporal stability of BNPP and
 TNPP, but not ANPP. Significant interactive effects of nitrogen and
 phosphorus addition were observed on the stability of ANPP because of the
 opposite phosphorus effects under ambient and enriched nitrogen
 conditions. We found that the stability of TNPP was primarily driven by
 that of BNPP rather than that of ANPP. The responses of BNPP stability
 cannot be predicted by those of ANPP stability, as the variations in
 responses of ANPP and BNPP to enriched nutrients, with ANPP increased
 while BNPP remained unaffected, resulted in asymmetric responses in their
 stability. The dynamics of grasses, the most abundant plant functional
 group, instead of community species diversity, largely contributed to the
 ANPP stability. Under the enriched nutrient condition, the
 synchronization of grasses reduced the grass stability, while the latter
 had a significant but weak negative impact on the BNPP stability. These
 findings challenge the prevalent view that species diversity regulates the
 responses of ecosystem stability to nutrient enrichment. Our findings also
 suggest that the ecological consequences of nutrient enrichment on
 ecosystem stability cannot be accurately predicted from the responses of
 aboveground components, and highlight the need for a better understanding
 of the belowground ecosystem dynamics.
description: # Dataset for: Asymmetric response of aboveground and belowground temporal
 stability to nitrogen and phosphorus addition in a Tibetan alpine
 grassland ## Description of the data and file structure The uploaded files
 include a .R script file and two .csv files for the data. The R codes
 include all codes and results used for the paper. The three .csv files
 include a file for yearly mean values (HB\_NP\_Ann\_Dataset.csv) of
 measured ANPP, BNPP and TNPP, as well as ANPP, species richness and
 relative species biomass of different plant functional groups, i.e.,
 grasses, forbs, legumes and sedges. Description of variables included in
 HB\_NP\_Ann\_Dataset.csv * Site (categorical data): Study site, Haibei
 Station (shortly HB); * Year (categorical data): Measurement year,
 2011-2017; * Block (categorical data): Block * N\_Treat (categorical
 data): Nitrogen addition treatment, N0 for ambient nitrogen and N1 for
 addition of 10 g N m-2 yr-1; * P\_Treat (categorical data): Phosphorus
 addition treatment, P0 for ambient phosphorus and P1 for addition of 5 g P
 m-2 yr-1; * Treat (categorical data): N and P treatments; * Plot\_No.
 (categorical data): Original plot number; * Plot (categorical data): Plot
 number; * ANPP\_MN1 (continuous data): Annual aboveground net primary
 productivity (NPP); * BNPP\_MN1 (continuous data): Annual belowground NPP;
 * BNPP\_00\_10\_MN1 (continuous data): Annual BNPP at 00-10 cm depth of
 soil; * BNPP\_10\_20\_MN1 (continuous data): Annual BNPP at 10-20 cm depth
 of soil; * BNPP\_20\_40\_MN1 (continuous data): Annual BNPP at 20-40 cm
 depth of soil; * TNPP\_MN1 (continuous data): Annual total NPP; *
 alls\_NUM (continuous data): Annual community species richness; *
 gras\_MN1 (continuous data): Annual grass ANPP; * forb\_MN1 (continuous
 data): Annual forb ANPP; * legu\_MN1 (continuous data): Annual legume
 ANPP; * sedg\_MN1 (continuous data): Annual sedge ANPP; * gras\_RSB1
 (continuous data): Annual grass relative species biomass; * forb\_RSB1
 (continuous data): Annual forb relative species biomass; * legu\_RSB1
 (continuous data): Annual legume relative species biomass; * sedg\_RSB1
 (continuous data): Annual sedge relative species biomass; * gras\_NUM1
 (continuous data): Annual grass species richness; * forb\_NUM1 (continuous
 data): Annual forb species richness; * legu\_NUM1 (continuous data):
 Annual legume species richness; * sedg\_NUM1 (continuous data): Annual
 sedge species richness; * Ann\_Precip（continuous data）：Annual
 precipitation (mm); * GS\_Precip (continuous data): Growing-season
 precipitation (MM); * Ann\_Temp (continuous data): Annual mean temperature
 (degree C); * GS\_Temp (continuous data): Growing-season mean temperature
 (degree C); Another two .csv file includes variables calculated across
 years (the overall 7-year data, HB\_CVs\_Dataset.csv, and the 4-year
 paired measurements of ANPP and BNPP, HB\_CVs\_Dataset\_4ys.csv), e.g.,
 the coefficients of variation (CV) of ANPP, BNPP, TNPP, as well as the
 species synchrony and population CV estimated with all species or only
 grasses. Description of variables included in HB\_CVs\_Dataset.csv (or
 HB\_CVs\_Dataset\_4ys.csv) * Site (categorical data): Study site, Haibei
 Station (shortly HB); * Block (categorical data): Block * N\_Treat
 (categorical data): Nitrogen addition treatment, N0 for ambient nitrogen
 and N1 for addition of 10 g N m-2 yr-1; * P\_Treat (categorical data):
 Phosphorus addition treatment, P0 for ambient phosphorus and P1 for
 addition of 5 g P m-2 yr-1; * Treat (categorical data): N and P
 treatments; * Plot (categorical data): Plot number; * ANPP\_MN (continuous
 data): Cross-year mean value of ANPP; * BNPP\_MN (continuous data):
 Cross-year mean value of BNPP; * BNPP\_00\_10\_MN (continuous data):
 Cross-year mean value of BNPP at 00-10 cm depth of soil; *
 BNPP\_10\_20\_MN (continuous data): Cross-year mean value of BNPP at 10-20
 cm depth of soil; * BNPP\_20\_40\_MN (continuous data): Cross-year mean
 value of BNPP at 20-40 cm depth of soil; * TNPP\_MN (continuous data):
 Cross-year mean value of TNPP; * ANPP\_TCV (continuous data): the temporal
 coefficient of variation (CV) of ANPP; * BNPP\_TCV (continuous data): the
 temporal CV of BNPP; * BNPP\_00\_10\_TCV (continuous data): the temporal
 CV of BNPP at 00-10 cm depth of soil; * BNPP\_10\_20\_TCV (continuous
 data): the temporal CV of BNPP at 10-20 cm depth of soil; *
 BNPP\_20\_40\_TCV (continuous data): the temporal CV of BNPP at 20-40 cm
 depth of soil; * TNPP\_TCV (continuous data): the temporal CV of TNPP; *
 alls\_WCV (continuous data): population CV (weighted average population
 CV) estimated with all species; * alls\_SYN (continuous data): species
 synchrony estimated with all species; * alls\_NUM (continuous data):
 Cross-year mean value of community species richness; * gras\_MN
 (continuous data): Cross-year mean value of grass ANPP; * gras\_SD
 (continuous data): temporal standard deviation (SD) of grass ANPP; *
 gras\_RSB (continuous data): Cross-year mean value of grass relative
 species biomass; * forb\_RSB (continuous data): Cross-year mean value of
 forb relative species biomass; * legu\_RSB (continuous data): Cross-year
 mean value of legume relative species biomass; * sedg\_RSB (continuous
 data): Cross-year mean value of sedge relative species biomass; *
 gras\_TCV (continuous data): the temporal CV of grass ANPP; * forb\_TCV
 (continuous data): the temporal CV of forbs ANPP; * legu\_TCV (continuous
 data): the temporal CV of legume ANPP; * sedg\_TCV (continuous data): the
 temporal CV of sedge ANPP; * gras\_NUM (continuous data): Cross-year mean
 value of grass species richness; * gras\_WCV (continuous data): population
 CV estimated with only grasses; * gras\_SYN (continuous data): species
 synchrony estimated with only grasses; * gras\_sumSD (continuous data):
 sum of SD of grass species ANPP; ## Code/Software This is an optional,
 freeform section for describing any code in your submission and the
 software used to run it. All R codes and results used in the manuscript
 were shown in the uploaded .R script.