Flowering phenology for seven California annual species under two rainfall treatments
Data files
Jan 16, 2025 version files 42.13 KB
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all_species_flower_data.csv
26.79 KB
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boots_pairs_w_sup.csv
1.46 KB
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README.md
7.49 KB
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sedg_rain_2020.csv
6.40 KB
Abstract
Premise: Shifts in the timing of life history events, or phenology, have been recorded across many taxa and biomes in response to global change. These phenological changes are often studied in a single species context, but considering the community context is essential for anticipating the cascading effects on biotic interactions that are likely to occur. Focusing on an annual grassland plant community, we examined how experimental changes in precipitation affect flowering phenology in a community context and explore the implications of these shifts for competitive interactions and species coexistence.
Methods: We experimentally manipulated rainfall with rainout shelters and recorded detailed flowering phenology data for seven annual species including two grasses and five forbs. We assessed how their first and peak flowering days were affected by changes in rainfall and explored how flowering overlap between competing species changed.
Results: Changes in rainfall shifted flowering phenology of some species, but sensitivity differed among neighboring species. Four of the seven species studied started and/or peaked flowering earlier in response to reduced water availability. The idiosyncratic shifts in flowering phenology have the potential to alter existing temporal dynamics that may be maintaining coexistence, such as temporal separation of resource-use among neighbors.
Conclusions: Our results show how species-specific phenological consequences of global change can impact community dynamics and competition between neighboring plants and warrant future research.
README: Flowering phenology for seven California annual species under two rainfall treatments
This is the data and analysis code for the manuscript entitled, "Changes in flowering phenology with altered rainfall and the potential community impacts in an annual grassland." It includes the number of flowers visible for 7 annual plant species (5 forbs, 2 grasses), grown in mixed competition plots under two precipitation periods during the 2020 growing season.
Contact Mary Van Dyke (mary.vandyke@colostate.edu) with any questions. This manuscript has been accepted for publication in the American Journal of Botany (1/15/2025):
Van Dyke, M.N., N.J.B. Kraft. Changes in flowering phenology with altered rainfall and the potential community impacts in an annual grassland. American Journal of Botany (accepted).
There are three data files and three R scripts
Data files include:
all_species_flower_data.csv
This file contains the flowering phenology data for 7 annual plant species under two precipitation treatments. All data was collected by the authors.
variables | units | description | |
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species | categorical | species codes for 7 species: ACWR = Acmispon wrangelianus, FEMI = Festuca microstachys, HOMU = Hordeum murinum, LACA = Lasthenia californica, NAAT = Navarretia atractyloides, PLER = Plantago erecta, URLI = Uropappus lindleyi californica | |
plot | number | plots are numbered 1 through 20 | |
block | number | there were ten blocks which each included two plots of the same precipitation treatment | |
treatment | categorical | precipitation treatment, c = control, s = shelter | |
doy | number | day of year with January 1, 2020 as 1 | |
flower | number | number of flowers in bloom within the plot |
sedg_rain_2020.csv
This file contains rainfall data collected at the experimental site from October, 2019 to August, 2020.
variables | units | description |
---|---|---|
year | number | year data was collected - always 2020 |
month | number | month data was collected |
day | number | day of the month data was collected |
rain_cumulative | number | cumulative rainfall on ambient plots in mm since October 1, 2019 |
d_o_y | number | day of year with January 1, 2020 as 1 |
selter_rain | number | cumulative rainfall on reduced rainfall plots since October 1, 2019, assuming a 50 percent reduction after February 8, 2020 when rainout shelters were erected. |
boots_pairs_w_sup.csv
This file contains competition parameter estimates from previous experiment performed in the 2019 growing season.
variables | units | description | |
---|---|---|---|
focal | categorical | species codes for 7 species, ACWR = Acmispon wrangelianus, FEMI = Festuca microstachys, HOMU = Hordeum murinum, LACA = Lasthenia californica, NAAT = Navarretia atractyloides, PLER = Plantago erecta, URLI = Uropappus lindleyi californica | |
competitor | categorical | species codes for 7 species, same codes as focal variable | |
treatment | categorical | precipitation treatment, c = control (ambient), s = shelter (reduced rain) | |
snd | number | estimated stabilizing niche difference between the pair of species | |
fd_superior | number | estimated fitness difference between the pair |
All phenology data was collected in person and from photographs in the spring of 2020 from Sedgwick reserve in Santa Barbara county, CA
Code files include:
boots_final.R
all code needed for analysis, need to run this before running either of the figure scripts
final_figures.R
code needed to create figures in the manuscript
supplemental_figures.R
code needed for all figures in supplementary material appendix 1
Methods
The experiment was conducted at the University of California, Santa Barbara’s Sedgwick Reserve in Santa Barbara County, USA. Twenty 0.75m*0.75m plots were established and seeded in October 2019 in a fenced area designed to exclude deer and gophers, the two primary mammalian herbivores in the system. One hundred seeds of seventeen cooccuring annual grasses and forbs were mixed and hand sown in each plot. The plots were paired into ten blocks. Rain reduction shelters designed to divert 50% of incoming rain were placed over five of the blocks and therefore half of the plots on February 8, 2020. This timing allowed all plants to germinate and establish in late December and January with the same ambient rainfall conditions, resulting in the rainfall exclusion treatment impacting just the growth and reproduction phase of the plants’ life cycle. The seven most abundent species that germinated were tracked over the course of their lifetime. We used daily photographs from cameras mounted at each plot to identify the flowering window for each species (i.e. first and last days of flowering). We then counted the number of flowers in the photos over that time period, avoiding images that were obscured by condensation, rain, or wind-driven camera and plant movement. This resulted in counts of open flowers every 1 to 5 days for each species during their flowering period. The plots were also visited in person every two weeks and every flowering individual was identified and counted.