DOI: 10.5061/dryad.80gb5mm10
title: Data from: Reassessing adaptational lag in <em>Eriophorum vaginatum</em>: Short-term responses to reciprocal transplant and passive warming experiments in northern Alaska

description: Previous studies of Eriophorum vaginatum have detected adaptational lag in
 response to climate change. We revisit this concept through a short-term
 reciprocal transplant experiment combined with passive warming via
 open-top chambers (OTCs). We asked: 1) if population growth rates of
 different ecotypes responded differently to reciprocal transplant, 2) if
 home-site advantage existed, and 3) whether there is an interaction of
 ecotype, transplant garden, and OTC treatment. Three transplant gardens
 were established, two north of the Brooks Range (Toolik and Sagwon) and
 one south (Coldfoot), and OTCs were deployed in the northern gardens.
 Tillers were censused in 2016 and 2017. Yellow Taxi Analysis of Lefkovitch
 matrices quantified each tiller’s individual contribution to overall
 population growth rate, which was used as the dependent variable in nested
 ANOVAs. Of tussocks grown in ambient temperature, mean tiller population
 growth from different source ecotypes did not respond differently to
 transplant. Home site advantage was not observed. Mean growth rate of
 warmed tillers was higher at Toolik than Sagwon. Unlike prior long-term
 studies, this study failed to detect differences in tiller population
 growth as a function of garden or ecotype, emphasizing the need for
 long-term monitoring to capture the impact of warming on Arctic species.
description: Three reciprocal transplant gardens were established along the
 Dalton Highway in Alaska, U.S.A. The Coldfoot site (CF; 67.26° N, 150.17°
 W) was situated south of the Brooks Range, while two additional sites,
 Toolik Lake (TL; 68.63° N, 149.36° W) and Sagwon (SG; 69.42° N, 148.72°
 W), were north of the Brooks Range. Haphazardly selected tussocks of
 <em>E. vaginatum</em> were cut from the soil at each site in
 August 2014 by using a serrated knife to slice the roots below the moss
 line. Severed tussocks of each ecotype were reciprocally transplanted to
 each of the three gardens by placing the harvested tussocks in the same
 open location in the tundra where the local tussocks had been removed.
 Controls were established by re-planting severed tussocks into the garden
 from which they originated. Sixty tussocks per ecotype were planted into
 each of the three gardens. Tussocks from the same ecotype were clustered
 in groups of three separated by approximately 0.5 m. At the two most
 northern sites (SG and TL), the twenty resulting clusters were randomly
 assigned to either an ambient treatment (n = 10) or to passive warming (n
 = 10) using open-top chambers (OTC). Open-top chambers were deployed from
 July 11 – August 28, 2015, June 2 – August 28, 2016, and May 30 – August
 26, 2017 in order to raise growing season temperatures experienced by the
 tussocks. Open-top chambers were not deployed at the most southern CF site
 due to the site’s close proximity to the Dalton Highway.
 Two clusters of tussocks (6 total tussocks) from each ecotype and
 garden combination and from each warming treatment were randomly selected,
 and were visited while in peak leaf biomass in July 2016. Eighteen
 haphazardly selected tillers from each tussock were tagged using numbered
 plant tags affixed to each tiller using a zip tie. In instances where
 fewer than 18 tillers were present in a tussock, all living tillers were
 tagged. During the 2016 census, the total number of green, living leaves
 per tagged tiller was tallied, and the length of the two longest leaves in
 each tiller was measured. All the tagged tillers were re-censused in July
 2017 using the same technique as in 2016. After being censused in the
 field, each tussock was carefully removed from its location and dissected
 to count the number of daughter shoots (easily distinguished from older
 leaves by the lack of any browned, over-wintered tips) produced
 vegetatively by each adult tiller. Tillers that died over the transition
 period were identified by the lack of any living leaves. Sixteen tillers
 were removed from the dataset due to the loss of tags from tillers during
 transportation and potential double-tagging.  Total
 leaf areas of each tiller for both 2016 and 2017 were estimated using the
 allometric relationship between leaf area and the tiller size index, which
 is the product of the number of leaves per tiller and the sum of the
 length of the two longest leaves. Four size-based stage classes were
 identified using the 2017 tillers, in addition to a separate stage class
 (stage class 1; S<sub>1</sub>) comprised of 2016 daughter
 tillers. A stage-based Lefkovitch model was constructed based on the
 possible transitions among these stage classes. The
 transition of daughter tillers (in 2016) to higher stage classes (in 2017)
 was inferred using previously collected data. This inference was
 necessary, because while S<sub>1</sub> tillers were tallied in
 2017, their 2017 size was unintentionally excluded, and so it was
 impossible to determine the size transition of those tillers between 2016
 and 2017. Using this prior dataset, daughter tillers (from 2010) from the
 same garden and ecotype combinations used in the current study were
 identified (N = 84). The 2011 leaf area of these identified daughter
 tillers was noted and was used to determine the proportion of those
 daughter tillers that fell into each of the size-based stage classes (2-5)
 identified in the 2017 study. None of the daughter tillers died over the
 transition period, 69% of daughter tillers transitioned into the
 equivalent of the 2017 size class two, 16.7% into class three, 10.7% into
 class four, and 3.6% into class five. These calculated transition
 probabilities along with the actual number of daughter tillers identified
 in the 2017 study were used to estimate the number of daughter tillers (in
 2016) that transitioned to each stage within each garden, ecotype, and
 warming treatment combination in 2017. Each daughter tiller (2016) was
 assigned a random number, and a cumulative distribution was used to assign
 2017 classes to these individuals using the derived proportions.
 Two separate 5x5 matrices were constructed using MATLAB version
 R2019B. The first excluded all tillers exposed to OTC treatments and
 focused only on the transplanted tillers in all combinations of garden and
 ecotype. The second excluded the CF garden, as no OTC treatments were
 deployed at CF. However, all other tillers in the design were analyzed,
 which included all tillers from the combination of garden (TL and SG),
 source ecotypes (CF, TL, and SG), and treatment (ambient vs. OTC).
 Population growth rates (λ) were calculated as the dominant eigenvalue of
 each matrix. Yellow Taxi Analysis (YTA), a derivative of Tukey’s
 Jackknife, was performed to provide the replication necessary to run
 statistical analyses. Yellow Taxi Analysis provides pseudovalues of lambda
 (f<sub>i</sub>) for each observation, which measure each
 tiller’s contribution to overall population growth rate.
 A mixed model two-way ANOVA design was developed and analyzed
 using restricted maximum likelihood (REML) in order to determine if
 tussocks from different source ecotypes responded differentially to
 transplanting along the latitudinal gradient. The pseudovalue of lambda
 (f<sub>i</sub>) was the dependent variable, garden and source
 ecotype were the main effects, cluster (of three tussocks) was a nested
 random effect within the garden x ecotype interaction term, and tussock
 was a nested random effect within the cluster(garden x ecotype) term. Only
 tussocks subjected to ambient temperature treatments (non-OTC) were used
 in this analysis.  A separate mixed model two-way ANOVA
 was constructed and analyzed by REML using data from all ambient
 temperature (non-OTC) combinations of garden (CF, TL, and SG) and source
 ecotype (CF, TL, and SG) to determine if tussocks that were planted back
 into their original home garden differed in performance from those
 tussocks that were transplanted to different “away” gardens. The
 pseudovalue of lambda (f<sub>i</sub>) was the dependent
 variable, garden was the first independent variable, and source ecotype
 re-coded as “home” or “away” was the second independent variable. Cluster
 (of three tussocks) was a nested random effect within the garden x
 home/away interaction term, and tussock was a nested random effect within
 the cluster(garden x home/away) term.  Using data only
 from tillers growing in the two most northern sites (TL and SG), a
 three-way ANOVA model was constructed and analyzed using REML to determine
 if the two-way interaction of garden (TL and SG) and source ecotype (TL,
 SG, and CF) depended on warming treatment (Ambient
 <em>vs</em>. OTC). Pseudovalue of lambda
 (f<sub>i</sub>) was the dependent variable, while garden,
 source ecotype, and warming treatment were main effects. Cluster (of three
 tussocks) was a nested random effect within the garden x ecotype x
 treatment three-way interaction term, and tussock was a nested random
 effect within the cluster(garden x ecotype x treatment) term.
description: # Data from: Reassessing adaptational lag in *Eriophorum vaginatum*:
 Short-term responses to reciprocal transplant and passive warming
 experiments in northern Alaska Dataset DOI:
 [https://doi.org/10.5061/dryad.80gb5mm10](https://doi.org/10.5061/dryad.80gb5mm10) ## Description of the data and file structure ### Files and variables #### File: Chandler_AK_16-17_Dryad.xlsx **Description:** Data are stored in .xlsx format Data collected in 2016 and 2017 are included in the .xlsx file Missing data are represented by blank cells ##### Variables * "Garden" refers to the location of transplant (CF - Coldfoot, TL - Toolik Lake, SAG - Sagwon) * "Source" refers to the ecotype of tussock being transplanted (CF - Coldfoot, TL - Toolik Lake, SAG - Sagwon) * "Cluster" refers to the physical group of 3 tussocks in the study * "Tussock" refers to the single tussock within a cluster * "OTC (Y/N)" refers to whether passive warming* via* open-top chamber was applied to the cluster * "Tag" refers to the identity of each of the separate tillers that were tagged in each given tussock * "NumOld" refers to number of old leaves * "NumNew" refers to number of new leaves * "LL1(mm)" refers to the length of leaf number one in millimeters * "LL1(cm)" refers to the length of leaf number one in centimeters * "LL2(mm)" refers to the length of leaf number two in millimeters * "LL2(cm)" refers to the length of leaf number two in centimeters * "Total Leaf Count" refers to the total number of leaves in the tiller * "LL1+LL2" refers to the leaf length (in cm) of leaf one plus leaf two * "Index" refers to the product of the total leaf count and LL1+LL2 * "Leaf Area" refers to the inferred leaf area of the tiller * "Stage Class" represents the size class assigned to each tiller * "Comments" refers to any field or lab comments  * "2017 Flower (y/n)" refers to whether a tiller produced a flower in 2017 * "2017 Type" refers to tiller type (1 - dead, 2 - non-reproductive adult, 3 - vegetatively reproductive adult) * "2017 #S~o~" refers to the number of current year daughter tillers produced vegetatively * "2017 #S~1~" refers to the number of last year daughter tillers produced vegetatively ## Code/software Excel, CSV