Article Figures & Data
Figures
Cylindropuntia multigeniculata (Blue Diamond cholla [Cactaceae]) in habitat at Sloan Canyon National Conservation Area, Nevada. Photo by Alex Stosich, USGS
Flower buds on C. multigeniculata propagated at shade house in Boulder City, Nevada. Photo by Lesley DeFalco, USGS
Cylindropuntia multigeniculata at Blue Diamond Hill type locality. Photo by Alex Stosich, USGS
- Figure 1.
Terminal joints of C. multigeniculata were collected from adult plants on Blue Diamond Hill, Nevada (A), dusted with sulfur (B), and dried at the USGS Boulder City, Nevada, shade house for 25 d before planting under 2 soil and 2 watering treatments (C). Potted joint cuttings were arranged on a bench in the shade house (D) and grew actively (E) before being removed from pots to assess root and shoot growth (F) at the end of the experiment. Photos by Alex Stosich, USGS (A, B, E, F); Lesley DeFalco, USGS (C); Todd Esque, USGS (D)
- Figure 2.
Precipitation prior to joint collection at Blue Diamond Hill, Nevada. The shaded area represents 95% CI around monthly 30-y normal precipitation, and the line represents monthly rainfall preceding collection in June 2020. Data from PRISM Climate Group.
- Figure 3.
Survival functions for the variable that best explained survival, soil mix (highest weight in model with lowest AICc value), for C. multigeniculata joint cuttings at the greenhouse after watering treatments were initiated on 13 August 2020 (N = 36).
- Figure 4.
Measurements of C. multigeniculata joint cuttings (lsmean ± SE) 4 mo after planting in the USGS shade house: shoot biomass (A) and root biomass (B) by soil mix, and root length (C) by watering schedule. Root length lsmean and SE values are back-transformed for clarity. Statistical differences at the P < 0.05 level are denoted by different lowercase letters within each graph.
- Figure 5.
Relative growth rate (lsmean ± SE) over soil and watering treatments for C. multigeniculata joint cuttings at the USGS shade house in Boulder City, Nevada, from 6 July through 20 November 2020. Statistical differences at the P < 0.05 level are denoted by different lowercase letters within the graph.
Tables
- TABLE 1
Mean (± SD) monthly temperatures for collection site at Blue Diamond (30-y normal, PRISM Climate Group 2020) and propagation site at USGS shade house in Boulder City, Nevada, during study period (2020).
Blue Diamond (1067 m elev)
36.05361 N, 115.40083 WBoulder City (770 m elev)
35.97897 N, 114.84136 W————————————°C———————————— June 25.5 ± 0.14 28.3 ± 0.78 July 30.0 ± 0.49 32.0 ± 0.35 August 30.8 ± 1.77 33.2 ± 0.99 September 26.0 ± 1.27 28.9 ± 0.71 October 20.1 ± 1.91 23.9 ± 1.91 November 11.3 ± 0.71 13.8 ± 0.07 - TABLE 2
Water dynamics of soil mixes prior to (6 July–13 Aug, 38 d) and after (13 Aug–16 Nov, 95 d) watering treatment implementation.
Water added (ml) Water lost (ml) WHC (%) Pre-watering treatment (6 July–13 Aug) 85:15 soil mix 3647 ± 51 −3090 ± 12 16.83 ± 1.90 50:50 soil mix 3764 ± 56 −3039 ± 66 24.24 ± 4.09 Watering treatment (13 Aug–16 Nov) 85:15 Infrequent 4228 ± 66 Aa −3936 ± 61 Aa n/a 85:15 Frequent 4570 ± 40 Ab −4259 ± 38 Ab n/a 50:50 Infrequent 4431 ± 53 Ba −4051 ± 59 Ba n/a 50:50 Frequent 4638 ± 20 Bb −4563 ± 65 Bb n/a Notes: A subset of pots was weighted before and after each watering (1 g water = 1 ml) to determine mean total water (± SE) added during watering and lost to evaporation and transpiration. Water dynamics were not significantly different between soil mixes before the watering treatments began. Differences after watering treatments were implemented are denoted by different uppercase letters (soil mix main effect) and lowercase letters (watering frequency main effect). See text for statistical results. The water-holding capacity (WHC) of the 2 soil mixes was determined by weighing pots filled with oven-dried soil and then weighing them again after slowly adding water to pot capacity.
- TABLE 3
Comparison of ordinal logistic regression models for survival of C. multigeniculata joint cuttings prior to initiating watering treatment (6 July–13 Aug) and comparison of failure-time models for survival of joint cuttings during watering treatment (13 Aug–20 Nov).
Survival prior to watering treatmentz Model AICc ΔAIC wi Intercept 112.9053 45.8534 0.0000 CI 67.0518 0.0000 0.8963 CI Soil|Water 71.3648 4.3130 0.1037 Survival during watering treatmenty Model AICc ΔAIC wi Intercept 57.316 9.678 0.0040 Soil 47.638 0.000 0.5101 Soil Water 49.191 1.553 0.2347 Soil Water Vol 51.355 3.717 0.0795 Soil Water CI 51.571 3.933 0.0714 Soil|Water 51.894 4.256 0.0607 Notes: Models are ranked by ΔAICc and only those models with some level of support (ΔAICc < 7) are presented, along with the intercept model for comparison. Akaike weights (wi) are included for comparing the relative importance of the initial joint cutting and treatment attributes: Joint cutting condition index (CI), joint cutting volume (Vol), soil mix (Soil), and watering treatment (Water). Maternal plant did not occur in any of the models with ΔAICc < 7.
↵z Analysis prior to watering treatment implementation (1 mo) included all 80 C. multigeniculata joint cuttings collected.
↵y Analysis during watering treatment included the 39 C. multigeniculata joint cuttings that remained alive after 1 mo, minus 3 joint cuttings that never rooted during the experiment although the shoots remained green and succulent (N = 36).
