Ecological Archives E088-026-A1

F. Leland Russell, Svata M. Louda, Tatyana A. Rand, and Steven D. Kachman. 2007. Variation in herbivore-mediated indirect effects of an invasive plant on a native plant. Ecology 88:413–423.

Appendix A. Characteristics of focal musk thistle patches sampled.

TABLE A1. Characteristics of focal musk thistle patches sampled. See Notes at end of table for more details.

Site
Year
R. conicus
egg load
Musk thistle
density (per m2)
Musk patch
area  (m2)
Total bolting
musk thistles
Adult R. conicus
population size
Adult R. conicus
per musk flower head
Bauman
2001
11 (2.04)
0.74
775.7
573.8
1804.5
0.808 (0.545)
 
2003
3.54 (1.07)
0.64
698.9
446.6
192.6
0.241 (0.128)
Bartlett
2001
26.5 (4.37)
0.13
389.8
52.6
462.4
2.273 (0.673)
 
2002
12.2 (0.98)
0.59
517.0
303.4
1089.1
0.924 (0.542))
 
2003
12.4 (3.56)
0.79
1059.2
841.0
3082.1
0.587 (0.222)
Bogle
2001
15.8 (2.32)
0.44
1153.3
505.1
2471.3
1.262 (0.547)
Burkhalter
2001
26.1 (5.14)
0.59
1025.9
608.4
5257.1
2.235 (0.666)
 
2003
16.7 (3.8)
0.06
371.9
21.6
112.6
1.347 (0.552)
Fleecs
2001
20.7 (5.48)
0.14
261.2
36.8
245.9
1.725 (0.587)
Lehman
2001
15 (1.23)
0.09
3020.8
268.8
1237.0
1.186 (0.544)
Malcom
2001
13.6 (4.15)
0.69
363.5
249.4
1020.2
1.054 (0.541)
 
2003
5.7 (2.07)
0.09
386.9
35.2
43.4
0.312 (0.586)
Neal
2001
21.8 (9.16)
0.23
561.9
130.9
926.4
1.829 (0.6)
 
2003
20 (5.15)
0.10
616.6
59.8
384.1
1.659 (0.579)
Patterson
2001
18.6 (2.2)
0.08
8314.9
681.8
4030.5
1.527 (0.565)
Peterson
2001
31.7 (7.87)
0.80
517.8
412.2
4401.9
2.76 (0.776)
 
2002
3.2 (2.55)
1.51
813.6
1230.2
362.7
0.07 (0.619)
 
2003
25 (4.38)
0.31
1529.6
480.3
3958.1
1.911 (0.436)
Winkenwerder
2001
8.5 (1.7)
9.75
1491.2
14542.2
32713.5
0.58 (0.559)
 
2002
16.1 (4.28)
1.74
1329.8
2308.5
11545.5
1.29 (0.548)
 
2003
16.7 (6.05)
0.21
1312.6
282.2
1473.1
2.04 (0.632)
Beveridge
2002
23.6 (3.01)
1.81
1963.5
3553.9
2795.2
1.99 (0.625)
 
2003
7.2 (3.31)
0.14
268.6
37.1
64.9
0.45 (0.57)
Hilton
2002
20.7 (6.87)
0.15
4715.5
721.5
4816.4
1.72 (0.587)
Horn
2002
23.4 (4.1)
0.36
2629.1
935.9
7168.2
1.98  (0.622)
Howell
2002
3.7 (3.17)
0.58
1478.4
854.5
416.8
0.12 (0.611)
 
2003
6.7 (2.29)
1.93
523.4
1010.1
1614.1
0.41 (0.575)
School
2002
35.8 (12.27)
0.31
282.6
88.2
1073.1
3.15 (0.869)
 
2003
8.2 (1.75)
0.78
1562.2
1221.7
2588.1
0.294 (0.119)
Crawford
2003
5.2 (1.52)
0.64
145.4
93.5
96.1
0.26 (0.592)
Koch
2003
11.4 (4.96)
0.17
695.7
118.9
390.4
0.84 (0.544)
Rawson
2003
5.8 (2.15)
0.58
231.8
135.4
169.5
0.32 (0.585)
Schmeekle
2003
7.9 (2.72)
0.46
824.3
377.5
757.2
0.52 (0.564)

   Notes: "Egg Load" is the mean number (SE) of R. conicus egg cases laid on the terminal flower head of the first subsidiary branch of musk thistle plants in the focal patch. "Total bolting musk thistles" was estimated as bolting musk thistle density × patch area.  "Adult R. conicus population size" was estimated by multiplying "total bolting musk thistles" by the predicted density of R. conicus adults per musk thistle in the focal patch. Density of R. conicus adults per musk thistle in the patch was predicted from the mean egg load on the terminal head of the first subsidiary branch using the equation: mean adult R. conicus per bolting musk thistle = -0.859 + 0.364 (mean number of egg cases per terminal head of first subsidiary branch). Adult R. conicus per musk thistle flower head at the time of peak adult weevil activity in June was predicted using the equation: mean adult R. conicus per head = -0.231 + 0.095 (mean number of egg cases per terminal head first subsidiary branch). For sites in 2003 where adult weevils were counted on musk thistles in June, means (SE) are given in bold type. For sites where mean adult weevils per musk thistle flower head in a focal patch was predicted using the observed egg load for that site, the predicted mean and standard error of prediction are shown.



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