Potential for ants and vertebrate predators to shape seed-dispersal dynamics of the invasive thistles Cirsium arvense and Carduus nutans in their introduced range (North America)

Plant Ecology ◽  
2010 ◽  
Vol 210 (2) ◽  
pp. 291-301 ◽  
Author(s):  
Christina Alba-Lynn ◽  
Shanna Henk
Keyword(s):  
North America ◽  
Seed Dispersal ◽  
Cirsium Arvense ◽  
Carduus Nutans ◽  
Introduced Range ◽  
Vertebrate Predators

scholarly journals Impact of perennial ryegrass seeding densities on weed emergence growth and development

2000 ◽  
Vol 53 ◽  
pp. 38-43
Author(s):  
S.S. Seefeldt ◽  
M.L. Armstrong
Keyword(s):  
Perennial Ryegrass ◽  
Growth And Development ◽  
Field Experiments ◽  
Cirsium Arvense ◽  
Seeding Density ◽  
Senecio Jacobaea ◽  
Carduus Nutans ◽  
Weed Growth ◽  
Californian Thistle ◽  
Weed Emergence

Research was conducted to determine the effect of perennial ryegrass (Lolium perenne) sowing density on weed growth and development In glasshouse and field experiments perennial ryegrass was sown at rates of 0 5 10 20 40 and 80 kg/ha with 5 kg/ha of white clover (Trifolium repens) With increasing seeding density perennial ryegrass enhanced its competitiveness against all five of the weeds studied viz nodding thistle (Carduus nutans) Californian thistle (Cirsium arvense) Scotch thistle (Cirsium vulgare) ragwort (Senecio jacobaea) and hedge mustard (Sisymbrium officinale) In both trials increases in the perennial ryegrass seeding density did not reduce weed emergence However as perennial ryegrass density increased weed biomass decreased and time to flowering increased

Geographic Patterns of Interspecific Hybridization between Spotted Knapweed (Centaurea stoebe) and Diffuse Knapweed (C. diffusa)

2009 ◽  
Vol 2 (1) ◽  
pp. 55-69 ◽  
Author(s):  
Amy C. Blair ◽  
Ruth A. Hufbauer
Keyword(s):  
North America ◽  
North American ◽  
Management Strategies ◽  
Spotted Knapweed ◽  
The North ◽  
Hybrid Swarms ◽  
Hybrid Plants ◽  
Introduced Range ◽  
Diffuse Knapweed ◽  
A Site

AbstractHybridization between species has the potential to change invasion dynamics. Field observations suggest that spotted knapweed and diffuse knapweed, two ecologically and economically destructive invasive plants, hybridize in their introduced range. As a first step towards understanding whether hybridization has affected the dynamics of the invasion of these species, we conducted field surveys in the introduced (North American) and native (European) ranges to discern patterns of hybridization and measured fitness-related traits among field hybrids and parental species. In North America we detected plants with hybrid morphology in 97% of the diffuse knapweed sites (n= 40); such hybrid plants were taller and more often exhibited polycarpy than plants with typical diffuse knapweed morphology. Hybrids were not detected in North American spotted knapweed sites (n= 22). In most regions surveyed in Europe, diffuse knapweed and spotted knapweed were isolated from each other and existed as distinct, nonhybridizing species. However, in Ukraine, the two species frequently coexisted within a site, resulting in hybrid swarms. On average, the plants from the North American diffuse knapweed sites (including plants with both diffuse and hybrid morphology), were larger than the apparently pure diffuse knapweed in the native range. The cross-continental patterns of hybridization likely are explained by differences in cytology. It recently has been confirmed that the spotted knapweed in North America is tetraploid whereas the diffuse knapweed is diploid. Genetic incompatibilities associated with these two cytotypes likely prevent ongoing hybridization. We hypothesize that hybrid individuals were introduced to North America along with diffuse knapweed. Because plants with hybrid morphology are found in nearly all North American diffuse knapweed sites, the introduction of hybrids likely occurred early in the invasion of diffuse knapweed. Thus, although the presence of hybrids might facilitate the ongoing invasion of diffuse knapweed into North America, elevated concern regarding their presence might not be warranted. Because such individuals are not likely to represent a new hybridization event, currently effective management strategies used in diffuse knapweed sites should not need alteration.

Dispersal of Musk Thistle (Carduus nutans) Seeds

Weed Science ◽  
1984 ◽  
Vol 32 (1) ◽  
pp. 120-125 ◽  
Author(s):  
Lane M. Smith ◽  
L. T. Kok
Keyword(s):  
Seed Dispersal ◽  
Gaussian Model ◽  
Published Data ◽  
Carduus Nutans ◽  
Wind Velocities

Dispersal studies of musk thistle (Carduus nutansL =C. thoermeriWeinmann) seeds by wind were performed to determine the percentage of seeds removed from the vicinity of the plant where the seeds originated. For the different wind velocities tested (up to 5.6 m/s) less than 1% of the seeds were blown further than 100 m. Most seeds were deposited within 50 m of the point of release. A Gaussian model of seed dispersal based on experimentally determined parameters and published data adequately described these results.

scholarly journals Polyphyletic ancestry of expanding Patagonian Chinook salmon populations

2016 ◽  
Author(s):  
Cristian Correa ◽  
Paul Moran
Keyword(s):  
Genetic Diversity ◽  
North America ◽  
Mixture Models ◽  
Chinook Salmon ◽  
Future Research ◽  
Potential Donor ◽  
Genetic Lineages ◽  
The North ◽  
Introduced Range ◽  
Lineage Admixture

AbstractChinook salmon native to North America are spreading through South America’s Patagonia and have become the most widespread anadromous salmon invasion ever documented. To better understand the colonization history and role that genetic diversity might have played in the founding and radiation of these new populations, we characterized ancestry and genetic diversity across latitude (39-48°S). Samples from four distant basins in Chile were genotyped for 13 microsatellite loci, and allocated, through probabilistic mixture models, to 148 potential donor populations in North America representing 46 distinct genetic lineages. Patagonian Chinook salmon clearly had a diverse and heterogeneous ancestry. Lineages from the Lower Columbia River were introduced for salmon open-ocean ranching in the late 1970s and 1980s, and were prevalent south of 43°S. In the north, however, a diverse assembly of lineages was found, associated with net-pen aquaculture during the 1990s. Finally, we showed that possible lineage admixture in the introduced range can confound allocations inferred from mixture models, a caveat previously overlooked in studies of this kind. While we documented high genetic and lineage diversity in expanding Patagonian populations, the degree to which diversity drives adaptive potential remains unclear. Our new understanding of diversity across latitude will guide future research.

scholarly journals First Report of Powdery Mildew Caused by Erysiphe cichoracearum on Creeping Thistle (Cirsium arvense) in North America

Plant Disease ◽  
2004 ◽  
Vol 88 (3) ◽  
pp. 312-312
Author(s):  
G. Newcombe ◽  
C. Nischwitz
Keyword(s):  
South Carolina ◽  
North America ◽  
Powdery Mildew ◽  
Cirsium Arvense ◽  
Broad Host Range ◽  
Perennial Weed ◽  
Erysiphe Cichoracearum ◽  
Ampelomyces Quisqualis ◽  
On Line ◽  
Resources Conservation

Creeping or Canada thistle (Cirsium arvense (L.) Scop.) is a perennial weed of Eurasian origin that arrived in North America as early as the 1700s (3). Spreading by seeds and rhizomes, it is now widely distributed in Canada, Alaska, and 40 other states. It is apparently absent from Texas, Oklahoma, Louisiana, Mississippi, Alabama, Georgia, Florida, and South Carolina (1). Powdery mildew is common on C. arvense in Europe, but it has never been observed in North America (4). In Europe and Asia, powdery mildew of C. arvense is caused by any one of the following fungi: Leveillula taurica, two species of Sphaerotheca, and varieties of Erysiphe cichoracearum and E. mayorii. Specimens of C. arvense infected with powdery mildew (deposited in the U.S. National Fungus Collections as BPI 843471) were collected in the fall of 2003 near Moscow, ID and in two areas in Oregon (the canyon of the Grande Ronde River and near the base of the Wallowa Mountains). Mycelium and cleistothecia were observed on stems and upper and lower surfaces of leaves. The mean diameter of the cleistothecia was 122 (±11.6) μm. Basally inserted, mycelioid appendages were hyaline or brown and varied considerably in length, but most were in the range of 80 to 120 μm. Asci averaged 58 (±5.5) μm × 35 (±4.1) μm in length and width, respectively. Each ascus bore two ascospores averaging 23 (±1.4) μm × 14 (±1.7) μm. Conidia averaged 30 (±3.0) μm × 14 (±0.8) μm. The specimens fit the description of E. cichoracearum DC. (2). Because the length/breadth ratio of conidia is greater than 2, the specimens could be further diagnosed as E. cichoracearum var. cichoracearum (2). Also noteworthy was the presence of the hyperparasitic Ampelomyces quisqualis Ces. ex Schlechtend. E. cichoracearum is thought to be a cosmopolitan powdery mildew of broad host range, but this concept is difficult to reconcile with the absence of mildew on North American populations of C. arvense for more than 200 years. References: (1) Anonymous. USDA Natural Resources Conservation Service Plants Profile for Cirsium arvense. On-line publication, 2003. (2) U. Braun. A monograph of the Erysiphales (powdery mildews), J. Cramer, Berlin-Stuttgart, 1987. (3) G. Cox. Alien Species in North America and Hawaii, Island Press, Washington, D.C., 1999. (4) D. F. Farr et al. Fungal Databases, Systematic Botany and Mycology Laboratory, ARS, USDA. On-line publication, 2003.

scholarly journals Spill-over attack by the gall fly, Urophora stylata, on congeners of its target weed, Cirsium vulgare

2020 ◽  
Vol 73 ◽  
pp. 24-32
Author(s):  
Michael Cripps ◽  
Jovesa Navukula ◽  
Benjamin Kaltenbach ◽  
Chikako Van Koten ◽  
Seona Casonato ◽  
...  
Keyword(s):  
New Zealand ◽  
Host Range ◽  
Biocontrol Agent ◽  
Cirsium Arvense ◽  
Cirsium Vulgare ◽  
Carduus Nutans ◽  
Limited Supply ◽  
Californian Thistle ◽  
Attack Intensity ◽  
Selection Of

The gall fly, Urophora stylata, was released in New Zealand in 1998 as a biocontrol agent for the thistle weed, Cirsium vulgare (Scotch thistle). In the summer of 2018, a survey was conducted to assess the field host range of the biocontrol agent in New Zealand.  A random selection of 18 pasture populations under sheep and/or beef production, where C. vulgare was present, was surveyed to quantify the attack intensity (gall size relative to seedhead size) on C. vulgare, and the presence of attack on other thistle weeds within the same population. At each location, seedheads were collected from C. vulgare and all other thistle species (Cardueae) present, which included Cirsium arvense (Californian thistle), Cirsium palustre (marsh thistle), Carduus nutans (nodding thistle), and an Arctium species (burdock). In addition to attack on C. vulgare, the gall fly was recorded on C. arvense (at six locations) and C. palustre (at one location). The probability of the presence of attack on C. arvense was positively correlated with the attack intensity on C. vulgare, suggesting that attack on C. arvense is a ‘spill-over effect’ occurring where seedheads of C. vulgare are in limited supply.

A biosystematic study of the Carduus nutans complex in Canada

1988 ◽  
Vol 66 (8) ◽  
pp. 1621-1631 ◽  
Author(s):  
A. M. Desrochers ◽  
J. F. Bain ◽  
S. I. Warwick
Keyword(s):  
Discriminant Analysis ◽  
North America ◽  
Genetic Variability ◽  
Genetic Identity ◽  
Correct Classification ◽  
Carduus Nutans ◽  
Biosystematic Study ◽  
Isozyme Analyses ◽  
Subspecific Level

The Carduus nutans L. complex in North America has been treated either as one species with four subspecies (ssp. nutans, ssp. leiophyllus (Petrovic) Stoj. & Stef., ssp. macrolepis (Peterm.) Kazmi, and ssp. macrocephalus (Desf.) Nyman) or as three species: Carduus nutans with two subspecies (ssp. nutans and ssp. macrolepis), C. thoermeri Weinm., and C. macrocephalus Desf. A biosystematic study of this complex, including morphological, flavonoid, and isozyme analyses, of 19 populations, was conducted to clarify the taxonomy of this complex in Canada. Both the morphological and flavonoid analyses clearly indicate the existence of only two closely related groups of taxa referable to ssp. nutans and ssp. leiophyllus. The classificatory discriminant analysis indicated correct classification rates of individuals of 93.6% and 96.0% for ssp. nutans and ssp. leiophyllus, respectively. Each taxon has a distinct flavonoid profile. Given the high mean genetic identity value (ī = 0.93) between the two taxa in the complex, and the estimates of genetic variability obtained, the taxa are best treated at the subspecific level, as ssp. nutans and ssp. leiophyllus.

HOST RANGE OF LEMA CYANELLA (COLEOPTERA: CHRYSOMELIDAE), A CANDIDATE FOR BIOCONTROL OF CANADA THISTLE, AND OF FOUR STENOPHAGOUS, FOREIGN THISTLE INSECTS IN NORTH AMERICA

1984 ◽  
Vol 116 (10) ◽  
pp. 1377-1384 ◽  
Author(s):  
D. P. Peschken
Keyword(s):  
North America ◽  
Host Range ◽  
Host Plants ◽  
Biocontrol Agent ◽  
Cirsium Arvense ◽  
Choice Test ◽  
Canada Thistle ◽  
Field Cage ◽  
Rhinocyllus Conicus ◽  
Cage Test

AbstractIn the field in Europe, Lenta cyanella (L.) has been reported to breed only on Canada thistle (Cirsium arvense (L.) Scop.) whereas in the laboratory it breeds on species in the genera Cirsium, Carduus, and Silybum. In one laboratory choice test, L. cyanella preferred Cirsium drummondii T.&G. over Canada thistle. In one field-cage test, it concentrated feeding and oviposition on one C. drummondii which thrived in preference to three other C. drummondii and Canada thistle which grew poorly. In a second field-cage test, Canada thistle predominated and L. cyanella fed and oviposited most on Canada thistle although its intrinsic preference for C. drummondii was still apparent. A review of the field host-plants of three accidentally introduced thistle-feeding insects, Orellia ruficauda (F.), Cleonus piger Scop, and Cassida rubiginosa Müller, and the introduced biocontrol agent Rhinocyllus conicus Froel., showed that these insects, which have a wider range of hosts than has L. cyanella, concentrate breeding on introduced species of Cynareae (Compositae). Based on this evidence, it is extrapolated that L. cyanella will exploit Canada thistle and will not damage populations of native Cirsium species when established in North America.

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