Melissa Kolb McCormick

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Despite advances owing to molecular approaches, several hurdles still obstruct the identification of fungi forming orchid mycorrhizas. The Tulasnellaceae exhibit accelerated evolution of the nuclear ribosomal operon, causing most standard primers to fail in polymerase chain reaction (PCR) trials. Insufficient sequences are available from well characterized(More)
1. The distribution of genetic variation can be interpreted to understand the timing and mechanisms of invasive species spread. Allee effects, positive relationships between fitness and density or number of conspecific individuals, can play a substantial role in determining the time lag between initial introduction and invasive spread and can produce(More)
Although coevolution is acknowledged to occur in nature, coevolutionary patterns in symbioses not involving species-to-species relationships are poorly understood. Mycorrhizal plants are thought to be too generalist to coevolve with their symbiotic fungi; yet some plants, including some orchids, exhibit strikingly narrow mycorrhizal specificity. Here, we(More)
BACKGROUND AND AIMS We review evidence for hybridization of Phragmites australis in North America and the implications for the persistence of native P. australis ssp. americanus populations in North America. We also highlight the need for an updated classification system, which takes P. australis intraspecific variation and hybridization into account. (More)
In order to reveal some of the germination requirements of the boreal-alpine terrestrial orchid Dactylorhiza lapponica, several experiments were carried out on seeds collected from the Sølendet nature reserve, central Norway. Seeds were sown in seed packets made of nylon cloth and deployed in situ vertically in the peat in order to study the temporal(More)
The number of patches of non-native Phragmites australis in brackish tidal wetlands in the Rhode River subestuary increased from 5 in 1971–72 to 212 in 2007, and the area covered by the patches increased more than 25 times during the same time interval. Genetic analysis of the patches showed that the expansion has primarily been from seed, and genetic(More)
The characteristics of plant-mycorrhizae associations are known to vary in both time and space, but the ecological consequences of variation in the dynamics of plant-fungus interactions are poorly understood. For example, do plants associate with single fungi or multiple fungi simultaneously, and do the associations persist through a plant's lifetime or do(More)
Mycorrhizal fungi have substantial potential to influence plant distribution, especially in specialized orchids and mycoheterotrophic plants. However, little is known about environmental factors that influence the distribution of mycorrhizal fungi. Previous studies using seed packets have been unable to distinguish whether germination patterns resulted from(More)
Host breadth is often assumed to have no evolutionary significance in broad interactions because of the lack of cophylogenetic patterns between interacting species. Nonetheless, the breadth and suite of hosts utilized by one species may have adaptive value, particularly if it underlies a common ecological niche among hosts. Here, we present a preliminary(More)