BACKGROUND AND AIMS Populations of many epiphytes show a patchy distribution where clusters of plants growing on individual trees are spatially separated and may thus function as metapopulations. Seed dispersal is necessary to (re)colonize unoccupied habitats, and to transfer seeds from high- to low-competition patches. Increasing dispersal distances, however, reduces local fecundity and the pr...

We tested the hypothesis that leaf modifying arthropod communities are correlated with cottonwood host plant genetic variation from local to regional scales. Although recent studies found that host plant genetic composition can structure local dependent herbivore communities, the abiotic environment is a stronger factor than the genetic effect at increasingly larger spatial scales. In contrast ...

Fungi play crucial roles in the biogeochemistry of terrestrial ecosystems, most notably as saprophytes decomposing organic matter and as mycorrhizal fungi enhancing plant nutrient uptake. However, a recurrent problem in fungal ecology is to establish the trophic status of species in the field. Our interpretations and conclusions are too often based on extrapolations from laboratory microcosm ex...

Epiphytes are strongly dependent on the conditions created by their host's traits and a certain degree of specificity is expected between them, even if these species are largely abundant in a series of tree hosts of a given environment, as in the case of atmospheric bromeliads. Despite their considerable abundance in these environments, we hypothesize that stochasticity alone cannot explain the...

Molecular trees of trypanosomes have confirmed conventionally accepted genera, but often produce topologies that are incongruent with knowledge of the evolution, systematics, and biogeography of hosts and vectors. These distorted topologies result largely from incorrect assumptions about molecular clocks. A host-based phylogenetic tree could serve as a broad outline against which the reasonabil...

Specialization makes resource use more efficient and should therefore be a common process in animal evolution. However, this process is not as universal in nature as one might expect. Our study shows that Sphecodes (Halictidae) cuckoo bees frequently change their host over the course of their evolution. To test the evolutionary scenario of host specialization in cuckoo bees, we constructed well...

Phytopathological examination of orchards various forms ownership reveal that every year the rust pip fruit trees has become widespread and reached its epiphytosis. In 2008, we detected symptoms on in form single yellow spots pear leaves different ages ownership. The identifcation found fungus Gymnosporangium sabinae G. Winter, (1882) (syn. fuscum DC. (1805)) was causative agent rust. prevalenc...

Anopiophora glabripennis (Motsch.) (Coleoptera: Cerambycidae) is a destructive woodborer, attacking many species of deciduous hardwood trees. Apriona swainsoni (Hope) (Coleoptera: Cerambycidae) is a woodborer of Sophora japonica L. (Angiospermae: Fabaceae). Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae) is an important natural enemy of both Cerambycid species in China. Kairomon...

We study the limiting distribution of the degree of a given node in a scaled attachment random recursive tree, a generalized random recursive tree, which is introduced by Devroye et. al (2011). In a scaled attachment random recursive tree, every node $i$ is attached to the node labeled $lfloor iX_i floor$ where $X_0$, $ldots$ , $X_n$ is a sequence of i.i.d. random variables, with support in [0,...