seed bank is a central topic for plant community restoration. we determined the potential and regeneration capacity of soil seed banks of woody plant patches in conservation of the vegetation in an alpine habitat, since vegetation has completely disappeared in some sites by intensive grazing in the habitat. the study was done in mountainous area of alborz in iran. a total of 20 individual shrub...

abstract competition is a phenomenon that influences the size, structure and stability of insect communities, particularly on solitary endoparasitoids species. although, competition normally incurs costs, it might be adaptive for the surviving individual. to determine which factors affect the patch use strategy of foragers under competition, the effect of previous experience with hosts already-...

Through empirical studies and simulation, I demonstrate how simple behaviors can be used in lieu of detailed dispersal studies to predict the effects of corridors on interpatch movements. Movement paths of three butterfly species were measured in large (1.64 ha) experimental patches of open habitat, some of which were connected by corridors. Butterflies that "reflected" off boundaries between o...

A comparative study of simultaneous heat and gas exchange measurements was performed in the large annular Heidelberg Air–Sea Interaction Facility, the Aeolotron, under homogeneous water surface conditions. The use of two gas tracers, N2O and C2HF5, resulted not only in gas transfer velocities, but also in the measurement of the Schmidt number exponent n with a precision of ±0.025. The original ...

A would adopt a new fashion, j u m p on a new bandwagon. At best it would endorse somewhat bela tedly--abst ract policies of resource management . At worst, it would blunder into grossly Selfish ecological programmes which effectively serve the interest of the rich and the powerful. There are m a n y shades of green! Some ecological policies are unacceptable in that they overlook disadvantaged ...

A comparative study of simultaneous heat and gas exchange measurements was performed in the large annular Heidelberg Air-Sea Interaction Facility, the Aeolotron, under homogeneous water surface conditions. The use of two gas tracers, N2O and C2HF5, resulted not only in gas transfer ve5 locities, but also in the measurement of the Schmidt number exponent n with a precision of ±0.025. The origina...

the dynamic response of a transversely isotropic, linearly elastic layer bonded to the surface of a half-space of a different transversely isotropic material under arbitrary shape surface loads is considered. with the help of displacements and stresses green’s functions, an analytical formulation is presented for the determination of the displacements and stresses at any point in both surface l...

Budding is a good method of propagation in the Persian walnut (Juglans regia L.)., However, success of budding is low due to higher root pressure as well as the presence of phenolic compounds in the xylem sap. This study was conducted to compare various budding methods and cut below budding union on two and three-year-old Persian walnut under field conditions. The experiment was conducted based...

abstract parasitic insects face many decisions when foraging for host, some for example frequently have to make decisions with regard to staying in or leaving their current patch. in this study, we investigated how the foraging and oviposition behavior of lysiphlebus fabarum is influenced by (1) a female’s previous experience of encountering aphids host and (2) age of female parasitoids. to tes...