The effect of fungicides on vesicular-arbuscular mycorrhizal symbiosis. II. The effects on area of interface and efficiency of P uptake and transfer to plant

Two experiments were conducted under controlled environmental conditions to determine the effects of the three fungicides, Benlate®. Aliette® and Ridomil®, on efficiency of P uptake from the soil and transfer across the living plant-fungal interface- of onion plants (Allium cepa L.) associated with Glomus sp. 'City Beach' (WUM 16), P applied to the soil did not apparently increase the rate of transfer (flux) of P to the plant via the fungal partner of the mytorrhiza. Benlate reduced P inflow and transfer across the interface in one of the experiments. The rate of P uptake per m living external hyphae was not affected but, as development of living external hyphae in the soil was reduced, the contribution of the fungus to P uptake was small. Aliette reduced growth of both shoots and roots, but apparently increased the accumulation of P in the tissues compared with controls. Ridomil reduced P inflow per m of root and P uptake per m living external hyphae, hut had no effect on the rate of P transfer across the interface. This led to a reduction in the overall contribution of the fungus to P nutrition.N. Sukarno, F. A. Smith, S. E. Smith, E. S. Scot

Larval Connectivity and the International Management of Fisheries

Predicting the oceanic dispersal of planktonic larvae that connect scattered marine animal populations is difficult, yet crucial for management of species whose movements transcend international boundaries. Using multi-scale biophysical modeling techniques coupled with empirical estimates of larval behavior and gamete production, we predict and empirically verify spatio-temporal patterns of larval supply and describe the Caribbean-wide pattern of larval connectivity for the Caribbean spiny lobster (Panulirus argus), an iconic coral reef species whose commercial value approaches $1 billion USD annually. Our results provide long sought information needed for international cooperation in the management of marine resources by identifying lobster larval connectivity and dispersal pathways throughout the Caribbean. Moreover, we outline how large-scale fishery management could explicitly recognize metapopulation structure by considering larval transport dynamics and pelagic larval sanctuaries