J. Emmett Duffy*, J. Paul Richardson and Kristin E. France School of Marine Science and Virginia Institute of Marine Science, The College of William and Mary, Gloucester Point, VA 23062-1346, USA *Correspondence: E-mail: [email protected] Abstract Biodiversity and food chain length each can strongly influence ecosystem functioning, yet their interactions rarely have been tested. We manipulated g...

In the mode of rotational grazing, herds sheep from 11 herdsmen were monitored in such aspects as plant yield grasslands, production process and corresponding market prices mutton, structure herd changes number, cost composition its change, value transfer among entities external chain within 15 months. On this basis, paper attempted to deconstruct relationship between above factors well model v...

Lodge, D.M., 1991. Herbivory on freshwater macrophytes. Aquat. Bot., 41: 195-224. Conventional wisdom holds that live macrophytes are rarely consumed and are functionally unimportant in aquatic food webs. With a review of the literature, I first demonstrate that macrophyte biomass, productivity, and species composition is often influenced by a variety of vertebrate and invertebrate grazers. Man...

BACKGROUND With world food demand expected to double by 2050, identifying farming systems that benefit both agricultural production and biodiversity is a fundamentally important challenge for the 21(st) century, but this has to be achieved in a sustainable way. Livestock grazing management directly influences both economic outputs and biodiversity on upland farms while contributing to potential...

We investigated the impact of copepods on the seston community in a mesocosm set-up, and assessed how the changes in food quantity, quality and size affected the condition of the grazers, by measuring the RNA:DNA ratios in different developmental stages of Calanus finmarchicus. Manipulated copepod densities did not affect the particulate carbon concentration in the mesocosms. On the other hand,...

with the growth of public awareness for environmental protection, green production was raised as an important issue for each producer, which will guarantee its activity in long term. creating suppliers, performance assessment system is so necessary and important that it measures suitability of the suppliers for long-term cooperation with the company. many activities have been performed for sele...

The fatty acid (FA) composition of bulk milk fat was examined on three mountain dairy farms in the Czech Republic. Milk samples were collected in the period of indoor grass silage feeding (November–April) and in the grazing period (May–October). In total fifty FAs were identified in the milk fat. The two-way ANOVA with factors of the farm and of the period of milk sample collection was used for...

Direct and indirect effects of diesel-contaminated sediment on microalgae, meiofauna, and meiofauna-microalgae trophic interactions were examined in a microcosm study of the sediment community from a Spartina aZterniJora salt marsh. Microcosms of natural sediment were given small daily doses of contaminated sediment over a 28-d period, creating low-, medium-, and high-diesel treatment concentra...