Herbivores generally have strong structural and compositional effects on vegetation, which in turn determines the plant forage species available. We investigated how selected large mammalian herbivore assemblages use and alter herbaceous vegetation structure and composition in a southern African savanna in and adjacent to the Kruger National Park, South Africa. We compared mixed and mono-specif...

Droughts can have a severe impact on the dynamics of animal populations, particularly in semi-arid and arid environments where herbivore populations are strongly limited by resource availability. Increased drought intensity under projected climate change scenarios can be expected to reduce the viability of such populations, yet this impact has seldom been quantified. In this study, we aim to fi...

Dense localized blooms of the toxic dinoflagellate Alexandrium ostenfeldii are a recent phenomenon in the low salinity waters of the Baltic Sea. This study reports results from laboratory experiments investigating the interaction between PSP toxin producing strains of A. ostenfeldii and two copepod species, Eurytemora affinis and Acartia bifilosa, from the northern Baltic Sea. Copepod grazing r...

Aims We tested the establishment success of grassland species in presence or absence zoochory by livestock and identified traits associated with successful establishment. Location Hortobágy National Park, Hungary. Methods In six restored species-poor grasslands we established two species-rich 4 m × source plots per site 2013. One plot was managed extensive cattle grazing (“zoochory on”), other ...

I . An isotope dilution method, known to be satisfactory for measurement of volatile fatty acid (VFA) production in the rumen under steady-state conditions, was tested for its applicability where the VFA pool in the rumen could vary irregularly. The method indicated mean production rates closely similar to those obtained when the pool size was virtually constant. Tests carried out in a model ru...

Proper grazing management reduces ET from grasslands by reducing transpiration losses and grazingManagement of forage production for livestock grazing on semiarid induced surface energy relationships that reduce evapograsslands depends on water availability. Evapotranspiration (ET) ration (Svejcar and Christiansen, 1987; Wraith et al., was measured using the Bowen ratio energy balance method on...

al., 1994). Summed to 1-m depth, SOC content was not different between cropland and conservation reserve. Estimates of potential soil organic C (SOC) and total N (TN) In a shortgrass-steppe with 56 yr of grazing in Colorado, sequestration at depths below the traditional plow layer (i.e., 0–0.3 m) in agricultural systems are needed to improve our understanding of SOC was not different between un...

Introduction The vegetation of great areas of Mixed Prairie has been destroyed by plowing. But even larger ones, still intact , have degenerated far from a climax condition. The almost universal cause for such deterioration, aside from drought, is grazing. The objective of this study has been to ascertain the changes in vegetation that have resulted from 60-70 years of different intensities of ...

INTRODUCTION We evaluated periphytic algal and microbial communities to assess the influence of human and cattle impact on Sierra water quality. METHODS 64 sites (lakes and streams from Lake Tahoe to Sequoia National Park, California) were sampled for suspended indicator bacteria and algae following standardized procedures. The potential for nonpoint pollution was divided into three categorie...

The use of anthelmintics is strongly limited in organic farming. This may induce a change in the intensity (no of worms) and diversity (proportions of species) of helminth infection. Helminths remain a major preoccupation in organic sheep farming: high levels of infection have been recorded on several farms and helminth diversity is always higher. The helminth infection in milk cattle of northe...