Mass development of cyanobacteria can deprive the water of oxygen and produce toxins. But cyanobacteria can become sick, when for instance infected by fungal parasites. The authors show that these infections do not only kill cyanobacteria, they also make them easier to consume for their natural predators. Fungal parasites thus help to slow down the growth of blue-green algae.
Spatial and temporal variability of methane emissions from cascading reservoirs in the Upper Mekong River
Potential sediment methane production rates increase along the reservoir cascade in the Upper Mekong River. Ebullition is an important but previously overlooked pathway for methane emission. Both diffusive and ebullitive fluxes show high intra and inter reservoir variability. Fluxes fall into the low-to-mid range of global estimates for hydropower reservoirs.
Geochemical focusing and sequestration of manganese during eutrophication of Lake Stechlin (NE Germany)
Eutrophication of Lake Stechlin leads to changes in the sediment by an intensification of internal matter cycles. The reductive dissolution of Mn in shallow areas and the precipitation result in the fixation of Mn as rhodochrosite in the sediment below 56 m depth. Geochemical Mn focusing indicates oxygen-free conditions in deep water and can be used to reconstruct former environmental conditions.
Transformation of redox-sensitive to redox-stable iron-bound phosphorus in anoxic lake sediments under laboratory conditions
Under oxic conditions, iron hydroxide bound phosphorus is formed at the sediment-water interface, which is not stable in the long term. Laboratory tests show that under anoxic conditions (also under seasonal anoxia) this P form is converted to insoluble vivianite. The addition of Fe as a management measure can promote the formation of vivianite and thus the permanent storage of P in the sediment.
Urbanization is a complex process that impacts both the ecology and evolution of species. The researchers identified five key urban drivers of this change and highlight the direct consequences of urbanization-driven eco-evolutionary change for nature’s contributions to people. They subsequently explored five emerging complexities that need to be tackled in future research.
Diet and Genotype of an Aquatic Invertebrate Affect the Composition of Free-Living Microbial Communities
Associations with microbial communities are crucial for most plants and animals. The authors show that in Daphnia, host genotype does not only influence gut microbiome composition, but also the structure of free-living microbial communities, i.e. the bacterioplankton. This interaction is expected to lead to feedback loops where evolutionary changes in the host might impact bacterioplankton.
A field survey along a food quantity and quality gradient revealed that both host population density as well as prevalence and diversity of epibionts (i.e. organisms living on a host) in the water flea Daphnia pulex are significantly affected by phytoplankton N:P ratio. A laboratory experiment using Daphnia magna confirmed that P‐limitation affects infestation by epibionts.
The deep biodiversity crisis calls for effective targets for its preservation. The authors argue for a “safety net” made up of multiple interlinked and ambitious goals to tackle nature’s alarming decline. No single target captures the broad range of biodiversity components that are dependent on each other. The study outlines the scientific basis for redesigning the new set of biodiversity goals.
This comprehensive study analyses the relationship between urbanization and biodiversity across multiple aquatic and terrestrial animal groups and at multiple spatial scales. The study reveals an overall strong negative impact of urbanization on both abundance and species richness within habitat patches. The study highlights the importance of considering multiple spatial scales and taxa.
Does evolution influence ecological patterns in space? The authors synthesized 500 studies to develop a predictive framework for whether and when evolution amplifies, dampens, or creates ecological patterns. They show that local adaptation can alter spatial variation in population, community and ecosystem features. Dampening of ecological differences is the most prominent effect of evolution.