Ecosystem functions

RESIST targets four inherently linked functional attributes:

CPOM degradation

Coarse Particulate Organic Matter (CPOM) degradation is a key function, particularly in forest streams, where the process is jointly performed by microorganisms (fungi, bacteria) and detritivorous invertebrates.

A meta-analysis conducted in Phase I of RESIST showed an overall antagonistic effect in the effects of multiple stressors on litter decomposition. In our experiments, we observed that the involvement of macroinvertebrates in litter decomposition, the type of habitat, and the quality of the litter used shaped the stressor interactions.

DOC degradation

Dissolved organic carbon (DOC) refers to the mass of carbon in the dissolved organic material which results from CPOM degradation and organic pollution.

In RESIST, we observed that DOC degradation appears to be mainly performed by bacterial organisms.

Food web complexity

Food web complexity refers amongst others to the number of species involved in a food web and their connection by trophic links, which integrate autochthonous and allochthonous sources, consumers and decomposers.

We found that trophic similarity increases with time since restoration, suggesting that the stability and redundancy of the food webs increase with ecosystem recovery.

Nutrient cycling

The cycling of nutrients is an important component of lotic systems since primary producers mostly depend on the nutrients recycled by microorganisms.

We found that parasites’ nutrient assimilation is closely linked to the liver metabolism of the fish host.