PNZ6 – Effects of habitat cascade on the secondary production in rocky intertidal seaweeds-dominated systems

This project, finally, described how habitat cascades (the same described in the previous project) can affect the secondary production in rocky shore systems. Compared to all the previous projects, where classical community descriptors (such as abundance, richness and community structure) were considered, here I estimated the secondary production as function of epifaunal body biomass and water temperature using an allometric equation.


Here, I am described a rocky shore habitat cascade, based on the interaction between the seaweeds Cystophora spp. and the epiphytes naturally supported, testing the effects on the secondary production:

(1) three congeneric Cystophora species provide similar secondary production as a result of similar epifaunal load resulting from their taxonomic relatedness;

(2) the presence of epiphytes on Cystophora increases the secondary production as a result of a higher abundance and richness of invertebrates;

(3) the production varies across latitudes and peaks in northern locations, due to the higher physiological rates;

(4) the production varies across seasons and summer productivity exceeds the winter productivity as a consequence of temperature on the metabolic rates;

(5) the secondary production is strongly dependent on the biological attributes of the epiphytes (here living vs artificial mimic) and I expect that productivity in treatments with living epiphytes exceeds the production of treatments with artificial epiphytes, because of the duplex function of epiphytes in providing habitat and trophic resources.