| Abstract | Eutrophication still is one of the greatest anthropogenic impacts affecting aquatic ecosystems. Food web manipulations to reverse eutrophic conditions have been applied, mainly by reducing fish stocks. However, the long-term results of biomanipulation are still ambiguous. The objective of this study was to evaluate biomanipulation effects on zooplankton functional diversity and production during 24 years of monitoring a shallow temperate lake. Temporal variation in crustacean biomass (CB), zooplankton resource use efficiency (RUE), limnological variables, functional diversity indices and functional traits were assessed using the Mann-Kendall test. The effects of the limnological and functional variables on zooplankton production (CB and RUE) were analyzed by generalized least squares models (GLSs). We found decreasing trends for almost all the limnological variables, indicating a reduction in lake eutrophic conditions. We also observed a decreasing trend in functional traits related to pelagic habitat, filter-feeding mode, herbivore feeding preference and body size. The GLS results showed that functional dispersion and chlorophyll a are important determinants of zooplankton production. The effects of fish biomanipulation produced no significant temporal trends in zooplankton biomass. In fact, the increase in submerged macrophytes promoted littoral food webs, which was likely the main determining factor of the changes in zooplankton functional traits and production. |
| Text | 421698 2020 10.1007/s10201 020 00617 z Scopus 2 s2.0 85082920968 Biomass resource use efficiency macrophyte covering food web functional traits Long term effects of fish biomanipulation and macrophyte management on zooplankton functional diversity and production in a temperate shallow lake Setubal R.B.; Riccardi N. Laboratory of Limnology, Ecology Department, Federal University of Rio de Janeiro UFRJ, Av. Carlos Chagas Filho, 373, Centro de Ciencias da Saude, Bloco A, Sala A0 008, Cidade Universitaria, Ilha Do Fundão, Rio de Janeiro, RJ, CEP 21949 900, Laboratory of Limnology, Ecology Department, Federal University of Rio de Janeiro UFRJ, Av. Carlos Chagas Filho, 373, Centro de Ciencias da Saude, Bloco A, Sala A0 008, Cidade Universitaria, Ilha Do Fundão, Rio de Janeiro, RJ, CEP 21949 900, Brasil, , Brazil; Istituto Di Ricerca Sulle Acque IRSA, Sede di Verbania, Consiglio Nazionale Dele Ricerche CNR, VialeTonolli 50, Verbania Pallanza, Istituto Di Ricerca Sulle Acque IRSA, Sede di Verbania, Consiglio Nazionale Dele Ricerche CNR, VialeTonolli 50, Verbania Pallanza, Italy, , Italy Eutrophication still is one of the greatest anthropogenic impacts affecting aquatic ecosystems. Food web manipulations to reverse eutrophic conditions have been applied, mainly by reducing fish stocks. However, the long term results of biomanipulation are still ambiguous. The objective of this study was to evaluate biomanipulation effects on zooplankton functional diversity and production during 24 years of monitoring a shallow temperate lake. Temporal variation in crustacean biomass CB , zooplankton resource use efficiency RUE , limnological variables, functional diversity indices and functional traits were assessed using the Mann Kendall test. The effects of the limnological and functional variables on zooplankton production CB and RUE were analyzed by generalized least squares models GLSs . We found decreasing trends for almost all the limnological variables, indicating a reduction in lake eutrophic conditions. We also observed a decreasing trend in functional traits related to pelagic habitat, filter feeding mode, herbivore feeding preference and body size. The GLS results showed that functional dispersion and chlorophyll a are important determinants of zooplankton production. The effects of fish biomanipulation produced no significant temporal trends in zooplankton biomass. In fact, the increase in submerged macrophytes promoted littoral food webs, which was likely the main determining factor of the changes in zooplankton functional traits and production. Postprint http //www.scopus.com/record/display.url eid=2 s2.0 85082920968 origin=inward Articolo in rivista Springer. 1439 8621 Limnology Tokyo, Print Limnology Tokyo, Print Limnology Tokyo, Print Limnology. Tokyo, Print nicolettarita.riccardi RICCARDI NICOLETTA RITA |
