1
|
Rubio-Ríos J, Pérez J, Salinas MJ, Fenoy E, López-Rojo N, Boyero L, Casas JJ. Key plant species and detritivores drive diversity effects on instream leaf litter decomposition more than functional diversity: A microcosm study. Sci Total Environ 2021; 798:149266. [PMID: 34340079 DOI: 10.1016/j.scitotenv.2021.149266] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/19/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
Anthropogenic impacts on freshwater ecosystems cause critical losses of biodiversity that can in turn impair key processes such as decomposition and nutrient cycling. Forest streams are mainly subsidized by terrestrial organic detritus, so their functioning and conservation status can be altered by changes in forest biodiversity and composition, particularly if these changes involve the replacement of functional groups or the loss of key species. We examined this issue using a microcosm experiment where we manipulated plant functional diversity (FD) (monocultures and low-FD and high-FD mixtures, resulting from different combinations of deciduous and evergreen Quercus species) and the presence of a key species (Alnus glutinosa), all in presence and absence of detritivores, and assessed effects on litter decomposition, nutrient cycling, and fungal and detritivore biomass. We found (i) positive diversity effects on detritivore-mediated decomposition, litter nutrient losses and detritivore biomass exclusively when A. glutinosa was present; and (ii) negative effects on the same processes when microbially mediated and on fungal biomass. Most positive trends could be explained by the higher litter palatability and litter trait variability obtained with the inclusion of alder leaves in the mixture. Our results support the hypothesis of a consistent slowing down of the decomposition process as a result of plant biodiversity loss, and hence effects on stream ecosystem functioning, especially when a key (N-fixing) species is lost; and underscore the importance of detritivores as drivers of plant diversity effects in the studied ecosystem processes.
Collapse
Affiliation(s)
- J Rubio-Ríos
- Department of Biology and Geology, University of Almeria (UAL), 04120 Almería, Spain; Andalusian Centre for the Evaluation and Monitoring of Global Change, CAESCG, Almería, Spain.
| | - J Pérez
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - M J Salinas
- Department of Biology and Geology, University of Almeria (UAL), 04120 Almería, Spain; Andalusian Centre for the Evaluation and Monitoring of Global Change, CAESCG, Almería, Spain
| | - E Fenoy
- Department of Biology and Geology, University of Almeria (UAL), 04120 Almería, Spain; Andalusian Centre for the Evaluation and Monitoring of Global Change, CAESCG, Almería, Spain
| | - N López-Rojo
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - L Boyero
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - J J Casas
- Department of Biology and Geology, University of Almeria (UAL), 04120 Almería, Spain; Andalusian Centre for the Evaluation and Monitoring of Global Change, CAESCG, Almería, Spain
| |
Collapse
|