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Agriculture impairs stream ecosystem functioning in a tropical catchment
- Source :
- Addi. Archivo Digital para la Docencia y la Investigación, Universidad de Cantabria (UC), instname, Addi: Archivo Digital para la Docencia y la Investigación, Universidad del País Vasco
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- The expansion of agriculture is particularly worrying in tropical regions of the world, where native forests are being replaced by crops at alarming rates, with severe consequences for biodiversity and ecosystems. However, there is little information about the potential effects of agriculture on the functioning of tropical streams, which is essential if we are to assess the condition and ecological integrity of these ecosystems. We conducted a litter decomposition experiment in streams within a tropical catchment, which were subjected to different degrees of agricultural influence: low (protected area, PA), medium (buffer area, BA) and high (agricultural area, AA). We quantified decomposition rates of litter enclosed within coarse-mesh and fine-mesh bags, which allowed the distinction of microbial and detritivore-mediated decomposition pathways. We used litter of three riparian species representing a gradient in litter quality (Alnus acuminate > Ficus irtsipida > Querns burnelioides), and examined detritivore assemblages through the contents of litterbags and benthic samples. We found that the increasing agricultural influence promoted microbial decomposition, probably due to nutrient-mediated stimulation; and inhibited detritivore-mediated and total decomposition because of reduced detritivore numbers, most likely caused by pesticides and sedimentation. Effects were evident for Alnus and Ficus, but not for Querns, which was barely decomposed across the gradient. Our study provides key evidence about the impact of agriculture on topical stream ecosystem functioning, which is associated to changes in stream assemblages and may have far-reaching repercussions for global biochemical cycles. (C) 2020 The Authors. Published by Elsevier B.V. Thisworkwas supported by the National Secretariat for Science, Technology and Innovation (SENACYT; project APY-GC-2018B-052; contract no. 259-2018) and the Ministry of Economy and Finance (MEF; project 019910.001). AC was supported by a fellowship from SENACYT (contract no. 001-2015) and by the National Research System of Panama (SNI; PhD category; contract no. 186-2018). GC was supported by a fellowship from IFARHU-SENACYT (contract no. 270-2018-1011).
- Subjects :
- Environmental Engineering
010504 meteorology & atmospheric sciences
Biodiversity
feeding groups
010501 environmental sciences
01 natural sciences
Pesticide toxicity
ecosystem functional integrity
water-quality
nutrient enrichment
Rivers
Environmental Chemistry
Ecosystem
nutrient concentrations
Waste Management and Disposal
detritivore assemblages
leaf litter breakdown
0105 earth and related environmental sciences
Riparian zone
geography
breakdown
geography.geographical_feature_category
Ecology
Detritivore
land use
temperature
Tropics
Agriculture
Environmental impact of agriculture
Pollution
people.cause_of_death
indicators
Plant Leaves
communities
Litter
Environmental science
microbial decomposition
pesticide toxicity
people
Subjects
Details
- ISSN :
- 00489697
- Volume :
- 745
- Database :
- OpenAIRE
- Journal :
- Science of The Total Environment
- Accession number :
- edsair.doi.dedup.....4d576a5f054db822cc0bb183469e66d3