Nitrate pollution reduces bryophyte diversity in Mediterranean springs.
Sci Total Environ
; 705: 135823, 2020 Feb 25.
Article
in En
| MEDLINE
| ID: mdl-31972951
ABSTRACT
Anthropogenic activities and intensive farming are causing nitrate pollution in groundwater bodies. These aquifers are drained by springs which, in the Mediterranean region, act as refugia for preserving biodiversity of species that need continuous water. Some springs are also used for drinking water for wild animals, livestock and humans, so if their water quality is compromised it can become a threat to public health. However, the impact of nitrate pollution on these biotic communities remains unknown. We sampled 338 assemblages of aquatic and semi-aquatic bryophytes (i.e., hygrophytic mosses and liverworts) growing in springs in a gradient of water conductivity, nitrate concentration and climate and distributed across the north-east of the Iberian Peninsula to investigate the impact of nitrate pollution on the diversity of bryophytes and moss functional traits in Mediterranean springs. Based on previous literature suggesting that increased nitrogen load decreases biodiversity in grasslands and freshwater ecosystems, we hypothesised that water nitrate pollution in springs decreases bryophyte diversity at the local and regional scales. Our results indicated that, at the local scale (spring), nitrate pollution reduced the number and the likelihood of finding a rare species in springs. Rare species were found in 4% of the springs with nitrate above 50â¯mgâ¯L-1 but in 32% of the springs with nitrate below 50â¯mgâ¯L-1. Moss, liverwort and overall bryophyte diversity were not directly affected by nitrate at the local scale but nitrate consistently decreased diversity of mosses, liverworts and rare bryophyte species at the regional scale. We also found that warmer and drier springs presented fewer bryophyte species. Our results show that the combination of nitrate pollution, increasing temperature and drought could severely threaten bryophyte diversity in Mediterranean springs. Our results indicate that the absence of rare bryophytes could be used as a bioindicator of nitrate pollution in springs.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Bryophyta
/
Natural Springs
Limits:
Animals
Language:
En
Journal:
Sci Total Environ
Year:
2020
Document type:
Article