TY  - JOUR
A1  - Lozano, Yudi M.
A1  - Aguilar-Trigueros, Carlos A.
A1  - Onandia, Gabriela
A1  - Maaß, Stefanie
A1  - Zhao, Tingting
A1  - Rillig, Matthias C.
T1  - Effects of microplastics and drought on soil ecosystem functions and multifunctionality
T2  - Journal of applied ecology : an official journal of the British Ecological Society
N2  - 1. Microplastics in soils have become an important threat for terrestrial systems as they may potentially alter the geochemical/biophysical soil environment and can interact with drought. As microplastics may affect soil water content, this could exacerbate the well-known negative effects of drought on ecosystem functionality. Thus, functions including litter decomposition, soil aggregation or those related with nutrient cycling can be altered. Despite this potential interaction, we know relatively little about how microplastics, under different soil water conditions, affect ecosystem functions and multifunctionality. 
2. To address this gap, we performed an experiment using grassland plant communities growing in microcosms. Microplastic fibres (absent, present) and soil water conditions (well-watered, drought) were applied in a fully factorial design. At harvest, we measured soil ecosystem functions related to nutrient cycling (beta-glucosaminidase, beta-D-cellobiosidase, phosphatase, beta-glucosidase enzymes), respiration, nutrient retention, pH, litter decomposition and soil aggregation (water stable aggregates). As terrestrial systems provide these functions simultaneously, we also assessed ecosystem multifunctionality, an index that encompasses the array of ecosystem functions measured here. 
3. We found that the interaction between microplastic fibres and drought affected ecosystem functions and multifunctionality. Drought had negatively affected nutrient cycling by decreasing enzymatic activities by up to similar to 39%, while microplastics increased soil aggregation by similar to 18%, soil pH by similar to 4% and nutrient retention by up to similar to 70% by diminishing nutrient leaching. Microplastic fibres also impacted soil enzymes, respiration and ecosystem multifunctionality, but importantly, the direction of these effects depended on soil water status. That is, under well-watered conditions, these functions decreased with microplastic fibres by up to similar to 34% while under drought they had similar values irrespective of the microplastic presence, or tended to increase with microplastics. Litter decomposition had a contrary pattern increasing with microplastics by similar to 6% under well-watered conditions while decreasing to a similar percentage under drought. 
4. Synthesis and applications. Single ecosystem functions can be positively or negatively affected by microplastics fibres depending on soil water status. However, our results suggest that microplastic fibres may cause negative effects on ecosystem soil multifunctionality of a similar magnitude as drought. Thus, strategies to counteract this new global change factor are necessary.
KW  - enzymatic activities
KW  - grasslands ecosystem
KW  - litter decomposition
KW  - nutrient cycling
KW  - nutrient leaching
KW  - soil aggregation
KW  - soil pH
KW  - soil respiration
Y1  - 2021
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/63745
SN  - 1365-2664
VL  - 58
IS  - 5
SP  - 988
EP  - 996
PB  - Wiley-Blackwell
CY  - Oxford [u.a.]
ER  -