Back to Search Start Over

Agricultural impacts on lowland tropical streams detected through leaf litter decomposition.

Authors :
Pérez, Javier
Boyero, Luz
Raquel Tuñón, Ana
Checa, Brenda
Correa-Araneda, Francisco
Guerra, Alisson
Tuñón, Anyi
Castillo, Dania
Pérez, Edgar
García, Gabriela
Rodríguez, Randhy
Cornejo, Aydeé
Source :
Ecological Indicators. Oct2023, Vol. 154, pN.PAG-N.PAG. 1p.
Publication Year :
2023

Abstract

[Display omitted] • Tropical lowland stream functioning was assessed through leaf litter decomposition. • Three litter types differing in their nativeness were examined. • Microbial decomposition was dominant across an agricultural intervention gradient. • Detritivore-mediated decomposition reflected the intervention gradient. • Microbial decomposition indicated differences among leaf litter types. Stream ecosystems are highly vulnerable to changes in land use and vegetation in their catchments for two reasons: firstly, they receive inputs of nutrients, contaminants and sediments through runoff; and secondly, terrestrial leaf litter is the major basal resource supporting their food webs. Leaf litter decomposition by microorganisms and detritivores is thus a key stream ecosystem process, and a valuable functional indicator of impacts associated to agriculture and other alterations of human origin. Here, we investigated the joint effects of land use changes associated to agriculture (low, medium and high intervention areas: LI, MI and HI, respectively) in a tropical lowland catchment in Panama, through a decomposition experiment using three leaf litter types differing in nativeness (Ficus insipida , native to the study area; Alnus acuminata , native to Panama but not present in the study area; and Musa balbisiana , exotic to Panama). Lowland tropical areas are often poor in litter-consuming detritivores, and we accordingly observed a high contribution of microorganisms to total decomposition (>60% on average). However, only in the presence of detritivores, decomposition of Alnus discriminated among different degrees of agricultural intervention, being higher at the LI area. Leaf litter of the native Ficus showed higher microbial decomposition than the other types, possibly in relation to a home-field advantage effect. Despite the scarcity of detritivores in tropical lowland streams compared to tropical highland or temperate streams, our study indicates that their activity reflects impacts of land use change on these streams and they should therefore be included in assessments of anthropogenic impacts. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
1470160X
Volume :
154
Database :
Academic Search Index
Journal :
Ecological Indicators
Publication Type :
Academic Journal
Accession number :
171955359
Full Text :
https://doi.org/10.1016/j.ecolind.2023.110819