Land use effects on leaf litter breakdown in low-order streams draining a rapidly developing tropical watershed in Puerto Rico

 

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Autores: Torres, Pedro J., Ramírez, Alonso
Formato: artículo original
Estado:Versión publicada
Fecha de Publicación:2014
Descripción:Land use has an important role influencing stream ecosystem processes, such as leaf litter breakdown. Here, we assessed rates of leaf litter breakdown in low-order tropical streams draining forest, agriculture, and urban land uses in Puerto Rico. To measure leaf breakdown rates, we placed litter bags made of coarse mesh in nine streams, three for each land use type. At each stream, we measured changes in leaf mass over time, leaf breakdown rates, macroinvertebrate assemblages, and stream physicochemistry. Streams differed in their water physicochemistry, with urban streams showing high values for most variables. Stream physical habitat was evaluated using a visual assessment protocol, which indicated that agricultural and urban streams were more degraded than forested streams. Leaf breakdown rates were fast in all streams (k values ranging 0.006-0.024). Breakdown rates were significantly related to the physical conditions of the stream channel (e.g., visual protocol scores), with fastest rates in forested streams. Invertebrates colonizing leaves were mainly mayflies (Leptophlebiidae, Baetidae, and Caenidae), dipterans (Chironomidae), caddisflies (Polycentropodidae), and beetles (Elmidae and Gyrinidae). Our streams lacked large decapod populations, contrasting with other Puerto Rican streams. We found little evidence for an insect effect on leaf breakdown. Results suggest that land use is an important factor affecting leaf litter processing in streams. In contrast to studies in temperate regions, we found little evidence for a positive nutrient related effect of agricultural land use on decomposition rates. Changes in the physical characteristics of streams appear to be the main drivers behind observed decomposition patterns. Rev. Biol. Trop. 62 (Suppl. 2): 129-142. Epub 2014 April 01.
País:Portal de Revistas UCR
Institución:Universidad de Costa Rica
Repositorio:Portal de Revistas UCR
Lenguaje:Inglés
OAI Identifier:oai:portal.ucr.ac.cr:article/15783
Acceso en línea:https://revistas.ucr.ac.cr/index.php/rbt/article/view/15783
Access Level:acceso abierto
Palabra clave:tropical streams
land use
detritivores
human impacts
decay rates
Puerto Rico.
riachuelos tropicales
uso de tierra
detritivoros
impactos humanos
tasa de descomposición