A Comparative Study of Leaf Breakdown of Three Native Tree Species in a Slowly‐Flowing Headwater Stream in the Colombian Andes

Abstract

The dynamics of leaf breakdown in a headwater Colombian stream were evaluated for the native tree species Myrsine guianensis, Cupania latifolia and Nectandra lineatifolia using coarse and fine mesh litter bags. Ten bags of each species (five of each mesh size) were retrieved from the stream at 1, 8, 15, 30, 60 and 120 days. k values ranged from 0.0008 to 0.0058 day -1 and density of macroinvertebrates from 35 to 55 individuals per leaf bag, peaking at day 8. Myrsine guianensis degraded more rapidly than the other species for both coarse and fine mesh bags. This species and Nectandra lineatifolia presented differences in k values between coarse and fine mesh bags, suggesting that macroinvertebrates influenced the decay rate. Despite the low densities of macroinvertebrates found, shredders represented 12.7% of individuals and 50 to 68% of the invertebrate biomass in bags, indicating that this functional feeding group was an important component of fauna associated with litter breakdown in this first order tropical stream.

Clasificación trófica de insectos acuáticos en ocho quebradas protegidas de la ecorregión cafetera colombiana

“…Otra tendencia interesante registrada en estudios de quebradas protegidas de los Andes colombianos (10,25), es que a pesar de la dominancia numérica de los colectores, los fragmentadores son más importantes en términos de biomasa por tratarse de individuos de mayor tamaño. Por esta razón sería recomendable evaluar la biomasa relativa de los grupos dietarios de la cuenca del río La Vieja, con el fin de establecer si se mantiene esta condición, que confirma la relevancia ecológica de los fragmentadores.…”

Diets of leaf litter-associated invertebrates in three tropical streams

“…Several studies have suggested that tropical shredders are scarce (Dobson et al, 2002;Rueda-Delgado et al, 2006;Wantzen and Wagner, 2006;Gonc¸alves et al, 2007), while others have shown the opposite (Cheshire et al, 2005;Wright and Covich, 2005;Chara´et al, 2007;Camacho et al, 2009;Rı´os-Touma et al, 2009;Yule et al, 2009). A recent global study has demonstrated not only that shredder diversity increases with latitude (Boyero et al, 2011b) but also that variability in shredder abundance and diversity within the tropics is higher than within temperate areas (Boyero et al, 2011c).…”

Trophic Ecology of Hyalella sp. (Crustacea: Amphipoda) in a High Andes Headwater River with Travertine Deposits

“…In contrast, some studies have reported the importance of the activity of macroinvertebrate shredders in tropical streams (YULE, 1996;CHESHIRE et al, 2005;BOYERO et al, 2006;CHARA et al, 2007;RÍOS et al, 2009;YULE et al, 2009). In this context, TOMANOVA et al (2006) and CAMACHO et al (2009) indicated that this function has been underestimated due to the deceptive assumption that taxa in the tropics belong to the same feeding groups as in temperate rivers.…”

“…For example, in Australian streams, CHESHIRE et al (2005) based on gut contents analysis, found that despite of many invertebrates were generalist in their diets, shredders were an important component of the assemblages, especially in biomass and richness taxa. Also, CHARA et al (2007) evaluated the decomposition of three native plant species in a river headwater in the Colombian Andes indicating that shredders represent an important role in litter breakdown. Furthermore, RÍOS et al (2009) reported a shredder activity of 35% (by gut content analysis) on the basis of the relative density of 11 most abundant taxa in a river headwater in the highlands of Ecuador.…”