TY - JOUR
T1 - Dispersal capacity as assessed by distance-decay relationships is lower for aquatic shredder insects than aquatic non-shredder insects in a Neotropical river network
AU - García, Pavel
AU - Hall, Robert O.
N1 - Publisher Copyright:
© Pavel García & Robert O. Hall Jr.
PY - 2024
Y1 - 2024
N2 - Aquatic shredder insect diversity declines latitudinally toward the equator, contrary to the general latitudinal biodiversity gradient. Shredder diversity along tropical elevational gradients mimics this shredder latitudinal pattern. One of the hypotheses proposed to explain this pattern of diversity is that dispersal capacity drives variation in shredder assemblages given their low dispersal capacity in tropical streams. Additionally, tropical shredders probably have lower dispersal capacity than the rest of tropical aquatic in-sects, which have lower dispersal capacities than their counterparts in temperate areas. We tested this hypothesis in an elevational gradient of more than 2000 m in 16 reaches of streams distributed in the Usumacinta, Cahabon, and Polochic river watersheds. We quantitatively sampled aquatic insects and measured 12 environmental variables. We found a regional pool of 118 taxa, with 13 taxa classified as shredders, and 2 taxa of predator-shredders. Contrary to expectations, shredder rarefied richness decreased with increasing elevation, which suggests that dispersal capacity did not change with elevation. Assemblage similarity decreased with increasing distance between reaches due to low capacity to fly long distances. This relationship had a smaller slope when using the shortest spatial distances between pairs of reaches due to potential lateral scatter by flying adults. In sum, the results support the hypothesis that dispersal capacity drove aquatic shredder assemblage structure in these 16 tropical streams.
AB - Aquatic shredder insect diversity declines latitudinally toward the equator, contrary to the general latitudinal biodiversity gradient. Shredder diversity along tropical elevational gradients mimics this shredder latitudinal pattern. One of the hypotheses proposed to explain this pattern of diversity is that dispersal capacity drives variation in shredder assemblages given their low dispersal capacity in tropical streams. Additionally, tropical shredders probably have lower dispersal capacity than the rest of tropical aquatic in-sects, which have lower dispersal capacities than their counterparts in temperate areas. We tested this hypothesis in an elevational gradient of more than 2000 m in 16 reaches of streams distributed in the Usumacinta, Cahabon, and Polochic river watersheds. We quantitatively sampled aquatic insects and measured 12 environmental variables. We found a regional pool of 118 taxa, with 13 taxa classified as shredders, and 2 taxa of predator-shredders. Contrary to expectations, shredder rarefied richness decreased with increasing elevation, which suggests that dispersal capacity did not change with elevation. Assemblage similarity decreased with increasing distance between reaches due to low capacity to fly long distances. This relationship had a smaller slope when using the shortest spatial distances between pairs of reaches due to potential lateral scatter by flying adults. In sum, the results support the hypothesis that dispersal capacity drove aquatic shredder assemblage structure in these 16 tropical streams.
KW - Bayesian linear models
KW - Central America
KW - dendritic network structure
KW - freshwater insect assemblages
KW - Guatemala
UR - http://www.scopus.com/inward/record.url?scp=85198325896&partnerID=8YFLogxK
U2 - 10.3897/neotropical.19.e113285
DO - 10.3897/neotropical.19.e113285
M3 - Article
AN - SCOPUS:85198325896
SN - 1809-9939
VL - 19
SP - 185
EP - 202
JO - Neotropical Biology and Conservation
JF - Neotropical Biology and Conservation
IS - 2
ER -