TY - JOUR
T1 - Plant genetic identity of foundation tree species and their hybrids affects a litter-dwelling generalist predator
AU - Wojtowicz, Todd
AU - Compson, Zacchaeus G.
AU - Lamit, Louis J.
AU - Whitham, Thomas G.
AU - Gehring, Catherine A.
N1 - Funding Information:
Acknowledgments We thank the Ogden Nature Center staff, especially M. McKinley, for supporting the common garden and for field accommodations. We also thank the Gehring lab, the Cottonwood Ecology Research Group, and three anonymous reviewers for helpful comments on the manuscript. This studied benefited from the field assistance provided by C. Sanfiorenzo-Barnhard, C. VanCamp, and B. Harrop, and statistical assistance from M. Lau. This research was supported by the National Science Foundation Frontiers in Integrative Biological Research grant (DEB-0425908) to the Cottonwood Ecology Research Group and MRI (DBI-1126840) for the Southwest Experimental Garden Array.
Publisher Copyright:
© 2014, Springer-Verlag Berlin Heidelberg.
PY - 2014/10/24
Y1 - 2014/10/24
N2 - The effects of plant genetics on predators, especially those not living on the plant itself, are rarely studied and poorly understood. Therefore, we investigated the effect of plant hybridization and genotype on litter-dwelling spiders. Using an 18-year-old cottonwood common garden, we recorded agelenid sheet-web density associated with the litter layers of replicated genotypes of three tree cross types: Populus fremontii,Populus angustifolia, and their F1 hybrids. We surveyed 118 trees for agelenid litter webs at two distances from the trees (0–100 and 100–200 cm from trunk) and measured litter depth as a potential mechanism of web density patterns. Five major results emerged: web density within a 1-m radius of P. angustifolia was approximately three times higher than within a 1-m radius of P. fremontii, with F1 hybrids having intermediate densities; web density responded to P. angustifolia and F1 hybrid genotypes as indicated by a significant genotype × distance interaction, with some genotypes exhibiting a strong decline in web density with distance, while others did not; P. angustifolia litter layers were deeper than those of P. fremontii at both distance classes, and litter depth among P. angustifolia genotypes differed up to 300 %; cross type and genotype influenced web density via their effects on litter depth, and these effects were influenced by distance; web density was more sensitive to the effects of tree cross type than genotype. By influencing generalist predators, plant hybridization and genotype may indirectly impact trophic interactions such as intraguild predation, possibly affecting trophic cascades and ecosystem processes.
AB - The effects of plant genetics on predators, especially those not living on the plant itself, are rarely studied and poorly understood. Therefore, we investigated the effect of plant hybridization and genotype on litter-dwelling spiders. Using an 18-year-old cottonwood common garden, we recorded agelenid sheet-web density associated with the litter layers of replicated genotypes of three tree cross types: Populus fremontii,Populus angustifolia, and their F1 hybrids. We surveyed 118 trees for agelenid litter webs at two distances from the trees (0–100 and 100–200 cm from trunk) and measured litter depth as a potential mechanism of web density patterns. Five major results emerged: web density within a 1-m radius of P. angustifolia was approximately three times higher than within a 1-m radius of P. fremontii, with F1 hybrids having intermediate densities; web density responded to P. angustifolia and F1 hybrid genotypes as indicated by a significant genotype × distance interaction, with some genotypes exhibiting a strong decline in web density with distance, while others did not; P. angustifolia litter layers were deeper than those of P. fremontii at both distance classes, and litter depth among P. angustifolia genotypes differed up to 300 %; cross type and genotype influenced web density via their effects on litter depth, and these effects were influenced by distance; web density was more sensitive to the effects of tree cross type than genotype. By influencing generalist predators, plant hybridization and genotype may indirectly impact trophic interactions such as intraguild predation, possibly affecting trophic cascades and ecosystem processes.
KW - Agelenidae
KW - Cross type
KW - Genotype
KW - Intraspecific plant variation
KW - Populus
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U2 - 10.1007/s00442-014-2998-3
DO - 10.1007/s00442-014-2998-3
M3 - Article
C2 - 25205028
AN - SCOPUS:84919342509
SN - 0029-8519
VL - 176
SP - 799
EP - 810
JO - Oecologia
JF - Oecologia
IS - 3
ER -