TY - JOUR
T1 - Slow-cycle effects of foliar herbivory alter the nitrogen acquisition and population size of Collembola
AU - Bradford, Mark A.
AU - Gancos, Tara
AU - Frost, Christopher J.
N1 - Funding Information:
The Analytical Chemistry Laboratory (University of Georgia) performed element and isotope analyses. Thanks to Christian Davies, Mike Strickland and Jaya Srivistava for technical comments. Our research was supported by grants from the National Science Foundation, Coweeta LTER Programme.
PY - 2008/5
Y1 - 2008/5
N2 - In terrestrial systems there is a close relationship between litter quality and the activity and abundance of decomposers. Therefore, the potential exists for aboveground, herbivore-induced changes in foliar chemistry to affect soil decomposer fauna. These herbivore-induced changes in chemistry may persist across growing seasons. While the impacts of such slow-cycle, 'legacy' effects of foliar herbivory have some support aboveground, such impacts have not been evaluated for soil invertebrates. Here, we investigate legacy effects on Collembola population structure and nitrogen acquisition. We collected foliar material (greenfall) from trees that had, in the preceding season, been exposed to insect herbivory by leaf-chewing Lepidoptera. Collembola populations were grown with the greenfall in soil microcosms across 16 weeks. While there were only modest effects of herbivory on the greenfall mass loss, Collembola abundance and biomass after 8 weeks of greenfall exposure were approximately 2.5-fold greater in the controls. Given that Collembola biomass percentage nitrogen was relatively fixed, this translated to approximately 2.5-fold greater biomass nitrogen. The herbivore treatment decreased the absolute amount of Collembola biomass nitrogen derived from both greenfall and soil, and the relative contribution of litter nitrogen and soil nitrogen to Collembola biomass nitrogen was dependent on both the herbivory treatment and greenfall initial nitrogen. Our results show that slow-cycle, legacy effects of foliar herbivory may affect soil faunal population structure and nitrogen acquisition, demonstrating the potential for aboveground herbivory to influence belowground animal ecology and nitrogen cycling across multi-annual timescales.
AB - In terrestrial systems there is a close relationship between litter quality and the activity and abundance of decomposers. Therefore, the potential exists for aboveground, herbivore-induced changes in foliar chemistry to affect soil decomposer fauna. These herbivore-induced changes in chemistry may persist across growing seasons. While the impacts of such slow-cycle, 'legacy' effects of foliar herbivory have some support aboveground, such impacts have not been evaluated for soil invertebrates. Here, we investigate legacy effects on Collembola population structure and nitrogen acquisition. We collected foliar material (greenfall) from trees that had, in the preceding season, been exposed to insect herbivory by leaf-chewing Lepidoptera. Collembola populations were grown with the greenfall in soil microcosms across 16 weeks. While there were only modest effects of herbivory on the greenfall mass loss, Collembola abundance and biomass after 8 weeks of greenfall exposure were approximately 2.5-fold greater in the controls. Given that Collembola biomass percentage nitrogen was relatively fixed, this translated to approximately 2.5-fold greater biomass nitrogen. The herbivore treatment decreased the absolute amount of Collembola biomass nitrogen derived from both greenfall and soil, and the relative contribution of litter nitrogen and soil nitrogen to Collembola biomass nitrogen was dependent on both the herbivory treatment and greenfall initial nitrogen. Our results show that slow-cycle, legacy effects of foliar herbivory may affect soil faunal population structure and nitrogen acquisition, demonstrating the potential for aboveground herbivory to influence belowground animal ecology and nitrogen cycling across multi-annual timescales.
KW - Aboveground
KW - Belowground
KW - Decomposition
KW - Greenfall
KW - Litter quality
KW - Nitrogen immobilisation
KW - Nitrogen mineralisation
KW - Soil fauna
UR - http://www.scopus.com/inward/record.url?scp=41449091339&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=41449091339&partnerID=8YFLogxK
U2 - 10.1016/j.soilbio.2007.12.001
DO - 10.1016/j.soilbio.2007.12.001
M3 - Article
AN - SCOPUS:41449091339
SN - 0038-0717
VL - 40
SP - 1253
EP - 1258
JO - Soil Biology and Biochemistry
JF - Soil Biology and Biochemistry
IS - 5
ER -