Root carbon flow from an invasive plant to belowground foodwebs

• Published in: Plant and soil Vol. 359; no. 1/2; pp. 233 - 244
• Main Authors: Bradford, Mark A., Strickland, Michael S., DeVore, Jayna L., Maerz, John C.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.10.2012; Springer Netherlands; Springer Nature B.V
• Subjects: Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Araneae; Biochemistry and biology; Biological and medical sciences; Biomass; Biomedical and Life Sciences; Carbon; Carbon content; Chemical, physicochemical, biochemical and biological properties; Dissolved organic carbon; Ecology; Flowers & plants; Food chains; Forest floor; Forest soils; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Grasses; Grassland soils; Invasive plants; Invasive species; Life Sciences; Microbial biomass; Photosynthesis; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Pipelines; Plant Physiology; Plant production; Plant roots; Plant Sciences; Plants; Predators; Regular Article; Soil ecology; Soil microorganisms; Soil science; Soil Science & Conservation; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Soils; Spiders; Stable isotopes; Understory; Soil organisms; Exotic species; Soil foodweb; Detrital foodweb; Rhizodeposition; Non metal; Introduced species; Rhizodeposit; Root; Trophic structure; Property of soil; Group IVA element; Carbon; Biological activity; Soils; Invasive species; Food web; Vegetative apparatus; Soil science; Soil plant relation; Microstegium vimineum
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-012-1210-y

Aims Soil foodwebs are based on plant production. This production enters belowground foodwebs via numerous pathways, with root pathways likely dominating supply. Indeed, root exudation may fuel 30—50 % of belowground activity with photosynthate fixed only hours earlier. Yet we have limited knowledge of root fluxes of recent-photosynthate from invasive plants to belowground foodwebs. Methods Using stable isotopes, we quantify the proportion of recent-photosynthate transferred belowground from the invasive grass Microstegium vimineum A. Camus, a widespread invader of forest understory. Given its minimal root biomass (~8 % of individual mass), we expected exudation to contribute little to belowground foodwebs. Results Within 2 days of 13C-labeling, we recover ~ 15 % of photosynthate carbon in microbial biomass. Recovery in root and dissolved organic carbon pools is consistently low (<2 %), suggesting these pools operate as 'pipelines' for carbon transport to soil microbes. The recovery of the label in wolf spiders — forest floor predators that feed on soil animals — highlights that root inputs of recent photosynthate can propagate rapidly through belowground foodwebs. Conclusions Our results suggest that root carbonexudation, an unexplored process of invasive grass inputs to forest foodwebs, may be an important pathway through which invasive species affect the structure and function of recipient ecosystems.