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Data from: Acceleration or deceleration of litter decomposition by herbivory depends on nutrient availability through intraspecific differences in induced plant resistance traits

Citation

Burghardt, Karin T.; Bradford, Mark A.; Schmitz, Oswald J. (2019), Data from: Acceleration or deceleration of litter decomposition by herbivory depends on nutrient availability through intraspecific differences in induced plant resistance traits, Dryad, Dataset, https://doi.org/10.5061/dryad.st104qv

Abstract

1. Herbivores often induce changes in plant defensive chemistry or nutrient content that may respectively inhibit or promote microbial decomposition of senesced litter. Often the directional impact of herbivores on decomposition is considered to be a property of a species or ecosystem. While rarely explored, intraspecific plasticity in the induction of defensive strategies across environmental gradients may also result in divergent impacts of herbivores on decomposition (deceleration vs. acceleration). 2. Here, we examined how soil nutrient conditions determine after-life effects of herbivory, using nine goldenrod (Solidago altissima) genotypes grown across four levels of nutrient supply and with or without grasshopper herbivory. In this species, herbivory induces defensive traits in genotypes grown in high soil nutrient conditions but induces tolerance (compensatory growth) in low nutrient conditions. We combined senesced litter from each treatment with a common soil inoculum in experimental microcosms and measured soil respiration and litter mass loss over 100 days as estimates of decomposition. 3. Plant genotype, nutrient environment, and herbivory all had significant effects on decomposition. The legacy effect of herbivory overwhelmed the positive effects of high soil nutrient supply on decomposition. This significant herbivory nutrient environment interaction meant that herbivore-induced plants grown in high nutrient environments produced litter that was more resistant to microbial breakdown than litter from the same genotype not exposed to herbivory. But the opposite occurred at low nutrient levels where litter from herbivore-induced plants was most readily decomposed. Further we mechanistically tie nutrient and herbivory legacy treatments to decomposition rates through predictable changes in leaf trait expression. Lastly, we demonstrate a significant correlation among herbivore growth rates on the living tissue and decomposition efficiencies by the microbial community of the senesced tissue, suggesting that herbivores and microbes perceive the "quality" of the induced substrate similarly. 4. Synthesis: Herbivore-induced changes in leaf palatability and trait expression due to defense induction or compensatory growth can cascade through to either promote or inhibit the decomposability of leaf litter within a single species. These findings offer mechanistic understanding of how spatial heterogeneity in ecosystem process rates can be generated by spatial variation in herbivory and nutrient availability.

Usage Notes

Funding

National Science Foundation, Award: DEB-1404120

Location

USA
Connecticut