Nonadditive effects of mixing cottonwood genotypes on litter decomposition and nutrient dynamics

By J. Schweitzer, J. Bailey, S. Hart, T. Whitham. 2005

126 citations recorded by the source corpus.

Plant species litter mixtures often result in nonadditive differences in ecosystem processes when compared to the average of their individual components. However, these studies are just beginning to be extended to the genotype level and to our knowledge have not incorporated the effects of herbivory or genotype-by-herbivore interactions. With a two-year field study, using genotypes that differed by as few as three restriction length polymorphism (RFLP) molecular markers, we found three major patterns when we mixed leaf litters from different genotypes both with and without previous herbivory. First, leaf litter genotype mixtures, regardless of herbivory, demonstrated nonadditive rates of decomposition and nutrient flux. Second, mixed genotype litter without herbivory decomposed faster than the same genotypes with herbivory. Third, in genotype mixtures, with and without herbivory, we found that net rates of immobilization of both nitrogen and phosphorus can differ from expected values (based on genotype means) by as much as 57%. These results show that mixing litter genotypes can alter rates of decay and nutrient flux and that the effects are reduced with herbivory. Nonadditive effects at the genotype level that we report here are nearly as large as what has been recorded for plant species mixtures and may have important, though under-appreciated, roles in ecosystems. These data further suggest that genetic diversity and genotype-by-herbivore interactions can affect fundamental ecosystem processes such as litter decomposition and nutrient flux.

Subfields: Ecology, Evolution, Behavior and Systematics, Nature and Landscape Conservation, Soil Science

View Paper: https://www.semanticscholar.org/paper/2ad07d90ec22c5aee45edda3ceb914a0d1b30111

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Ecology, Evolution, Behavior and Systematics

In Nature and Landscape Conservation

In Soil Science

Citations in the corpus

Ecological consequences of genetic diversity. (2008, background): “Although ecological effects of genetic diversity depend upon a strong association between genotype and phenotype, few studies in this field have quantified the specific phenotypic traits underlying genetic diversity effects (but see Schweitzer et al. 2005; Wimp et al. 2004; Lankau & Strauss 2007).”
What type of diversity yields synergy during mixed litter decomposition in a natural forest ecosystem? (2007, background): “Schweitzer et al. (2005) showed that litter diversity at the genotype level impacted decomposition rates as profoundly as species diversity.”
Plant genetic diversity yields increased plant productivity and herbivore performance (2010, background): “…community resistance to extreme climatic events (Reusch et al. 2005) and grazing (Hughes & Stachowicz 2004), accelerate litter decomposition rates (Schweitzer et al. 2005), maintain long-term species diversity (Booth & Grime 2003; Vellend 2006), reduce plant disease severity (Zhu et al. 2000) and…”