Genotypic diversity of an invasive plant species promotes litter decomposition and associated processes

Abstract

Following studies that showed negative effects of species loss on ecosystem functioning, newer studies have started to investigate if similar consequences could result from reductions of genetic diversity within species. We tested the influence of genotypic richness and dissimilarity (plots containing one, three, six or 12 genotypes) in stands of the invasive plant Solidago canadensis in China on the decomposition of its leaf litter and associated soil animals over five monthly time intervals. We found that the logarithm of genotypic richness was positively linearly related to mass loss of C, N and P from the litter and to richness and abundance of soil animals on the litter samples. The mixing proportion of litter from two sites, but not genotypic dissimilarity of mixtures, had additional effects on measured variables. The litter diversity effects on soil animals were particularly strong under the most stressful conditions of hot weather in July: at this time richness and abundance of soil animals were higher in 12-genotype litter mixtures than even in the highest corresponding one-genotype litter. The litter diversity effects on decomposition were in part mediated by soil animals: the abundance of Acarina, when used as covariate in the analysis, fully explained the litter diversity effects on mass loss of N and P. Overall, our study shows that high genotypic richness of S. canadensis leaf litter positively affects richness and abundance of soil animals, which in turn accelerate litter decomposition and P release from litter.

Explaining ecosystem multifunction with evolutionary models

“…Further, strong selection that increases average carbon use efficiency (similar to what is expected by OU evolution) can weaken these relationships (Gravel et al 2012). While our results confirm that species' evolved differences contribute to ecosystem function, an additional factor that we did not consider is the role of intraspecific variability and plasticity in influencing ecosystem function (Burns and Strauss 2012, Violle et al 2012, Wang et al 2014. Work by Burns and Strauss (2011) has shown that closely related plant species are more likely to exhibit phenotypic plasticity, which contributes to their coexistence.…”

“…, Wang et al. ). Work by Burns and Strauss () has shown that closely related plant species are more likely to exhibit phenotypic plasticity, which contributes to their coexistence.…”

“…Here we show the mass lost after 2 months as our measure of decomposition. We chose S. altissima as our indicator species as it was the most abundant species surrounding our experimental plots, but we did not assess within species diversity which could influence decomposition and other functions (Crutsinger et al 2006, Wang et al 2014.…”

Intraspecific genetic diversity modulates plant–soil feedback and nutrient cycling

“…The effect of plant genetic diversity on ecosystem processes may also be mediated by microbial and invertebrate composition and activity in the soil. Mixed-genotype plant litter has been shown to decompose faster than expected from the decomposition rates of single-genotype litters (Schweitzer et al, 2005;Wang et al, 2014). This effect has been attributed to resource complementarity whereby mixed litter provides a more complete range of substrates to a more diverse set of decomposers.…”

A review on the relationships between plant genetic diversity and ecosystem functioning

“…的 研 究 , 有 关 GD-EF 及 其 内 在 机 制 的 探 讨 较 少 (Hughes & Stachowicz, 2004;沈栋伟等, 2007) (Whitham et al, 2006;Bailey et al, 2009;Bailey, 2011;Hersch-Green et al, 2011) (Wolfe, 1985;Smithson & Lenné, 1996)。无独有偶, 保护生物学家 也在试图通过增加稀有物种种群的遗传多样性来提 高稀有物种种群的适合度 (Lande, 1988 (Loreau & Hector, 2001;Crutsinger et al, 2006;Johnson et al, 2006;Crawford & Rudgers, 2013;Wang et al, 2014;Hughes et al, 2016;申俊芳等, 2016) 基因丰富度 Allelic richness 所检测位点上等位基因的平均数目。 The average number of alleles detected at the detected locus.…”