Allelopathic potential of Artemisia frigida and successional changes of plant communities in the northern China steppe

Abstract

In the northern China steppe, overgrazing has decreased the abundance of many species that were originally dominant, but increased the abundance of Artemisia frigida. We aimed to determine whether the adaptive and competitive abilities of A. frigida are associated with allelopathy. Soil nutrient characteristics could not explain the poor growth of the originally dominant species. Volatile compounds released from A. frigida leaves and aqueous extracts (0.025, 0.05, 0.075, 0.10, and 0.15 g ml −1 ) from A. frigida leaves and roots and from soil under A. frigida inhibited seed germination and seedling growth of three dominant species (Leymus chinensis, Stipa krylovii, and Cleistogenes squarrosa). Allelopathic activity varied according to extract concentration, test species, and extract source. Germination was most strongly inhibited in S. krylovii, followed by L. chinensis and then C. squarrosa. Seedling growth was most strongly inhibited in L. chinensis, followed by S. krylovii and then C. squarrosa. Gas chromatography-mass spectrometry analyses of the leaf volatiles identified 27 compounds, primarily monoterpene or sesquiterpene compounds and their oxygencontaining derivatives, such as eucalyptol, beta.-myrcene, 1,6-octadien-3-ol,3,7-dimethyl, 3-carene, bicyclo[2.2.1]heptan-2-one,1,7,7-trimethyl-,(1R), cissabinenehydrate, camphene, and alpha-Pinene. These findings suggest that allelochemicals from A. frigida can modify the surrounding micro-habitat. The responses of target plants to allelopathy of A. frigida may be one reason for changes in plant community succession in the northern China steppe.

Legacy effects of historical grazing affect the response of vegetation dynamics to water and nitrogen addition in semi‐arid steppe

“…With supplementary irrigation, the shallow‐rooted (usually <15 cm) perennial grass Cleistogenes squarrosa increased quickly and became the dominant species at the MG site (Figure ). Cleistogenes squarrosa is a C 4 grass, it has a competitive advantage over many other species in N and water‐limited environments and is an indicator species of heavily grazed grassland (Li, Wang, Huang, Wang, & Wang, ; Wang & Wang, ; Wang et al., ). Increasing N limitation at the MG site could be the reason for the C. squarrosa increase after water addition.…”

“…The positive response of S. grandis (and the related Stipa krylovii ), Artemisia frigida and A gropyron cristatum to N addition has been reported in other studies (Ronnenberg & Wesche, ). High grazing intensity in steppes favours Artemisia species (Li et al., ) as L. chinensis and S. grandis lose dominance. Artemisia frigida communities may form a relatively stable state that helps to prevent further progression to desertification in Inner Mongolian steppe (Li et al., ; Wang, Liang, Liu, & Hao, ), but could also constrain responses of the more palatable perennial grasses and forbs and inhibit grassland recovery (Wang et al., ).…”

Does endophyte symbiosis resist allelopathic effects of an invasive plant in degraded grassland?

“…In this new environment, the invaders can utilize their full competitive potential, due to their natural enemies not being present (Callaway and Aschehoug, 2000), e.g. high seed production, poor palatability to many native herbivores and allelopathic effects on neighbors Chen et al, 2011;Li et al, 2011).…”

Does the phytotoxic shrub Heterothalamus psiadioides affect a plant community through allelopathy?

“…Allelopathy is a process in which one plant produces phytotoxic chemicals that suppress the growth and establishment of other plants, and has been proposed to influence plant populations and communities (e.g., Bais et al 2003;El-Keblawy and Al-Rawai 2007;Li et al 2011). The occurrence of allelopathy has been suggested, based on laboratory studies, for many aromatic shrub species, such as Artemisia frigida (Li et al 2011), Salvia spp.…”

“…The occurrence of allelopathy has been suggested, based on laboratory studies, for many aromatic shrub species, such as Artemisia frigida (Li et al 2011), Salvia spp. (Muller et al 1964;Nishida et al 2005), and Chrysanthemoides monilifera (Ens et al 2009).…”