A native parasitic plant and soil microorganisms facilitate a native plant co‐occurrence with an invasive plant

Abstract

Invasive plants often interact with antagonists that include native parasitic plants and pathogenic soil microbes, which may reduce fitness of the invaders. However, to date, most of the studies on the ecological consequences of antagonistic interactions between invasive plants and the resident biota focused only on pairwise interactions. A full understanding of invasion dynamics requires studies that test the effects of multiple antagonists on fitness of invasive plants and co‐occurring native plants. Here, we used an invasive plant Mikania micrantha , a co‐occurring native plant Coix lacryma‐jobi, and a native holoparasitic plant Cuscuta campestris to test whether parasitism on M. micrantha interacts with soil fungi and bacteria to reduce fitness of the invader and promote growth of the co‐occurring native plant. In a factorial setup, M. micrantha and C. lacryma‐jobi were grown together in pots in the presence versus absence of parasitism on M. micrantha by C. campestris and in the presence versus absence of full complements of soil bacteria and fungi. Fungicide and bactericide were used to suppress soil fungi and bacteria, respectively. Findings show that heavy parasitism by C. campestris caused the greatest reduction in M. micrantha biomass when soil fungi and bacteria were suppressed. In contrast, the co‐occurring native plant C. lacryma‐jobi experienced the greatest increase in biomass when grown with heavily parasitized M. micrantha and in the presence of a full complement of soil fungi and bacteria. Taken together, our results suggest that selective parasitism on susceptible invasive plants by native parasitic plants and soil microorganisms may diminish competitive ability of invasive plants and facilitate native plant coexistence with invasive plants.

A parasite indirectly affects nutrient distribution by common mycorrhizal networks between host and neighboring plants

“…A limited number of studies have reported that AMF can alleviate damage to host plants by suppressing the growth of parasitic plants, because AMF competes with the parasitic plants for host-derived resources (Tesitel et al 2011, Li et al 2012, Sui et al 2019, especially carbon (Li et al 2019). To the best of our knowledge, our study provides the first direct evidence that the growth of parasitic plants is also inhibited by the presence of CMNs.…”

Parasitism induces negative effects of physiological integration in a clonal plant

“…Parasitism and clonal integration each have strong community‐level effects on their own. For example, through differential effects on hosts and nonhosts and by decreasing the density of vegetation, parasitic plants can change plant community structure (Press & Phoenix, 2005), promote plant species diversity (Grewell, 2008; Heer et al ., 2018), and control invasive plant species (Shen et al ., 2007; Yu et al ., 2008; Cirocco et al ., 2017; Tĕšitel et al ., 2017, 2020; Li et al ., 2019). Clonal integration may modify the response of plants to grazing (Liu et al ., 2020) and help explain why increased dominance by tall, wide‐spreading clonal plants accounts for much of the negative effects of elevated N levels on diversity in some grasslands (Gough et al ., 2012; Dickson et al ., 2014), and why clonal growth in plants is associated with invasiveness (Pyšek et al ., 1995; Pyšek, 1997; Liu et al ., 2006; Song et al ., 2013).…”

Parasitism Shifts the Effects of Native Soil Microbes on the Growth of the Invasive Plant Alternanthera philoxeroides

“…Recent studies have shown that the parasitism of Cuscuta species can indirectly affect the structure and function of rhizosphere soil microbial communities [ 20 , 21 , 22 ]. Li et al [ 23 ] used fungicide and bactericide to diminish native fungi and bacteria and found that the parasitism of C. campestris could benefit the growth of the co-occurring native plant Coix lacryma-jobi only in the presence of a full complement of soil fungi and bacteria. However, little has been focused on the effect of parasitic Cuscuta species on the effect of native soil microbes on plant invasion success.…”