Responses in Phenotypic Plasticity of Amaranthus palmeri and Polygonum orientale to Soil Factors under Different Habitats

Abstract

The extension and structure of functional traits variation in response to different soil factors between invasive and native plants are poorly understood. Functional traits and soil factors of the invasive plant Amaranthus palmeri and its coexisting plant Polygonum orientale are investigated under three heterogeneous habitats: roadside (rs), wasteland (wl), and riverbank (rb) in Tianjin, China. The shoot dry weight (SDW) and leaf nitrogen (LN) of A. palmeri are significantly higher compared with P. orientale, while A. palmeri has significantly lower leaf dry weight (LDW), leaf area (LA), leaf carbon (LC), and leaf C/N ratio under different habitats. The larger phenotypic plasticity of A. palmeri is one of the important reasons for their successful invasion to heterogeneous habitats. Similarly, the soil water content (SWC) of both species shows a significant difference (p < 0.05) with maximum in riverbank habitat to lowest in roadside habitat. Soil N/P ratio, C/N ratio, and C/P ratio of rb habitats are significantly lower compared to wl and rs habitats (p < 0.05). A redundancy analysis indicates that SWC is the dominant soil factor affecting the functional traits of A. palmeri and P. orientale. However, A. palmeri forms an environmental adaptation strategy by changing traits of SDW, LN, and leaf C/N ratio, which is different from P. orientale by changing traits of LA and LDW.

Study on Environmental Conditions of Seed Germination and Seedling Growth of Invasive Plant <i>Amaranthus palmeri</i> S. Watson

“…There is a correlation between the viability of Amaranthus palmeri seeds and vigor during artificial aging. After 3 years of naturally existing in soils in Nebraska, vigor of Amaranthus palmeri seeds was found to be less than 10% [19,57]; after 5 months of waterflooding, their vigor was found to be 86% [18]. Therefore, Amaranthus palmeri seeds exhibit a certain tolerance to short-term high temperatures and high humid environments [58,59].…”

Contrasting effects of experiencing temporally heterogeneous light availability versus homogenous shading on plant subsequent responses to light conditions

“…Greater plasticity is hypothesized to correlate with high heterogeneity in resource availability [ 3 - 6 ]. Many studies have been focused on plant plasticity in relation to spatial-scale environmental heterogeneity [ 7 - 9 ], much less attention has been paid to the relationship between time-scale environmental heterogeneity and plasticity. However, temporally heterogeneous environments may be more ubiquitous than environmental heterogeneity at spatial scale, plants can experience fluctuations in light, water and nutrient availability at scales of hours, days and months in their lifetime It is reported that Convolvulus chilensis experiencing the greatest temporal variation in nature has shown the greatest plasticity in four traits [ 10 ].…”

Responses of Fungal Assembly and Co-Occurrence Network of Rhizosphere Soil to Amaranthus palmeri Invasion in Northern China

“…The presence of A. palmeri will result in significant yield losses if not fully controlled, and it has been regarded as the most agronomically challenging species in the United States [26,27]. In recent years, A. palmeri has spread rapidly throughout the Beijing-Tianjin-Hebei region of northern China, displacing native plants and endangering local biodiversity [28]. Previous studies have already indicated that A. palmeri invasion enhanced functional traits (i.e., leaf number, plant height, and total biomass) [29], altered soil chemical and biological properties (e.g., total carbon, ammonium nitrogen, and soil extracellular enzyme activities) [30], and influenced bacterial composition and co-occurrence patterns [31].…”