Soil heterogeneity affects ramet placement of Hydrocotyle vulgaris

Abstract

Aims Soil heterogeneity is common in natural habitats. It may trigger foraging responses (placing more ramets and/or roots in nutrient-rich patches than in nutrient-poor patches) and further affect the growth of plants. However, the impact of soil heterogeneity on competitive interactions has been little tested. Methods We conducted a greenhouse experiment to investigate the effects of soil heterogeneity on intraspecific competition with a stoloniferous herb Hydrocotyle vulgaris. We grew one (without competition) or nine ramets (with competition) of H. vulgaris under a homogeneous environment and two heterogeneous environments differing in patch size (large or small patches). In the heterogeneous treatment, the soil consisted of the same number of nutrient-rich and nutrient-poor patches arranged in a chessboard manner, and in the homogeneous treatment, the soil was an even mixture of the same amount of the nutrient-rich and the nutrientpoor soil. Important Findings Irrespective of intraspecific competition, H. vulgaris showed foraging responses to soil heterogeneity in the large patch treatment, e.g. it produced significantly more biomass, ramets, aboveground mass and root mass in the nutrient-rich patches than in the nutrientpoor patches. In the small patch treatment, foraging responses were observed when intraspecific competition was present, but responses were not observed when there was no competition. However, we find a significant effect of soil heterogeneity on neither overall growth nor competitive intensity of H. vulgaris. Our results suggest that foraging responses to soil heterogeneity may not necessarily be adaptive and intraspecific competition may not be influenced by soil heterogeneity.

Invasive Eichhornia crassipes Affects the Capacity of Submerged Macrophytes to Utilize Nutrients

“…In addition, M. spicatum may be insensitive to the effects of the heterogeneous substrate at this mesoscale. Previous studies illustrated that inappropriate sizes of heterogeneous patches may not affect the growth of plants [35][36][37], because inappropriate patch sizes cause plants to meet only one type of patch and the effects will thus be small. The positive effect of environmental heterogeneity on submerged macrophytes may be transitory; a previous study reported that nutrient heterogeneity could increase the growth of an annual herb species only at the early stage of growth (first month), but not in the long run (second month) [23].…”

Constraints on the evolution of phenotypic plasticity in the clonal plant Hydrocotyle vulgaris

“…It originated from Europe and was introduced to China in the 1990s as an ornamental plant (Liu et al ., ). The species mainly relies on vegetative propagation via stem fragments to form large clones and spread, although it still can flower and may produce viable seeds (Dong et al ., ; Liu et al ., ).…”

Nutrient enrichment alters impacts of Hydrocotyle vulgaris invasion on native plant communities

“…Hydrocotyle vulgaris L. (Apiaceae) is a perennial clonal herb52. It commonly occurs in bogs, valleys, and dune grasslands.…”

“…It was introduced to China as an ornamental plant in the 1990 s and is now considered to be a species with high potential invasiveness53. Each ramet, which consists of a leaf and adventitious roots, may be formed by a node along stolons5254. In the field, H. vulgaris can produce extensive shoot systems and experience heterogeneous micro-environments created by either resource availability or aggregations of neighboring plants54.…”