Effects of temporal heterogeneity of water supply and nutrient levels on plant biomass growth depend on the plant's relative size within its population

Abstract

Temporal heterogeneity of water supply can alter the biomass growth of plants, even when the same total amount of water is provided. Most studies of heterogeneous watering have focused on responses of whole populations rather than individuals in a population. The effects of water supply heterogeneity may also depend on nutrient levels. Thus, we investigated the integrated effects of water supply heterogeneity and nutrient levels on plants within a population. Six plants of Perilla frutescens per pot were grown under different combinations of frequency of water supply and nutrient level. The effects on yield per pot, individual biomass, and allocation to roots were analyzed after a 44‐day watering regime. A homogeneous water supply resulted in a greater yield per pot and greater biomass of individual plants than a heterogeneous supply. However, the interaction between water supply heterogeneity and nutrient level was significant only in larger individuals, not in smaller plants or at the p. Water supply heterogeneity affected the growth of all plants, but the effects differed among individuals depending on their relative size within their population. It is therefore important to focus not only on whole‐population characteristics such as yield but also on individuals in a population in order to reveal the detailed effects of water supply heterogeneity.

Growth and Yield Variability of Corn (Zea mays), Carrot (Daucus carota), Peas (Pisum sativum) and Potatoes (Solanum tuberosum) Grown in Fallow and Unfallow Standoff Alberta Community Garden Soils

“…Water supply is the one of the requirement for plant growth. It was confirmed that a stable water supply (homogeneity of water supply) can promote plant root systems to absorb water more efficiently and thus grow larger plants (Novoplansky and Goldberg, 2001;Hagiwara et al, 2012, Yu et al 2019).…”

Heterogeneous water supply affects growth and benefits of clonal integration between co-existing invasive and native Hydrocotyle species

“…Although many studies have tested effects of spatial patchiness or temporal heterogeneity in the supply of water on growth or clonal integration of plants 3 7 10 12 14 16 , none has examined the effects of both spatial and temporal heterogeneity in water supply. Our results obviously indicated that both spatial patchiness and temporal interval in water supply could partly alter growth and clonal integration of both species, especially for the invasive species H. vulgaris .…”

“…The proximal ramets might take up higher amounts of resources than distal ramets when exposed to such relatively high resource conditions (the homogeneous low interval in water) 27 . In the field, many natural habitats and some anthropogenic habitats are probably relatively homogeneous in space 29 and heterogeneous in time 7 10 , such as some shallow wetlands where water movement can homogenize fine-scale conditions. In consistent with a recently study in such relatively homogeneous water supply, the net effects of integration on clonal performance should be more positive at the high levels of spatially uniform water supply 26 27 .…”

“…Water resource usually exhibits obviously spatial and temporal heterogeneity in natural habitats 3 9 10 . Some studies have shown that even at very small scales, e.g.…”

“…In temporal heterogeneous (high interval) water supply, the integrative ramet system can also support each other to adapt to long-time drought or flooding. However, some species showed a better performance under a more homogeneous (low interval) water supply, as these plants can take up water more stably under such conditions 7 10 . In results of integrative cooperative systems, plants enable buffering of any differences in water supply among ramets in fine-grained water heterogeneity and might further enhance the development of the whole plant 12 14 16 17 19 .…”