Males and females of Juniperus communis L. and Taxus baccata L. show different seasonal patterns of nitrogen and carbon content in needles

Abstract

Genders of dioecious species often show secondary sexual dimorphisms (not directly related to the sex organs), which may be related to reproductive demand for resources during the year. Our working hypothesis stated that phenology influences yearly sex-specific pattern of foliar nitrogen concentration in dioecious species. The concentration of carbon (C) and nitrogen (N) of last year's needles (on part of twigs where strobili are bearing) was measured in 1-month intervals from March to November in Taxus baccata L. and Juniperus communis L. separately for males and females. Seasonal C concentration of needles was unrelated to gender, probably due to storage elsewhere in the plants. Needles of J. communis females had higher N concentration in March and April but this dropped to the same level as males after flowering and vegetative growth began. This suggests that females of J. communis, a species of N-poor habitats, have a long-term strategy of N storage. Nitrogen concentration was not different between the sexes during the rest of the growing season. In T. baccata, N concentration was higher in males throughout the analysed period, but the highest differences were in the period of intensive shoot elongation and radial growth. The high demand for N in the period of intensive growth and female cone maturation may result in restrictions in the vegetative growth of females. The results indicate that the time (phenology) and species-specific strategy significantly affect the concentration of N in females and males.

Red Arils of Taxus baccata L.—A New Source of Valuable Fatty Acids and Nutrients

“…Contrary to expectations, lipids of RAs samples derived from Zielona Góra site, which had better climatic conditions (temperature) than other locations, contained a significantly higher amount of total PUFA (54.4 g/100 g FA), as compared with samples of the other three sites (50.7 g/100 g FA on average; Table 5 ), most likely due to better parameters of the brown soil there ( Table 2 ). An impressive amount of α-linolenic acid in RAs from the Cracow sample could be attributed to favorable soil conditions and high precipitation, appropriate for the demanding Taxus baccata trees [ 48 ].…”

“…Except Warsaw location, RAs proved to be a substantial source of linoleic (n-6 PUFA; 429–757 mg/100 g RA). High blood levels of n-6 acids were considered an increased risk of inflammatory and allergic conditions in epidemiological studies [ 48 ]. An increased intake of α-linolenic from the diet has the potential to limit the production of n-6 derived proinflammatory mediators and to enhance the biological efficacy of long chain n-3 PUFA [ 50 ].…”

Photochemistry and Antioxidative Capacity of Female and Male Taxus baccata L. Acclimated to Different Nutritional Environments

“…Taxus baccata is a suitable model for studying dioecious species because males and females are known to respond differently to environmental conditions. Males of T. baccata grow taller (Iszkuło et al, 2009 ), show greater radial growth than females after the beginning of sexual maturity (Cedro and Iszkuło, 2011 ; Iszkuło et al, 2011a ), and females have lower N concentration in needles, especially when undergoing intensive shoot elongation and radial growth (Nowak-Dyjeta et al, 2017 ). T .…”

Rich but not poor conditions determine sex‐specific differences in growth rate of juvenile dioecious plants

“…Nevertheless, these mechanisms may function regardless of habitat conditions, as seen by the larger needle area of yew and juniper females regardless of fertilization. This is a common feature in female individuals of dioecious species (Wallace and Rundel 1979;Meagher 1992;Kohorn 1994), and has previously been demonstrated in adult yew and juniper individuals (Iszkuło et al 2009(Iszkuło et al , 2011bNowak-Dyjeta et al 2017). A larger needle surface may be associated with greater gas exchange and photosynthesis activity (Dawson and Bliss 1989;Dawson and Ehleringer 1993) increasing the growth of females and allowing them to achieve better growth in favourable conditions such as fertilization.…”

“…In response to resource availability, different genders may have specific compensatory mechanisms (Ueno et al 2006 ; Tozawa et al 2009 ) allowing better uptake or more efficient use of resources. These include differences in the time spent on reproduction and growth (Delph 1990 ; Obeso 2002 ; Milla et al 2006 ), photosynthetic capacity (Dawson and Ehleringer 1993 ; Obeso 2002 ; Nicotra et al 2003 ), or morphological differences such as leaf area (Wallace and Rundel 1979 ; Meagher 1992 ; Kohorn 1994 ; Nowak-Dyjeta et al 2017 ). These mechanisms may be of particular importance during masting events (Montesinos et al 2012 ).…”