Plant Development, Water Relations, and Carbon Allocation of Heart‐Podded Hoary Cress

Abstract

Attempts to control the noxious weed heart‐podded hoary cress [Cardaria draba (L.) Desv.] in the Pacific Northwest have been relatively ineffective, and this species has expanded its distribution from irrigated hayland onto adjacent semiarid rangelands. The objective of this study was to define the seasonal pattern of development and biological activity of heart‐podded hoary cress growing on semiarid rangeland. The study was conducted in the field over a 2‐yr period on a terrace site that has deep Cumulic Haploxeroll soil and an adjacent upland site that has a shallow Lithic Argixeroll soil. Soil water content, phenology, xylem pressure potential and leaf conductance were measured at both sites. Aboveand belowground biomass and spring C allocation pattern, determined by labeling plants with 13C, were measured at the terrace location. Regardless of location, no heart‐podded hoary cress seedlings were found; all shoots developed from rhizome buds. The majority (76%) of heartpodded hoary cress biomass was located belowground. Although drought occurred earlier on the upland than the terrace site, phenology was similar on the two sites. Carbon was translocated to belowground tissues within 1 h of labeling and reached peak accumulation within 24 h. The greatest 13C enrichment of roots and rhizomes occurred during the flowering stage. The peak in belowground C allocation occurred at a stage when leaf conductance was declining rapidly. The short period of maximum C allocation to belowground tissue, the large proportion of belowground tissue, and the wide variation of phenology among plants at a given time may account for the difficulty in chemically controlling this species.

Shared and host‐specific microbiome diversity and functioning of grapevine and accompanying weed plants

“…The extensive and thick, root system of the perennial weed L. draba , which can account for up to 75% of the total plant biomass, may additionally promote bacterial diversity. Its foliage dies back during herbicide application, freezing temperature or drought but roots survive (DiTomaso et al ., ), and its eradication is considered to be extremely difficult (Miller et al ., ). Plant species investigated in this study show different root morphologies (Supporting Information Table S1), which are likely to influence resource uptake and the formation of an interaction with microbial communities (Bardgett et al ., ).…”

Organic matter economy of Euphorbia adenochlora with special reference to its life cycle

“…In particular, translocation of carbohydrate reserves from the rhizomes that have many annual segments to shoots, and the retranslocation of the current photo-assimilates in shoots to each segment of the rhizome were examined in detail. In the latter, the stable carbon isotope 13 C has been applied to trace the carbon flow (Mordacq et al 1986;Svejcar et al 1990;Miller et al 1994;Hemminga et al 1996). To estimate the retranslocation to each rhizome segment, an experiment involving feeding 13 CO 2 to leaves was conducted.…”

Effect of generalist insect herbivores on introduced Lepidium draba (Brassicaceae): implications for the enemy release hypothesis

“…The clonal nature of L. draba in field populations may help it tolerate feeding by above‐ground herbivores because its biomass is predominately located in below‐ground storage tissues (Miller et al. 1994), which are not directly attacked by any herbivores in North America (Cripps et al.…”