scholarly journals Subspecies differentiation in an enigmatic chaparral shrub species

2020 ◽  
Vol 107 (6) ◽  
pp. 923-940 ◽  
Author(s):  
Yi Huang ◽  
Glen R. Morrison ◽  
Alan Brelsford ◽  
Janet Franklin ◽  
Diana D. Jolles ◽  
...  
HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 503c-503
Author(s):  
Paul H. Henry ◽  
John E. Preece

A propagation method is being developed that allows softwood shoots to be generated from stem sections of dormant woody plant species. These shoots, forced in the greenhouse during the winter, are subsequently collected and processed as softwood stem cuttings to produce clonal plant material. Many species in the nursery industry can only be propagated using softwood cuttings, and this technique allows propagation of these species to be initiated several months earlier than what is typically possible. Current studies involve expanded screening of ornamental tree and shrub species to determine if commercial production using this technique is feasible. Results demonstrate that many species may be propagated using this method, but that some species are more prolific than others with respect to number of softwood shoots produced. Additional studies are currently in progress to determine the environmental (light regime, moisture regime) and cultural (type of media) conditions that are optimal when producing clonal plant material via this technique.


Author(s):  
Karen J. Esler ◽  
Anna L. Jacobsen ◽  
R. Brandon Pratt

The archetypal shrub type that dominates most of the regions that experience mediterranean-type climate (MTC) is an evergreen shrub with thick and leathery leaves (sclerophyllous). The occurrence of large stands of such shrubs in all MTC regions led early biogeographers to hypothesize that the MTC selects for this growth form and leaf type and that this had led to convergent evolution (see Chapters 1 and 2). This hypothesis has received considerable research interest and continues to be examined. In this chapter we consider the structure and physiology of these archetypal MTC region shrub species and examine evidence for convergent evolution in their structure and function. We also assess the key adaptive traits that enable the shrub species that compose mediterranean-type vegetation (MTV) communities to thrive in MTC regions.


Zootaxa ◽  
2005 ◽  
Vol 829 (1) ◽  
pp. 1
Author(s):  
SHAHAB MANZARI ◽  
HASSAN ALEMANSOOR

Acaudaleyrodes ebeni sp. nov. is described and illustrated here from Ebenus stellata (Fabaceae: Papilionoideae) an endemic shrub species in Iran. Its taxonomic affinities are discussed and an identification guide to described species of the genus Acaudaleyrodes Takahashi is presented.


2021 ◽  
Vol 11 (7) ◽  
pp. 2979
Author(s):  
Maxime Fortin Faubert ◽  
Dominic Desjardins ◽  
Mohamed Hijri ◽  
Michel Labrecque

The Salix genus includes shrub species that are widely used in phytoremediation and various other phytotechnologies due to their advantageous characteristics, such as a high evapotranspiration (ET) rate, in particular when cultivated in short rotation intensive culture (SRIC). Observations made in past field studies suggest that ET and its impact on soil hydrology can also lead to increases in soil pollutant concentrations near shrubs. To investigate this, sections of a mature willow plantation (seven years old) were cut to eliminate transpiration (Cut treatment). Soil concentrations of polychlorinated biphenyls (PCBs), aliphatic compounds C10–C50, polycyclic aromatic hydrocarbons (PAHs) and five trace elements (Cd, Cr, Cu, Ni and Zn) were compared between the Cut and the uncut plots (Salix miyabeana ‘SX61’). Over 24 months, the results clearly show that removal of the willow shrubs limited the contaminants’ increase in the soil surface, as observed for C10–C50 and of 10 PAHs under the Salix treatment. This finding strongly reinforces a hypothesis that SRIC of willows may facilitate the migration of contaminants towards their roots, thus increasing their concentration in the surrounding soil. Such a “pumping effect” in a high-density willow crop is a prominent characteristic specific to field studies that can lead to counterintuitive results. Although apparent increases of contaminant concentrations contradict the purification benefits usually pursued in phytoremediation, the possibility of active phytoextraction and rhizodegradation is not excluded. Moreover, increases of pollutant concentrations under shrubs following migration suggest that decreases would consequently occur at the source points. Some reflections on interpreting field work results are provided.


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