Undergraduate technician Jodi Stewart climbing
H. canariense to collect seed in Kula, HI.

 
Hand pollinations. 

Hypericum canariense was the focus of Dr. Katrina Dlugosch's PhD work at the University of California - Santa Cruz, under Dr. Ingrid Parker, and they are continuing to study its ecology and evolution.  Katrina is now an Assistant Professor in the Department of Ecology and Evolutionary Biology at the University of Arizona. 

A summary of our work:

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Part of our work is to describe the basic features of this plant, such as germination requirements and rates, growth rates, flowering time, and fruit production.

In addition to being an understudied invader generally, H canariense is also of interest as a model system in which to learn more about invasive species as a group. We currently know very little about how much genetic variation from the native range establishes in a new invasion. This is an important issue in terms of understanding the likelihood of an invader adapting to different types of habitat or control efforts, and therefore the importance of preventing dispersal (genetic exchange) between existing invasions.  We are using the invasion of California and Hawaii by H. canariense to get at some of these issues. This work is being funded by the US Department of Agriculture. If you would like to see a full description of this work, please contact Katrina directly.  Generally, we are...

1) Surveying DNA variation to (i) establish which regions in the native range are the source for each invasion and (ii) determine how much of the overall genetic diversity has made it from the native range to the introduced populations. Our findings to date indicate that the invasions share the same source on the island of Tenerife.  The invasions harbor about half of the genetic diversity seen in native populations on Tenerife.

2) Comparing variation in life history traits (growth, reproduction, survival) between the native and introduced ranges using a common garden of plants from all populations and controlled matings within populations (to estimate the heritability of traits). Our common gardens suggest that variability has been sufficient for the evolution of faster growth and local adaptation in flowering time. 

3) Comparing the mating systems used by in old and young individuals within the introduced populations. We are finding that H. canariense is adept at self-pollination, and may be relying heavily upon this method of reproduction.

4) Investigations of plant chemistry and defensive properties - stay tuned!

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Publications:

Dlugosch KM & IM Parker  (2008)  Invading populations of an ornamental shrub show rapid life history evolution despite genetic bottlenecks.  Ecology Letters 11(7): 701-709.  PDF

Dlugosch KM & IM Parker  (2008)  Founding events in species invasions: genetic variation, adaptive evolution, and the role of multiple introductions.  Molecular Ecology 17 (1): 431-449.  PDF

Dlugosch KM & IM Parker  (2007)  Molecular and life history trait variation across the native range of the invasive species Hypericum canariense: evidence for ancient patterns of colonization via pre-adaptation?  Molecular Ecology 16 (20): 4269-4283.  PDF