Dr. Lyn Baldwin's Website at Thompson Rivers University

Lyn Baldwin

Ph.D. candidate (2000 - present)

Thesis Title:

Effects of forest fragmentation on bryophyte communities in southern-coastal British Columbia

Funded (in part) by: NSERC, Killam, UBC Graduate Fellowship, MacMillan Bloedel, and Vancouver Foundation Bryology & Lichenology Fund.

Outline of Ph.D. Research: My doctoral research is determining the effect of forest fragmentation on bryophyte (mosses and liverworts) communities in coastal forests on Vancouver Island.  Specifically I am asking two main questions  (1) What is the relationship between forest fragment size and bryophyte diversity?  and  (2)  What is the effect of an introduced edge on bryophyte communities?  Plant species loss in fragmented forests has been hypothesized to result either from changes in microclimate (isolated forest fragments experience higher wind levels and greater temperature fluctuations) or from changes in seed availability (fewer seeds are dispersed to isolated forest fragments than to similar sites in continuous forest).  To determine which of theses hypotheses is most important, I will simplify the biological diversity of bryophytes into two different “plant functional groupings” consisting of species that react in a similar manner to an environmental disturbance.  One grouping will be based on bryophyte growth form (which has been strongly correlated with moisture stress) and one grouping will be based on dispersal ability. 

The introduction of an edge has been shown to either have no effect, to increase, or to decrease plant species richness depending on the system being studied.  Forest edges have been shown to have both altered microclimates and higher disturbance regimes due to higher windfall.  To determine whether there is an “edge effect” I  am comparing bryophyte communities at the fragment edges with communities found at the center of forest fragments.  Both altered microclimatic regimes and tree tip-ups would create suitable habitat for more drought-resistant moss genera such as Polytrichum  however higher wind levels may lead to fewer pendant genera such as Neckera.