Richard Hebda
Botany Unit
Royal British Columbia Museum
Victoria, B.C.   V8V 1X4
Presented at the "British Columbia Native Plants, their current Status and 
Colloquium at Botany Dept., University of British Columbia, May 12, 1990
General Effects and Summary
	In the preceding sections I have identified some of the changes we 
might expect in specific vegetation zones and habitats.  In this section I 
will make some general comments on the effect of global warming on our 
native flora:
1.	Change in species distribution and in vegetation composition is 
natural and is well-demonstrated by studies of vegetation history.
2.	The change associated with the global warming will be as rapid or 
likely more rapid than any change since the last glaciation.
3.	Species will behave individualistically.  Biogeoclimatic zones will 
not migrate, rather, new biogeoclimatic zones will arise.
4.	Weedy adventive species will become more abundant and find 
permanent niches in new vegetation types.
5.	Some rare species will be able to expand their populations whereas 
other will decline and disappear.
6.	Moisture-and acid-loving species may decline in number, and 
drought resistant and alkaline-tolerant species increase.  
7.	Wetland and southern alpine species are potentially at greatest risk.
8.	Re-equilibration of the flora into new vegetation units will be a 
lengthy process because the process of climatic change will 
continue for many years, as will the changes in distribution of 
9.	Loss of populations will likely be sudden rather than gradual, 
precipitated by climatic extremes or resultant effects.  In general, 
this will lead to impoverishment of local and regional floras before 
re-establishment of new species.

1.	We must establish a long term project to inventory our flora and 
identify populations of rare plant species, especially in the south.
2.	We must take steps to protect rare plant populations for they 
may/will serve as the reservoir for the new native vegetation to 
come (demonstrated by fossil record-i.e. western redcedar).  Extant 
and new ecological reserves could function as sources from which 
new genetic strains, adapted to the new conditions can arise.
3.	We must begin a program of ecological gradient conservation to 
provide opportunities for future dispersal.  Climatic and hydrologic 
gradients must be conserved.
4.	We must complete paleoecological studies for major biogeoclimatic 
to provide information on potential scenarios of change in species 
range, vegetation, hydrology and landscape process.  These may 
help us develop a strategy to conserve land areas and environments 
to ensure that the native 	flora persists and the new 
vegetation types arise from as broad a base of native species as 

	In conclusion we must change our philosophy of conservation.  By 
all means we must continue to preserve or set aside tracts of land to act as 
reservoirs of native species and vegetation, not only for economically 
valuables species, but especially for rare taxa and rare vegetation 
assemblages.  However, we must also look at conserving the continuity of 
the natural setting from a much broader perspective.  Rather than only 
trying to save or reserve small parcels, we must begin with the 
assumption that all of the provincial area merits a conservation strategy.  
Further disruptions to the natural environment must be sufficiently 
important to make withdrawals from our inherited portfolio of life forms 
and life assemblages.  For unlike a financial investment portfolio we 
cannot buy and sell to meet our long term goals.  When the life-form 
portfolio loses a species it is gone forever and we will never experience 
what it may have been, or benefit from what it may have to offer.