header

 

 
 
History of deer colonization - Response of vegetation to deer - Response of animals to deer and squirrel - Deer biology
Menu
Home
Haida Gwaii
Introduced Species
RGIS
What did we learn?
Research
Publications
RGIS symposium
School curriculum
Contacts   
 
English
Français 

    

Effect of browsing history on the vegetation - Effect of chemical defences on deer browsing - Effects of reduced plant abundance on pollination - Effect of hunting on tree regeneration - Effect of prolonged deer population reduction on the vegetation


Effect of hunting on tree regeneration:
exploring the ecology of fear

Aim & scope - Where & when - How - Main results - Conclusion - Scientific Publications

Aim and scope
Empirical evidence suggested that after logging tree regeneration varied from locality to locality in relationship to road access and thus to the occurrence of hunting. clearcut
hunting Although the number of deer killed by hunters is small relative to the overall deer population we hypothesized that a combination of lethal and non lethal effects (fear and vigilance) of deer hunting could explain spatial variation in deer feeding behaviour and in their impact on the vegetation.
We took advantage of the existence of areas that differed essentially in their accessibility to hunters to study of the effects of accessibility to hunters on tree regeneration after logging. The emphasis was put on the regeneration of Western redcedar (Thuya plicata).
return to top of page

Where and when
In 1997 Christophe Baltzinger and co-workers studied browsing stress and abundance in logged areas on Graham, Moresby and Louise islands.
 
On Graham Island:
  • Ian Lake: difficult access
  • Mainline: easy access
Moresby Island:
  • Alliford Bay: easy access.
Louise Island: difficult access.
study areas

return to top of page

How

The study took place on naturally regenerating blocks cut 10 to 15 years before the study. This time interval allowed natural regeneration to occur.
 
All 60 sites sampled had high redcedar abundance before cutting.
 
The information on tree and tree age class distribution and on browsing stress was collected in 50 m² circular sampling plots.

return to top of page

Main Results

Redcedar regeneration was related to redcedar abundance before cutting. The number of saplings and small trees within the sampling sites was very low compared to the density of redcedar before cutting.
Main results
However, browse stress was lower and regeneration was better in areas accessible to hunters.
The deer population in our accessible areas was estimated to amount about 12 500 animals. The proportion of animals killed in these areas did not exceed 10%.  deer
 
The differences in deer impact on the vegetation between accessible and non accessible areas might as much result from changes in deer behaviour caused by hunting than from the direct removal of animals.

Conclusion

measuring regeneration In areas with easy access, browsing stress was lower and tree regeneration better than in areas difficult to access.  We speculate that this difference might be related to variation in hunting pressure.

The persistence of redcedar in the forests of Haida Gwaii may depend on the amount and distribution of deer hunting. Even a relatively modest hunting pressure can improve redcedar regeneration.

Scientific Publications

return to top of page