06.04.2013 Views

ENVIRONMENTAL CONSEQUENCES in rocky mountain coniferous ...

ENVIRONMENTAL CONSEQUENCES in rocky mountain coniferous ...

ENVIRONMENTAL CONSEQUENCES in rocky mountain coniferous ...

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Overall shrub recovery rates do not necessarily reflect <strong>in</strong>dividual species<br />

responses to different treatments. Four typical shrub species were chosen to illustrate<br />

relative changes <strong>in</strong> shrub volumes, but these relative values should not be confused<br />

with absolute changes. For example, relative shrub volume of mounta<strong>in</strong> maple could<br />

decl<strong>in</strong>e even though its absolute values <strong>in</strong>creased. It simply is not grow<strong>in</strong>g as fast <strong>in</strong><br />

relative terms as the shrub population as a whole.<br />

As shown <strong>in</strong> figure 8, mounta<strong>in</strong> maple, a large shrub, accounted for about three-<br />

fourths of the total preharvest shrub volume on all of the different study sites. All<br />

treatments produced a decl<strong>in</strong>e <strong>in</strong> relative importance of maple, but the treatment that<br />

protected the understory showed the least loss <strong>in</strong> relative volume of maple at 2 years.<br />

The other three treatments reduced maple to less than a third of the total shrub volume<br />

2 years after harvest<strong>in</strong>g.<br />

r ACER<br />

loo<br />

YEAR<br />

Understory Protected<br />

Intermediate Utilization and Burned<br />

All Residues Removed<br />

Conventional Utilization and Burned<br />

Figure 8. --Re Zative voZwne response of mounta<strong>in</strong> maple to four residues management<br />

treatments, 2 and 4 bears after harvest<strong>in</strong>g.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!