Transcript FREP-Biodiversity-Feb-27

2005 Stand Level Biodiversity
Final Report
“Proof of Concept”
Richard Thompson and Nancy Densmore
January 2007
Question?
Is the structural retention (WT and CWD) left
associated with cutblocks adequately
maintaining habitat for dependent species at the
site and across the landscape now and in the
future?
Stand Level Biodiversity
What are we measuring?
•% area retained
•Tree size
•Wildlife tree class
•tree species
•CWD Size
•CWD decay class
•Ecological Anchors – e.g. large
hollow trees, bear dens
•Windthrow
•Invasive Species
How are we measuring it?
Standardized protocol
Plot base and overview
Randomized design
Quality assurance
Protocol Available on the Web:
http://www.for.gov.bc.ca/hfp/frep/values/biodiversity.htm
2005 Provincial Sample
Summary of retention levels (hectares) on 201 sampled
cutblocks
Total gross block area
6,916
A
B
Total patch retention area (includes 33 hectares of
temporary patch retention)
932
C
Total dispersed retention area1 (includes 99 hectares of
temporary dispersed retention)
385
D
Total rotational Patch area2
899
E
Total rotational Patch area2 considered unconstrained3
471
F
Total rotational dispersed area1 2
286
Average Indicator Value by BEC
BEC Zone
Blocks
Sampled
(ave %
retained)
Vet Trees
#/ha of
patch
Ecological
Anchors
#/ha of
patch
Large
Dead
trees #/ha
of total
retention
Large
trees live
and dead
#/ha of
total
retention
BWBS
16 (15%)
0.4
3.5
16.2
14.3
CDF
1 (24%)
12
4.2
0.4
51.8
CWH
47 (24%
15.5
5.1
28.1
74.2
ESSF
14 (14%)
0.5
1.8
63.7
16.4
ICH
6 (30%)
0.3
0.7
24.1
57.5
IDF
20 (37%)
22
5.7
1.9
9.7
MH
3 (20%)
2.7
2.7
46.4
93.6
MS
7 (26%)
3
3.0
2.5
5.7
SBPS
15 (7%)
0
0.6
26.0
0.3
SBS
72 (14%)
2.8
2.3
22.3
11.5
Cumulative frequency
(% blocks)
Distribution of baseline
indicator data
120.0
100.0
80.0
60.0
40.0
20.0
0.0
0.0
5.0
10.0
15.0
20.0
Trees > 50 cm dbh (sph)
25.0
% sampled cutblocks
Retained species abundance
SBS blocks
80.0
60.0
40.0
baseline
20.0
0.0
<4 species 4 species
5 species >5 species
categories of tree species abundance
% sampled cutblocks
WT class 3 or higher, dbh
>30 cm and height >10m for
72 SBS blocks
60.0
50.0
40.0
30.0
20.0
10.0
0.0
<2.1sph
2.1-6.1 sph
6.1-17.6
sph
>17.6 sph
abundance of large dead trees
Comparison of Data on Large
Dead Tree Abundance for
Kolmogorov-Smirnov test
100
Cumulative frequency (%)
SBS
80
60
40
20
2005 SLBD
Cruise (equally w eighted blocks)
0
0
25
50
75
100
125
Wildlife tree class 3+, DBH 30cm+, height 10m+
(stems per ha)
150
% of sampled
cutblocks
CWD Patch/Harvest Volume
60.0
50.0
40.0
30.0
20.0
10.0
0.0
Patch
baseline
Harvest
<33.7
33.792.9
92.9206.1
>206.1
categories of CWD volume (m3/ha)
% of sampled
cutblocks
CWD Patch/Harvest Length
80.0
60.0
40.0
20.0
0.0
Patch
baseline
<7.6
Harvest
7.664.0
64.0155.3
>155.3
Density categories of CWD pieces
>10m (SPH)
% of sampled
cutblocks
Categories of windthrow 70 SBS
cutblocks
80.0
60.0
40.0
20.0
0.0
>30%
16-30
5-15%
categories of windthrow
<5%
% of sampled
cutblocks
Patch location 69 SBS Blocks
:
50.0
40.0
30.0
20.0
10.0
0.0
none
external
edge
internal
Patch location in relation to cutblock
Summary
Trend or indicator
Good for
Biodiversity
13.7% overall retention (32% <75
retention, 10% >30% retention)
42% of blocks with large patches
Risky for
Biodiversity
X
X
9% of blocks with external noncontiguous patches
X
7% of blocks with zero retention
X
84% of blocks have patch retention
X
63% of blocks with 3 or less tree species
retained
X
43% of blocks with few large trees
X
51% of blocks with many large trees
X
CWD volume comparable patch to
harvest area and baseline
X
Long pieces of CWD less common in
harvest area compared to retention
patches and baseline
X
Where to Next?
Data sets continue to be built
Data Management Systems being built
Work to build baselines
Work to put stand structure into landscape